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OvmfPkg/VirtioScsiDxe: map virtio-scsi request and response buffers 

When device is behind the IOMMU, driver is require to pass the device
address of virtio request, response and any memory referenced by those
request/response to the bus master.

The patch uses IOMMU-like member functions from VIRTIO_DEVICE_PROTOCOL to
map request and response buffers system physical address to the device
address.

- If the buffer need to be accessed by both the processor and a bus
  master then map with BusMasterCommonBuffer.

- If the buffer need to be accessed for a write operation by a bus master
  then map with BusMasterWrite.

  However, after a BusMasterWrite Unmap() failure, error reporting via
  EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET would be very complex,
  therefore we map such buffers too with BusMasterCommonBuffer.

- If the buffer need to be accessed for a read  operation by a bus master
  then map with BusMasterRead.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
[lersek@redhat.com: restore lost sentence/paragraph in commit message]
[lersek@redhat.com: reindent/reflow "InDataBuffer" comment block]
[lersek@redhat.com: cast arg, not result, of EFI_SIZE_TO_PAGES() to UINTN]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Brijesh Singh 2017-08-31 10:25:27 -04:00 committed by Laszlo Ersek
parent 1b15eb06c7
commit 9d0d5050c7
1 changed files with 205 additions and 16 deletions
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221
OvmfPkg/VirtioScsiDxe/VirtioScsi.c
View File

@ -440,26 +440,157 @@ VirtioScsiPassThru (
UINT16 TargetValue;
EFI_STATUS Status;
volatile VIRTIO_SCSI_REQ Request;
volatile VIRTIO_SCSI_RESP Response;
volatile VIRTIO_SCSI_RESP *Response;
VOID *ResponseBuffer;
DESC_INDICES Indices;
VOID *RequestMapping;
VOID *ResponseMapping;
VOID *InDataMapping;
VOID *OutDataMapping;
EFI_PHYSICAL_ADDRESS RequestDeviceAddress;
EFI_PHYSICAL_ADDRESS ResponseDeviceAddress;
EFI_PHYSICAL_ADDRESS InDataDeviceAddress;
EFI_PHYSICAL_ADDRESS OutDataDeviceAddress;
VOID *InDataBuffer;
UINTN InDataNumPages;
BOOLEAN OutDataBufferIsMapped;
ZeroMem ((VOID*) &Request, sizeof (Request));
ZeroMem ((VOID*) &Response, sizeof (Response));
Dev = VIRTIO_SCSI_FROM_PASS_THRU (This);
CopyMem (&TargetValue, Target, sizeof TargetValue);
InDataBuffer = NULL;
OutDataBufferIsMapped = FALSE;
InDataNumPages = 0;
Status = PopulateRequest (Dev, TargetValue, Lun, Packet, &Request);
if (EFI_ERROR (Status)) {
return Status;
}
VirtioPrepare (&Dev->Ring, &Indices);
//
// Map the virtio-scsi Request header buffer
//
Status = VirtioMapAllBytesInSharedBuffer (
Dev->VirtIo,
VirtioOperationBusMasterRead,
(VOID *) &Request,
sizeof Request,
&RequestDeviceAddress,
&RequestMapping);
if (EFI_ERROR (Status)) {
return ReportHostAdapterError (Packet);
}
//
// Map the input buffer
//
if (Packet->InTransferLength > 0) {
//
// Allocate a intermediate input buffer. This is mainly to handle the
// following case:
// * caller submits a bi-directional request
// * we perform the request fine
// * but we fail to unmap the "InDataMapping"
//
// In that case simply returing the EFI_DEVICE_ERROR is not sufficient. In
// addition to the error code we also need to update Packet fields
// accordingly so that we report the full loss of the incoming transfer.
//
// We allocate a temporary buffer and map it with BusMasterCommonBuffer. If
// the Virtio request is successful then we copy the data from temporary
// buffer into Packet->InDataBuffer.
//
InDataNumPages = EFI_SIZE_TO_PAGES ((UINTN)Packet->InTransferLength);
Status = Dev->VirtIo->AllocateSharedPages (
Dev->VirtIo,
InDataNumPages,
&InDataBuffer
);
if (EFI_ERROR (Status)) {
Status = ReportHostAdapterError (Packet);
goto UnmapRequestBuffer;
}
ZeroMem (InDataBuffer, Packet->InTransferLength);
Status = VirtioMapAllBytesInSharedBuffer (
Dev->VirtIo,
VirtioOperationBusMasterCommonBuffer,
InDataBuffer,
Packet->InTransferLength,
&InDataDeviceAddress,
&InDataMapping
);
if (EFI_ERROR (Status)) {
Status = ReportHostAdapterError (Packet);
goto FreeInDataBuffer;
}
}
//
// Map the output buffer
//
if (Packet->OutTransferLength > 0) {
Status = VirtioMapAllBytesInSharedBuffer (
Dev->VirtIo,
VirtioOperationBusMasterRead,
Packet->OutDataBuffer,
Packet->OutTransferLength,
&OutDataDeviceAddress,
&OutDataMapping
);
if (EFI_ERROR (Status)) {
Status = ReportHostAdapterError (Packet);
goto UnmapInDataBuffer;
}
OutDataBufferIsMapped = TRUE;
}
//
// Response header is bi-direction (we preset with host status and expect
// the device to update it). Allocate a response buffer which can be mapped
// to access equally by both processor and device.
//
Status = Dev->VirtIo->AllocateSharedPages (
Dev->VirtIo,
EFI_SIZE_TO_PAGES (sizeof *Response),
&ResponseBuffer
);
if (EFI_ERROR (Status)) {
Status = ReportHostAdapterError (Packet);
goto UnmapOutDataBuffer;
}
Response = ResponseBuffer;
ZeroMem ((VOID *)Response, sizeof (*Response));
//
// preset a host status for ourselves that we do not accept as success
//
Response.Response = VIRTIO_SCSI_S_FAILURE;
Response->Response = VIRTIO_SCSI_S_FAILURE;
//
// Map the response buffer with BusMasterCommonBuffer so that response
// buffer can be accessed by both host and device.
//
Status = VirtioMapAllBytesInSharedBuffer (
Dev->VirtIo,
VirtioOperationBusMasterCommonBuffer,
ResponseBuffer,
sizeof (*Response),
&ResponseDeviceAddress,
&ResponseMapping
);
if (EFI_ERROR (Status)) {
Status = ReportHostAdapterError (Packet);
goto FreeResponseBuffer;
}
VirtioPrepare (&Dev->Ring, &Indices);
//
// ensured by VirtioScsiInit() -- this predicate, in combination with the
@ -470,31 +601,49 @@ VirtioScsiPassThru (
//
// enqueue Request
//
VirtioAppendDesc (&Dev->Ring, (UINTN) &Request, sizeof Request,
VRING_DESC_F_NEXT, &Indices);
VirtioAppendDesc (
&Dev->Ring,
RequestDeviceAddress,
sizeof Request,
VRING_DESC_F_NEXT,
&Indices
);
//
// enqueue "dataout" if any
//
if (Packet->OutTransferLength > 0) {
VirtioAppendDesc (&Dev->Ring, (UINTN) Packet->OutDataBuffer,
Packet->OutTransferLength, VRING_DESC_F_NEXT, &Indices);
VirtioAppendDesc (
&Dev->Ring,
OutDataDeviceAddress,
Packet->OutTransferLength,
VRING_DESC_F_NEXT,
&Indices
);
}
//
// enqueue Response, to be written by the host
//
VirtioAppendDesc (&Dev->Ring, (UINTN) &Response, sizeof Response,
VRING_DESC_F_WRITE | (Packet->InTransferLength > 0 ?
VRING_DESC_F_NEXT : 0),
&Indices);
VirtioAppendDesc (
&Dev->Ring,
ResponseDeviceAddress,
sizeof *Response,
VRING_DESC_F_WRITE | (Packet->InTransferLength > 0 ? VRING_DESC_F_NEXT : 0),
&Indices
);
//
// enqueue "datain" if any, to be written by the host
//
if (Packet->InTransferLength > 0) {
VirtioAppendDesc (&Dev->Ring, (UINTN) Packet->InDataBuffer,
Packet->InTransferLength, VRING_DESC_F_WRITE, &Indices);
VirtioAppendDesc (
&Dev->Ring,
InDataDeviceAddress,
Packet->InTransferLength,
VRING_DESC_F_WRITE,
&Indices
);
}
// If kicking the host fails, we must fake a host adapter error.
@ -503,10 +652,50 @@ VirtioScsiPassThru (
//
if (VirtioFlush (Dev->VirtIo, VIRTIO_SCSI_REQUEST_QUEUE, &Dev->Ring,
&Indices, NULL) != EFI_SUCCESS) {
return ReportHostAdapterError (Packet);
Status = ReportHostAdapterError (Packet);
goto UnmapResponseBuffer;
}
return ParseResponse (Packet, &Response);
Status = ParseResponse (Packet, Response);
//
// If virtio request was successful and it was a CPU read request then we
// have used an intermediate buffer. Copy the data from intermediate buffer
// to the final buffer.
//
if (InDataBuffer != NULL) {
CopyMem (Packet->InDataBuffer, InDataBuffer, Packet->InTransferLength);
}
UnmapResponseBuffer:
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, ResponseMapping);
FreeResponseBuffer:
Dev->VirtIo->FreeSharedPages (
Dev->VirtIo,
EFI_SIZE_TO_PAGES (sizeof *Response),
ResponseBuffer
);
UnmapOutDataBuffer:
if (OutDataBufferIsMapped) {
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, OutDataMapping);
}
UnmapInDataBuffer:
if (InDataBuffer != NULL) {
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, InDataMapping);
}
FreeInDataBuffer:
if (InDataBuffer != NULL) {
Dev->VirtIo->FreeSharedPages (Dev->VirtIo, InDataNumPages, InDataBuffer);
}
UnmapRequestBuffer:
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, RequestMapping);
return Status;
}