OvmfPkg/VirtioNetDxe: map VRINGs using VirtioRingMap()

When device is behind the IOMMU then driver need to pass the device
address when programing the bus master. The patch uses VirtioRingMap() to
map the VRING system physical address[es] to device address[es].

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>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>

OvmfPkg/VirtioNetDxe/SnpInitialize.c

@@ -35,11 +35,13 @@
                            the network device.
   @param[out]    Ring      The virtio-ring inside the VNET_DEV structure,
                            corresponding to Selector.
+  @param[out]    Mapping   A resulting token to pass to VirtioNetUninitRing()
 
   @retval EFI_UNSUPPORTED  The queue size reported by the virtio-net device is
                            too small.
   @return                  Status codes from VIRTIO_CFG_WRITE(),
-                           VIRTIO_CFG_READ() and VirtioRingInit().
+                           VIRTIO_CFG_READ(), VirtioRingInit() and
+                           VirtioRingMap().
   @retval EFI_SUCCESS      Ring initialized.
 */
 
@@ -49,11 +51,14 @@ EFIAPI
 VirtioNetInitRing (
   IN OUT VNET_DEV *Dev,
   IN     UINT16   Selector,
-  OUT    VRING    *Ring
+  OUT    VRING    *Ring,
+  OUT    VOID     **Mapping
   )
 {
   EFI_STATUS Status;
   UINT16     QueueSize;
+  UINT64     RingBaseShift;
+  VOID       *MapInfo;
 
   //
   // step 4b -- allocate selected queue
@@ -80,29 +85,42 @@ VirtioNetInitRing (
   }
 
   //
-  // Additional steps for MMIO: align the queue appropriately, and set the
+  // If anything fails from here on, we must release the ring resources.
-  // size. If anything fails from here on, we must release the ring resources.
   //
-  Status = Dev->VirtIo->SetQueueNum (Dev->VirtIo, QueueSize);
+  Status = VirtioRingMap (Dev->VirtIo, Ring, &RingBaseShift, &MapInfo);
   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, Ring, 0);
+  Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, Ring, RingBaseShift);
   if (EFI_ERROR (Status)) {
-    goto ReleaseQueue;
+    goto UnmapQueue;
   }
 
+  *Mapping = MapInfo;
+
   return EFI_SUCCESS;
 
+UnmapQueue:
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, MapInfo);
+
 ReleaseQueue:
   VirtioRingUninit (Dev->VirtIo, Ring);
 
@@ -456,12 +474,22 @@ VirtioNetInitialize (
   //
   // step 4b, 4c -- allocate and report virtqueues
   //
-  Status = VirtioNetInitRing (Dev, VIRTIO_NET_Q_RX, &Dev->RxRing);
+  Status = VirtioNetInitRing (
+             Dev,
+             VIRTIO_NET_Q_RX,
+             &Dev->RxRing,
+             &Dev->RxRingMap
+             );
   if (EFI_ERROR (Status)) {
     goto DeviceFailed;
   }
 
-  Status = VirtioNetInitRing (Dev, VIRTIO_NET_Q_TX, &Dev->TxRing);
+  Status = VirtioNetInitRing (
+             Dev,
+             VIRTIO_NET_Q_TX,
+             &Dev->TxRing,
+             &Dev->TxRingMap
+             );
   if (EFI_ERROR (Status)) {
     goto ReleaseRxRing;
   }
@@ -510,10 +538,10 @@ AbortDevice:
   Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
 
 ReleaseTxRing:
-  VirtioNetUninitRing (Dev, &Dev->TxRing);
+  VirtioNetUninitRing (Dev, &Dev->TxRing, Dev->TxRingMap);
 
 ReleaseRxRing:
-  VirtioNetUninitRing (Dev, &Dev->RxRing);
+  VirtioNetUninitRing (Dev, &Dev->RxRing, Dev->RxRingMap);
 
 DeviceFailed:
   //

OvmfPkg/VirtioNetDxe/SnpSharedHelpers.c

@@ -55,15 +55,19 @@ VirtioNetShutdownTx (
 /**
   Release TX and RX VRING resources.
 
-  @param[in,out] Dev   The VNET_DEV driver instance which was using the ring.
+  @param[in,out] Dev       The VNET_DEV driver instance which was using
-  @param[in,out] Ring  The virtio ring to clean up.
+                           the ring.
+  @param[in,out] Ring      The virtio ring to clean up.
+  @param[in]     RingMap   A token return from the VirtioRingMap()
 */
 VOID
 EFIAPI
 VirtioNetUninitRing (
   IN OUT VNET_DEV *Dev,
-  IN OUT VRING    *Ring
+  IN OUT VRING    *Ring,
+  IN     VOID     *RingMap
   )
 {
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, RingMap);
   VirtioRingUninit (Dev->VirtIo, Ring);
 }

OvmfPkg/VirtioNetDxe/SnpShutdown.c

@@ -67,8 +67,8 @@ VirtioNetShutdown (
   Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
   VirtioNetShutdownRx (Dev);
   VirtioNetShutdownTx (Dev);
-  VirtioNetUninitRing (Dev, &Dev->TxRing);
+  VirtioNetUninitRing (Dev, &Dev->TxRing, Dev->TxRingMap);
-  VirtioNetUninitRing (Dev, &Dev->RxRing);
+  VirtioNetUninitRing (Dev, &Dev->RxRing, Dev->RxRingMap);
 
   Dev->Snm.State = EfiSimpleNetworkStarted;
   Status = EFI_SUCCESS;

OvmfPkg/VirtioNetDxe/TechNotes.txt

@@ -70,8 +70,9 @@ faithfully indented) that implement the transition.
   VirtioNetInitialize          |  | VirtioNetShutdown
     VirtioNetInitRing {Rx, Tx} |  |   VirtioNetShutdownRx [SnpSharedHelpers.c]
       VirtioRingInit           |  |   VirtioNetShutdownTx [SnpSharedHelpers.c]
-    VirtioNetInitTx            |  |   VirtioNetUninitRing [SnpSharedHelpers.c]
+      VirtioRingMap            |  |   VirtioNetUninitRing [SnpSharedHelpers.c]
-    VirtioNetInitRx            |  |                       {Tx, Rx}
+    VirtioNetInitTx            |  |                       {Tx, Rx}
+    VirtioNetInitRx            |  |     VirtIo->UnmapSharedBuffer
                                |  |     VirtioRingUninit
                                v  |
                   +-----------------------------+

OvmfPkg/VirtioNetDxe/VirtioNet.h

@@ -82,10 +82,14 @@ typedef struct {
   EFI_HANDLE                  MacHandle;         // VirtioNetDriverBindingStart
 
   VRING                       RxRing;            // VirtioNetInitRing
+  VOID                        *RxRingMap;        // VirtioRingMap and
+                                                 // VirtioNetInitRing
   UINT8                       *RxBuf;            // VirtioNetInitRx
   UINT16                      RxLastUsed;        // VirtioNetInitRx
 
   VRING                       TxRing;            // VirtioNetInitRing
+  VOID                        *TxRingMap;        // VirtioRingMap and
+                                                 // VirtioNetInitRing
   UINT16                      TxMaxPending;      // VirtioNetInitTx
   UINT16                      TxCurPending;      // VirtioNetInitTx
   UINT16                      *TxFreeStack;      // VirtioNetInitTx
@@ -267,7 +271,8 @@ VOID
 EFIAPI
 VirtioNetUninitRing (
   IN OUT VNET_DEV *Dev,
-  IN OUT VRING    *Ring
+  IN OUT VRING    *Ring,
+  IN     VOID     *RingMap
   );
 
 //