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.
- If the buffer need to be accessed for a read operation by a bus master
then map with BusMasterRead.
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
---
OvmfPkg/VirtioBlkDxe/VirtioBlk.c | 157 ++++++++++++++++++--
1 file changed, 143 insertions(+), 14 deletions(-)
diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
index 663ba281ab73..ab69cb08a625 100644
--- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
+++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
@@ -232,7 +232,8 @@ VerifyReadWriteRequest (
@retval EFI_DEVICE_ERROR Failed to notify host side via VirtIo write, or
unable to parse host response, or host response
- is not VIRTIO_BLK_S_OK.
+ is not VIRTIO_BLK_S_OK or failed to map Buffer
+ for a bus master operation.
**/
@@ -249,8 +250,16 @@ SynchronousRequest (
{
UINT32 BlockSize;
volatile VIRTIO_BLK_REQ Request;
- volatile UINT8 HostStatus;
+ volatile UINT8 *HostStatus;
+ VOID *HostStatusBuffer;
DESC_INDICES Indices;
+ VOID *RequestMapping;
+ VOID *StatusMapping;
+ VOID *BufferMapping;
+ EFI_PHYSICAL_ADDRESS BufferDeviceAddress;
+ EFI_PHYSICAL_ADDRESS HostStatusDeviceAddress;
+ EFI_PHYSICAL_ADDRESS RequestDeviceAddress;
+ EFI_STATUS Status, Ret;
BlockSize = Dev->BlockIoMedia.BlockSize;
@@ -278,9 +287,89 @@ SynchronousRequest (
VirtioPrepare (&Dev->Ring, &Indices);
//
+ // Host status is bi-directional (we preset with a value and expect the
+ // device to update it). Allocate a host status buffer which can be mapped
+ // to access equally by both processor and the device.
+ //
+ Status = Dev->VirtIo->AllocateSharedPages (
+ Dev->VirtIo,
+ EFI_SIZE_TO_PAGES (sizeof *HostStatus),
+ &HostStatusBuffer
+ );
+ if (EFI_ERROR (Status)) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ //
+ // Map virtio-blk request header (must be done after request header is
+ // populated)
+ //
+ Status = VirtioMapAllBytesInSharedBuffer (
+ Dev->VirtIo,
+ VirtioOperationBusMasterRead,
+ (VOID *) &Request,
+ sizeof Request,
+ &RequestDeviceAddress,
+ &RequestMapping
+ );
+ if (EFI_ERROR (Status)) {
+ Status = EFI_DEVICE_ERROR;
+ goto FreeHostStatusBuffer;
+ }
+
+ //
+ // Map data buffer
+ //
+ if (BufferSize > 0) {
+ if (RequestIsWrite) {
+ Status = VirtioMapAllBytesInSharedBuffer (
+ Dev->VirtIo,
+ VirtioOperationBusMasterRead,
+ (VOID *) Buffer,
+ BufferSize,
+ &BufferDeviceAddress,
+ &BufferMapping
+ );
+ } else {
+ Status = VirtioMapAllBytesInSharedBuffer (
+ Dev->VirtIo,
+ VirtioOperationBusMasterWrite,
+ (VOID *) Buffer,
+ BufferSize,
+ &BufferDeviceAddress,
+ &BufferMapping
+ );
+ }
+
+ if (EFI_ERROR (Status)) {
+ Status = EFI_DEVICE_ERROR;
+ goto UnmapRequestBuffer;
+ }
+ }
+
+ //
+ // Map the Status Buffer with VirtioOperationBusMasterCommonBuffer so that
+ // both processor and device can access it.
+ //
+ Status = VirtioMapAllBytesInSharedBuffer (
+ Dev->VirtIo,
+ VirtioOperationBusMasterCommonBuffer,
+ HostStatusBuffer,
+ sizeof *HostStatus,
+ &HostStatusDeviceAddress,
+ &StatusMapping
+ );
+ if (EFI_ERROR (Status)) {
+ Status = EFI_DEVICE_ERROR;
+ goto UnmapDataBuffer;
+ }
+
+ HostStatus = HostStatusBuffer;
+
+ //
// preset a host status for ourselves that we do not accept as success
//
- HostStatus = VIRTIO_BLK_S_IOERR;
+ *HostStatus = VIRTIO_BLK_S_IOERR;
//
// ensured by VirtioBlkInit() -- this predicate, in combination with the
@@ -291,8 +380,13 @@ SynchronousRequest (
//
// virtio-blk header in first desc
//
- VirtioAppendDesc (&Dev->Ring, (UINTN) &Request, sizeof Request,
- VRING_DESC_F_NEXT, &Indices);
+ VirtioAppendDesc (
+ &Dev->Ring,
+ RequestDeviceAddress,
+ sizeof Request,
+ VRING_DESC_F_NEXT,
+ &Indices
+ );
//
// data buffer for read/write in second desc
@@ -311,27 +405,62 @@ SynchronousRequest (
//
// VRING_DESC_F_WRITE is interpreted from the host's point of view.
//
- VirtioAppendDesc (&Dev->Ring, (UINTN) Buffer, (UINT32) BufferSize,
+ VirtioAppendDesc (
+ &Dev->Ring,
+ BufferDeviceAddress,
+ (UINT32) BufferSize,
VRING_DESC_F_NEXT | (RequestIsWrite ? 0 : VRING_DESC_F_WRITE),
- &Indices);
+ &Indices
+ );
}
//
// host status in last (second or third) desc
//
- VirtioAppendDesc (&Dev->Ring, (UINTN) &HostStatus, sizeof HostStatus,
- VRING_DESC_F_WRITE, &Indices);
+ VirtioAppendDesc (
+ &Dev->Ring,
+ HostStatusDeviceAddress,
+ sizeof *HostStatus,
+ VRING_DESC_F_WRITE,
+ &Indices
+ );
//
// virtio-blk's only virtqueue is #0, called "requestq" (see Appendix D).
//
- if (VirtioFlush (Dev->VirtIo, 0, &Dev->Ring, &Indices,
- NULL) == EFI_SUCCESS &&
- HostStatus == VIRTIO_BLK_S_OK) {
- return EFI_SUCCESS;
+ Status = VirtioFlush (Dev->VirtIo, 0, &Dev->Ring, &Indices, NULL);
+
+ //
+ // Unmap the HostStatus buffer before accessing it
+ //
+ Ret = Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, StatusMapping);
+ if (EFI_ERROR (Ret)) {
+ Status = EFI_DEVICE_ERROR;
+ }
+
+ if (!EFI_ERROR (Status) &&
+ *HostStatus == VIRTIO_BLK_S_OK) {
+ Status = EFI_SUCCESS;
+ } else {
+ Status = EFI_DEVICE_ERROR;
}
- return EFI_DEVICE_ERROR;
+UnmapDataBuffer:
+ if (BufferSize > 0) {
+ Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, BufferMapping);
+ }
+
+UnmapRequestBuffer:
+ Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, RequestMapping);
+
+FreeHostStatusBuffer:
+ Dev->VirtIo->FreeSharedPages (
+ Dev->VirtIo,
+ EFI_SIZE_TO_PAGES (sizeof *HostStatus),
+ HostStatusBuffer
+ );
+
+ return Status;
}
--
2.7.4
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