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 <[email protected]> Cc: Jordan Justen <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Laszlo Ersek <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Brijesh Singh <[email protected]> --- OvmfPkg/VirtioRngDxe/VirtioRng.h | 1 + OvmfPkg/VirtioRngDxe/VirtioRng.c | 65 +++++++++++++++++--- 2 files changed, 58 insertions(+), 8 deletions(-) diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.h b/OvmfPkg/VirtioRngDxe/VirtioRng.h index 998f9fae48c2..b372d84c1ebc 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; // VirtioRngInit 1 } VIRTIO_RNG_DEV; #define VIRTIO_ENTROPY_SOURCE_FROM_RNG(RngPointer) \ diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c index 0abca488e6cd..fc01f1996654 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 the Buffers system phyiscal address to device address + // + Status = VirtioMapAllBytesInSharedBuffer ( + Dev->VirtIo, + VirtioOperationBusMasterWrite, + (VOID *)Buffer, + RNGValueLength, + &DeviceAddress, + &Mapping + ); + if (EFI_ERROR (Status)) { + goto FreeBuffer; + } // // 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, + (UINTN)DeviceAddress + Index, BufferSize, VRING_DESC_F_WRITE, &Indices); @@ -178,17 +194,30 @@ 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 accesing it. + // + Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Mapping); + for (Index = 0; Index < RNGValueLength; Index++) { RNGValue[Index] = Buffer[Index]; } Status = EFI_SUCCESS; + // + // Buffer is already Unmaped(), goto free it. + // + goto FreeBuffer; + +UnmapBuffer: + Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Mapping); + FreeBuffer: FreePool ((VOID *)Buffer); return Status; @@ -205,6 +234,7 @@ VirtioRngInit ( EFI_STATUS Status; UINT16 QueueSize; UINT64 Features; + UINT64 RingBaseShift; // // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence. @@ -281,26 +311,33 @@ VirtioRngInit ( goto Failed; } + 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. // 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 +347,7 @@ VirtioRngInit ( Features &= ~(UINT64)VIRTIO_F_VERSION_1; Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features); if (EFI_ERROR (Status)) { - goto ReleaseQueue; + goto UnmapQueue; } } @@ -320,7 +357,7 @@ VirtioRngInit ( NextDevStat |= VSTAT_DRIVER_OK; Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); if (EFI_ERROR (Status)) { - goto ReleaseQueue; + goto UnmapQueue; } // @@ -331,6 +368,9 @@ VirtioRngInit ( return EFI_SUCCESS; +UnmapQueue: + Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap); + ReleaseQueue: VirtioRingUninit (Dev->VirtIo, &Dev->Ring); @@ -359,6 +399,9 @@ 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 +428,12 @@ VirtioRngExitBoot ( // Dev = Context; Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0); + + // + // Umap the ring buffer so that hypervisor will not able to get readable data + // after device reset. + // + Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap); } -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
