On 08/23/17 14:22, Brijesh Singh wrote:
> 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>
> ---
> OvmfPkg/VirtioRngDxe/VirtioRng.h | 1 +
> OvmfPkg/VirtioRngDxe/VirtioRng.c | 82 +++++++++++++++++---
> 2 files changed, 74 insertions(+), 9 deletions(-)
>
> diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.h b/OvmfPkg/VirtioRngDxe/VirtioRng.h
> index 998f9fae48c2..389c8ddc8d31 100644
> --- a/OvmfPkg/VirtioRngDxe/VirtioRng.h
> +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.h
> @@ -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) \
> diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c
> index 0abca488e6cd..59f32d343179 100644
> --- a/OvmfPkg/VirtioRngDxe/VirtioRng.c
> +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c
> @@ -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 +161,20 @@ 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)) {
> + goto FreeBuffer;
> + }
(1) Sorry, I missed this in my previous review:
According to the interface contract of this protocol member function, we
should set Status to EFI_DEVICE_ERROR here, before jumping to the
FreeBuffer label. (Both old code, and new code other than this, do it.)
I can fix this up.
With that:
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Thanks,
Laszlo
>
> //
> // The Virtio RNG device may return less data than we asked it to, and can
> @@ -170,7 +186,7 @@ VirtioRngGetRNG (
>
> VirtioPrepare (&Dev->Ring, &Indices);
> VirtioAppendDesc (&Dev->Ring,
> - (UINTN)Buffer + Index,
> + DeviceAddress + Index,
> BufferSize,
> VRING_DESC_F_WRITE,
> &Indices);
> @@ -178,17 +194,35 @@ 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 +239,7 @@ VirtioRngInit (
> EFI_STATUS Status;
> UINT16 QueueSize;
> UINT64 Features;
> + UINT64 RingBaseShift;
>
> //
> // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence.
> @@ -282,25 +317,42 @@ VirtioRngInit (
> }
>
> //
> + // If anything fails from here on, we must release the ring resources.
> + //
> + 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 release the ring resources.
> + // 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 ReleaseQueue;
> + 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 +362,7 @@ VirtioRngInit (
> Features &= ~(UINT64)VIRTIO_F_VERSION_1;
> Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features);
> if (EFI_ERROR (Status)) {
> - goto ReleaseQueue;
> + goto UnmapQueue;
> }
> }
>
> @@ -320,7 +372,7 @@ VirtioRngInit (
> NextDevStat |= VSTAT_DRIVER_OK;
> Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);
> if (EFI_ERROR (Status)) {
> - goto ReleaseQueue;
> + goto UnmapQueue;
> }
>
> //
> @@ -331,6 +383,9 @@ VirtioRngInit (
>
> return EFI_SUCCESS;
>
> +UnmapQueue:
> + Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);
> +
> ReleaseQueue:
> VirtioRingUninit (Dev->VirtIo, &Dev->Ring);
>
> @@ -359,6 +414,9 @@ 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 +443,12 @@ 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);
> }
>
>
>
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel