In case device is constrained by IOMMU or guest is running under AMD SEV, input/output buffers provided to device (DataBuffer and SenseData) needs to be explicitly mapped to device by PciIo->Map().
To avoid the overhead of mapping/unmapping the DataBuffer and SenseData to the device for every SCSI requst (and to simplify code), introduce a single DMA communication buffer that will be mapped to device on initialization. When a SCSI request needs to be sent to device, the DataBuffer and SenseData will be copied from/to the DMA communication buffer as required. This will be done by the following commits. Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2567 Signed-off-by: Liran Alon <liran.a...@oracle.com> --- OvmfPkg/PvScsiDxe/PvScsi.c | 60 ++++++++++++++++++++++++++++++-------- OvmfPkg/PvScsiDxe/PvScsi.h | 20 +++++++++++++ 2 files changed, 68 insertions(+), 12 deletions(-) diff --git a/OvmfPkg/PvScsiDxe/PvScsi.c b/OvmfPkg/PvScsiDxe/PvScsi.c index c7d367e83a2d..6e350bb2d6e0 100644 --- a/OvmfPkg/PvScsiDxe/PvScsi.c +++ b/OvmfPkg/PvScsiDxe/PvScsi.c @@ -677,6 +677,19 @@ PvScsiInit ( goto RestorePciAttributes; } + // + // Allocate DMA communication buffer + // + Status = PvScsiAllocateSharedPages ( + Dev, + EFI_SIZE_TO_PAGES (sizeof (*Dev->DmaBuf)), + (VOID **)&Dev->DmaBuf, + &Dev->DmaBufDmaDesc + ); + if (EFI_ERROR (Status)) { + goto FreeRings; + } + // // Populate the exported interface's attributes // @@ -708,18 +721,7 @@ PvScsiInit ( return EFI_SUCCESS; -RestorePciAttributes: - PvScsiRestorePciAttributes (Dev); - - return Status; -} - -STATIC -VOID -PvScsiUninit ( - IN OUT PVSCSI_DEV *Dev - ) -{ +FreeRings: // // Reset device to stop device usage of the rings. // This is required to safely free the rings. @@ -728,6 +730,40 @@ PvScsiUninit ( PvScsiFreeRings (Dev); +RestorePciAttributes: + PvScsiRestorePciAttributes (Dev); + + return Status; +} + +STATIC +VOID +PvScsiUninit ( + IN OUT PVSCSI_DEV *Dev + ) +{ + // + // Reset device to: + // - Make device stop processing all requests. + // - Stop device usage of the rings. + // + // This is required to safely free the DMA communication buffer + // and the rings. + // + PvScsiResetAdapter (Dev); + + // + // Free DMA communication buffer + // + PvScsiFreeSharedPages ( + Dev, + EFI_SIZE_TO_PAGES (sizeof (*Dev->DmaBuf)), + Dev->DmaBuf, + &Dev->DmaBufDmaDesc + ); + + PvScsiFreeRings (Dev); + PvScsiRestorePciAttributes (Dev); } diff --git a/OvmfPkg/PvScsiDxe/PvScsi.h b/OvmfPkg/PvScsiDxe/PvScsi.h index 6d23b6e1eccf..fff12146dc75 100644 --- a/OvmfPkg/PvScsiDxe/PvScsi.h +++ b/OvmfPkg/PvScsiDxe/PvScsi.h @@ -31,6 +31,21 @@ typedef struct { PVSCSI_DMA_DESC RingCmpsDmaDesc; } PVSCSI_RING_DESC; +typedef struct { + // + // As EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET.SenseDataLength is defined + // as UINT8, defining here SenseData size to MAX_UINT8 will guarantee it + // cannot overflow when passed to device. + // + UINT8 SenseData[MAX_UINT8]; + // + // This size of the data is arbitrarily chosen. + // It seems to be sufficient for all I/O requests sent through + // EFI_SCSI_PASS_THRU_PROTOCOL.PassThru() for common boot scenarios. + // + UINT8 Data[0x2000]; +} PVSCSI_DMA_BUFFER; + #define PVSCSI_SIG SIGNATURE_32 ('P', 'S', 'C', 'S') typedef struct { @@ -38,6 +53,8 @@ typedef struct { EFI_PCI_IO_PROTOCOL *PciIo; UINT64 OriginalPciAttributes; PVSCSI_RING_DESC RingDesc; + PVSCSI_DMA_BUFFER *DmaBuf; + PVSCSI_DMA_DESC DmaBufDmaDesc; UINT8 MaxTarget; UINT8 MaxLun; EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru; @@ -47,4 +64,7 @@ typedef struct { #define PVSCSI_FROM_PASS_THRU(PassThruPointer) \ CR (PassThruPointer, PVSCSI_DEV, PassThru, PVSCSI_SIG) +#define PVSCSI_DMA_BUF_DEV_ADDR(Dev, MemberName) \ + (Dev->DmaBufDmaDesc.DeviceAddress + OFFSET_OF(PVSCSI_DMA_BUFFER, MemberName)) + #endif // __PVSCSI_DXE_H_ -- 2.20.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#56547): https://edk2.groups.io/g/devel/message/56547 Mute This Topic: https://groups.io/mt/72617148/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
