[PATCH 1/5] OvmfPkg/VirtioNetDxe: map VRING using VirtioRingMap()

[Brijesh Singh <brijesh.singh@amd.com>]

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 to device address.

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/VirtioNet.h     |  2 +
 OvmfPkg/VirtioNetDxe/Events.c        |  7 ++++
 OvmfPkg/VirtioNetDxe/SnpInitialize.c | 40 ++++++++++++++++----
 OvmfPkg/VirtioNetDxe/SnpShutdown.c   |  2 +
 4 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/OvmfPkg/VirtioNetDxe/VirtioNet.h b/OvmfPkg/VirtioNetDxe/VirtioNet.h
index 710859bc6115..d80d441b50a4 100644
--- a/OvmfPkg/VirtioNetDxe/VirtioNet.h
+++ b/OvmfPkg/VirtioNetDxe/VirtioNet.h
@@ -82,10 +82,12 @@ typedef struct {
   EFI_HANDLE                  MacHandle;         // VirtioNetDriverBindingStart
 
   VRING                       RxRing;            // VirtioNetInitRing
+  VOID                        *RxRingMap;        // VirtioRingMap
   UINT8                       *RxBuf;            // VirtioNetInitRx
   UINT16                      RxLastUsed;        // VirtioNetInitRx
 
   VRING                       TxRing;            // VirtioNetInitRing
+  VOID                        *TxRingMap;        // VirtioRingMap
   UINT16                      TxMaxPending;      // VirtioNetInitTx
   UINT16                      TxCurPending;      // VirtioNetInitTx
   UINT16                      *TxFreeStack;      // VirtioNetInitTx
diff --git a/OvmfPkg/VirtioNetDxe/Events.c b/OvmfPkg/VirtioNetDxe/Events.c
index 5be1af6ffbee..6950c4d56df1 100644
--- a/OvmfPkg/VirtioNetDxe/Events.c
+++ b/OvmfPkg/VirtioNetDxe/Events.c
@@ -88,4 +88,11 @@ VirtioNetExitBoot (
   if (Dev->Snm.State == EfiSimpleNetworkInitialized) {
     Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
   }
+
+  //
+  // Unmap Tx and Rx rings so that hypervisor will not be able get readable data
+  // after device is reset.
+  //
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->TxRingMap);
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RxRingMap);
 }
diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c
index 0ecfe044a977..803a38bd4239 100644
--- a/OvmfPkg/VirtioNetDxe/SnpInitialize.c
+++ b/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 token return from the VirtioRingMap().
 
   @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 +51,13 @@ 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;
 
   //
   // step 4b -- allocate selected queue
@@ -79,30 +83,38 @@ VirtioNetInitRing (
     return Status;
   }
 
+  Status = VirtioRingMap (Dev->VirtIo, Ring, &RingBaseShift, Mapping);
+  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, Ring, 0);
+  Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, Ring, RingBaseShift);
   if (EFI_ERROR (Status)) {
-    goto ReleaseQueue;
+    goto UnmapQueue;
   }
 
   return EFI_SUCCESS;
 
+UnmapQueue:
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Mapping);
+
 ReleaseQueue:
   VirtioRingUninit (Dev->VirtIo, Ring);
 
@@ -456,12 +468,22 @@ 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;
   }
@@ -510,9 +532,11 @@ AbortDevice:
   Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
 
 ReleaseTxRing:
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->TxRingMap);
   VirtioRingUninit (Dev->VirtIo, &Dev->TxRing);
 
 ReleaseRxRing:
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RxRingMap);
   VirtioRingUninit (Dev->VirtIo, &Dev->RxRing);
 
 DeviceFailed:
diff --git a/OvmfPkg/VirtioNetDxe/SnpShutdown.c b/OvmfPkg/VirtioNetDxe/SnpShutdown.c
index 5e84191fbbdd..36f3253e77ad 100644
--- a/OvmfPkg/VirtioNetDxe/SnpShutdown.c
+++ b/OvmfPkg/VirtioNetDxe/SnpShutdown.c
@@ -67,7 +67,9 @@ VirtioNetShutdown (
   Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);
   VirtioNetShutdownRx (Dev);
   VirtioNetShutdownTx (Dev);
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->TxRingMap);
   VirtioRingUninit (Dev->VirtIo, &Dev->TxRing);
+  Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RxRingMap);
   VirtioRingUninit (Dev->VirtIo, &Dev->RxRing);
 
   Dev->Snm.State = EfiSimpleNetworkStarted;
-- 
2.7.4