[PATCH v4 2/8] OvmfPkg/VirtioNetDxe: map VRINGs 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[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>
---
 OvmfPkg/VirtioNetDxe/VirtioNet.h        |  7 ++-
 OvmfPkg/VirtioNetDxe/SnpInitialize.c    | 50 +++++++++++++++-----
 OvmfPkg/VirtioNetDxe/SnpSharedHelpers.c | 10 ++--
 OvmfPkg/VirtioNetDxe/SnpShutdown.c      |  4 +-
 OvmfPkg/VirtioNetDxe/TechNotes.txt      |  5 +-
 5 files changed, 57 insertions(+), 19 deletions(-)

diff --git a/OvmfPkg/VirtioNetDxe/VirtioNet.h b/OvmfPkg/VirtioNetDxe/VirtioNet.h
index 87a0f06e01a4..6762fc9d1d6e 100644
--- a/OvmfPkg/VirtioNetDxe/VirtioNet.h
+++ b/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
   );
 
 //
diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c
index 637c978709fd..8eabdbff6f5e 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 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 (
   }
 
   //
+  // If anything fails from here on, we must release the ring resources.
+  //
+  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 release the ring resources.
+  // 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 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;
   }
 
+  *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:
   //
diff --git a/OvmfPkg/VirtioNetDxe/SnpSharedHelpers.c b/OvmfPkg/VirtioNetDxe/SnpSharedHelpers.c
index 5b75eabc7a6b..57c7395848bd 100644
--- a/OvmfPkg/VirtioNetDxe/SnpSharedHelpers.c
+++ b/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] Ring  The virtio ring to clean up.
+  @param[in,out] Dev       The VNET_DEV driver instance which was using
+                           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);
 }
diff --git a/OvmfPkg/VirtioNetDxe/SnpShutdown.c b/OvmfPkg/VirtioNetDxe/SnpShutdown.c
index 432e0691d457..d8c11f20de61 100644
--- a/OvmfPkg/VirtioNetDxe/SnpShutdown.c
+++ b/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->RxRing);
+  VirtioNetUninitRing (Dev, &Dev->TxRing, Dev->TxRingMap);
+  VirtioNetUninitRing (Dev, &Dev->RxRing, Dev->RxRingMap);
 
   Dev->Snm.State = EfiSimpleNetworkStarted;
   Status = EFI_SUCCESS;
diff --git a/OvmfPkg/VirtioNetDxe/TechNotes.txt b/OvmfPkg/VirtioNetDxe/TechNotes.txt
index 86b91f561495..37250b14a98c 100644
--- a/OvmfPkg/VirtioNetDxe/TechNotes.txt
+++ b/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]
-    VirtioNetInitRx            |  |                       {Tx, Rx}
+      VirtioRingMap            |  |   VirtioNetUninitRing [SnpSharedHelpers.c]
+    VirtioNetInitTx            |  |                       {Tx, Rx}
+    VirtioNetInitRx            |  |     VirtIo->UnmapSharedBuffer
                                |  |     VirtioRingUninit
                                v  |
                   +-----------------------------+
-- 
2.9.5