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| author | Arthur Hanson Rasmusson <arthur@vgpu.io> | 2026-10-05 12:25:05 -0400 |
|---|---|---|
| committer | Arthur Hanson Rasmusson <arthur@vgpu.io> | 2026-10-05 12:25:05 -0400 |
| commit | 708a3802824358c1770d5ad0b3c2e24fae114eb8 (patch) | |
| tree | 6d4d98c9279a74464be8c6ba796d994eef81bbce /kernel/bar_emulation.c | |
| parent | f90b1a123a60dea44ac98f05529ec2fd545c26eb (diff) | |
| download | open-iov-708a3802824358c1770d5ad0b3c2e24fae114eb8.tar.gz open-iov-708a3802824358c1770d5ad0b3c2e24fae114eb8.zip | |
vgsp: per-mdev emulated VRAM size (1.0 multiple mediate sizes)
- nv_vgpu_type_info/ioctl gain vram_mb; nv_vgpu_device gains fb_emul_size
bound from the mdev type at create (default 512 MiB).
- New nvidia-vgpu-turing-1g type (1024 MiB); turing max_instances 1 -> 2;
show_description reports the per-type framebuffer and max_instance.
- Thread fb_emul_size through GSCI fb_length/region/frtsOffset, WPR2,
NV_PFB_PRI_MMU_LOCAL_MEMORY_RANGE, the vidmem allocator bound and the BAR1
shadow; bar_info callback uses the per-device size.
- UNTESTED at commit time: builds clean; validation blocked by the Xid 140
incident (reboot pending). See Handoff-vGPU-IO.md ADDENDUM 48.
Diffstat (limited to 'kernel/bar_emulation.c')
| -rw-r--r-- | kernel/bar_emulation.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/kernel/bar_emulation.c b/kernel/bar_emulation.c index e095d8b..8e3f8cf 100644 --- a/kernel/bar_emulation.c +++ b/kernel/bar_emulation.c @@ -279,7 +279,25 @@ int nv_vgpu_bar_emul_init(struct nv_vgpu_device *vgpu) * "WPR2 initialized at an unexpected location". Must stay in * lockstep with GSCI fb_length/frtsOffset and wpr2_addr_lo. */ - *(u32 *)((u8 *)ctx->bar0_shadow + 0x100ce0) = 0x00000019; + { + /* + * Derive the encoding from the mdev's emulated FB size: + * fbSize = MAG << (SCALE + 20), SCALE bits 3:0, MAG bits 9:4. + * 512 MiB -> mag=1 scale=9 -> 0x19 (the historical value); + * 1 GiB -> 0x1a; 2 GiB -> 0x1b. Sizes that are not exactly + * representable round down; the emulation keeps GSCI + * fb_length/frtsOffset derived from the same value, so the + * guest's fbSize - reserved arithmetic stays consistent. + */ + u64 fb = nv_vgpu_fb_emul_size(ctx->vgpu); + u32 scale = 0; + + while (scale < 15 && (fb >> (scale + 20)) > 0x3f) + scale++; + *(u32 *)((u8 *)ctx->bar0_shadow + 0x100ce0) = + ((((u32)(fb >> (scale + 20))) & 0x3f) << 4) | + (scale & 0xf); + } /* * NV_PCFG (BAR0+0x88000) - PCI config space mirror the driver reads |