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-rw-r--r--kernel/gsp_sema_service.c213
1 files changed, 184 insertions, 29 deletions
diff --git a/kernel/gsp_sema_service.c b/kernel/gsp_sema_service.c
index bcd8ac3..28e5906 100644
--- a/kernel/gsp_sema_service.c
+++ b/kernel/gsp_sema_service.c
@@ -486,6 +486,12 @@ struct svc_vaspace {
u64 pdb;
u32 entries; /* root entry count */
int ap; /* SVC_APERTURE_* of the directory itself */
+ unsigned long stamp; /* r459: last registration/use; LRU evict
+ * when the table is full (a stale entry from
+ * a dead client otherwise blocks every new
+ * client after the 8th registration: the
+ * mid-boot walk failure that made the 10th+
+ * client's copies fail rc=-2) */
};
struct svc_lat {
@@ -819,6 +825,7 @@ struct sema_svc {
u64 pushtrace_all; /* fail4: de-windowed push decode
* trace (every push, bounded) */
u64 opadd_log; /* fail4: every op appended */
+ u64 op2d_raw_log; /* r458: raw 2D-shaped copy pushes */
u64 dmatrace_log; /* fail4: denied-transfer trace */
u64 pend_dbg_log; /* fail4 r305: pending/hold witness */
u64 snap_gate_log; /* fail4 r311: capture-gate witness */
@@ -1599,12 +1606,40 @@ void gsp_sema_service_vaspace_add(const struct sema_vaspace_desc *desc)
if (!vs && !svc.vas[i].valid)
vs = &svc.vas[i];
}
+ /*
+ * r459: the table is 8 slots and the guest driver does not always
+ * send a teardown for a client's VA space (observed: 23 distinct
+ * registrations, 0 drops in one boot). Once all slots hold a dead
+ * client's directory, a NEW client's registration found no slot and
+ * every walk of its VAs failed (copies rc=-2, launches reading
+ * stale pages - the 10th-client mid-boot degradation). Evict the
+ * least-recently-registered entry instead of refusing the new one;
+ * the old client is gone and its directory pointer is dead guest
+ * memory, so the eviction can only remove stale authority.
+ */
+ if (!vs) {
+ unsigned long oldest = 0;
+ int oi = 0;
+
+ for (i = 0; i < SVC_MAX_VASPACES; i++) {
+ if (!svc.vas[i].valid)
+ continue;
+ if (!oldest || time_before(svc.vas[i].stamp, oldest)) {
+ oldest = svc.vas[i].stamp;
+ oi = i;
+ }
+ }
+ vs = &svc.vas[oi];
+ pr_info("sema-svc: VA space table full; evicting 0x%x (pdb=0x%llx) for 0x%x\n",
+ vs->h_vaspace, vs->pdb, desc->h_vaspace);
+ }
if (vs) {
vs->valid = true;
vs->h_vaspace = desc->h_vaspace;
vs->pdb = desc->pdb;
vs->entries = desc->num_entries;
vs->ap = desc->b_vidmem ? SVC_APERTURE_FB : SVC_APERTURE_SYS;
+ vs->stamp = jiffies;
/* A new directory invalidates what we learned from the old one. */
memset(svc.lat, 0, sizeof(svc.lat));
}
@@ -1932,6 +1967,26 @@ static int svc_walk_vaspaces(struct nv_vgpu_device *vgpu, u64 va,
}
spin_unlock_irqrestore(&svc.vas_lock, flags);
+ /*
+ * r459: try the NEWEST registration first. A dead client's stale
+ * directory (the table outlives clients; only 8 slots) can still
+ * resolve a VA - through guest memory the driver has since reused -
+ * to a wrong page, and the first success wins. Ordering by the
+ * registration stamp makes the live client's directory the
+ * authority and only falls through to older ones when it cannot
+ * answer.
+ */
+ for (i = 1; i < n; i++) {
+ struct svc_vaspace k = local[i];
+ int j = i - 1;
+
+ while (j >= 0 && time_before(local[j].stamp, k.stamp)) {
+ local[j + 1] = local[j];
+ j--;
+ }
+ local[j + 1] = k;
+ }
+
for (i = 0; i < n; i++) {
int alt;
@@ -5997,14 +6052,18 @@ static void svc_copy_snap_free(u64 dst, u64 src, size_t total,
}
/*
- * r444: drop every snapshot still owned by one entry. A snapshot that was
- * not consumed by the entry's own copy execution (the copy ran via the
- * forwarded hardware path, or a post-execution re-decode re-captured the
- * unchanged staging) has no future consumer once the entry's release is
- * delivered - leaving it behind let a LATER entry whose copy shares the
- * (dst,src,total) triple execute from the stale bytes.
+ * r456/r457: the snapshot lifecycle is capture-once -> free on the copy's
+ * own successful consumption (svc_copy) -> free on ring-slot reuse with a
+ * new push hash (svc_copy_snap_capture) -> free when a re-decode skips an
+ * already-done op (svc_run_ops) -> TTL. The old per-entry owner free was
+ * removed from every opdef_clear caller: an entry whose release was
+ * delivered can still be REPLAYED (the pin-batch rewind) with its copy
+ * still owed, and freeing at that point let the replay re-capture the
+ * driver's refilled ping-pong staging (the r457 mode-C b1 H2D wrote b2's
+ * bytes into db1). A stale snapshot can only ever serve its own
+ * (ch, idx, hash) owner, so the r444 cross-entry poisoning stays closed.
*/
-static void svc_copy_snap_free_owner(u32 owner_ch, u32 owner_idx)
+static void __maybe_unused svc_copy_snap_free_owner(u32 owner_ch, u32 owner_idx)
{
u32 i;
@@ -9903,6 +9962,23 @@ static void svc_decode_stream(struct nv_vgpu_device *vgpu, const u8 *buf,
break;
case CE_M_LINE_LENGTH_IN:
st.line_length = v0;
+ /*
+ * r458 THE memset2d root cause: the driver encodes
+ * LINE_LENGTH_IN (0x418) and the adjacent LINE_COUNT
+ * (0x41c) as ONE count=2 method group - observed raw
+ * push bytes `20028106 00001000 00000100` = header
+ * (subch 4, count 2, addr 0x418), line length 4096,
+ * line count 0x100 = 256. Reading only v0 left
+ * line_count = 0, so the 2D-copy builder below took
+ * the single-row path: one 4 KB op per push, and a
+ * 4 MB cudaMemcpy2D delivered exactly one page per
+ * 1 MB block (memset2d probe: per-MB ok=4096,
+ * bad=12.5M/12.58M). The GRCE variant below has
+ * always decoded the count=2 form; the CE path did
+ * not.
+ */
+ if (count >= 2)
+ st.line_count = v1;
break;
/* r402: 2D geometry (cudaMemset2D / cudaMemcpy2D). */
case CE_M_LINE_COUNT:
@@ -10210,6 +10286,39 @@ static void svc_decode_stream(struct nv_vgpu_device *vgpu, const u8 *buf,
m->spitch = spitch;
}
}
+ /*
+ * r458 memset2d forensics: the
+ * driver's cudaMemcpy2D pushes decode
+ * LINE_LENGTH=4096 with PITCH_IN/OUT
+ * present but LINE_COUNT absent
+ * (lc=0), so only one 4 KB row per
+ * push executes and a 4 MB copy
+ * delivers 4 pages. Dump the raw push
+ * (bounded) for every pitch-shaped
+ * copy so the method stream that
+ * carries the row count is on record.
+ */
+ if (gsp_sema_dbg &&
+ (st.have_pitch_out ||
+ st.have_pitch_in) &&
+ svc.op2d_raw_log < 12) {
+ u32 dl = len < 220 ? len : 220;
+
+ svc.op2d_raw_log++;
+ pr_info("sema-op2d-raw: h=0x%x push=0x%llx len=%u off=0x%x line=%u lc=%u po=%u/%u pi=%u/%u out=0x%llx in=0x%llx bytes=%u dma=0x%08x\n",
+ ch->h_object, push_va,
+ len, off,
+ st.line_length,
+ st.line_count,
+ st.have_pitch_out,
+ st.pitch_out,
+ st.have_pitch_in,
+ st.pitch_in,
+ m->dst, m->src,
+ (u32)m->bytes, dma);
+ pr_info("sema-op2d-raw: raw %*phN\n",
+ dl, buf);
+ }
n_ops++;
ops_seq++;
} else if (gsp_sema_dbg && svc.dma_skip_log < 32) {
@@ -15907,28 +16016,28 @@ static void svc_opdef_clear(struct svc_opdef_ent *e, u32 caller)
e->n ? e->rel[0].payload : 0u);
}
/*
- * r444: the entry is being consumed; no retry can need its
- * staging snapshot any more (see svc_copy_snap_free_owner).
- *
- * r456: EXCEPT on the APPLY path. The apply runs at the head of a
- * re-decode pass of an entry whose copy is still held for its
- * operand pins; the pass's own op execution (which consumes the
- * snapshot on success) follows the apply. Freeing here destroyed
- * the pipeline-order snapshot before it could ever be read and
- * the next pass's guard re-capture then read the driver's
- * REFILLED ping-pong staging - the r455 operand-shift: the a1 H2D
- * executed ~3 s after its push with a2's bytes (owner
- * 0x5c00005c/0/6076682fa76b8792, snapshot first4 flipped from
- * 00000000 3f000000... to 00000000 3e000000... across retries;
- * dst16_after=000000000000003e0000803e0000c03e proves the a2
- * pattern landed in da1's page). The snapshot now survives the
- * retries and is consumed (and freed) by the copy that finally
- * executes; svc_copy_snap_free_owner still runs on every genuine
- * consume path (FINISH/FLUSH/DROP/STALE/COUNTED/SWEEP/STOP) and
- * the TTL covers the rest.
+ * r456/r457: the snapshot lifecycle is now "capture once, consume
+ * on the copy's success, evict on ring-slot reuse, TTL". Every
+ * opdef_clear caller can still re-decode the entry:
+ * - APPLY (0): the pass's own op execution (which consumes the
+ * snapshot on success) follows the apply;
+ * - FINISH (1): the entry can be REPLAYED after a consume (the
+ * pin-batch rewind replays entries while mappings stream in),
+ * and an owed copy still needs the pipeline-order bytes;
+ * - FLUSH (2): the op stays skipped this pass but a later replay
+ * may run it.
+ * The r457 mode-C evidence: the b1 H2D's snapshot was captured at
+ * 191607.816388 with b1's bytes (first4=00000000 3e800000 ...),
+ * FINISH freed it on the entry's consume, the rewind replay
+ * re-captured at 191608.798838 from the REFILLED staging
+ * (first4=00000000 3d800000 ... = b2) and the deferred execution
+ * wrote b2's bytes into db1 (dst16_after=000000000000803d...).
+ * The r444 leak the old free guarded against is already covered
+ * by the owner key (a stale snapshot can only ever serve its own
+ * (ch, idx, hash)), the slot-reuse eviction in
+ * svc_copy_snap_capture, the ops_done skip free in svc_run_ops
+ * and the 30 s TTL.
*/
- if (e->active && caller != SVC_OPDEF_CLR_APPLY)
- svc_copy_snap_free_owner(e->h_object, e->entry_idx);
memset(e, 0, sizeof(*e));
}
@@ -21358,10 +21467,55 @@ static void svc_pump_channels(struct nv_vgpu_device *vgpu)
* through to the historical
* consume so the channel can
* never livelock.
+ *
+ * r470: an ALL-ZERO push page is
+ * the same "not the client's work
+ * yet" condition - the ring entry
+ * is written (the previous
+ * session's or the client's own
+ * slot reuse) but the push
+ * CONTENT has not landed, so the
+ * decode sees no QMD and the
+ * entry would be consumed as a
+ * no-op; the end-of-pass counter
+ * publish then advances the
+ * guest's completion word while
+ * the real push was never read,
+ * and the client drains a
+ * staging buffer that still holds
+ * the PREVIOUS copy's bytes
+ * (streams_events: h_c[2] = c0
+ * because the c2 D2H's
+ * completion was published 4.5 s
+ * before its copy ran, the ring
+ * slots having been decoded as
+ * all-zero pushes). Deliberately
+ * NARROWER than the CE-shaped
+ * plausibility verdict: compute
+ * pushes legitimately fail that
+ * matcher, so only an entirely
+ * zero page counts as unwritten.
*/
+ {
+ bool all_zero = false;
+
+ if (!ch->engine_type &&
+ va && len) {
+ u32 zi;
+
+ all_zero = true;
+ for (zi = 0; zi < len;
+ zi++)
+ if (pb[zi]) {
+ all_zero =
+ false;
+ break;
+ }
+ }
if (!ch->engine_type && va && len &&
gsp_phys_gr_forward_enabled() &&
- svc_gr_qmd_seen > 0 &&
+ (svc_gr_qmd_seen > 0 ||
+ all_zero) &&
!entry_replay &&
!(svc_gr_cand.valid &&
svc_gr_cand.h_object ==
@@ -21413,6 +21567,7 @@ static void svc_pump_channels(struct nv_vgpu_device *vgpu)
ch->h_object,
(u32)idx, va, len);
}
+ }
/*
* A CE push that should carry this
* channel's next tracking release but