diff options
Diffstat (limited to 'hw/vfio/pci-quirks.c')
| -rw-r--r-- | hw/vfio/pci-quirks.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c index f0147a050a..0ed2fcd531 100644 --- a/hw/vfio/pci-quirks.c +++ b/hw/vfio/pci-quirks.c @@ -1490,6 +1490,9 @@ void vfio_setup_resetfn_quirk(VFIOPCIDevice *vdev) * +---------------------------------+---------------------------------+ * * https://lists.gnu.org/archive/html/qemu-devel/2017-08/pdfUda5iEpgOS.pdf + * + * Specification for Turning and later GPU architectures: + * https://lists.gnu.org/archive/html/qemu-devel/2023-06/pdf142OR4O4c2.pdf */ static void get_nv_gpudirect_clique_id(Object *obj, Visitor *v, const char *name, void *opaque, @@ -1530,7 +1533,9 @@ const PropertyInfo qdev_prop_nv_gpudirect_clique = { static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp) { PCIDevice *pdev = &vdev->pdev; - int ret, pos = 0xC8; + int ret, pos; + bool c8_conflict = false, d4_conflict = false; + uint8_t tmp; if (vdev->nv_gpudirect_clique == 0xFF) { return 0; @@ -1547,6 +1552,40 @@ static int vfio_add_nv_gpudirect_cap(VFIOPCIDevice *vdev, Error **errp) return -EINVAL; } + /* + * Per the updated specification above, it's recommended to use offset + * D4h for Turing and later GPU architectures due to a conflict of the + * MSI-X capability at C8h. We don't know how to determine the GPU + * architecture, instead we walk the capability chain to mark conflicts + * and choose one or error based on the result. + * + * NB. Cap list head in pdev->config is already cleared, read from device. + */ + ret = pread(vdev->vbasedev.fd, &tmp, 1, + vdev->config_offset + PCI_CAPABILITY_LIST); + if (ret != 1 || !tmp) { + error_setg(errp, "NVIDIA GPUDirect Clique ID: error getting cap list"); + return -EINVAL; + } + + do { + if (tmp == 0xC8) { + c8_conflict = true; + } else if (tmp == 0xD4) { + d4_conflict = true; + } + tmp = pdev->config[tmp + PCI_CAP_LIST_NEXT]; + } while (tmp); + + if (!c8_conflict) { + pos = 0xC8; + } else if (!d4_conflict) { + pos = 0xD4; + } else { + error_setg(errp, "NVIDIA GPUDirect Clique ID: invalid config space"); + return -EINVAL; + } + ret = pci_add_capability(pdev, PCI_CAP_ID_VNDR, pos, 8, errp); if (ret < 0) { error_prepend(errp, "Failed to add NVIDIA GPUDirect cap: "); |