vgsp: end-to-end CUDA acceptance in the guest

The no-claim emulation path now runs a stock CUDA program end to end:
device properties, cudaMalloc, a GPU-authored string kernel read back
byte-for-byte, two 4 MB host-to-device copies, a 1 M-element vectorAdd
executed on the physical GPU through the host bridge, and the
device-to-host copy-back verified element by element. Three consecutive
supervised cycles report MAIL + VADD bad=0 checksum=392344090.500000 +
STATUS OK with identical input/output hashes.

Two data-path correctness fixes make the transfers sound:

- Once-only op execution per GPFIFO entry. The pump replays recently
  consumed ring entries when translation batches are injected so missed
  releases can land; re-executing a CE copy is not idempotent because
  its source is a client staging buffer that may have been refilled.
  Slots now record their raw entry words and a replayed entry matching
  that identity suppresses operations while still processing releases.

- Per-page translation of virtual operands. svc_copy resolved only the
  first page of a VA range and walked the PA linearly; client staging
  ranges are frequently split (observed 195 + 61 pages), so the tail of
  alternating chunks was read from unrelated memory. Multi-page copies
  now re-resolve each 4 KB page through the trusted resolver.

Also carries the earlier uncommitted emulation fixes that got the client
to the launch (QMD address-window gate, counter registration
persistence, 512 MiB emulated FB, bridge slot hygiene) and bounded
diagnostics (sema-bigop, sema-bigcopy, bridge-in/out hashes, daemon
INCHECK/OUTCHECK/dumps).

1 files changed, 19 insertions, 1 deletions

diff --git a/kernel/include/nvidia-vgpu-vfio.h b/kernel/include/nvidia-vgpu-vfio.h
index 1c2f67b..ccd7262 100644
--- a/kernel/include/nvidia-vgpu-vfio.h
+++ b/kernel/include/nvidia-vgpu-vfio.h
@@ -25,7 +25,18 @@
 #define NV_VGPU_MAX_IRQS NVIDIA_VGPU_MAX_IRQS
 
 #define NV_VGPU_BAR0_SIZE (16 * 1024 * 1024)
-#define NV_VGPU_BAR1_SIZE (256 * 1024 * 1024)
+/*
+ * BAR1 (VRAM aperture) and the emulated framebuffer size. These two move
+ * together: the guest derives its BAR1 size from fbLength
+ * (kbusInitBarsSize_VF: pciBarSizes[1] = pGpu->fbLength), and its vidmem
+ * address space is [0, fbLength). The shadow backing bars[1].vaddr is
+ * NV_VGPU_BAR1_SIZE, so any guest vidmem PA the emulation translates must
+ * stay inside it. 512 MiB gives UVM enough headroom after its own
+ * reservations to satisfy the acceptance program's 3x4 MiB vadd buffers
+ * (at 256 MiB the guest reported only ~5 MiB free).
+ */
+#define NV_VGPU_BAR1_SIZE (512 * 1024 * 1024)
+#define NV_VGPU_EMUL_FB_SIZE (512ULL * 1024 * 1024)
 #define NV_VGPU_BAR2_SIZE (32 * 1024 * 1024)
 #define NV_VGPU_BAR3_SIZE (32 * 1024 * 1024)
 
@@ -56,6 +67,13 @@ struct nv_vgpu_bar {
 	void *vaddr;
 	bool mapped;
 	bool trapped;
+	/*
+	 * True when vaddr is a host-RAM shadow (vzalloc) owned by this module
+	 * instead of an ioremap'd physical BAR. Guest mappings must then remap
+	 * the shadow's own pages; a real BAR must never be exposed to the
+	 * guest outside the supervised physical claim.
+	 */
+	bool emulated;
 	struct mutex lock;
 };