The SynchronousRequest(), programs the vring descriptor with the buffers
pointed-by virtio-blk requests, status and memory that is referenced
inside the request header.
The patch uses newly introduced VIRTIO_DEVICE_PROTOCOL.MapSharedBuffer()
function to map system memory to device address and programs the vring
descriptor with device addresses.
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.h | 1 +
OvmfPkg/VirtioBlkDxe/VirtioBlk.c | 97 ++++++++++++++++++--
2 files changed, 91 insertions(+), 7 deletions(-)
diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.h b/OvmfPkg/VirtioBlkDxe/VirtioBlk.h
index 6c402ca88ea4..612994d261bc 100644
--- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.h
+++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.h
@@ -41,6 +41,7 @@ typedef struct {
VRING Ring; // VirtioRingInit 2
EFI_BLOCK_IO_PROTOCOL BlockIo; // VirtioBlkInit 1
EFI_BLOCK_IO_MEDIA BlockIoMedia; // VirtioBlkInit 1
+ VOID *RingMapping; // VirtioBlkInit 1
} VBLK_DEV;
#define VIRTIO_BLK_FROM_BLOCK_IO(BlockIoPointer) \
diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
index 61b9cab4ff02..324403543f24 100644
--- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
+++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
@@ -251,6 +251,11 @@ SynchronousRequest (
volatile VIRTIO_BLK_REQ Request;
volatile UINT8 HostStatus;
DESC_INDICES Indices;
+ VOID *RequestMapping;
+ VOID *StatusMapping;
+ VOID *BufferMapping;
+ EFI_PHYSICAL_ADDRESS DeviceAddress;
+ EFI_STATUS Status;
BlockSize = Dev->BlockIoMedia.BlockSize;
@@ -289,14 +294,24 @@ SynchronousRequest (
ASSERT (Dev->Ring.QueueSize >= 3);
//
+ // Map virtio-blk request header
+ //
+ Status = VirtioMapSharedBufferRead (Dev->VirtIo, (VOID *) &Request,
+ sizeof Request, &DeviceAddress, &RequestMapping);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
// virtio-blk header in first desc
//
- VirtioAppendDesc (&Dev->Ring, (UINTN) &Request, sizeof Request,
+ VirtioAppendDesc (&Dev->Ring, (UINTN) DeviceAddress, sizeof Request,
VRING_DESC_F_NEXT, &Indices);
//
// data buffer for read/write in second desc
//
+ BufferMapping = NULL;
if (BufferSize > 0) {
//
// From virtio-0.9.5, 2.3.2 Descriptor Table:
@@ -309,29 +324,70 @@ SynchronousRequest (
ASSERT (BufferSize <= SIZE_1GB);
//
+ // Map data buffer
+ //
+ if (RequestIsWrite) {
+ Status = VirtioMapSharedBufferRead (Dev->VirtIo, (VOID *) Buffer,
+ BufferSize, &DeviceAddress, &BufferMapping);
+ } else {
+ Status = VirtioMapSharedBufferWrite (Dev->VirtIo, (VOID *) Buffer,
+ BufferSize, &DeviceAddress, &BufferMapping);
+ }
+
+ if (EFI_ERROR (Status)) {
+ goto Mapping_Failed;
+ }
+
+ //
// VRING_DESC_F_WRITE is interpreted from the host's point of view.
//
- VirtioAppendDesc (&Dev->Ring, (UINTN) Buffer, (UINT32) BufferSize,
+ VirtioAppendDesc (&Dev->Ring, (UINTN) DeviceAddress, (UINT32) BufferSize,
VRING_DESC_F_NEXT | (RequestIsWrite ? 0 : VRING_DESC_F_WRITE),
&Indices);
}
//
+ // Map virtio-blk status header
+ //
+ Status = VirtioMapSharedBufferWrite (Dev->VirtIo, (VOID *) &HostStatus,
+ sizeof HostStatus, &DeviceAddress, &StatusMapping);
+ if (EFI_ERROR (Status)) {
+ goto Mapping_Failed;
+ }
+
+ //
// host status in last (second or third) desc
//
- VirtioAppendDesc (&Dev->Ring, (UINTN) &HostStatus, sizeof HostStatus,
+ VirtioAppendDesc (&Dev->Ring, (UINTN) DeviceAddress, 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 &&
+ if (VirtioFlush (Dev->VirtIo, 0, &Dev->Ring, &Indices, NULL) != EFI_SUCCESS)
{
+ Status = EFI_DEVICE_ERROR;
+ }
+
+ //
+ // Unmap the HostStatus buffer before accessing it
+ //
+ VirtioUnmapSharedBuffer (Dev->VirtIo, StatusMapping);
+
+ if (Status != EFI_DEVICE_ERROR &&
HostStatus == VIRTIO_BLK_S_OK) {
- return EFI_SUCCESS;
+ Status = EFI_SUCCESS;
+ } else {
+ Status = EFI_DEVICE_ERROR;
}
- return EFI_DEVICE_ERROR;
+Mapping_Failed:
+ VirtioUnmapSharedBuffer (Dev->VirtIo, RequestMapping);
+
+ if (BufferMapping != NULL) {
+ VirtioUnmapSharedBuffer (Dev->VirtIo, BufferMapping);
+ }
+
+ return Status;
}
@@ -728,6 +784,11 @@ VirtioBlkInit (
goto Failed;
}
+ Status = VirtioRingMap (Dev->VirtIo, &Dev->Ring, &Dev->RingMapping);
+ if (EFI_ERROR (Status)) {
+ goto Failed;
+ }
+
//
// Additional steps for MMIO: align the queue appropriately, and set the
// size. If anything fails from here on, we must release the ring resources.
@@ -812,6 +873,11 @@ VirtioBlkInit (
return EFI_SUCCESS;
ReleaseQueue:
+ if (Dev->RingMapping != NULL) {
+ VirtioRingUnmap (Dev->VirtIo, &Dev->Ring, Dev->RingMapping);
+ Dev->RingMapping = NULL;
+ }
+
VirtioRingUninit (Dev->VirtIo, &Dev->Ring);
Failed:
@@ -849,6 +915,14 @@ VirtioBlkUninit (
//
Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
+ //
+ // If ring buffer is mapped then Umap() it before uninitializing it.
+ //
+ if (Dev->RingMapping != NULL) {
+ VirtioRingUnmap (Dev->VirtIo, &Dev->Ring, Dev->RingMapping);
+ Dev->RingMapping = NULL;
+ }
+
VirtioRingUninit (Dev->VirtIo, &Dev->Ring);
SetMem (&Dev->BlockIo, sizeof Dev->BlockIo, 0x00);
@@ -885,6 +959,15 @@ VirtioBlkExitBoot (
//
Dev = Context;
Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
+
+ //
+ // Unmap the ring buffer so that hypervisor can not get a readable data
+ // after device is reset.
+ //
+ if (Dev->RingMapping != NULL) {
+ VirtioRingUnmap (Dev->VirtIo, &Dev->Ring, Dev->RingMapping);
+ Dev->RingMapping = NULL;
+ }
}
/**
--
2.7.4
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