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OvmfPkg/VirtioRngDxe: map host address to device address 

patch maps the host address to a device address for buffers (including
rings, device specifc request and response pointed by vring descriptor,
and any further memory reference by those request and response).

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: return EFI_DEVICE_ERROR if mapping fails in GetRNG]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Brijesh Singh 2017-08-23 06:57:19 -04:00 committed by Laszlo Ersek
parent 4b725858de
commit 0a568ccbcb
2 changed files with 76 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

85
OvmfPkg/VirtioRngDxe/VirtioRng.c
View File

@ -140,6 +140,8 @@ VirtioRngGetRNG (
UINT32 Len;
UINT32 BufferSize;
EFI_STATUS Status;
EFI_PHYSICAL_ADDRESS DeviceAddress;
VOID *Mapping;
if (This == NULL || RNGValueLength == 0 || RNGValue == NULL) {
return EFI_INVALID_PARAMETER;
@ -159,6 +161,21 @@ VirtioRngGetRNG (
}
Dev = VIRTIO_ENTROPY_SOURCE_FROM_RNG (This);
//
// Map Buffer's system phyiscal address to device address
//
Status = VirtioMapAllBytesInSharedBuffer (
Dev->VirtIo,
VirtioOperationBusMasterWrite,
(VOID *)Buffer,
RNGValueLength,
&DeviceAddress,
&Mapping
);
if (EFI_ERROR (Status)) {
Status = EFI_DEVICE_ERROR;
goto FreeBuffer;
}
//
// The Virtio RNG device may return less data than we asked it to, and can
@ -170,7 +187,7 @@ VirtioRngGetRNG (
VirtioPrepare (&Dev->Ring, &Indices);
VirtioAppendDesc (&Dev->Ring,
(UINTN)Buffer + Index,
DeviceAddress + Index,
BufferSize,
VRING_DESC_F_WRITE,
&Indices);
@ -178,17 +195,35 @@ VirtioRngGetRNG (
if (VirtioFlush (Dev->VirtIo, 0, &Dev->Ring, &Indices, &Len) !=
EFI_SUCCESS) {
Status = EFI_DEVICE_ERROR;
goto FreeBuffer;
goto UnmapBuffer;
}
ASSERT (Len > 0);
ASSERT (Len <= BufferSize);
}
//
// Unmap the device buffer before accessing it.
//
Status = Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Mapping);
if (EFI_ERROR (Status)) {
Status = EFI_DEVICE_ERROR;
goto FreeBuffer;
}
for (Index = 0; Index < RNGValueLength; Index++) {
RNGValue[Index] = Buffer[Index];
}
Status = EFI_SUCCESS;
UnmapBuffer:
//
// If we are reached here due to the error then unmap the buffer otherwise
// the buffer is already unmapped after VirtioFlush().
//
if (EFI_ERROR (Status)) {
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Mapping);
}
FreeBuffer:
FreePool ((VOID *)Buffer);
return Status;
@ -205,6 +240,7 @@ VirtioRngInit (
EFI_STATUS Status;
UINT16 QueueSize;
UINT64 Features;
UINT64 RingBaseShift;
//
// Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence.
@ -282,25 +318,42 @@ VirtioRngInit (
}
//
// Additional steps for MMIO: align the queue appropriately, and set the
// size. If anything fails from here on, we must release the ring resources.
// If anything fails from here on, we must release the ring resources.
//
Status = Dev->VirtIo->SetQueueNum (Dev->VirtIo, QueueSize);
Status = VirtioRingMap (
Dev->VirtIo,
&Dev->Ring,
&RingBaseShift,
&Dev->RingMap
);
if (EFI_ERROR (Status)) {
goto ReleaseQueue;
}
//
// Additional steps for MMIO: align the queue appropriately, and set the
// size. If anything fails from here on, we must unmap the ring resources.
//
Status = Dev->VirtIo->SetQueueNum (Dev->VirtIo, QueueSize);
if (EFI_ERROR (Status)) {
goto UnmapQueue;
}
Status = Dev->VirtIo->SetQueueAlign (Dev->VirtIo, EFI_PAGE_SIZE);
if (EFI_ERROR (Status)) {
goto ReleaseQueue;
goto UnmapQueue;
}
//
// step 4c -- Report GPFN (guest-physical frame number) of queue.
//
Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, &Dev->Ring, 0);
Status = Dev->VirtIo->SetQueueAddress (
Dev->VirtIo,
&Dev->Ring,
RingBaseShift
);
if (EFI_ERROR (Status)) {
goto ReleaseQueue;
goto UnmapQueue;
}
//
@ -310,7 +363,7 @@ VirtioRngInit (
Features &= ~(UINT64)VIRTIO_F_VERSION_1;
Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features);
if (EFI_ERROR (Status)) {
goto ReleaseQueue;
goto UnmapQueue;
}
}
@ -320,7 +373,7 @@ VirtioRngInit (
NextDevStat |= VSTAT_DRIVER_OK;
Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);
if (EFI_ERROR (Status)) {
goto ReleaseQueue;
goto UnmapQueue;
}
//
@ -331,6 +384,9 @@ VirtioRngInit (
return EFI_SUCCESS;
UnmapQueue:
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);
ReleaseQueue:
VirtioRingUninit (Dev->VirtIo, &Dev->Ring);
@ -359,6 +415,9 @@ VirtioRngUninit (
// the old comms area.
//
Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);
VirtioRingUninit (Dev->VirtIo, &Dev->Ring);
}
@ -385,6 +444,12 @@ VirtioRngExitBoot (
//
Dev = Context;
Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
//
// Unmap the ring buffer so that hypervisor will not be able to get readable
// data after device reset.
//
Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);
}

1
OvmfPkg/VirtioRngDxe/VirtioRng.h
View File

@ -38,6 +38,7 @@ typedef struct {
EFI_EVENT ExitBoot; // DriverBindingStart 0
VRING Ring; // VirtioRingInit 2
EFI_RNG_PROTOCOL Rng; // VirtioRngInit 1
VOID *RingMap; // VirtioRingMap 2
} VIRTIO_RNG_DEV;
#define VIRTIO_ENTROPY_SOURCE_FROM_RNG(RngPointer) \