Files
NX2navi/runtime/memory.c

1821 lines
94 KiB
C

// Contains code Copyright (c) 2026 MacNativeGames contributors, Copyright (c) 2026 Peiikai (MIT; see
// THIRD_PARTY_NOTICES.md).
// Guest address space and the memory SVCs: heap, module data permissions, stack moves,
// QueryMemory, physical memory in the alias region, GetInfo memory ids, and the kernel-region allocator.
//
// Every region is a plain reservation; pages are committed and decommitted at 4 KiB granularity. Decommitted pages
// come back zeroed, so no stale-page bookkeeping is needed. The stack and heap block and the alias region are
// reserved write-watched (platform.h plat_mem_reserve): mem_written_pages reports the pages the CPU wrote, which
// the Vulkan back end uploads again.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cfg.h"
#include "host.h"
#include "layout.h"
#include "mem_need.h"
#include "platform/platform.h"
#define PAGE 0x1000ull
#define GiB (1ull << 30)
#define LOW_SEARCH_FROM 0x100000000ull
#define LOW_SIZE (14 * GiB) // stack + heap block: room for a Switch 2 heap (HEAP_CAP)
#define STACK_OFF 0x10000000ull
#define STACK_SIZE 0x10000000ull
#define HEAP_OFF (STACK_OFF + STACK_SIZE + 0x10000000ull)
#define HEAP_CAP (12 * GiB) // heap region: a Switch 2 application pool is 9809 MiB (the 12 GB console arrangement)
#define ALIAS_SIZE (64 * GiB)
#define ALIAS_ALIGN (4 * GiB)
#define ALIAS_PAGES (ALIAS_SIZE / PAGE)
#define DEFAULT_POOL rt_app_pool_bytes // retail application pool of the title (generated: NX2NAVI 0xCD500000, Switch 2 9809 MiB)
#define SYSTEM_RESOURCE_BUDGET (32ull << 20)
#define MAX_STACK_MAPS 4096
#define REEXEC_LIMIT 20
// Horizon memory states, permissions, attributes and results used here.
enum { ST_FREE = 0, ST_CODE = 3, ST_CODEDATA = 4, ST_NORMAL = 5, ST_STACK = 0xB, ST_THREADLOCAL = 0xC,
ST_INACCESSIBLE = 0x10 };
enum { PERM_NONE = 0, PERM_R = 1, PERM_RW = 3, PERM_RX = 5 };
enum { ATTR_PERMISSION_LOCKED = 16 };
#define R_OK 0u
#define R_INVALID_ADDRESS 0xcc01u // misaligned address
#define R_INVALID_SIZE 0xca01u
#define R_INVALID_NEW_PERM 0xd801u
#define R_INVALID_STATE 0xd401u // InvalidCurrentMemory
#define R_INVALID_REGION 0xdc01u
#define R_LIMIT_REACHED 0x10801u
static RtGuestLayout L;
static uint64_t mods_lo, mods_hi; // fixed module window
static PlatMutex lock = PLAT_MUTEX_INIT;
static uint64_t heap_size, alias_bytes;
static int heap_lazy; // NX2NAVI_HEAP_LAZY, Windows: the heap is committed page run by page run on first use
static uint64_t heap_lazy_faults, heap_lazy_bytes; // accesses that committed heap pages, and the bytes they committed
static uint64_t heap_lazy_ns, heap_lazy_max_ns; // time in those faults, lock wait included, since the last report
static uint8_t *alias_pages; // 1 per mapped 4 KiB page of the alias region
typedef struct { uint64_t dst, src, size; } StackMap;
static StackMap stack_maps[MAX_STACK_MAPS];
static unsigned nstack_maps;
static uint8_t *module_perm[MOD_COUNT]; // per data page of each module: perm | ATTR_PERMISSION_LOCKED
static uint64_t align_up(uint64_t v, uint64_t a) { return (v + a - 1) & ~(a - 1); }
static int reserve_at(uint64_t at, uint64_t size, int watch) { return plat_mem_reserve(at, size, watch); }
// ---- frozen regions
// A 2 MiB region of the watched reservations that nothing wrote for a while can be made read-only (mem_freeze), so the
// back end's write-watch queries skip it: no page of a frozen region changes before a thaw. The first write faults and
// thaw_handler makes the region writable again before the write retries. A kernel write into guest memory (a file
// read) fails on a read-only page instead of faulting, so file reads thaw their buffer first (mem_thaw), and so does
// every commit, decommit and protection change here. A region stays thawed for FRZ_HOLD_MS after a mem_thaw: a file
// read still in flight writes its buffer later. frz_lock is a leaf lock: nothing writes guest memory under it.
#define FRZ_SHIFT 21
#define FRZ_SIZE (1ull << FRZ_SHIFT)
#define FRZ_HOLD_MS 5000u
static volatile uint8_t frz[RT_ADDRESS_LIMIT >> FRZ_SHIFT];
static uint32_t thaw_ms[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: GetTickCount of the last thaw request, 0 never
// Hot regions. A region a write thaws soon after its freeze is one the game keeps writing (the buffers its loaders
// stream an area into): frozen again as soon as it was idle a moment, it was thawed again moments later. Running
// through Hyrule Field froze and thawed about 8,000 regions in 6,000 frames, and while the loaders wrote and the
// driver locked new memory each thaw's VirtualQuery took 15 to 20 ms: a loader thread stalled 78 to 111 ms in thaws in
// each of the hitches of 125 to 140 ms of that walk, with the game's main thread waiting for it. So a write that thaws a
// region within FRZ_QUICK_MS of its freeze holds the region thawed for its hot time, FRZ_HOT_MIN_MS at first and
// doubled at each such thaw up to FRZ_HOT_MAX_MS; a region that stayed frozen longer starts again from nothing. A
// freeze only saves later write-watch queries over the region, which a region written that often needs anyway.
#define FRZ_QUICK_MS 60000u
#define FRZ_HOT_MIN_MS 4000u
#define FRZ_HOT_MAX_MS 600000u
static uint32_t frz_ms[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: GetTickCount | 1 of its last freeze, 0 never
static uint32_t frz_hot_ms[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: its hot time now, 0 not hot
static uint32_t frz_hot_until[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: no freeze before this GetTickCount, 0 none
static volatile int64_t frz_hot_holds; // quick thaws that held a region, since the last stats
static volatile int32_t nfrz;
static PlatMutex frz_lock = PLAT_MUTEX_INIT;
static volatile int64_t frz_count[4]; // freezes; thaws by a write fault, by mem_thaw, by a mapping change
// Thaws outside frz_lock (NX2NAVI_FREEZE_ASYNC, default 1; 0: every thaw under the lock, as before). While the game
// streams an area it creates and finalizes up to 1,500 memory pools a second, the driver pins and unpins the imported
// ones, and the VirtualQuery and VirtualProtect calls of a thaw then take 10-20 ms each. Under frz_lock that held the
// replay (mem_lazy_skip, the freeze pass) and every other thread that faulted or thawed, a 25-45 ms frame. So a thaw by
// a write fault or by mem_thaw marks its regions FRZ_THAWING under the lock, makes their pages read-write without it and
// ends them under it again. A region being thawed is no longer frozen for anyone who asks (a freeze, an arm, a probe
// leave it alone); a fault in it waits for the thaw to end and runs again; a mapping change waits for it first
// (thaw_wait_locked), so a late VirtualProtect never undoes the change; mem_thaw makes its pages read-write itself.
// freeze_locked keeps the runs it made read-only (frz_runs), so a thaw needs no VirtualQuery.
#define FRZ_THAWING 2
static int frz_async = 1; // the setting, read in mem_init
typedef struct { uint8_t n; uint16_t run[16][2]; } FrzRuns; // pages of the region, [first, end)
static FrzRuns *frz_runs[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock (written at a freeze): NULL or n 0 = not kept
// vm_lock, a leaf lock held around every write-watch query (written_pages) and around the page calls of a freeze and a
// thaw: on Windows each kind takes the process's address-space lock, and with both running at once a game thread's
// thaw waited about 16 ms per page call behind the replay's queries, 100-300 ms for a thaw of several runs (a frame of
// that length about every second standing in Hyrule Field on an RX 580). Taken in turns here, a thaw waits for one
// query at most.
static PlatMutex vm_lock = PLAT_MUTEX_INIT;
static volatile int64_t frz_async_n; // thaws done outside the lock, since the start
static volatile int64_t frz_protect_fails; // VirtualProtect failures of those thaws, since the start
// Probed regions (NX2NAVI_WB_PROBE=1, a diagnosis). The back end copies what the GPU wrote into a mirrored pool back
// into guest memory after every submission, in case the CPU or a host path reads it; whether anything does is what
// the probe finds out. A 2 MiB region that lies wholly inside a range just written back is made inaccessible
// (mem_probe). Its first read or write faults: probe_fault gives the region back the protection it had (read-only
// when frozen, else read-write), notes the address, the instruction and the thread, and the access runs again. The
// bytes are in guest memory all along, so the probe only watches. A probed region is not frozen anew (freeze_locked
// finds pages that are not read-write), and every thaw, which precedes file reads into guest memory and mapping
// changes, ends the probe of its region first.
#define PRB_HITS 64
static volatile uint8_t prb[RT_ADDRESS_LIMIT >> FRZ_SHIFT];
static volatile int32_t nprb, prb_on;
static struct { uint64_t addr, ip; uint32_t tid; uint8_t write; } prb_hit[PRB_HITS]; // frz_lock: the first of each report
static int prb_nhit; // frz_lock
static uint64_t prb_arms, prb_ends[2]; // frz_lock: regions armed; probes ended by a read, by a write
static int watched(uint64_t addr, uint64_t size) {
const RtGuestLayout *g = &L;
return (addr >= g->aslr.base && size <= LOW_SIZE && addr - g->aslr.base <= LOW_SIZE - size) ||
(addr >= g->alias.base && size <= ALIAS_SIZE && addr - g->alias.base <= ALIAS_SIZE - size);
}
// frz_lock held exclusively: the pages of a probed region get back what they had, read-only in a frozen region.
static void unprobe_locked(uint64_t r) {
if (!prb[r]) return;
int prot = frz[r] == 1 ? PLAT_PROT_READ : PLAT_PROT_RW;
uint64_t a = r << FRZ_SHIFT, end = a + FRZ_SIZE, b;
for (; a < end; a = b) // every inaccessible run is the probe's: mem_probe took only regions without one
if (plat_mem_state(a, end, &b) == PLAT_PROT_NONE && !plat_mem_protect(a, b - a, prot))
rt_fatal("memory: ending the probe of %#llx+%#llx failed", (unsigned long long)a, (unsigned long long)(b - a));
__atomic_store_n(&prb[r], 0, __ATOMIC_RELEASE);
plat_dec32(&nprb);
}
// Lazy write-back (NX2NAVI_WB_LAZY; unset: on under Windows except on AMD's own driver, off elsewhere, as
// wb_lazy_choice.h decides and gives the reasons for; vk_memory.c "lazy write-back"). It was off
// by default in 0.7.0: with it on, single frames came out with the whole scene's shadowing missing, 10 to 180 of 1,800
// presents standing in Hyrule Field with other programs keeping the CPU busy and none found with it off. That was
// not this code's doing: frames were drawn from copies taken before the game's signal that their data was written
// (vk_exec_xfer.c "events the CPU signals"), and with the write-backs gone the frames came faster and the signal fell
// into the replay more often. With that fixed, two such runs under eight busy threads showed none.
// What a shader wrote into a mirrored pool is
// copied back into guest memory at the end of every submission, in case the CPU reads it. Ocarina's CPU does not read
// most of it: standing in Hyrule Field, 66 MiB a frame went back over PCIe, 7 to 9 ms of each frame's 13 to 15 ms of
// GPU time, and the write-back probe found no access to it in 40 s. So a range that went back once is armed here: its
// whole pages are made inaccessible (mem_lazy_arm), and while it stays armed the back end leaves its later writes in
// the mirror (mem_lazy_skip marks it stale). The first read or write of an armed page faults: lazy_fault has the
// back end copy the range's bytes down now (lz_fetch, a GPU copy after everything submitted so far), gives the pages
// back and runs the access again, and the range stays out for a while (lz_hot: 1 s, doubling to 32 s while it keeps
// being touched), written back every submission as before; by default only the piece around the address goes that
// way and the rest of the range stays armed (NX2NAVI_WB_LAZY_CHUNK, below). Every thaw (before the kernel writes or reads guest
// memory, and before mapping changes) releases the armed ranges of its regions the same way.
// A region with armed pages is not frozen (freeze_locked wants every page read-write), and a frozen one is not armed.
// A fetch brings what the GPU work handed over so far wrote. The part of a submission that is being recorded has left
// its writes out as well, and makes up for it when it finds a range it skipped no longer armed (vk_memory.c
// lazy_part_check). Between that check and the part's hand-over a release would be seen by neither side, so the
// replay opens a window there (mem_lazy_window) and a fault on an armed page waits for it to close: the fetch then
// has the part's writes. Only a fault of the replay thread itself, a wait of 20 ms, or a release by a thaw goes ahead
// inside the window (lz_gaps counts the faults): that part's writes to the range then reach guest memory with the
// range's next write-back.
// The list of armed segments has a lock of its own, lz_lock, held only for a few steps over the list and never across a
// system call or a fetch: the replay asks it at every draw that writes a mirrored pool (mem_lazy_skip) and at the end of
// every part (mem_lazy_armed, mem_lazy_window). Under frz_lock it waited for freezes, thaws and arms on other threads,
// whose page queries and protection changes take that lock for tens to hundreds of microseconds: 8% of the replay
// thread's samples standing in Hyrule Field on an RX 580 (0.7.1, lazy write-back on by default). A change of the list
// holds both locks (frz_lock first); a read holds either.
typedef struct { uint64_t lo, hi, h0, h1; int64_t delta; uint8_t stale; } LzSeg; // pages [lo, hi); buffer offset = address + delta
static PlatMutex lz_lock = PLAT_MUTEX_INIT; // inside frz_lock, never the other way round
static LzSeg *lzs; // changed under frz_lock and lz_lock, read under either
static int lz_n, lz_cap; // the same
static volatile uint8_t lzr[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // a segment reaches into the region
static uint32_t lz_hot[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: plat_now_ms() | 1 until which nothing is armed here
static uint8_t lz_back[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: seconds of the region's last hold
static volatile int32_t lz_on;
static int lz_want; // the setting, read in mem_init
static void (*lz_fetch)(uint64_t h0, uint64_t h1, uint64_t off, uint64_t size);
// The back end's test that the mirror holds every CPU write to [lo, hi) (vk_memory.c lazy_clean): a fetch copies the
// mirror's bytes over the whole range, so a CPU write the mirror does not have yet would be lost to it.
static int (*lz_clean)(uint64_t lo, uint64_t hi, void *ctx);
static uint64_t lz_unclean; // frz_lock: arms refused since the last report because the mirror lacked a CPU write
// frz_lock: bytes mem_lazy_arm left unarmed since the last report, by reason: the region is frozen, held after a touch
// (lz_hot), held after a thaw, has pages that are not read-write (or lacks a CPU write in the mirror), or the bytes lie
// in the partial pages at a range's ends. They are written back at every submission that writes them.
enum { LZ_NO_FROZEN, LZ_NO_HOT, LZ_NO_THAW, LZ_NO_PAGES, LZ_NO_EDGE, LZ_NO_N };
static uint64_t lz_no[LZ_NO_N], lz_no_small, lz_arm_calls; // ranges without a whole page; ranges written back
// NX2NAVI_WB_LAZY_CHUNK (default 0 = a touch releases its whole range and holds its regions; off because with it on
// the graphics device was lost about 2 s after a save load in Hyrule Field at night, in 7 of about 22 loads on an
// RTX 5090, a GPU read fault at the start of a large buffer, and in 0 of 15 with it off; why is not known yet): the
// first touch of an armed range gives back only the LZ_CHUNK bytes around the address, fetched alone, and only that
// piece is held (lz_hots, 1 s doubling to 32 s like a region's hold); the rest of the range stays armed. More than
// LZ_HEAVY_N touches in one region within LZ_HEAVY_MS are a reader going through the range: its range goes whole
// and its regions are held, as before, and while the region is touched again within LZ_HEAVY_KEEP_MS its touches go
// that way at once, so such a reader pays LZ_HEAVY_N faults more, once.
// Ocarina's CPU reads a few words at the start of buffers its shaders fill (12 bytes into ranges of 6.3 and 15.2 MiB,
// among others), about twice a second in a village and in Hyrule Field. Each read gave back the whole range and held
// every 2 MiB region it reached for up to 32 s, in which nothing was armed: 22 to 26 MiB a frame went back to guest
// memory at the end of every submission although nothing read them, inside the GPU work the game's fence waits for.
// With the pieces 1.7 MiB a frame go back, on 17 to 18 faults in 1,000 frames where there were 14 to 16 and with the
// same time spent fetching (4 to 5 ms in 1,000 frames), and the village ran at 135 to 138 frames a second where it
// had run at 122 to 124.
#define LZ_CHUNK_SHIFT 16
#define LZ_CHUNK (1ull << LZ_CHUNK_SHIFT)
#define LZ_HOTS 1024 // a power of two
#define LZ_HEAVY_N 4
#define LZ_HEAVY_MS 1000
#define LZ_HEAVY_KEEP_MS 60000
typedef struct { uint64_t key; uint32_t until; uint8_t back; } LzHot; // key: chunk number + 1, 0 free; until as lz_hot
static LzHot lz_hots[LZ_HOTS]; // frz_lock: open addressing, a short linear probe
static int lz_nhots; // frz_lock: entries ever used (0: no lookup needed)
static uint32_t lz_touch_ms[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: plat_now_ms() | 1 of the first piece of the region's run
static uint8_t lz_touch_n[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: pieces given back in that run
static uint32_t lz_heavy_ms[RT_ADDRESS_LIMIT >> FRZ_SHIFT]; // frz_lock: ... of its last touch taken as a reader's
static int lz_chunk; // the setting, read in mem_init
static uint64_t lz_pieces, lz_piece_bytes, lz_heavy; // frz_lock, since the last report
static uint64_t lz_foreign; // frz_lock, since the start: segments of another buffer mem_lazy_skip gave back
// frz_lock: the first faults on armed pages since the last report, for its lines (trace perf)
#define LZ_NOTES 8
static struct { uint64_t addr, lo, hi, out; uint32_t tid; uint8_t write, stale, hold; } lz_note[LZ_NOTES];
static int lz_nnote;
// frz_lock: since the last report: faults by a read, by a write, other releases, fetches, their bytes and time
static uint64_t lz_faults[2], lz_other, lz_fetches, lz_fetch_bytes, lz_fetch_ns, lz_gaps;
static volatile uint32_t lz_win_tid; // lz_lock: the replay thread's id while its part is between check and hand-over
// For a fatal error's summary line (mem_lazy_note): written under frz_lock and read without it, since the thread that
// fails may be the one inside a fetch.
static volatile uint64_t lz_fetch_total; // fetches since the start
static volatile uint32_t lz_fetch_ms; // plat_now_ms() | 1 at the end of the last one; 0: none yet
static volatile uint32_t lz_fetch_tid; // the thread inside a fetch now; 0: none
static volatile uint64_t lz_fetch_now; // that fetch's bytes
static void lazy_flags_locked(uint64_t lo, uint64_t hi) {
for (uint64_t r = lo >> FRZ_SHIFT; r <= (hi - 1) >> FRZ_SHIFT; r++) {
int any = 0;
for (int j = 0; j < lz_n && !any; j++)
any = lzs[j].lo < ((r + 1) << FRZ_SHIFT) && lzs[j].hi > (r << FRZ_SHIFT);
__atomic_store_n(&lzr[r], (uint8_t)any, __ATOMIC_RELEASE);
}
}
// frz_lock and lz_lock held: segment i leaves the list, with the stale mark mem_lazy_skip may have set until now. A
// later mem_lazy_skip no longer finds it and writes its range back as ever.
static LzSeg lazy_take_locked(int i) {
LzSeg s = lzs[i];
lzs[i] = lzs[--lz_n];
return s;
}
static void lazy_gone_locked(LzSeg s, int why);
// frz_lock held exclusively. Segment i goes: its bytes come down first when the mirror's are newer, then its pages
// are read-write again. why: 0 a read fault, 1 a write fault (both hold the regions back), else a thaw or the mirror
// going away.
static void lazy_drop_locked(int i, int why) {
plat_mutex_lock(&lz_lock);
LzSeg s = lazy_take_locked(i);
plat_mutex_unlock(&lz_lock);
lazy_gone_locked(s, why);
}
// frz_lock held exclusively: the pages of s, out of the list already, get their bytes and their access back.
static void lazy_gone_locked(LzSeg s, int why) {
if (s.stale && lz_fetch) {
uint64_t t0 = plat_now_ns();
__atomic_store_n(&lz_fetch_now, s.hi - s.lo, __ATOMIC_RELAXED);
__atomic_store_n(&lz_fetch_tid, plat_thread_id(), __ATOMIC_RELEASE);
lz_fetch(s.h0, s.h1, (uint64_t)((int64_t)s.lo + s.delta), s.hi - s.lo);
__atomic_store_n(&lz_fetch_ms, (uint32_t)plat_now_ms() | 1, __ATOMIC_RELAXED);
__atomic_store_n(&lz_fetch_total, lz_fetch_total + 1, __ATOMIC_RELAXED);
__atomic_store_n(&lz_fetch_tid, 0, __ATOMIC_RELEASE);
lz_fetches++, lz_fetch_bytes += s.hi - s.lo, lz_fetch_ns += plat_now_ns() - t0;
}
for (uint64_t a = s.lo, b; a < s.hi; a = b)
if (plat_mem_state(a, s.hi, &b) == PLAT_PROT_NONE && !plat_mem_protect(a, b - a, PLAT_PROT_RW))
rt_fatal("memory: giving back the lazily written pages %#llx+%#llx failed", (unsigned long long)a,
(unsigned long long)(b - a));
lazy_flags_locked(s.lo, s.hi);
if (why > 1) { lz_other++; return; }
lz_faults[why]++;
uint32_t now = (uint32_t)plat_now_ms();
for (uint64_t r = s.lo >> FRZ_SHIFT; r <= (s.hi - 1) >> FRZ_SHIFT; r++) {
int again = lz_hot[r] && (int32_t)(now - lz_hot[r]) < 60000; // touched again within a minute of its last hold
uint8_t b = again ? (uint8_t)(lz_back[r] < 32 ? lz_back[r] * 2 : 32) : 1;
lz_back[r] = b ? b : 1;
lz_hot[r] = (now + (uint32_t)lz_back[r] * 1000u) | 1;
}
}
// frz_lock held. The hold entry of chunk c; make: 1 takes a free slot of the probe for it, or the one whose hold
// ended longest ago.
static LzHot *lazy_hot_locked(uint64_t c, int make) {
uint32_t h = (uint32_t)((c * 0x9e3779b97f4a7c15ull) >> 40);
LzHot *take = NULL;
for (int k = 0; k < 8; k++) {
LzHot *e = &lz_hots[(h + (uint32_t)k) & (LZ_HOTS - 1)];
if (e->key == c + 1) return e;
if (!take || (take->key && (!e->key || (int32_t)(e->until - take->until) < 0))) take = e;
}
if (!make) return NULL;
*take = (LzHot){c + 1, 0, 0};
lz_nhots++;
return take;
}
static int lazy_chunk_held_locked(uint64_t c, uint32_t now) {
if (!lz_nhots) return 0;
const LzHot *e = lazy_hot_locked(c, 0);
return e && e->until && (int32_t)(e->until - now) > 0;
}
static void lazy_push_locked(LzSeg s) {
if (lz_n == lz_cap) {
lz_cap = lz_cap ? lz_cap * 2 : 256;
lzs = realloc(lzs, sizeof *lzs * (size_t)lz_cap);
if (!lzs) rt_fatal("memory: out of memory for the lazily written ranges");
}
lzs[lz_n++] = s;
}
// frz_lock held exclusively. A fault at a in segment i: the LZ_CHUNK piece around a goes (its bytes come down first
// when the mirror's are newer, then its pages are read-write again) and is held; what is left of the segment on
// either side stays armed. Returns the piece's size.
static uint64_t lazy_piece_locked(int i, uint64_t a, int write) {
LzSeg s = lzs[i];
uint64_t c0 = a & ~(LZ_CHUNK - 1), c1 = c0 + LZ_CHUNK;
if (c0 < s.lo) c0 = s.lo;
if (c1 > s.hi) c1 = s.hi;
if (s.stale && lz_fetch) {
uint64_t t0 = plat_now_ns();
__atomic_store_n(&lz_fetch_now, c1 - c0, __ATOMIC_RELAXED);
__atomic_store_n(&lz_fetch_tid, plat_thread_id(), __ATOMIC_RELEASE);
lz_fetch(s.h0, s.h1, (uint64_t)((int64_t)c0 + s.delta), c1 - c0);
__atomic_store_n(&lz_fetch_ms, (uint32_t)plat_now_ms() | 1, __ATOMIC_RELAXED);
__atomic_store_n(&lz_fetch_total, lz_fetch_total + 1, __ATOMIC_RELAXED);
__atomic_store_n(&lz_fetch_tid, 0, __ATOMIC_RELEASE);
lz_fetches++, lz_fetch_bytes += c1 - c0, lz_fetch_ns += plat_now_ns() - t0;
}
for (uint64_t x = c0, y; x < c1; x = y)
if (plat_mem_state(x, c1, &y) == PLAT_PROT_NONE && !plat_mem_protect(x, y - x, PLAT_PROT_RW))
rt_fatal("memory: giving back the lazily written pages %#llx+%#llx failed", (unsigned long long)x,
(unsigned long long)(y - x));
lzs[i] = lzs[--lz_n];
if (c0 > s.lo) lazy_push_locked((LzSeg){s.lo, c0, s.h0, s.h1, s.delta, s.stale});
if (c1 < s.hi) lazy_push_locked((LzSeg){c1, s.hi, s.h0, s.h1, s.delta, s.stale});
lazy_flags_locked(s.lo, s.hi);
lz_faults[write != 0]++, lz_pieces++, lz_piece_bytes += c1 - c0;
uint32_t now = (uint32_t)plat_now_ms();
LzHot *e = lazy_hot_locked(a >> LZ_CHUNK_SHIFT, 1);
int again = e->until && (int32_t)(now - e->until) < 60000; // touched again within a minute of its last hold
e->back = again ? (uint8_t)(e->back < 32 ? e->back * 2 : 32) : 1;
if (!e->back) e->back = 1;
e->until = (now + (uint32_t)e->back * 1000u) | 1;
return c1 - c0;
}
// frz_lock held exclusively: every segment that reaches into region r goes.
static void lazy_drop_region_locked(uint64_t r, int why) {
for (int i = lz_n; i-- > 0;)
if (lzs[i].lo < ((r + 1) << FRZ_SHIFT) && lzs[i].hi > (r << FRZ_SHIFT)) lazy_drop_locked(i, why);
}
static int lazy_covered_locked(uint64_t lo, uint64_t hi) {
for (int i = 0; i < lz_n; i++)
if (lzs[i].lo <= lo && lzs[i].hi >= hi) return 1;
return 0;
}
// frz_lock held exclusively: [x, e), inside one region, becomes inaccessible when every committed page of it is
// read-write, or inaccessible as part of a segment already; anything else (a read-only page, a hole, a page the game
// made inaccessible itself) leaves it as it is. Then the back end checks that the mirror ctx belongs to holds every CPU
// write to [x, e) (lz_clean): after the protection no write can come in, so a write that came before it is in the
// write-watch or the page generations. When the mirror lacks one, the pages are given back and nothing is armed: the
// CPU wrote into the range after its write-back reached guest memory and before this arm, and the next sync of the
// mirror carries that write up; a fetch before it would have copied the mirror's older bytes over it (single frames
// with another frame's lighting constants, or a black scene).
static int lazy_protect_locked(uint64_t x, uint64_t e, void *ctx) {
uint64_t run[16][2];
int k = 0;
for (uint64_t a = x, b; a < e; a = b) {
int st = plat_mem_state(a, e, &b);
if (st == PLAT_PROT_RW) {
if (k == 16) return 0;
run[k][0] = a, run[k][1] = b, k++;
} else if (st != PLAT_PROT_NONE || !lazy_covered_locked(a, b)) return 0;
}
for (int i = 0; i < k; i++)
if (!plat_mem_protect(run[i][0], run[i][1] - run[i][0], PLAT_PROT_NONE)) {
while (i--) plat_mem_protect(run[i][0], run[i][1] - run[i][0], PLAT_PROT_RW);
return 0;
}
if (lz_clean && !lz_clean(x, e, ctx)) {
for (int i = 0; i < k; i++) plat_mem_protect(run[i][0], run[i][1] - run[i][0], PLAT_PROT_RW);
lz_unclean++;
return 0;
}
return 1;
}
// Arms the whole pages of [a, a + n), which the back end has just written back from the buffer h0 into h1 at offset
// off: they fault on their next access. Returns the bytes armed now. Not in a frozen, probed, held or thaw-held region.
uint64_t mem_lazy_arm(uint64_t a, uint64_t n, uint64_t h0, uint64_t h1, uint64_t off, void *ctx) {
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED) || a >= RT_ADDRESS_LIMIT || !watched(a, n)) return 0;
uint64_t lo = (a + PAGE - 1) & ~(PAGE - 1), hi = (a + n) & ~(PAGE - 1), armed = 0;
int64_t delta = (int64_t)off - (int64_t)a;
plat_mutex_lock(&frz_lock);
lz_arm_calls++;
if (hi <= lo) {
lz_no[LZ_NO_EDGE] += n, lz_no_small++;
plat_mutex_unlock(&frz_lock);
return 0;
}
lz_no[LZ_NO_EDGE] += n - (hi - lo);
if (lazy_covered_locked(lo, hi)) {
plat_mutex_unlock(&frz_lock);
return 0;
}
uint32_t now = (uint32_t)plat_now_ms();
for (uint64_t x = lo, e; x < hi; x = e) {
uint64_t r = x >> FRZ_SHIFT;
e = (r + 1) << FRZ_SHIFT;
if (e > hi) e = hi;
if (lz_nhots) { // a held piece stays out: this turn arms what lies before it, the next ones what lies behind
uint64_t c = x >> LZ_CHUNK_SHIFT, y = x;
while (y < e && lazy_chunk_held_locked(c, now)) y = ++c << LZ_CHUNK_SHIFT;
if (y > x) {
if (y > e) y = e;
lz_no[LZ_NO_HOT] += y - x;
e = y;
continue;
}
for (c++; c << LZ_CHUNK_SHIFT < e; c++)
if (lazy_chunk_held_locked(c, now)) {
e = c << LZ_CHUNK_SHIFT;
break;
}
}
int no = frz[r] ? LZ_NO_FROZEN : prb[r] ? LZ_NO_PAGES : lz_hot[r] && (int32_t)(lz_hot[r] - now) > 0 ? LZ_NO_HOT :
thaw_ms[r] && (int32_t)(now - thaw_ms[r]) < (int32_t)FRZ_HOLD_MS ? LZ_NO_THAW :
!lazy_protect_locked(x, e, ctx) ? LZ_NO_PAGES : -1;
if (no >= 0) {
lz_no[no] += e - x;
continue;
}
uint64_t slo = x, shi = e;
uint8_t stale = 0;
plat_mutex_lock(&lz_lock);
for (int j = 0; j < lz_n; j++) // one segment for what touches in the same buffer
if (lzs[j].h0 == h0 && lzs[j].delta == delta && lzs[j].lo <= shi && lzs[j].hi >= slo) {
if (lzs[j].lo < slo) slo = lzs[j].lo;
if (lzs[j].hi > shi) shi = lzs[j].hi;
stale |= lzs[j].stale;
lzs[j] = lzs[--lz_n];
j = -1;
}
lazy_push_locked((LzSeg){slo, shi, h0, h1, delta, stale});
plat_mutex_unlock(&lz_lock);
__atomic_store_n(&lzr[r], 1, __ATOMIC_RELEASE);
armed += e - x;
}
plat_mutex_unlock(&frz_lock);
return armed;
}
// The armed parts of [a, a + n), sorted, into out (at most max); they count as stale from here on: the caller leaves
// the bytes it is about to write there in the mirror h0, at buffer offset address + delta. Returns how many.
// A segment there that was armed for another buffer (a mirror evicted since, whose range a write-back armed while the
// eviction ran) is given back instead, without a fetch: its buffer may be gone, and since its mirror went every GPU
// write went to guest memory, so guest memory holds the bytes. Marked stale, it would have its next touch copy from the
// freed buffer, a GPU read fault that loses the device.
int mem_lazy_skip(uint64_t a, uint64_t n, uint64_t h0, int64_t delta, uint64_t out[][2], int max) {
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED) || !n || a >= RT_ADDRESS_LIMIT || a + n > RT_ADDRESS_LIMIT) return 0;
int any = 0, k = 0;
for (uint64_t r = a >> FRZ_SHIFT; r <= (a + n - 1) >> FRZ_SHIFT && !any; r++) any = lzr[r];
if (!any) return 0;
// A segment armed for another buffer goes back under frz_lock (lazy_gone_locked), with arms held off until the
// rest is marked, as before lz_lock; that is rare, and the replay's per-draw check holds lz_lock only.
int foreign = 0;
plat_mutex_lock(&lz_lock);
for (int i = 0; i < lz_n && !foreign; i++)
foreign = lzs[i].lo < a + n && lzs[i].hi > a && (lzs[i].h0 != h0 || lzs[i].delta != delta);
if (foreign) {
plat_mutex_unlock(&lz_lock);
plat_mutex_lock(&frz_lock);
for (;;) {
plat_mutex_lock(&lz_lock);
int i = lz_n;
while (i-- > 0 && !(lzs[i].lo < a + n && lzs[i].hi > a && (lzs[i].h0 != h0 || lzs[i].delta != delta))) {}
LzSeg s;
if (i >= 0) {
lzs[i].stale = 0;
lz_foreign++;
s = lazy_take_locked(i);
}
plat_mutex_unlock(&lz_lock);
if (i < 0) break;
lazy_gone_locked(s, 4);
}
plat_mutex_lock(&lz_lock);
}
for (int i = 0; i < lz_n && k < max; i++) {
uint64_t lo = lzs[i].lo > a ? lzs[i].lo : a, hi = lzs[i].hi < a + n ? lzs[i].hi : a + n;
if (lo >= hi) continue;
lzs[i].stale = 1;
int at = k++;
for (; at > 0 && out[at - 1][0] > lo; at--) out[at][0] = out[at - 1][0], out[at][1] = out[at - 1][1];
out[at][0] = lo, out[at][1] = hi;
}
plat_mutex_unlock(&lz_lock);
if (foreign) plat_mutex_unlock(&frz_lock);
return k;
}
// 0 when no page of [a, a + n) can be inaccessible right now (armed by the lazy write-back or probed), so the CPU can
// read it without a fault; 1 when one may be.
int mem_lazy_touches(uint64_t a, uint64_t n) {
if (!n) return 0;
if (a >= RT_ADDRESS_LIMIT || a + n > RT_ADDRESS_LIMIT || __atomic_load_n(&prb_on, __ATOMIC_RELAXED)) return 1;
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED)) return 0;
int any = 0;
for (uint64_t r = a >> FRZ_SHIFT; r <= (a + n - 1) >> FRZ_SHIFT && !any; r++) any = __atomic_load_n(&lzr[r], __ATOMIC_ACQUIRE);
if (!any) return 0;
int hit = 0;
plat_mutex_lock(&lz_lock);
for (int i = 0; i < lz_n && !hit; i++) hit = lzs[i].lo < a + n && lzs[i].hi > a;
plat_mutex_unlock(&lz_lock);
return hit;
}
// [a, a + n) is armed as a whole still.
int mem_lazy_armed(uint64_t a, uint64_t n) {
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED)) return 0;
plat_mutex_lock(&lz_lock);
int ok = lazy_covered_locked(a, a + n);
plat_mutex_unlock(&lz_lock);
return ok;
}
// Copies each of n ranges of guest memory, src[i] = {address, bytes}, to dst[i] when every page of it can be read
// without a fault; ok[i] says which were. An armed range, a probed region or a page the game made inaccessible is left
// out instead of faulting on the caller's thread (vk_memory.c mirror_capture runs inside a submission, where a fetch
// could not be sent). frz_lock is held over all of them, so nothing is armed or probed meanwhile; a range in regions
// with neither (lzr, prb: both change under that lock, with the pages' protection) is copied without asking the system
// for its pages' state. Returns how many were copied.
int mem_copy_readable(uint8_t *const *dst, const uint64_t (*src)[2], int n, uint8_t *ok) {
int got = 0;
plat_mutex_lock(&frz_lock);
for (int i = 0; i < n; i++) {
uint64_t a = src[i][0], len = src[i][1];
ok[i] = 0;
if (!len || a >= RT_ADDRESS_LIMIT || a + len > RT_ADDRESS_LIMIT) continue;
int quick = 1, can = 1;
for (uint64_t r = a >> FRZ_SHIFT; quick && r <= (a + len - 1) >> FRZ_SHIFT; r++)
quick = !__atomic_load_n(&lzr[r], __ATOMIC_RELAXED) && !__atomic_load_n(&prb[r], __ATOMIC_RELAXED);
for (uint64_t x = a, e; !quick && can && x < a + len; x = e) {
int st = plat_mem_state(x, a + len, &e);
can = (st == PLAT_PROT_RW || st == PLAT_PROT_READ) && e > x;
}
if (!can) continue;
memcpy(dst[i], (const void *)(uintptr_t)a, len);
ok[i] = 1, got++;
}
plat_mutex_unlock(&frz_lock);
return got;
}
// Releases what is armed in [a, a + n): before the buffers a fetch would read go away.
void mem_lazy_release(uint64_t a, uint64_t n) {
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED) || !n) return;
plat_mutex_lock(&frz_lock);
for (int i = lz_n; i-- > 0;)
if (lzs[i].lo < a + n && lzs[i].hi > a) lazy_drop_locked(i, 4);
plat_mutex_unlock(&frz_lock);
}
// The back end is ready to fetch: arming starts. 0 when the setting is off (or the probe is on, which watches the
// same pages).
int mem_lazy_enable(void (*fetch)(uint64_t h0, uint64_t h1, uint64_t off, uint64_t size),
int (*clean)(uint64_t lo, uint64_t hi, void *ctx)) {
if (!lz_want) return 0;
lz_fetch = fetch, lz_clean = clean;
__atomic_store_n(&lz_on, 1, __ATOMIC_RELEASE);
return 1;
}
// Opens (under lz_lock: a fault's segment is out of the list before it, or the fault sees it) or closes the window of
// the replay's part.
void mem_lazy_window(int open) {
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED)) return;
if (!open) {
__atomic_store_n(&lz_win_tid, 0, __ATOMIC_RELEASE);
return;
}
plat_mutex_lock(&lz_lock); // a fault takes its segment out before this or sees the window
__atomic_store_n(&lz_win_tid, plat_thread_id(), __ATOMIC_RELEASE);
plat_mutex_unlock(&lz_lock);
}
static int lazy_fault(uint64_t a, int write) {
if (a >= RT_ADDRESS_LIMIT || !__atomic_load_n(&lzr[a >> FRZ_SHIFT], __ATOMIC_ACQUIRE)) return 0;
uint32_t me = plat_thread_id();
for (int tries = 0;; tries++) {
plat_mutex_lock(&frz_lock);
plat_mutex_lock(&lz_lock); // the window's test and the segment's leaving the list in one step
int i = 0;
while (i < lz_n && !(a >= lzs[i].lo && a < lzs[i].hi)) i++;
if (i == lz_n) {
plat_mutex_unlock(&lz_lock);
plat_mutex_unlock(&frz_lock);
return 0;
}
uint32_t w = __atomic_load_n(&lz_win_tid, __ATOMIC_ACQUIRE);
if (w && w != me && tries < 400) { // up to 20 ms: after the hand-over the fetch has that part's writes
plat_mutex_unlock(&lz_lock);
plat_mutex_unlock(&frz_lock);
plat_wait_ns(50000);
continue;
}
if (w) lz_gaps++;
int k = lz_nnote < LZ_NOTES ? lz_nnote++ : -1;
if (k >= 0)
lz_note[k].addr = a, lz_note[k].lo = lzs[i].lo, lz_note[k].hi = lzs[i].hi, lz_note[k].tid = me,
lz_note[k].write = write != 0, lz_note[k].stale = lzs[i].stale;
uint64_t r = a >> FRZ_SHIFT, out = lzs[i].hi - lzs[i].lo;
uint32_t now = (uint32_t)plat_now_ms();
int reader = lz_heavy_ms[r] && (int32_t)(now - lz_heavy_ms[r]) < LZ_HEAVY_KEEP_MS;
if (lz_chunk && !reader) {
if (lz_touch_ms[r] && (int32_t)(now - lz_touch_ms[r]) < LZ_HEAVY_MS) {
if (++lz_touch_n[r] > LZ_HEAVY_N) reader = 1, lz_heavy++;
} else {
lz_touch_ms[r] = now | 1, lz_touch_n[r] = 1;
}
}
if (reader) lz_heavy_ms[r] = now | 1;
if (lz_chunk && !reader) { // the piece leaves the list and the rest goes back into it under lz_lock
out = lazy_piece_locked(i, a, write != 0);
plat_mutex_unlock(&lz_lock);
if (k >= 0) lz_note[k].hold = lazy_hot_locked(a >> LZ_CHUNK_SHIFT, 1)->back;
} else { // the segment leaves the list under lz_lock; its pages come back without it
LzSeg s = lazy_take_locked(i);
plat_mutex_unlock(&lz_lock);
lazy_gone_locked(s, write != 0);
if (k >= 0) lz_note[k].hold = lz_back[r];
}
if (k >= 0) lz_note[k].out = out;
plat_mutex_unlock(&frz_lock);
return 1;
}
}
// Test (NX2NAVI_WB_LAZY_TOUCH): the first addresses of up to max armed segments, another set each call, for a caller
// that reads them to make the faults a game's access would.
int mem_lazy_pick(uint64_t *addr, int max) {
static int next;
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED)) return 0;
int k = 0;
plat_mutex_lock(&frz_lock);
for (; k < max && k < lz_n; k++) addr[k] = lzs[(next + k) % lz_n].lo;
next += k;
plat_mutex_unlock(&frz_lock);
return k;
}
// The lazy write-back's state as a phrase for a fatal error's summary line, "" while nothing is armed by it. No lock:
// the count of armed ranges may be a moment old, and a fetch in progress is named with its thread, which tells a game
// that ended inside a fetch (the device lost under it, or its wait run out) from one that ended elsewhere.
void mem_lazy_note(char *out, size_t n) {
*out = 0;
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED)) return;
uint32_t tid = __atomic_load_n(&lz_fetch_tid, __ATOMIC_ACQUIRE), last = __atomic_load_n(&lz_fetch_ms, __ATOMIC_RELAXED);
int k = snprintf(out, n, "%d ranges armed, %llu fetches so far", lz_n,
(unsigned long long)__atomic_load_n(&lz_fetch_total, __ATOMIC_RELAXED));
if (k < 0 || (size_t)k >= n) return;
if (tid)
snprintf(out + k, n - (size_t)k, ", one of %llu bytes in progress on thread %u%s",
(unsigned long long)__atomic_load_n(&lz_fetch_now, __ATOMIC_RELAXED), tid,
tid == plat_thread_id() ? " (this one)" : "");
else if (last)
snprintf(out + k, n - (size_t)k, ", the last ended %u ms ago", (uint32_t)plat_now_ms() - last);
}
// One log line since the last one; skipped: the bytes the back end left in the mirror since then.
void mem_lazy_report(uint64_t frame, uint64_t skipped) {
static int64_t async_said = -1;
int64_t an = __atomic_load_n(&frz_async_n, __ATOMIC_RELAXED), af = __atomic_load_n(&frz_protect_fails, __ATOMIC_RELAXED);
if ((rt_trace & RT_TRACE_PERF) && an != async_said) {
async_said = an;
rt_log("mem: thaws outside the freeze lock so far %lld (NX2NAVI_FREEZE_ASYNC), page protections that failed there "
"%lld", (long long)an, (long long)af);
}
if (!__atomic_load_n(&lz_on, __ATOMIC_RELAXED)) return;
plat_mutex_lock(&frz_lock);
uint64_t bytes = 0, fr = lz_faults[0], fw = lz_faults[1], other = lz_other, nf = lz_fetches, fb = lz_fetch_bytes,
fns = lz_fetch_ns, gaps = lz_gaps, unclean = lz_unclean, no[LZ_NO_N];
int n = lz_n;
for (int i = 0; i < lz_n; i++) bytes += lzs[i].hi - lzs[i].lo;
lz_faults[0] = lz_faults[1] = lz_other = lz_fetches = lz_fetch_bytes = lz_fetch_ns = lz_gaps = lz_unclean = 0;
uint64_t small = lz_no_small, calls = lz_arm_calls;
int nnote = lz_nnote;
__typeof__(lz_note) note;
memcpy(note, lz_note, sizeof note);
lz_nnote = 0;
memcpy(no, lz_no, sizeof no);
memset(lz_no, 0, sizeof lz_no);
lz_no_small = lz_arm_calls = 0;
uint64_t pieces = lz_pieces, piece_bytes = lz_piece_bytes, heavy = lz_heavy, foreign = lz_foreign;
lz_pieces = lz_piece_bytes = lz_heavy = 0;
plat_mutex_unlock(&frz_lock);
static uint64_t foreign_said;
if (foreign != foreign_said) {
foreign_said = foreign;
rt_log("mem: lazy write-back: %llu armed ranges named a mirror that is no longer the pool's, given back without "
"a fetch so far", (unsigned long long)foreign);
}
rt_log("mem: lazy write-back at frame %llu: %d ranges armed, %.1f MiB; since the last line %.1f MiB left in the "
"mirror, %llu read and %llu write faults (%llu inside a part's window), %llu other releases, %llu fetches of "
"%.1f MiB in %.2f ms, %llu arms refused (a CPU write not in the mirror yet)", (unsigned long long)frame, n,
bytes / 1048576.0, skipped / 1048576.0, (unsigned long long)fr, (unsigned long long)fw,
(unsigned long long)gaps, (unsigned long long)other, (unsigned long long)nf, fb / 1048576.0, fns / 1e6,
(unsigned long long)unclean);
for (int i = 0; i < nnote && (rt_trace & RT_TRACE_PERF); i++)
rt_log("mem: lazy write-back: thread %u %s %#llx, %llu KiB into an armed range of %.2f MiB at %#llx; %llu KiB of "
"it given back%s and held for %u s", note[i].tid, note[i].write ? "wrote" : "read",
(unsigned long long)note[i].addr, (unsigned long long)((note[i].addr - note[i].lo) >> 10),
(note[i].hi - note[i].lo) / 1048576.0, (unsigned long long)note[i].lo, (unsigned long long)(note[i].out >> 10),
note[i].stale ? " (fetched)" : " (its bytes were current)", note[i].hold);
if (pieces || heavy)
rt_log("mem: lazy write-back at frame %llu: %llu touches gave back a piece only (%.2f MiB in all), %llu regions "
"were touched too often in a second and give back whole ranges for now",
(unsigned long long)frame, (unsigned long long)pieces, piece_bytes / 1048576.0, (unsigned long long)heavy);
if (no[LZ_NO_FROZEN] + no[LZ_NO_HOT] + no[LZ_NO_THAW] + no[LZ_NO_PAGES] + no[LZ_NO_EDGE])
rt_log("mem: lazy write-back at frame %llu: written back and not armed since the last line: %.1f MiB in frozen "
"regions, %.1f MiB in regions the CPU touched lately, %.1f MiB in regions held after a thaw, %.1f MiB in "
"regions with pages that are not read-write or with a CPU write not in the mirror, %.2f MiB in the "
"partial pages at the ends of ranges; %llu ranges written back, %llu of them without a whole page",
(unsigned long long)frame, no[LZ_NO_FROZEN] / 1048576.0, no[LZ_NO_HOT] / 1048576.0,
no[LZ_NO_THAW] / 1048576.0, no[LZ_NO_PAGES] / 1048576.0, no[LZ_NO_EDGE] / 1048576.0,
(unsigned long long)calls, (unsigned long long)small);
}
// Makes the pages region r's freeze made read-only read-write again: the runs freeze_locked kept, else every read-only
// run (freeze_locked left reserved holes, heap pages given back, as they were; every committed page of a frozen region
// was read-write at the freeze, and mapping changes thaw or wait before they run, so these are all ours). strict: under
// frz_lock, a failure ends the process; outside it (a thaw in flight, FRZ_THAWING) the pages are what the freeze left,
// and a failure is only counted.
static void thaw_pages_vm(uint64_t r, int strict);
static void thaw_pages(uint64_t r, int strict) {
plat_mutex_lock(&vm_lock);
thaw_pages_vm(r, strict);
plat_mutex_unlock(&vm_lock);
}
static void thaw_pages_vm(uint64_t r, int strict) { // vm_lock held
uint64_t base = r << FRZ_SHIFT;
const FrzRuns *k = frz_runs[r];
if (k && k->n) {
for (int i = 0; i < k->n; i++) {
uint64_t a = base + ((uint64_t)k->run[i][0] << 12), n = (uint64_t)(k->run[i][1] - k->run[i][0]) << 12;
if (!plat_mem_protect(a, n, PLAT_PROT_RW)) {
if (strict)
rt_fatal("memory: thawing %#llx+%#llx failed", (unsigned long long)a, (unsigned long long)n);
plat_inc64(&frz_protect_fails);
}
}
return;
}
uint64_t a = base, end = a + FRZ_SIZE, b;
for (; a < end; a = b)
if (plat_mem_state(a, end, &b) == PLAT_PROT_READ && !plat_mem_protect(a, b - a, PLAT_PROT_RW)) {
if (strict) rt_fatal("memory: thawing %#llx+%#llx failed", (unsigned long long)a, (unsigned long long)(b - a));
plat_inc64(&frz_protect_fails);
}
}
// frz_lock held exclusively: what a thaw does before the pages (the hold, the lazy write-back's ranges, a probe).
// Returns 1 when the region is frozen.
static int thaw_begin_locked(uint64_t r, int why) {
if (why == 2) thaw_ms[r] = (uint32_t)plat_now_ms() | 1;
if (lzr[r]) lazy_drop_region_locked(r, why + 1); // not a fault on an armed page: no hold
if (prb[r]) unprobe_locked(r);
return frz[r] == 1;
}
static void thaw_end_locked(uint64_t r, int why);
// frz_lock held exclusively. why: 1 a write fault, 2 mem_thaw (holds the region thawed), 3 a mapping change here.
// A region another thread is thawing (FRZ_THAWING) gets its pages made read-write here too, and is ended here.
static void thaw_locked(uint64_t r, int why) {
if (!thaw_begin_locked(r, why) && frz[r] != FRZ_THAWING) return;
thaw_pages(r, 1);
__atomic_store_n(&frz[r], FRZ_THAWING, __ATOMIC_RELEASE);
thaw_end_locked(r, why);
}
// frz_lock held exclusively: the end of a thaw. Nothing when another thread ended it meanwhile.
static void thaw_end_locked(uint64_t r, int why) {
if (frz[r] != FRZ_THAWING) return;
__atomic_store_n(&frz[r], 0, __ATOMIC_RELEASE);
plat_dec32(&nfrz);
plat_inc64(&frz_count[why]);
if (why == 1) { // a write: a quick one makes the region hot, a late one ends its hot time
uint32_t now = (uint32_t)plat_now_ms();
if (frz_ms[r] && now - frz_ms[r] < FRZ_QUICK_MS) {
uint32_t h = frz_hot_ms[r] ? frz_hot_ms[r] * 2 : FRZ_HOT_MIN_MS;
frz_hot_ms[r] = h > FRZ_HOT_MAX_MS ? FRZ_HOT_MAX_MS : h;
frz_hot_until[r] = (now + frz_hot_ms[r]) | 1;
plat_inc64(&frz_hot_holds);
} else {
frz_hot_ms[r] = 0;
}
}
}
// frz_lock held exclusively.
static void thaw_range_locked(uint64_t a, uint64_t n, int why) {
if (!n || a >= RT_ADDRESS_LIMIT) return;
uint64_t r0 = a >> FRZ_SHIFT, r1 = (a + n - 1 < RT_ADDRESS_LIMIT ? a + n - 1 : RT_ADDRESS_LIMIT - 1) >> FRZ_SHIFT;
for (uint64_t r = r0; r <= r1; r++) thaw_locked(r, why);
}
// frz_lock held exclusively: returns once no region of [a, a + n) is being thawed outside the lock (FRZ_THAWING),
// releasing the lock while it waits. A mapping change runs after this: the thaw's VirtualProtect then cannot land on
// the pages after the change and undo it.
static void thaw_wait_locked(uint64_t a, uint64_t n) {
if (!n || a >= RT_ADDRESS_LIMIT) return;
uint64_t r0 = a >> FRZ_SHIFT, r1 = (a + n - 1 < RT_ADDRESS_LIMIT ? a + n - 1 : RT_ADDRESS_LIMIT - 1) >> FRZ_SHIFT;
for (uint64_t r = r0; r <= r1; r++)
while (__atomic_load_n(&frz[r], __ATOMIC_ACQUIRE) == FRZ_THAWING) {
plat_mutex_unlock(&frz_lock);
plat_wait_ns(20000);
plat_mutex_lock(&frz_lock);
}
}
// Lazy heap (NX2NAVI_HEAP_LAZY, Windows only; off by default). Windows charges every committed page to the system's
// commit at once, and SetHeapSize asks for the whole application heap up front: in Castle Town after Hyrule Field the
// heap held 6.8 GiB of commit of which 3.4 GiB had ever been resident, with 0.45 GB in the page file. With it on,
// SetHeapSize only moves the heap's end, and a page of the heap is committed when something first reaches it: an access
// of the game's or the runtime's code faults into access_fault, which commits the reserved runs of the 64 KiB around
// it; a kernel read or write of a buffer (mem_thaw, mem_kernel_access) and a pointer check (mem_host_readable)
// commit their range first, as the kernel and VirtualQuery do not fault. On Linux pages are committed on first touch
// already.
// frz_lock held exclusively. Commits the reserved pages of [a, a + n) inside the heap; returns the bytes committed. A
// page another path committed is left alone: committing it again would make a read-only or inaccessible page (a
// freeze, a probe, an armed lazy write-back) read-write behind their backs. The regions it commits into are thawed
// first, as for any mapping change, so that no frozen region holds a read-write page.
static uint64_t heap_lazy_commit_locked(uint64_t a, uint64_t n) {
uint64_t lo = a > L.heap.base ? a : L.heap.base, top = L.heap.base + __atomic_load_n(&heap_size, __ATOMIC_ACQUIRE);
uint64_t end = a + n < a ? UINT64_MAX : a + n, hi = end < top ? end : top, got = 0;
if (lo >= hi) return 0;
lo &= ~(PAGE - 1), hi = align_up(hi, PAGE);
int thawed = 0;
for (uint64_t x = lo, y; x < hi; x = y) {
if (plat_mem_state(x, hi, &y) != PLAT_MEM_RESERVED) continue;
if (!thawed) thaw_range_locked(lo, hi - lo, 3), thawed = 1;
if (!plat_mem_commit(x, y - x))
rt_fatal("memory: committing the heap's pages %#llx+%#llx on first use failed: the system's commit is "
"used up", (unsigned long long)x, (unsigned long long)(y - x));
got += y - x;
}
heap_lazy_bytes += got;
return got;
}
// Commits the heap pages of [a, a + n) that the lazy heap left reserved; nothing when it is off.
void mem_kernel_access(uint64_t a, uint64_t n) {
if (!heap_lazy || !n) return;
plat_mutex_lock(&frz_lock);
heap_lazy_commit_locked(a, n);
plat_mutex_unlock(&frz_lock);
}
// For a host scan of guest memory (camera_speed.c rewrite): the end of the run of pages at a that the lazy heap left
// reserved, at most end, or 0 when the page at a is not such a page. Nothing was ever written there, so a scan steps
// over the run; reading it would commit every page of the heap and undo what the setting saves.
uint64_t mem_untouched_run(uint64_t a, uint64_t end) {
if (!heap_lazy || a < L.heap.base || a >= L.heap.base + L.heap.size) return 0;
uint64_t y, x = a & ~(PAGE - 1);
return plat_mem_state(x, end, &y) == PLAT_MEM_RESERVED && y > a ? y : 0;
}
// plat_mem_readable for a pointer the host is about to read: untouched heap pages of a lazy heap count as readable
// (they are committed here, and read zero as they would have).
int mem_host_readable(uint64_t a, uint64_t n) {
mem_kernel_access(a, n);
return plat_mem_readable(a, n);
}
// An access fault on a reserved page of the lazy heap: the 64 KiB around it is committed and the access runs again.
// 0 when nothing was reserved there, so that a frozen, probed or armed page goes on to its own hook (a page another
// thread committed meanwhile is retried by thaw_fault or the end of access_fault, as the heap is watched).
static int heap_lazy_fault(uint64_t a) {
uint64_t heap = L.heap.base;
if (a < heap || a - heap >= __atomic_load_n(&heap_size, __ATOMIC_ACQUIRE)) return 0;
uint64_t t0 = plat_now_ns();
plat_mutex_lock(&frz_lock);
uint64_t got = heap_lazy_commit_locked(a & ~0xFFFFull, 0x10000);
if (got) {
uint64_t ns = plat_now_ns() - t0;
heap_lazy_faults++, heap_lazy_ns += ns;
if (ns > heap_lazy_max_ns) heap_lazy_max_ns = ns;
}
plat_mutex_unlock(&frz_lock);
return got != 0;
}
void mem_thaw(uint64_t a, uint64_t n) {
plat_mutex_lock(&frz_lock); // also when nothing is frozen: the hold keeps a read's buffer writable
if (heap_lazy || !frz_async || !n || a >= RT_ADDRESS_LIMIT) {
if (heap_lazy) {
thaw_wait_locked(a, n); // it commits pages: a mapping change
heap_lazy_commit_locked(a, n); // the kernel's write would fail on a reserved page as well
}
thaw_range_locked(a, n, 2);
plat_mutex_unlock(&frz_lock);
return;
}
// The regions frozen now are marked FRZ_THAWING and made read-write without the lock (see FRZ_THAWING), up to
// MANY at a time; those another thread is thawing are made read-write here too, as the caller's kernel access needs
// every page of them now, and that thread ends them.
enum { MANY = 64 };
uint64_t r0 = a >> FRZ_SHIFT, r1 = (a + n - 1 < RT_ADDRESS_LIMIT ? a + n - 1 : RT_ADDRESS_LIMIT - 1) >> FRZ_SHIFT;
for (uint64_t r = r0; r <= r1;) {
uint64_t mine[MANY], theirs[MANY];
int nm = 0, nt = 0;
for (; r <= r1 && nm < MANY && nt < MANY; r++) {
if (thaw_begin_locked(r, 2)) {
__atomic_store_n(&frz[r], FRZ_THAWING, __ATOMIC_RELEASE);
mine[nm++] = r;
} else if (frz[r] == FRZ_THAWING) {
theirs[nt++] = r;
}
}
if (!nm && !nt) continue;
plat_mutex_unlock(&frz_lock);
for (int i = 0; i < nm; i++) thaw_pages(mine[i], 0);
for (int i = 0; i < nt; i++) thaw_pages(theirs[i], 0);
plat_add64(&frz_async_n, nm);
plat_mutex_lock(&frz_lock);
for (int i = 0; i < nm; i++) thaw_end_locked(mine[i], 2);
}
plat_mutex_unlock(&frz_lock);
}
// frz_lock held exclusively. Makes the committed pages of region r read-only when every one of them is read-write;
// reserved holes (heap pages given back) stay as they are, and thaw_locked finds the read-only runs again.
static int freeze_locked(uint64_t r) {
uint64_t a = r << FRZ_SHIFT, end = a + FRZ_SIZE, run[16][2];
int n = 0, ok = 1;
plat_mutex_lock(&vm_lock);
for (uint64_t x = a, y; x < end && ok; x = y) {
int st = plat_mem_state(x, end, &y);
if (st >= PLAT_PROT_NONE) {
if (st != PLAT_PROT_RW || n == 16) ok = 0;
else run[n][0] = x, run[n][1] = y, n++;
} else if (st != PLAT_MEM_RESERVED) ok = 0;
}
for (int i = 0; ok && i < n; i++)
if (!plat_mem_protect(run[i][0], run[i][1] - run[i][0], PLAT_PROT_READ)) {
while (i--) plat_mem_protect(run[i][0], run[i][1] - run[i][0], PLAT_PROT_RW);
ok = 0;
}
plat_mutex_unlock(&vm_lock);
if (!ok) return 0;
// the runs, for a thaw without VirtualQuery (thaw_pages); kept per region from its first freeze on
if (n && !frz_runs[r]) frz_runs[r] = calloc(1, sizeof *frz_runs[r]);
if (frz_runs[r]) {
frz_runs[r]->n = (uint8_t)n;
for (int i = 0; i < n; i++)
frz_runs[r]->run[i][0] = (uint16_t)((run[i][0] - a) >> 12), frz_runs[r]->run[i][1] = (uint16_t)((run[i][1] - a) >> 12);
}
return n > 0;
}
int mem_freeze(uint64_t a) {
if ((a & (FRZ_SIZE - 1)) || !watched(a, FRZ_SIZE)) return 0;
uint64_t r = a >> FRZ_SHIFT;
int ok = 0;
plat_mutex_lock(&frz_lock);
uint32_t now = (uint32_t)plat_now_ms();
if (frz[r]) ok = 1;
else if (thaw_ms[r] && (int32_t)(now - thaw_ms[r]) < (int32_t)FRZ_HOLD_MS) ok = 0; // |1 may be ahead
else if (frz_hot_until[r] && (int32_t)(frz_hot_until[r] - now) > 0) ok = 0; // hot: held thawed
else if (freeze_locked(r)) {
frz_ms[r] = now | 1;
__atomic_store_n(&frz[r], 1, __ATOMIC_RELEASE);
plat_inc32(&nfrz);
plat_inc64(&frz_count[0]);
ok = 1;
}
plat_mutex_unlock(&frz_lock);
return ok;
}
int mem_frozen(uint64_t a) { return a < RT_ADDRESS_LIMIT && __atomic_load_n(&frz[a >> FRZ_SHIFT], __ATOMIC_ACQUIRE); }
// Probes the 2 MiB regions that lie wholly inside [a, a + n): makes them inaccessible until their first access.
// Returns how many it armed. Not a region a file read may still be writing into (the thaw hold), nor one with a page
// that is not plainly read-write (read-only when frozen): those are left alone.
int mem_probe(uint64_t a, uint64_t n) {
if (!__atomic_load_n(&prb_on, __ATOMIC_RELAXED) || n < FRZ_SIZE || a >= RT_ADDRESS_LIMIT || !watched(a, n)) return 0;
uint64_t r0 = (a + FRZ_SIZE - 1) >> FRZ_SHIFT, r1 = (a + n) >> FRZ_SHIFT; // [r0, r1)
int armed = 0;
plat_mutex_lock(&frz_lock);
for (uint64_t r = r0; r < r1; r++) {
if (prb[r]) continue;
if (thaw_ms[r] && (int32_t)((uint32_t)plat_now_ms() - thaw_ms[r]) < (int32_t)FRZ_HOLD_MS) continue;
int want = frz[r] ? PLAT_PROT_READ : PLAT_PROT_RW, k = 0, ok = 1;
uint64_t run[16][2];
for (uint64_t x = r << FRZ_SHIFT, end = x + FRZ_SIZE, y; x < end && ok; x = y) {
int st = plat_mem_state(x, end, &y);
if (st >= PLAT_PROT_NONE) {
if (st != want || k == 16) ok = 0;
else run[k][0] = x, run[k][1] = y, k++;
} else if (st != PLAT_MEM_RESERVED) ok = 0;
}
if (!ok || !k) continue;
for (int i = 0; i < k && ok; i++)
if (!plat_mem_protect(run[i][0], run[i][1] - run[i][0], PLAT_PROT_NONE)) {
while (i--) plat_mem_protect(run[i][0], run[i][1] - run[i][0], want);
ok = 0;
}
if (!ok) continue;
__atomic_store_n(&prb[r], 1, __ATOMIC_RELEASE);
plat_inc32(&nprb);
prb_arms++, armed++;
}
plat_mutex_unlock(&frz_lock);
return armed;
}
// Pages of guest memory may be inaccessible (the probe, or the lazy write-back): a kernel read of them has to thaw first.
int mem_probing(void) { return __atomic_load_n(&prb_on, __ATOMIC_RELAXED) || __atomic_load_n(&lz_on, __ATOMIC_RELAXED); }
// The platform's access-fault hook while the probe is on: the first access of a probed region ends its probe and is
// noted; 1 runs the access again. A read that faulted in a region another thread gave back meanwhile retries too; a
// write goes on to thaw_fault, and any other fault to the crash handler.
static int probe_fault(uint64_t a, int write, uint64_t ip) {
if (a >= RT_ADDRESS_LIMIT || !watched(a, 1)) return 0;
uint64_t r = a >> FRZ_SHIFT;
plat_mutex_lock(&frz_lock);
int was = prb[r];
if (was) {
unprobe_locked(r);
prb_ends[write != 0]++;
if (prb_nhit < PRB_HITS) prb_hit[prb_nhit++] = (typeof(prb_hit[0])){a, ip, plat_thread_id(), (uint8_t)(write != 0)};
}
plat_mutex_unlock(&frz_lock);
if (was) return 1;
if (write) return 0;
uint64_t end;
return plat_mem_state(a & ~(PAGE - 1), (a & ~(PAGE - 1)) + PAGE, &end) >= PLAT_PROT_READ;
}
// The platform's access-fault hook: a reserved page of the lazy heap first, then an armed page of the lazy write-back,
// then the probe. A read that faulted on
// a page another thread gave back meanwhile runs again; a write goes on to thaw_fault.
static int access_fault(uint64_t a, int write, uint64_t ip) {
if (heap_lazy && heap_lazy_fault(a)) return 1;
if (__atomic_load_n(&lz_on, __ATOMIC_RELAXED) && lazy_fault(a, write)) return 1;
if (__atomic_load_n(&prb_on, __ATOMIC_RELAXED)) return probe_fault(a, write, ip);
if (write || a >= RT_ADDRESS_LIMIT || !watched(a, 1)) return 0;
uint64_t end;
return plat_mem_state(a & ~(PAGE - 1), (a & ~(PAGE - 1)) + PAGE, &end) >= PLAT_PROT_READ;
}
// One log block for the probe since the last one: how many regions were armed, how many probes a read or a write
// ended, and the first accesses by instruction (an address inside the executable as nx2navi+offset, for the linker
// map or nm). Nothing while the probe is off.
void mem_probe_report(uint64_t frame) {
if (!__atomic_load_n(&prb_on, __ATOMIC_RELAXED)) return;
typeof(prb_hit[0]) hit[PRB_HITS];
plat_mutex_lock(&frz_lock);
uint64_t arms = prb_arms, reads = prb_ends[0], writes = prb_ends[1];
int n = prb_nhit;
memcpy(hit, prb_hit, sizeof hit[0] * (size_t)n);
prb_arms = prb_ends[0] = prb_ends[1] = 0, prb_nhit = 0;
plat_mutex_unlock(&frz_lock);
rt_log("mem: write-back probe at frame %llu: %llu regions of 2 MiB armed, probes ended by %llu reads and %llu writes "
"since the last line; %d probed now", (unsigned long long)frame, (unsigned long long)arms,
(unsigned long long)reads, (unsigned long long)writes, (int)__atomic_load_n(&nprb, __ATOMIC_RELAXED));
uintptr_t exe = plat_exe_base();
for (int i = 0, lines = 0; i < n && lines < 12; i++) {
if (!hit[i].ip) continue; // counted with an earlier access of the same instruction
int same = 1;
for (int j = i + 1; j < n; j++)
if (hit[j].ip == hit[i].ip && hit[j].write == hit[i].write) same++, hit[j].ip = 0;
rt_log("mem: %d x a %s at %#llx.. from %s%#llx (thread %u)", same, hit[i].write ? "write" : "read",
(unsigned long long)hit[i].addr, hit[i].ip >= exe && hit[i].ip - exe < (1ull << 32) ? "nx2navi+" : "",
(unsigned long long)(hit[i].ip >= exe && hit[i].ip - exe < (1ull << 32) ? hit[i].ip - exe : hit[i].ip),
hit[i].tid);
lines++;
}
}
void mem_freeze_stats(uint64_t *frozen, uint64_t *freezes, uint64_t *fault_thaws, uint64_t *other_thaws,
uint64_t *hot_holds) {
*frozen = (uint64_t)__atomic_load_n(&nfrz, __ATOMIC_RELAXED);
*hot_holds = (uint64_t)plat_xchg64(&frz_hot_holds, 0);
*freezes = (uint64_t)plat_xchg64(&frz_count[0], 0);
*fault_thaws = (uint64_t)plat_xchg64(&frz_count[1], 0);
*other_thaws = (uint64_t)plat_xchg64(&frz_count[2], 0) + (uint64_t)plat_xchg64(&frz_count[3], 0);
}
// The first write into a frozen region thaws it and retries. A fault in a region another thread thawed meanwhile
// retries too; any other fault goes on to the crash handler.
// The platform's write-fault hook (plat_mem_fault_hook): 1 retries the write.
static int thaw_fault(uint64_t a) {
if (a >= RT_ADDRESS_LIMIT || !watched(a, 1)) return 0;
uint64_t r = a >> FRZ_SHIFT;
plat_mutex_lock(&frz_lock);
int was = frz[r];
if (was == FRZ_THAWING) { // another thread's thaw: the write runs again once it ended
while (frz[r] == FRZ_THAWING) {
plat_mutex_unlock(&frz_lock);
plat_wait_ns(20000);
plat_mutex_lock(&frz_lock);
}
plat_mutex_unlock(&frz_lock);
return 1;
}
if (frz_async && was == 1) { // its pages outside the lock (FRZ_THAWING)
thaw_begin_locked(r, 1);
__atomic_store_n(&frz[r], FRZ_THAWING, __ATOMIC_RELEASE);
plat_mutex_unlock(&frz_lock);
thaw_pages(r, 0);
plat_inc64(&frz_async_n);
plat_mutex_lock(&frz_lock);
thaw_end_locked(r, 1);
plat_mutex_unlock(&frz_lock);
return 1;
}
thaw_locked(r, 1);
plat_mutex_unlock(&frz_lock);
if (was) return 1;
uint64_t end;
return plat_mem_state(a & ~(PAGE - 1), (a & ~(PAGE - 1)) + PAGE, &end) == PLAT_PROT_RW;
}
// Mapping changes thaw the regions they touch and run under frz_lock, so no freeze sees them half done.
static void commit(uint64_t a, uint64_t n, const char *what) {
plat_mutex_lock(&frz_lock);
thaw_wait_locked(a, n);
thaw_range_locked(a, n, 3);
int ok = !n || plat_mem_commit(a, n);
plat_mutex_unlock(&frz_lock);
if (!ok) rt_fatal("memory: commit %s %#llx+%#llx failed", what, (unsigned long long)a, (unsigned long long)n);
}
static void decommit(uint64_t a, uint64_t n, const char *what) {
plat_mutex_lock(&frz_lock);
thaw_wait_locked(a, n);
thaw_range_locked(a, n, 3);
int ok = !n || plat_mem_decommit(a, n);
plat_mutex_unlock(&frz_lock);
if (!ok) rt_fatal("memory: decommit %s %#llx+%#llx failed", what, (unsigned long long)a, (unsigned long long)n);
}
static void protect(uint64_t a, uint64_t n, int prot, const char *what) {
plat_mutex_lock(&frz_lock);
thaw_wait_locked(a, n);
thaw_range_locked(a, n, 3);
int ok = !n || plat_mem_protect(a, n, prot);
plat_mutex_unlock(&frz_lock);
if (!ok) rt_fatal("memory: protect %s %#llx+%#llx failed", what, (unsigned long long)a, (unsigned long long)n);
}
// The process is re-run when a region is taken: Windows places DLLs, heaps and thread stacks at random addresses,
// and a fresh process gets a fresh layout.
static void reexec_or_fail(const char *what) {
const char *e = cfg_get("NX2NAVI_REEXEC");
int n = e ? atoi(e) : 0;
if (n >= REEXEC_LIMIT) rt_fatal("memory: %s is not free after %d attempts", what, n);
char buf[16];
snprintf(buf, sizeof buf, "%d", n + 1);
cfg_setenv("NX2NAVI_REEXEC", buf);
plat_reexec();
}
void mem_init(void) {
if (L.pool) return;
// Fixed window: modules, kernel region, host-function addresses.
mods_lo = MOD_MAIN_BASE;
mods_hi = align_up(rt_layout[rt_layout_count - 1].base + rt_layout[rt_layout_count - 1].size, 0x10000);
if (mods_hi > RT_KERNEL_BASE) rt_fatal("memory: modules end at %#llx, inside the kernel region",
(unsigned long long)mods_hi);
if (!reserve_at(mods_lo, mods_hi - mods_lo, 0)) reexec_or_fail("the module window");
if (!reserve_at(RT_KERNEL_BASE, RT_KERNEL_SIZE, 0)) reexec_or_fail("the kernel region");
if (!reserve_at(RT_HOSTFN_BASE, RT_HOSTFN_SIZE, 0)) reexec_or_fail("the host-function window");
// Stack and heap block, then the alias region above it, both searched below the module window.
uint64_t low = 0, alias = 0;
for (uint64_t at = LOW_SEARCH_FROM; at + LOW_SIZE <= mods_lo && !low; at += GiB)
if (reserve_at(at, LOW_SIZE, 1)) low = at;
if (!low) reexec_or_fail("a 14 GiB stack and heap block below 2^39");
for (uint64_t at = align_up(low + LOW_SIZE, ALIAS_ALIGN); at + ALIAS_SIZE <= mods_lo && !alias; at += ALIAS_ALIGN)
if (reserve_at(at, ALIAS_SIZE, 1)) alias = at;
if (!alias) reexec_or_fail("a 64 GiB alias region below 2^39");
plat_mem_fault_hook(thaw_fault); // before the crash handler
alias_pages = calloc(ALIAS_PAGES, 1);
if (!alias_pages) rt_fatal("memory: cannot allocate the alias page map");
// nx2navi.ini is read here, once the address space is claimed and before the first setting: the pool size below
// depends on NX2NAVI_APP_POOL and on the resolution settings (resolution.c decides them once, on this first call).
cfg_init();
if (cfg_bool("NX2NAVI_WB_PROBE")) { // a diagnosis: off, no access fault reaches probe_fault and nothing is probed
plat_mem_access_hook(access_fault);
__atomic_store_n(&prb_on, 1, __ATOMIC_RELEASE);
} else if (cfg_bool("NX2NAVI_WB_LAZY")) { // armed once the back end wants it and can fetch (mem_lazy_enable)
plat_mem_access_hook(access_fault);
lz_want = 1;
lz_chunk = cfg_bool("NX2NAVI_WB_LAZY_CHUNK");
}
const char *fa = cfg_get("NX2NAVI_FREEZE_ASYNC"); // thaws outside frz_lock (FRZ_THAWING); unset: on
frz_async = !fa || !*fa || atoi(fa) != 0;
const char *pool = cfg_get("NX2NAVI_APP_POOL");
L = (RtGuestLayout){
.aslr = {low, RT_ADDRESS_LIMIT - low},
.stack = {low + STACK_OFF, STACK_SIZE},
.heap = {low + HEAP_OFF, HEAP_CAP},
.alias = {alias, ALIAS_SIZE},
.kernel = {RT_KERNEL_BASE, RT_KERNEL_SIZE},
.hostfn = {RT_HOSTFN_BASE, RT_HOSTFN_SIZE},
.pool = pool ? strtoull(pool, NULL, 0) : DEFAULT_POOL + res_heap_extra_bytes(), // resolution.c
};
if (!L.pool) rt_fatal("memory: NX2NAVI_APP_POOL is 0");
#ifdef _WIN32
if (cfg_bool("NX2NAVI_HEAP_LAZY")) { // set before the game's first SetHeapSize
plat_mem_access_hook(access_fault);
heap_lazy = 1;
rt_log("mem: the heap is committed on first use (NX2NAVI_HEAP_LAZY)");
}
#endif
}
const RtGuestLayout *mem_layout(void) { return &L; }
// The start of a game (main.c, before the boot): one line when the machine's free commit is below what the game takes
// in play (mem_need.h; NX2NAVI_MEM_NEED_MB, 0 no check), so a log that ends in a failed allocation, dropped textures
// or a lost device says at its top that the machine was short before the game took anything. 1 when it was.
// probe: --probe-memneed, which prints the numbers either way.
int mem_start_note(int probe) {
double proc, used, limit, need = strtod(cfg_value("NX2NAVI_MEM_NEED_MB"), NULL);
plat_commit_info(&proc, &used, &limit);
int is_short = mem_need_short(proc, used, limit, need);
if (probe)
printf("probe-memneed: system commit %.0f of %.0f MB in use, this process %.0f MB, the game needs %.0f MB "
"(NX2NAVI_MEM_NEED_MB): %s\n", used, limit, proc, need,
need <= 0 ? "not checked" : limit < 0 ? "no limit known" : is_short ? "short" : "enough");
if (!is_short) return 0;
char note[400] = "";
plat_commit_note(note, sizeof note);
rt_log("mem: WARNING: this machine has %.0f MB of memory left for the game and the game takes about %.0f MB in play "
"(system commit: %.0f of %.0f MB in use; the limit is RAM plus page file%s%s). Short of memory the game "
"stutters, loses textures or stops with an out-of-memory or lost-device error. Closing other programs or a "
"larger page file gives it room (mem_need_mb = 0 in nx2navi.ini turns this warning off)",
mem_need_room(proc, used, limit), need, used, limit, note[0] ? "; " : "", note);
return 1;
}
// A range inside one watched reservation (stack and heap block, or alias region) only.
static uint64_t written_pages(uint64_t addr, uint64_t size, uint64_t *pages, uint64_t max, int reset) {
if (!max || !size) return 0;
if (!watched(addr, size)) return UINT64_MAX;
plat_mutex_lock(&vm_lock);
uint64_t n = plat_mem_written(addr, size, pages, max, reset);
plat_mutex_unlock(&vm_lock);
return n;
}
uint64_t mem_written_pages(uint64_t addr, uint64_t size, uint64_t *pages, uint64_t max) {
return written_pages(addr, size, pages, max, 1);
}
uint64_t mem_written_peek(uint64_t addr, uint64_t size, uint64_t *pages, uint64_t max) {
return written_pages(addr, size, pages, max, 0);
}
static uint64_t image_bytes(void) {
uint64_t n = 0;
for (int i = 0; i < ldr_count(); i++) n += ldr_module(i)->size;
return align_up(n, PAGE);
}
static int overlaps(uint64_t a, uint64_t n, uint64_t b, uint64_t m) { return a < b + m && b < a + n; }
static int inside(uint64_t a, uint64_t n, RtRange r) { return a >= r.base && n <= r.size && a - r.base <= r.size - n; }
// Bumped (lock held exclusively) by every change of what is mapped or readable: vk_exec_draw.c's texture pool looks the
// slots over unreadable storage up again only then (and now and then).
static uint32_t map_gen;
uint32_t mem_map_gen(void) { return __atomic_load_n(&map_gen, __ATOMIC_ACQUIRE); }
// ---- 0x01 SetHeapSize
uint32_t mem_set_heap_size(uint64_t size, uint64_t *addr) {
uint64_t t0 = perf_mark_begin(); // NX2NAVI_TRACE=perf: the commit or decommit, the wait for the lock included
plat_mutex_lock(&lock);
if (size > HEAP_CAP || size % 0x200000 || size + image_bytes() > L.pool) {
plat_mutex_unlock(&lock);
return R_INVALID_STATE;
}
uint64_t was = heap_size;
if (size > was && !heap_lazy) commit(L.heap.base + was, size - was, "heap");
__atomic_store_n(&heap_size, size, __ATOMIC_RELEASE); // before a shrink: no first-use commit past the new end
if (size < was) decommit(L.heap.base + size, was - size, "heap"); // reserved pages in the range are fine
uint64_t moved = size > was ? size - was : was - size;
__atomic_store_n(&map_gen, map_gen + 1, __ATOMIC_RELEASE);
plat_mutex_unlock(&lock);
perf_mark_end(PERF_M_GMEM, t0, moved);
if (addr) *addr = L.heap.base;
return R_OK;
}
// ---- module data permissions (0x02, 0x03) and module pages for QueryMemory
static int module_index(uint64_t a) {
for (int i = 0; i < ldr_count(); i++) {
const RtLoaded *m = ldr_module(i);
if (a - m->base < m->size) return i;
}
return -1;
}
static uint8_t *perm_table(int i) { // under lock
if (!module_perm[i]) {
const RtLoaded *m = ldr_module(i);
size_t n = (m->size - m->data_off) / PAGE;
module_perm[i] = malloc(n);
if (!module_perm[i]) rt_fatal("memory: module permission table");
memset(module_perm[i], PERM_RW, n);
}
return module_perm[i];
}
static unsigned module_page_perm(int i, uint64_t off) { // under lock
const RtLoaded *m = ldr_module(i);
if (off < m->data_off) return off < align_up(m->text_end, PAGE) ? PERM_RX : PERM_R;
return module_perm[i] ? module_perm[i][(off - m->data_off) / PAGE] : PERM_RW;
}
// The module whose data segment holds [a, a+n), or -1.
static int module_data(uint64_t a, uint64_t n) {
int i = module_index(a);
if (i < 0) return -1;
const RtLoaded *m = ldr_module(i);
uint64_t off = a - m->base;
return off >= m->data_off && n <= m->size - off ? i : -1;
}
uint32_t mem_set_permission(uint64_t a, uint64_t n, uint32_t perm) {
if (a & (PAGE - 1)) return R_INVALID_ADDRESS;
if (!n || (n & (PAGE - 1))) return R_INVALID_SIZE;
if (perm != PERM_NONE && perm != PERM_R && perm != PERM_RW) return R_INVALID_NEW_PERM;
int i = module_data(a, n);
if (i < 0) return R_INVALID_STATE;
const RtLoaded *m = ldr_module(i);
plat_mutex_lock(&lock);
uint8_t *t = perm_table(i) + (a - m->base - m->data_off) / PAGE;
for (uint64_t p = 0; p < n / PAGE; p++)
if (t[p] & ATTR_PERMISSION_LOCKED) {
plat_mutex_unlock(&lock);
return R_INVALID_STATE;
}
memset(t, (int)perm, n / PAGE);
protect(a, n, perm == PERM_RW ? PLAT_PROT_RW : perm == PERM_R ? PLAT_PROT_READ : PLAT_PROT_NONE, "module data");
__atomic_store_n(&map_gen, map_gen + 1, __ATOMIC_RELEASE);
plat_mutex_unlock(&lock);
rt_log("%s data permission +%#llx size %#llx perm %u", m->name, (unsigned long long)(a - m->base),
(unsigned long long)n, perm);
return R_OK;
}
// The only module attribute the SDK sets is the irreversible RELRO lock.
uint32_t mem_set_attribute(uint64_t a, uint64_t n, uint32_t mask, uint32_t at) {
if (a & (PAGE - 1)) return R_INVALID_ADDRESS;
if (!n || (n & (PAGE - 1))) return R_INVALID_SIZE;
if (mask != ATTR_PERMISSION_LOCKED || at != ATTR_PERMISSION_LOCKED) return R_INVALID_NEW_PERM;
int i = module_data(a, n);
if (i < 0) return R_INVALID_STATE;
const RtLoaded *m = ldr_module(i);
plat_mutex_lock(&lock);
uint8_t *t = perm_table(i) + (a - m->base - m->data_off) / PAGE;
for (uint64_t p = 0; p < n / PAGE; p++) t[p] |= ATTR_PERMISSION_LOCKED;
plat_mutex_unlock(&lock);
return R_OK;
}
// ---- 0x04/0x05 MapMemory, UnmapMemory: thread stacks move from heap or alias into the stack region by copy; the
// source is inaccessible while moved and gets the contents back on unmap.
static int alias_all_mapped(uint64_t a, uint64_t n) { // under lock
uint64_t first = (a - L.alias.base) / PAGE;
for (uint64_t i = 0; i < n / PAGE; i++)
if (!alias_pages[first + i]) return 0;
return 1;
}
static uint32_t stack_move(int unmap, uint64_t dst, uint64_t src, uint64_t n) {
if (!n || ((dst | src | n) & (PAGE - 1))) return R_INVALID_ADDRESS;
if (!inside(dst, n, L.stack)) return R_INVALID_REGION;
int in_heap = inside(src, n, (RtRange){L.heap.base, heap_size});
int in_alias = inside(src, n, L.alias);
if (!in_heap && !in_alias) return R_INVALID_REGION;
plat_mutex_lock(&lock);
uint32_t r = R_OK;
if (in_alias && !alias_all_mapped(src, n)) {
r = R_INVALID_REGION;
goto out;
}
unsigned found = nstack_maps;
for (unsigned i = 0; i < nstack_maps; i++)
if (stack_maps[i].dst == dst && stack_maps[i].src == src && stack_maps[i].size == n) found = i;
if (unmap) {
if (found == nstack_maps) {
r = R_INVALID_STATE;
goto out;
}
protect(src, n, PLAT_PROT_RW, "moved stack source");
memcpy((void *)(uintptr_t)src, (const void *)(uintptr_t)dst, n);
decommit(dst, n, "moved stack");
stack_maps[found] = stack_maps[--nstack_maps];
} else {
if (nstack_maps == MAX_STACK_MAPS) {
r = R_INVALID_STATE;
goto out;
}
for (unsigned i = 0; i < nstack_maps; i++)
if (overlaps(dst, n, stack_maps[i].dst, stack_maps[i].size) ||
overlaps(src, n, stack_maps[i].src, stack_maps[i].size)) {
r = R_INVALID_REGION;
goto out;
}
commit(dst, n, "moved stack");
memcpy((void *)(uintptr_t)dst, (const void *)(uintptr_t)src, n);
protect(src, n, PLAT_PROT_NONE, "moved stack source");
stack_maps[nstack_maps++] = (StackMap){dst, src, n};
}
out:
__atomic_store_n(&map_gen, map_gen + 1, __ATOMIC_RELEASE);
plat_mutex_unlock(&lock);
return r;
}
uint32_t mem_map(uint64_t dst, uint64_t src, uint64_t n) { return stack_move(0, dst, src, n); }
uint32_t mem_unmap(uint64_t dst, uint64_t src, uint64_t n) { return stack_move(1, dst, src, n); }
// ---- 0x2C/0x2D MapPhysicalMemory, UnmapPhysicalMemory. Horizon maps only the still-unmapped pages of the range and
// leaves mapped pages and their contents alone; NX2navi's heaps grow by re-mapping ranges they partly own.
static void alias_runs(uint64_t first, uint64_t count, uint8_t want, int do_commit) { // under lock
uint64_t i = 0;
while (i < count) {
if (alias_pages[first + i] != want) { i++; continue; }
uint64_t j = i;
while (j < count && alias_pages[first + j] == want) j++;
uint64_t a = L.alias.base + (first + i) * PAGE, n = (j - i) * PAGE;
if (do_commit) commit(a, n, "physical memory");
else decommit(a, n, "physical memory");
memset(alias_pages + first + i, !want, j - i);
i = j;
}
}
static uint32_t alias_map(int unmap, uint64_t a, uint64_t n) {
if (!n) return R_INVALID_ADDRESS;
n = (n + PAGE - 1) & ~(uint64_t)(PAGE - 1); // the SDK asks for byte ranges; a mapping is whole pages
if ((a | n) & (PAGE - 1)) return R_INVALID_ADDRESS;
if (!inside(a, n, L.alias)) return R_INVALID_REGION;
uint64_t first = (a - L.alias.base) / PAGE, count = n / PAGE, t0 = perf_mark_begin();
plat_mutex_lock(&lock);
uint32_t r = R_OK;
if (unmap) {
for (unsigned i = 0; i < nstack_maps; i++)
if (overlaps(a, n, stack_maps[i].src, stack_maps[i].size)) {
r = R_INVALID_REGION;
goto out;
}
uint64_t released = 0;
for (uint64_t i = 0; i < count; i++) released += alias_pages[first + i];
alias_runs(first, count, 1, 0);
alias_bytes -= released * PAGE;
} else {
uint64_t fresh = 0;
for (uint64_t i = 0; i < count; i++) fresh += !alias_pages[first + i];
if (fresh * PAGE + alias_bytes + heap_size + image_bytes() > L.pool) {
r = R_LIMIT_REACHED; // the SDK maps LimitReached to its recoverable out-of-memory result
goto out;
}
alias_runs(first, count, 0, 1);
alias_bytes += fresh * PAGE;
}
out:
__atomic_store_n(&map_gen, map_gen + 1, __ATOMIC_RELEASE);
plat_mutex_unlock(&lock);
perf_mark_end(PERF_M_GMEM, t0, n);
if (r) rt_log("%sMapPhysicalMemory %#llx+%#llx failed %#x (alias %#llx used, heap %#llx)", unmap ? "Un" : "",
(unsigned long long)a, (unsigned long long)n, r, (unsigned long long)alias_bytes,
(unsigned long long)heap_size);
return r;
}
uint32_t mem_map_physical(uint64_t a, uint64_t n) { return alias_map(0, a, n); }
uint32_t mem_unmap_physical(uint64_t a, uint64_t n) { return alias_map(1, a, n); }
// ---- 0x06 QueryMemory
// The region around a that no known region covers: everything else below 2^39 belongs to the host and is reported
// as taken (Code, RX), so the SDK never picks it.
static void taken_gap(uint64_t a, uint64_t *base, uint64_t *size) {
uint64_t lo = 0, hi = RT_ADDRESS_LIMIT;
RtRange known[3 + MOD_COUNT + 2];
int n = 0;
known[n++] = (RtRange){L.aslr.base, LOW_SIZE};
known[n++] = L.alias;
known[n++] = L.kernel;
known[n++] = L.hostfn;
for (int i = 0; i < ldr_count(); i++) known[n++] = (RtRange){ldr_module(i)->base, ldr_module(i)->size};
for (int i = 0; i < n; i++) {
uint64_t e = known[i].base + known[i].size;
if (e <= a && e > lo) lo = e;
if (known[i].base > a && known[i].base < hi) hi = known[i].base;
}
*base = lo;
*size = hi - lo;
}
static uint64_t run_end(const uint8_t *p, uint64_t i, uint64_t n, uint8_t v) {
while (i < n && (i & 7)) { if (p[i] != v) return i; i++; }
uint64_t w = v ? 0x0101010101010101ull : 0;
while (i + 8 <= n && *(const uint64_t *)(p + i) == w) i += 8;
while (i < n && p[i] == v) i++;
return i;
}
static uint64_t run_start(const uint8_t *p, uint64_t i, uint8_t v) { // first index of the run that ends at i
while (i > 0 && (i & 7)) { if (p[i - 1] != v) return i; i--; }
uint64_t w = v ? 0x0101010101010101ull : 0;
while (i >= 8 && *(const uint64_t *)(p + i - 8) == w) i -= 8;
while (i > 0 && p[i - 1] == v) i--;
return i;
}
static void query_locked(uint64_t a, RtMemoryInfo *out);
static int readable_locked(uint64_t a, uint64_t n) {
for (uint64_t end = a + n; a < end;) {
RtMemoryInfo r;
query_locked(a, &r);
if (r.state == ST_FREE || r.state == ST_INACCESSIBLE || !(r.perm & PERM_R) || r.base + r.size <= a) return 0;
a = r.base + r.size;
}
return 1;
}
// Whether every byte of [a, a + n) can be read: no free, inaccessible or no-access page (mem_query's regions). For
// host reads of guest memory the guest itself may never make, such as a texture upload of a pool slot no shader
// samples (vk_exec_draw.c, texture pools: stale slots point at unmapped memory).
int mem_readable(uint64_t a, uint64_t n) {
plat_mutex_lock_shared(&lock);
int ok = readable_locked(a, n);
plat_mutex_unlock_shared(&lock);
return ok;
}
// mem_readable for a read that takes a while on another thread than the guest's: with 1 the range stays mapped until
// mem_read_release, as unmapping it (UnmapPhysicalMemory, a smaller heap, a moved stack) waits for the lock. A pool
// slot's storage the game has just released could otherwise be decommitted halfway through the copy (a texture
// upload faulted that way in tex_bl_copy). In between, the caller takes no lock of this file (mem_query, mem_readable
// and the mapping calls would wait for themselves). 0: not readable, and nothing held.
int mem_read_hold(uint64_t a, uint64_t n) {
plat_mutex_lock_shared(&lock);
if (readable_locked(a, n)) return 1;
plat_mutex_unlock_shared(&lock);
return 0;
}
void mem_read_release(void) { plat_mutex_unlock_shared(&lock); }
uint32_t mem_query(uint64_t a, RtMemoryInfo *out) {
plat_mutex_lock_shared(&lock);
query_locked(a, out);
plat_mutex_unlock_shared(&lock);
return R_OK;
}
static void query_locked(uint64_t a, RtMemoryInfo *out) {
RtMemoryInfo r = {.base = a & ~(PAGE - 1), .size = PAGE};
uint64_t low = L.aslr.base;
int mi;
if (a >= RT_ADDRESS_LIMIT) {
r.base = RT_ADDRESS_LIMIT;
r.size = 0 - RT_ADDRESS_LIMIT;
r.state = ST_INACCESSIBLE;
} else if (a < low) {
r.base = 0;
r.size = low;
r.state = ST_FREE;
} else if (a < low + LOW_SIZE) {
uint64_t heap = L.heap.base;
if (a >= heap && a < heap + heap_size) {
r = (RtMemoryInfo){.base = heap, .size = heap_size, .state = ST_NORMAL, .perm = PERM_RW};
} else if (a < heap) {
r = (RtMemoryInfo){.base = low, .size = heap - low, .state = ST_FREE};
} else {
r = (RtMemoryInfo){.base = heap + heap_size, .size = low + LOW_SIZE - heap - heap_size, .state = ST_FREE};
}
} else if (a - L.alias.base < L.alias.size) {
uint64_t p = (a - L.alias.base) / PAGE;
uint8_t v = alias_pages[p];
uint64_t s = run_start(alias_pages, p, v), e = run_end(alias_pages, p, ALIAS_PAGES, v);
r = (RtMemoryInfo){.base = L.alias.base + s * PAGE, .size = (e - s) * PAGE, .state = v ? ST_NORMAL : ST_FREE,
.perm = v ? PERM_RW : PERM_NONE};
} else if ((mi = module_index(a)) >= 0) {
const RtLoaded *m = ldr_module(mi);
uint64_t off = (a - m->base) & ~(PAGE - 1), lo = off, hi = off + PAGE;
unsigned perm = module_page_perm(mi, off);
int data = off >= m->data_off;
uint64_t limit = data ? m->data_off : 0, end = data ? m->size : m->data_off;
while (lo > limit && module_page_perm(mi, lo - PAGE) == perm) lo -= PAGE;
while (hi < end && module_page_perm(mi, hi) == perm) hi += PAGE;
r = (RtMemoryInfo){.base = m->base + lo, .size = hi - lo, .state = data ? ST_CODEDATA : ST_CODE,
.perm = perm & 7, .attr = perm & ATTR_PERMISSION_LOCKED};
} else if (a - L.kernel.base < L.kernel.size) {
r = (RtMemoryInfo){.base = L.kernel.base, .size = L.kernel.size, .state = ST_THREADLOCAL, .perm = PERM_RW};
} else if (a - L.hostfn.base < L.hostfn.size) {
r = (RtMemoryInfo){.base = L.hostfn.base, .size = L.hostfn.size, .state = ST_INACCESSIBLE};
} else {
taken_gap(a, &r.base, &r.size);
r.state = ST_CODE;
r.perm = PERM_RX;
}
// Moved stacks: the destination is Stack, the source Normal without access; free and normal regions around them
// are clipped.
for (unsigned i = 0; i < nstack_maps; i++) {
const StackMap *m = &stack_maps[i];
uint64_t end = m->dst + m->size, send = m->src + m->size;
if (a >= m->dst && a < end) {
r = (RtMemoryInfo){.base = m->dst, .size = m->size, .state = ST_STACK, .perm = PERM_RW};
break;
}
if (a >= m->src && a < send) {
r = (RtMemoryInfo){.base = m->src, .size = m->size, .state = ST_NORMAL, .perm = PERM_NONE, .attr = 4};
break;
}
uint64_t lo = r.base, hi = r.base + r.size;
uint64_t b = r.state == ST_FREE ? m->dst : r.state == ST_NORMAL ? m->src : 0;
uint64_t e = b + m->size;
if (!b) continue;
if (e <= a && e > lo) lo = e;
if (b > a && b < hi) hi = b;
r.base = lo;
r.size = hi - lo;
}
if (out) *out = r;
}
// ---- GetInfo memory ids
int mem_info(uint32_t id, uint64_t *out) {
uint64_t v;
switch (id) {
case 2: v = L.alias.base; break;
case 3: v = L.alias.size; break;
case 4: v = L.heap.base; break;
case 5: v = L.heap.size; break;
case 6: case 21: v = L.pool; break;
case 7: case 22:
plat_mutex_lock_shared(&lock);
v = image_bytes() + heap_size + alias_bytes;
plat_mutex_unlock_shared(&lock);
break;
case 12: v = L.aslr.base; break;
case 13: v = L.aslr.size; break;
case 14: v = L.stack.base; break;
case 15: v = L.stack.size; break;
case 16: v = SYSTEM_RESOURCE_BUDGET; break;
case 17: v = sizeof stack_maps + ALIAS_PAGES; break; // system resource in use: our bookkeeping
case 28: v = 0; break; // AliasRegionExtraSize: no kernel-owned extension
default: return 0;
}
*out = v;
return 1;
}
// ---- kernel region: power-of-two blocks, a free list per size, bump allocation with lazy commit.
#define KCLASSES 29 // 64 B .. 256 MiB
#define KMIN_SHIFT 6
#define KCOMMIT 0x10000ull
typedef struct KFree { struct KFree *next; } KFree;
static KFree *kfree_list[KCLASSES];
static uint64_t kbump, kcommitted;
static PlatMutex klock = PLAT_MUTEX_INIT;
static int kclass(uint64_t size) {
int s = KMIN_SHIFT;
while ((1ull << s) < size) s++;
return s - KMIN_SHIFT;
}
void *mem_kernel_alloc(uint64_t size, uint64_t align) {
if (!L.pool) rt_fatal("mem_kernel_alloc before mem_init");
if (align > KCOMMIT || (align & (align - 1))) rt_fatal("mem_kernel_alloc: alignment %#llx", (unsigned long long)align);
uint64_t want = size > align ? size : align;
int k = kclass(want ? want : 1);
if (k >= KCLASSES) rt_fatal("mem_kernel_alloc: %#llx bytes", (unsigned long long)size);
uint64_t bytes = 1ull << (k + KMIN_SHIFT), al = bytes < KCOMMIT ? bytes : KCOMMIT;
plat_mutex_lock(&klock);
KFree *f = kfree_list[k];
void *p;
if (f) {
kfree_list[k] = f->next;
p = f;
} else {
uint64_t a = align_up(kbump ? kbump : RT_KERNEL_BASE, al);
if (a + bytes > RT_KERNEL_BASE + RT_KERNEL_SIZE) rt_fatal("kernel region exhausted (%#llx bytes)",
(unsigned long long)bytes);
uint64_t need = align_up(a + bytes, KCOMMIT);
if (!kcommitted) kcommitted = RT_KERNEL_BASE;
if (need > kcommitted) {
commit(kcommitted, need - kcommitted, "kernel region");
kcommitted = need;
}
kbump = a + bytes;
p = (void *)(uintptr_t)a;
}
plat_mutex_unlock(&klock);
memset(p, 0, size ? size : 1);
return p;
}
void mem_kernel_free(void *p, uint64_t size) {
if (!p) return;
uint64_t a = (uintptr_t)p;
if (a - RT_KERNEL_BASE >= RT_KERNEL_SIZE) rt_fatal("mem_kernel_free(%p): not in the kernel region", p);
int k = kclass(size ? size : 1);
// A block allocated with a larger alignment sits in a larger class; freeing it into the smaller class only
// wastes the rest.
plat_mutex_lock(&klock);
KFree *f = p;
f->next = kfree_list[k];
kfree_list[k] = f;
plat_mutex_unlock(&klock);
}
// NX2NAVI_TRACE=perf: what the lazy heap's first-use faults cost since the last line (perf.c, every perf window that had
// some), so that a hitch can be told from them: the time includes the wait for frz_lock.
void mem_lazy_heap_report(uint64_t frame) {
static uint64_t faults_prv, bytes_prv;
if (!heap_lazy) return;
plat_mutex_lock(&frz_lock);
uint64_t faults = heap_lazy_faults, bytes = heap_lazy_bytes, ns = heap_lazy_ns, max = heap_lazy_max_ns;
heap_lazy_ns = heap_lazy_max_ns = 0;
plat_mutex_unlock(&frz_lock);
if (faults == faults_prv && bytes == bytes_prv) return;
rt_log("mem: lazy heap at frame %llu: %llu faults and %.1f MiB committed since the last line, %.2f ms in the faults "
"(longest %.3f ms); %.0f of %.0f MiB committed", (unsigned long long)frame,
(unsigned long long)(faults - faults_prv), (bytes - bytes_prv) / 1048576.0, ns / 1e6, max / 1e6,
bytes / 1048576.0, __atomic_load_n(&heap_size, __ATOMIC_ACQUIRE) / 1048576.0);
faults_prv = faults, bytes_prv = bytes;
}
// NX2NAVI_TRACE=perf: how many bytes of each guest region are committed, so a process that has grown says which region
// holds the memory. A region is reserved whole at start-up and committed page by page, so the walk reads each run of
// pages of the same state; the alias window is the largest and costs the most steps when it is full.
void mem_guest_census(uint64_t frame) {
const RtGuestLayout *g = mem_layout();
const struct { const char *name; RtRange r; } reg[] = {
{"aslr", g->aslr}, {"stack", g->stack}, {"heap", g->heap},
{"alias", g->alias}, {"kernel", g->kernel}, {"hostfn", g->hostfn},
};
char line[400];
int o = snprintf(line, sizeof line, "mem: guest regions at frame %llu (MiB committed):",
(unsigned long long)frame);
uint64_t all = 0;
for (unsigned i = 0; i < sizeof reg / sizeof *reg && o < (int)sizeof line - 40; i++) {
uint64_t x = reg[i].r.base, end = reg[i].r.base + reg[i].r.size, committed = 0, b = 0;
while (x < end) {
int st = plat_mem_state(x, end, &b);
if (b <= x) break;
if (st >= 0) committed += b - x; // a PLAT_PROT_* state: these pages are committed
x = b;
}
all += committed;
o += snprintf(line + o, sizeof line - o, " %s %.0f", reg[i].name, committed / 1048576.0);
}
rt_log("%s; all %.0f", line, all / 1048576.0);
if (heap_lazy)
rt_log("mem: lazy heap at frame %llu: %.0f of %.0f MiB committed, by %llu faults and the rest by kernel "
"accesses and pointer checks", (unsigned long long)frame, heap_lazy_bytes / 1048576.0,
__atomic_load_n(&heap_size, __ATOMIC_ACQUIRE) / 1048576.0, (unsigned long long)heap_lazy_faults);
}
// NX2NAVI_TRACE=perf "mem: sizes" (perf.c): the guest heap and physical maps, the kernel region's bump and commit, the
// moved stacks, and the lazily written ranges with their array's room.
void mem_sizes(PerfSizes *s) {
plat_mutex_lock_shared(&lock);
uint64_t heap = heap_size, alias = alias_bytes, stacks = nstack_maps;
plat_mutex_unlock_shared(&lock);
plat_mutex_lock_shared(&klock);
uint64_t kused = kbump ? kbump - RT_KERNEL_BASE : 0, kcom = kcommitted ? kcommitted - RT_KERNEL_BASE : 0;
plat_mutex_unlock_shared(&klock);
plat_mutex_lock_shared(&frz_lock);
uint64_t lz = (uint64_t)lz_n, lzc = (uint64_t)lz_cap;
plat_mutex_unlock_shared(&frz_lock);
perf_size(s, "guest heap", PERF_SIZE_NONE, 0, heap);
perf_size(s, "guest physical maps", PERF_SIZE_NONE, 0, alias);
perf_size(s, "kernel region used", PERF_SIZE_NONE, 0, kused);
perf_size(s, "kernel region committed", PERF_SIZE_NONE, 0, kcom);
perf_size(s, "moved stacks", stacks, sizeof stack_maps / sizeof *stack_maps, PERF_SIZE_NONE);
perf_size(s, "lazy write-back ranges", lz, 0, PERF_SIZE_NONE);
perf_size(s, "their array's room", lzc, 0, PERF_SIZE_NONE);
}