OvmfPkg: VirtioNetDxe: adapt virtio-net packet header size to virtio-1.0

In virtio-0.9.5, the size of the virtio-net packet header depends on
whether the VIRTIO_NET_F_MRG_RXBUF feature is negotiated -- the
"num_buffers" field is only appended to the header if the feature is
negotiated.

Since we never negotiate this feature, VirtioNetDxe never allocates room
for the "num_buffers" field.

With virtio-1.0, the "num_buffers" field is always there (although it
doesn't carry useful information without VIRTIO_NET_F_MRG_RXBUF). Adapt
the buffers that depend on the virtio-net header size (otherwise we have
skewed / truncated packets).

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c
index 38012a0df8d65f763ffe85beaad64f169753c835..430670a980f2fe7dc2033462b8b4928a8cf89fcb 100644 (file)
--- a/OvmfPkg/VirtioNetDxe/SnpInitialize.c
+++ b/OvmfPkg/VirtioNetDxe/SnpInitialize.c
@@ -138,6 +138,7 @@ VirtioNetInitTx (
   IN OUT VNET_DEV *Dev\r
   )\r
 {\r
+  UINTN TxSharedReqSize;\r
   UINTN PktIdx;\r
 \r
   Dev->TxMaxPending = (UINT16) MIN (Dev->TxRing.QueueSize / 2,\r
@@ -149,6 +150,14 @@ VirtioNetInitTx (
     return EFI_OUT_OF_RESOURCES;\r
   }\r
 \r
+  //\r
+  // In VirtIo 1.0, the NumBuffers field is mandatory. In 0.9.5, it depends on\r
+  // VIRTIO_NET_F_MRG_RXBUF, which we never negotiate.\r
+  //\r
+  TxSharedReqSize = (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) ?\r
+                    sizeof Dev->TxSharedReq.V0_9_5 :\r
+                    sizeof Dev->TxSharedReq;\r
+\r
   for (PktIdx = 0; PktIdx < Dev->TxMaxPending; ++PktIdx) {\r
     UINT16 DescIdx;\r
 \r
@@ -160,7 +169,7 @@ VirtioNetInitTx (
     // (unmodified by the host) virtio-net request header.\r
     //\r
     Dev->TxRing.Desc[DescIdx].Addr  = (UINTN) &Dev->TxSharedReq;\r
-    Dev->TxRing.Desc[DescIdx].Len   = sizeof Dev->TxSharedReq;\r
+    Dev->TxRing.Desc[DescIdx].Len   = (UINT32) TxSharedReqSize;\r
     Dev->TxRing.Desc[DescIdx].Flags = VRING_DESC_F_NEXT;\r
     Dev->TxRing.Desc[DescIdx].Next  = (UINT16) (DescIdx + 1);\r
 \r
@@ -174,8 +183,13 @@ VirtioNetInitTx (
   //\r
   // virtio-0.9.5, Appendix C, Packet Transmission\r
   //\r
-  Dev->TxSharedReq.Flags   = 0;\r
-  Dev->TxSharedReq.GsoType = VIRTIO_NET_HDR_GSO_NONE;\r
+  Dev->TxSharedReq.V0_9_5.Flags   = 0;\r
+  Dev->TxSharedReq.V0_9_5.GsoType = VIRTIO_NET_HDR_GSO_NONE;\r
+\r
+  //\r
+  // For VirtIo 1.0 only -- the field exists, but it is unused\r
+  //\r
+  Dev->TxSharedReq.NumBuffers = 0;\r
 \r
   //\r
   // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device\r
@@ -223,19 +237,28 @@ VirtioNetInitRx (
   )\r
 {\r
   EFI_STATUS Status;\r
+  UINTN      VirtioNetReqSize;\r
   UINTN      RxBufSize;\r
   UINT16     RxAlwaysPending;\r
   UINTN      PktIdx;\r
   UINT16     DescIdx;\r
   UINT8      *RxPtr;\r
 \r
+  //\r
+  // In VirtIo 1.0, the NumBuffers field is mandatory. In 0.9.5, it depends on\r
+  // VIRTIO_NET_F_MRG_RXBUF, which we never negotiate.\r
+  //\r
+  VirtioNetReqSize = (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) ?\r
+                     sizeof (VIRTIO_NET_REQ) :\r
+                     sizeof (VIRTIO_1_0_NET_REQ);\r
+\r
   //\r
   // For each incoming packet we must supply two descriptors:\r
   // - the recipient for the virtio-net request header, plus\r
   // - the recipient for the network data (which consists of Ethernet header\r
   //   and Ethernet payload).\r
   //\r
-  RxBufSize = sizeof (VIRTIO_NET_REQ) +\r
+  RxBufSize = VirtioNetReqSize +\r
               (Dev->Snm.MediaHeaderSize + Dev->Snm.MaxPacketSize);\r
 \r
   //\r
@@ -280,14 +303,13 @@ VirtioNetInitRx (
     // virtio-0.9.5, 2.4.1.1 Placing Buffers into the Descriptor Table\r
     //\r
     Dev->RxRing.Desc[DescIdx].Addr  = (UINTN) RxPtr;\r
-    Dev->RxRing.Desc[DescIdx].Len   = sizeof (VIRTIO_NET_REQ);\r
+    Dev->RxRing.Desc[DescIdx].Len   = (UINT32) VirtioNetReqSize;\r
     Dev->RxRing.Desc[DescIdx].Flags = VRING_DESC_F_WRITE | VRING_DESC_F_NEXT;\r
     Dev->RxRing.Desc[DescIdx].Next  = (UINT16) (DescIdx + 1);\r
     RxPtr += Dev->RxRing.Desc[DescIdx++].Len;\r
 \r
     Dev->RxRing.Desc[DescIdx].Addr  = (UINTN) RxPtr;\r
-    Dev->RxRing.Desc[DescIdx].Len   = (UINT32) (RxBufSize -\r
-                                                sizeof (VIRTIO_NET_REQ));\r
+    Dev->RxRing.Desc[DescIdx].Len   = (UINT32) (RxBufSize - VirtioNetReqSize);\r
     Dev->RxRing.Desc[DescIdx].Flags = VRING_DESC_F_WRITE;\r
     RxPtr += Dev->RxRing.Desc[DescIdx++].Len;\r
   }\r

diff --git a/OvmfPkg/VirtioNetDxe/VirtioNet.h b/OvmfPkg/VirtioNetDxe/VirtioNet.h
index 2d3f3d87eb1121639ac1a2291d2ef54ac9ecdd35..710859bc61159fee360494eb09a03d15baa378b1 100644 (file)
--- a/OvmfPkg/VirtioNetDxe/VirtioNet.h
+++ b/OvmfPkg/VirtioNetDxe/VirtioNet.h
@@ -89,7 +89,7 @@ typedef struct {
   UINT16                      TxMaxPending;      // VirtioNetInitTx\r
   UINT16                      TxCurPending;      // VirtioNetInitTx\r
   UINT16                      *TxFreeStack;      // VirtioNetInitTx\r
-  VIRTIO_NET_REQ              TxSharedReq;       // VirtioNetInitTx\r
+  VIRTIO_1_0_NET_REQ          TxSharedReq;       // VirtioNetInitTx\r
   UINT16                      TxLastUsed;        // VirtioNetInitTx\r
 } VNET_DEV;\r
 \r