This feature indicates that the device is behind an IOMMU that translates bus addresses from the device into physical addresses in memory. If this feature bit is set to 0, then the device emits physical addresses which are not translated further, even though an IOMMU may be present. see [1] for more infromation
[1] https://lists.oasis-open.org/archives/virtio-dev/201610/msg00121.html In previous patches, we have implemented IOMMU-like member functions in VIRTIO_DEVICE_PROTOCOL to translate the physical address to bus address and virtio drivers are updated to use those member functions. We do not need to do anything special when VIRTIO_F_IOMMU_PLATFORM bit is present hence treat it in parallel with VIRTIO_F_VERSION_1. Suggested-by: Laszlo Ersek <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Jordan Justen <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Laszlo Ersek <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Brijesh Singh <[email protected]> --- OvmfPkg/Include/IndustryStandard/Virtio10.h | 5 +++++ OvmfPkg/VirtioBlkDxe/VirtioBlk.c | 3 ++- OvmfPkg/VirtioNetDxe/SnpInitialize.c | 3 ++- OvmfPkg/VirtioRngDxe/VirtioRng.c | 2 +- OvmfPkg/VirtioScsiDxe/VirtioScsi.c | 3 ++- 5 files changed, 12 insertions(+), 4 deletions(-) diff --git a/OvmfPkg/Include/IndustryStandard/Virtio10.h b/OvmfPkg/Include/IndustryStandard/Virtio10.h index 4c9b62a3cf59..c62429d94432 100644 --- a/OvmfPkg/Include/IndustryStandard/Virtio10.h +++ b/OvmfPkg/Include/IndustryStandard/Virtio10.h @@ -83,4 +83,9 @@ typedef struct { // #define VIRTIO_F_VERSION_1 BIT32 +// +// VirtIo 1.0 reserved iommu platform feature bits +// +#define VIRTIO_F_IOMMU_PLATFORM BIT33 + #endif // _VIRTIO_1_0_H_ diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c index 57baceb20a19..a78ec0df9c7b 100644 --- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c +++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c @@ -773,7 +773,8 @@ VirtioBlkInit ( } Features &= VIRTIO_BLK_F_BLK_SIZE | VIRTIO_BLK_F_TOPOLOGY | VIRTIO_BLK_F_RO | - VIRTIO_BLK_F_FLUSH | VIRTIO_F_VERSION_1; + VIRTIO_BLK_F_FLUSH | VIRTIO_F_VERSION_1 | + VIRTIO_F_IOMMU_PLATFORM; // // In virtio-1.0, feature negotiation is expected to complete before queue diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c index 9bac19f8e3d1..b389f6243661 100644 --- a/OvmfPkg/VirtioNetDxe/SnpInitialize.c +++ b/OvmfPkg/VirtioNetDxe/SnpInitialize.c @@ -536,7 +536,8 @@ VirtioNetInitialize ( ASSERT (Dev->Snm.MediaPresentSupported == !!(Features & VIRTIO_NET_F_STATUS)); - Features &= VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS | VIRTIO_F_VERSION_1; + Features &= VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS | VIRTIO_F_VERSION_1 | + VIRTIO_F_IOMMU_PLATFORM; // // In virtio-1.0, feature negotiation is expected to complete before queue diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c index b19d90901430..81d8c7facc10 100644 --- a/OvmfPkg/VirtioRngDxe/VirtioRng.c +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c @@ -273,7 +273,7 @@ VirtioRngInit ( goto Failed; } - Features &= VIRTIO_F_VERSION_1; + Features &= VIRTIO_F_VERSION_1 | VIRTIO_F_IOMMU_PLATFORM; // // In virtio-1.0, feature negotiation is expected to complete before queue diff --git a/OvmfPkg/VirtioScsiDxe/VirtioScsi.c b/OvmfPkg/VirtioScsiDxe/VirtioScsi.c index 65e9bda0827a..286b005c994c 100644 --- a/OvmfPkg/VirtioScsiDxe/VirtioScsi.c +++ b/OvmfPkg/VirtioScsiDxe/VirtioScsi.c @@ -903,7 +903,8 @@ VirtioScsiInit ( goto Failed; } - Features &= VIRTIO_SCSI_F_INOUT | VIRTIO_F_VERSION_1; + Features &= VIRTIO_SCSI_F_INOUT | VIRTIO_F_VERSION_1 | + VIRTIO_F_IOMMU_PLATFORM; // // In virtio-1.0, feature negotiation is expected to complete before queue -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
