When device is behind the IOMMU, driver is require to pass the device
address of caller-supplied transmit buffer for the bus master operations.
The patch uses VirtioNetMapTxBuf() to map caller-supplied Tx packet to a
device-address and enqueue the device address in VRING for transfer and
perform the reverse mapping when transfer is completed so that we can
return the caller-supplied buffer.
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/VirtioNetDxe/SnpGetStatus.c | 35 ++++++++++++++++----
OvmfPkg/VirtioNetDxe/SnpTransmit.c | 27 +++++++++++----
2 files changed, 49 insertions(+), 13 deletions(-)
diff --git a/OvmfPkg/VirtioNetDxe/SnpGetStatus.c b/OvmfPkg/VirtioNetDxe/SnpGetStatus.c
index 694940ea1d97..9b1c352227b3 100644
--- a/OvmfPkg/VirtioNetDxe/SnpGetStatus.c
+++ b/OvmfPkg/VirtioNetDxe/SnpGetStatus.c
@@ -61,11 +61,12 @@ VirtioNetGetStatus (
OUT VOID **TxBuf OPTIONAL
)
{
- VNET_DEV *Dev;
- EFI_TPL OldTpl;
- EFI_STATUS Status;
- UINT16 RxCurUsed;
- UINT16 TxCurUsed;
+ VNET_DEV *Dev;
+ EFI_TPL OldTpl;
+ EFI_STATUS Status;
+ UINT16 RxCurUsed;
+ UINT16 TxCurUsed;
+ EFI_PHYSICAL_ADDRESS DeviceAddress;
if (This == NULL) {
return EFI_INVALID_PARAMETER;
@@ -141,14 +142,34 @@ VirtioNetGetStatus (
ASSERT (DescIdx < (UINT32) (2 * Dev->TxMaxPending - 1));
//
- // report buffer address to caller that has been enqueued by caller
+ // get the device address that has been enqueued for the caller's
+ // transmit buffer
//
- *TxBuf = (VOID *)(UINTN) Dev->TxRing.Desc[DescIdx + 1].Addr;
+ DeviceAddress = Dev->TxRing.Desc[DescIdx + 1].Addr;
//
// now this descriptor can be used again to enqueue a transmit buffer
//
Dev->TxFreeStack[--Dev->TxCurPending] = (UINT16) DescIdx;
+
+ //
+ // Unmap the device address and perform the reverse mapping to find the
+ // caller buffer address.
+ //
+ Status = VirtioNetUnmapTxBuf (
+ Dev,
+ TxBuf,
+ DeviceAddress
+ );
+ if (EFI_ERROR (Status)) {
+ //
+ // VirtioNetUnmapTxBuf should never fail, if we have reached here
+ // that means our internal state has been corrupted
+ //
+ ASSERT (FALSE);
+ Status = EFI_DEVICE_ERROR;
+ goto Exit;
+ }
}
}
diff --git a/OvmfPkg/VirtioNetDxe/SnpTransmit.c b/OvmfPkg/VirtioNetDxe/SnpTransmit.c
index 7ca40d5d0650..b39226e138b9 100644
--- a/OvmfPkg/VirtioNetDxe/SnpTransmit.c
+++ b/OvmfPkg/VirtioNetDxe/SnpTransmit.c
@@ -73,11 +73,12 @@ VirtioNetTransmit (
IN UINT16 *Protocol OPTIONAL
)
{
- VNET_DEV *Dev;
- EFI_TPL OldTpl;
- EFI_STATUS Status;
- UINT16 DescIdx;
- UINT16 AvailIdx;
+ VNET_DEV *Dev;
+ EFI_TPL OldTpl;
+ EFI_STATUS Status;
+ UINT16 DescIdx;
+ UINT16 AvailIdx;
+ EFI_PHYSICAL_ADDRESS DeviceAddress;
if (This == NULL || BufferSize == 0 || Buffer == NULL) {
return EFI_INVALID_PARAMETER;
@@ -144,10 +145,24 @@ VirtioNetTransmit (
}
//
+ // Map the transmit buffer system physical address to device address.
+ //
+ Status = VirtioNetMapTxBuf (
+ Dev,
+ Buffer,
+ BufferSize,
+ &DeviceAddress
+ );
+ if (EFI_ERROR (Status)) {
+ Status = EFI_DEVICE_ERROR;
+ goto Exit;
+ }
+
+ //
// virtio-0.9.5, 2.4.1 Supplying Buffers to The Device
//
DescIdx = Dev->TxFreeStack[Dev->TxCurPending++];
- Dev->TxRing.Desc[DescIdx + 1].Addr = (UINTN) Buffer;
+ Dev->TxRing.Desc[DescIdx + 1].Addr = DeviceAddress;
Dev->TxRing.Desc[DescIdx + 1].Len = (UINT32) BufferSize;
//
--
2.9.5
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