Re: [PATCH v2 17/18] OvmfPkg/XenPvBlkDxe: Add BlockFront client.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

> +/**
> +  Helper to read an interger from XenStore.

integer?

> +
> +  @param This         A pointer to a XENBUS_PROTOCOL instance.
> +  @param Node         The XenStore node to read from.
> +  @param FromBackend  Read frontend or backend value.
> +  @param ValuePtr     Where to put the value.
> +
> +  @retval XENSTORE_STATUS_SUCCESS  If succefull, will update ValuePtr.
> +  @return                          Any other return value indicate the error,
> +                                   ValuePtr is not updated in this case.
> +**/
> +STATIC
> +XENSTORE_STATUS
> +XenBusReadUint64 (
> +  IN  XENBUS_PROTOCOL *This,
> +  IN  CONST CHAR8     *Node,
> +  IN  BOOLEAN         FromBackend,
> +  OUT UINT64          *ValuePtr
> +  )
> +{
> +  XENSTORE_STATUS Status;
> +  CHAR8 *p;
> +
> +  if (!FromBackend) {
> +    Status = This->XsRead (This, XST_NIL, Node, (VOID**)&p);
> +  } else {
> +    Status = This->XsBackendRead (This, XST_NIL, Node, (VOID**)&p);
> +  }
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    return Status;
> +  }
> +  // FIXME Will ASSERT if p overflow UINT64 ...


Do you just want to add the ASSERT in the code then?

> +  *ValuePtr = AsciiStrDecimalToUint64 (p);
> +  FreePool (p);
> +  return Status;
> +}
> +
> +/**
> +  Free an instance of XEN_BLOCK_FRONT_DEVICE.
> +
> +  @param Dev  The instance to free.
> +**/
> +STATIC
> +VOID
> +XenPvBlockFree (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  )
> +{
> +  XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
> +
> +  if (Dev->RingRef != 0) {
> +    XenBusIo->GrantEndAccess (XenBusIo, Dev->RingRef);
> +  }
> +  if (Dev->Ring.sring != NULL) {
> +    FreePages (Dev->Ring.sring, 1);
> +  }
> +  if (Dev->EventChannel != 0) {
> +    XenBusIo->EventChannelClose (XenBusIo, Dev->EventChannel);
> +  }
> +  FreePool (Dev);
> +}
> +
> +/**
> +  Wait until until the backend have reach the ExpectedState.

s/have reached/has reached/
> +
> +  @param Dev            A XEN_BLOCK_FRONT_DEVICE instance.
> +  @param ExpectedState  The backend state expected.
> +  @param LastStatePtr   An optionnal pointer where to right the final state.

s/optionnal/optional/
> +
> +  @return Return XENSTORE_STATUS_SUCCESS if the new backend state is ExpectedState
> +          or return an error otherwise.
> +**/
> +STATIC
> +XENSTORE_STATUS
> +XenPvBlkWaitForBackendState (
> +  IN  XEN_BLOCK_FRONT_DEVICE *Dev,
> +  IN  XenbusState            ExpectedState,
> +  OUT XenbusState            *LastStatePtr OPTIONAL
> +  )
> +{
> +  XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
> +  XenbusState State;
> +  UINT64 Value;
> +  XENSTORE_STATUS Status = XENSTORE_STATUS_SUCCESS;
> +
> +  while (TRUE) {
> +    Status = XenBusReadUint64 (XenBusIo, "state", TRUE, &Value);
> +    if (Status != XENSTORE_STATUS_SUCCESS) {
> +      return Status;
> +    }
> +    if (Value > XenbusStateReconfigured) {
> +      //
> +      // Value is not a State value.
> +      //
> +      return XENSTORE_STATUS_EIO;
> +    }
> +    State = Value;
> +    if (State == ExpectedState) {
> +      break;
> +    } else if (State > ExpectedState) {
> +      Status = XENSTORE_STATUS_FAIL;
> +      break;
> +    }
> +    DEBUG ((EFI_D_INFO,
> +            "XenPvBlk: waiting backend state %d, current: %d\n",
> +            ExpectedState, State));
> +    XenBusIo->WaitForWatch (XenBusIo, Dev->StateWatchToken);
> +  }
> +
> +  if (LastStatePtr != NULL) {
> +    *LastStatePtr = State;
> +  }
> +
> +  return Status;
> +}
> +
> +EFI_STATUS
> +XenPvBlockFrontInitialization (
> +  IN  XENBUS_PROTOCOL         *XenBusIo,
> +  IN  CONST CHAR8             *NodeName,
> +  OUT XEN_BLOCK_FRONT_DEVICE  **DevPtr
> +  )
> +{
> +  XENSTORE_TRANSACTION xbt;
> +  CHAR8 *DeviceType;
> +  blkif_sring_t *SharedRing;
> +  XENSTORE_STATUS Status;
> +  XEN_BLOCK_FRONT_DEVICE *Dev;
> +  XenbusState State;
> +  UINT64 Value;
> +
> +  ASSERT (NodeName != NULL);
> +
> +  Dev = AllocateZeroPool (sizeof (XEN_BLOCK_FRONT_DEVICE));
> +  Dev->Signature = XEN_BLOCK_FRONT_SIGNATURE;
> +  Dev->NodeName = NodeName;
> +  Dev->XenBusIo = XenBusIo;
> +  Dev->DeviceId = XenBusIo->DeviceId;
> +
> +  XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", (VOID**)&DeviceType);
> +  if (AsciiStrCmp (DeviceType, "cdrom") == 0) {
> +    Dev->MediaInfo.CdRom = TRUE;
> +  } else {
> +    Dev->MediaInfo.CdRom = FALSE;
> +  }
> +  FreePool (DeviceType);
> +
> +  Status = XenBusReadUint64 (XenBusIo, "backend-id", FALSE, &Value);
> +  if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT16_MAX) {
> +    DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to get backend-id (%d)\n",
> +            Status));
> +    goto Error;
> +  }
> +  Dev->DomainId = Value;
> +  XenBusIo->EventChannelAllocate (XenBusIo, Dev->DomainId, &Dev->EventChannel);
> +
> +  SharedRing = (blkif_sring_t*) AllocatePages (1);
> +  SHARED_RING_INIT (SharedRing);
> +  FRONT_RING_INIT (&Dev->Ring, SharedRing, EFI_PAGE_SIZE);
> +  XenBusIo->GrantAccess (XenBusIo,
> +                         Dev->DomainId,
> +                         (INTN) SharedRing >> EFI_PAGE_SHIFT,
> +                         FALSE,
> +                         &Dev->RingRef);
> +
> +Again:
> +  Status = XenBusIo->XsTransactionStart (XenBusIo, &xbt);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_WARN, "XenPvBlk: Failed to start transaction, %d\n", Status));
> +    goto Error;
> +  }
> +
> +  Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName, "ring-ref", "%d",
> +                               Dev->RingRef);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write ring-ref.\n"));
> +    goto AbortTransaction;
> +  }
> +  Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName,
> +                               "event-channel", "%d", Dev->EventChannel);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write event-channel.\n"));
> +    goto AbortTransaction;
> +  }
> +  Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName,
> +                               "protocol", "%a", XEN_IO_PROTO_ABI_NATIVE);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write protocol.\n"));
> +    goto AbortTransaction;
> +  }
> +
> +  Status = XenBusIo->SetState (XenBusIo, xbt, XenbusStateConnected);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed switch state.\n"));

Failed to switch state

> +    goto AbortTransaction;
> +  }
> +
> +  Status = XenBusIo->XsTransactionEnd (XenBusIo, xbt, FALSE);
> +  if (Status == XENSTORE_STATUS_EAGAIN) {
> +    goto Again;
> +  }
> +
> +  XenBusIo->RegisterWatchBackend (XenBusIo, "state", &Dev->StateWatchToken);
> +
> +  //
> +  // Waiting backend

Waiting for backend.

> +  //
> +  Status = XenPvBlkWaitForBackendState (Dev, XenbusStateConnected, &State);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR,
> +            "XenPvBlk: backend for %a/%d not available, rc=%d state=%d\n",
> +            XenBusIo->Type, XenBusIo->DeviceId, Status, State));
> +    goto Error2;
> +  }
> +
> +  Status = XenBusReadUint64 (XenBusIo, "info", TRUE, &Value);
> +  if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT32_MAX) {
> +    goto Error2;
> +  }
> +  Dev->MediaInfo.VDiskInfo = Value;
> +  if (Dev->MediaInfo.VDiskInfo & VDISK_READONLY) {
> +    Dev->MediaInfo.ReadWrite = FALSE;
> +  } else {
> +    Dev->MediaInfo.ReadWrite = TRUE;
> +  }
> +
> +  Status = XenBusReadUint64 (XenBusIo, "sectors", TRUE, &Dev->MediaInfo.Sectors);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    goto Error2;
> +  }
> +
> +  Status = XenBusReadUint64 (XenBusIo, "sector-size", TRUE, &Value);
> +  if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT32_MAX) {
> +    goto Error2;
> +  }
> +  Dev->MediaInfo.SectorSize = Value;
> +
> +  // Default value
> +  Value = 0;
> +  Status = XenBusReadUint64 (XenBusIo, "feature-barrier", TRUE, &Value);
> +  if (Value == 1) {
> +    Dev->MediaInfo.FeatureBarrier = TRUE;
> +  } else {
> +    Dev->MediaInfo.FeatureBarrier = FALSE;
> +  }
> +
> +  // Default value
> +  Value = 0;
> +  XenBusReadUint64 (XenBusIo, "feature-flush-cache", TRUE, &Value);
> +  if (Value == 1) {
> +    Dev->MediaInfo.FeatureFlushCache = TRUE;
> +  } else {
> +    Dev->MediaInfo.FeatureFlushCache = FALSE;
> +  }
> +
> +  DEBUG ((EFI_D_INFO, "XenPvBlk: New disk with %ld sectors of %d bytes\n",
> +          Dev->MediaInfo.Sectors, Dev->MediaInfo.SectorSize));
> +
> +  *DevPtr = Dev;
> +  return EFI_SUCCESS;
> +
> +Error2:
> +  XenBusIo->UnregisterWatch (XenBusIo, Dev->StateWatchToken);
> +  XenBusIo->XsRemove (XenBusIo, XST_NIL, "ring-ref");
> +  XenBusIo->XsRemove (XenBusIo, XST_NIL, "event-channel");
> +  XenBusIo->XsRemove (XenBusIo, XST_NIL, "protocol");
> +  goto Error;
> +AbortTransaction:
> +  XenBusIo->XsTransactionEnd (XenBusIo, xbt, TRUE);
> +Error:
> +  XenPvBlockFree (Dev);
> +  return EFI_DEVICE_ERROR;
> +}
> +
> +VOID
> +XenPvBlockFrontShutdown (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  )
> +{
> +  XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
> +  XENSTORE_STATUS Status;
> +  UINT64 Value;
> +
> +  XenPvBlockSync (Dev);
> +
> +  Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateClosing);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR,
> +            "XenPvBlk: error while changing state to Closing: %d\n",
> +            Status));
> +    goto Close;
> +  }
> +
> +  Status = XenPvBlkWaitForBackendState (Dev, XenbusStateClosing, NULL);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR,
> +            "XenPvBlk: error while waiting for closing backend state: %d\n",
> +            Status));
> +    goto Close;
> +  }
> +
> +  Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateClosed);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR,
> +            "XenPvBlk: error while changing state to Closed: %d\n",
> +            Status));
> +    goto Close;
> +  }
> +
> +  Status = XenPvBlkWaitForBackendState (Dev, XenbusStateClosed, NULL);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR,
> +            "XenPvBlk: error while waiting for closed backend state: %d\n",
> +            Status));
> +    goto Close;
> +  }
> +
> +  Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateInitialising);
> +  if (Status != XENSTORE_STATUS_SUCCESS) {
> +    DEBUG ((EFI_D_ERROR,
> +            "XenPvBlk: error while changing state to initialising: %d\n",
> +            Status));
> +    goto Close;
> +  }
> +
> +  while (TRUE) {
> +    Status = XenBusReadUint64 (XenBusIo, "state", TRUE, &Value);
> +    if (Status != XENSTORE_STATUS_SUCCESS) {
> +      DEBUG ((EFI_D_ERROR,
> +              "XenPvBlk: error while waiting for new backend state: %d\n",
> +              Status));
> +      goto Close;
> +    }
> +    if (Value < XenbusStateInitWait || Value >= XenbusStateClosed) {
> +      break;
> +    }
> +    DEBUG ((EFI_D_INFO,
> +            "XenPvBlk: waiting backend state %d, current: %d\n",
> +            XenbusStateInitWait, Value));
> +    XenBusIo->WaitForWatch (XenBusIo, Dev->StateWatchToken);
> +  }
> +
> +Close:
> +  XenBusIo->UnregisterWatch (XenBusIo, Dev->StateWatchToken);
> +  XenBusIo->XsRemove (XenBusIo, XST_NIL, "ring-ref");
> +  XenBusIo->XsRemove (XenBusIo, XST_NIL, "event-channel");
> +  XenBusIo->XsRemove (XenBusIo, XST_NIL, "protocol");
> +
> +  XenPvBlockFree (Dev);
> +}
> +
> +STATIC
> +VOID
> +XenPvBlockWaitSlot (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  )
> +{
> +  /* Wait for a slot */
> +  if (RING_FULL (&Dev->Ring)) {
> +    while (TRUE) {
> +      XenPvBlockAsyncIoPoll (Dev);
> +      if (!RING_FULL(&Dev->Ring)) {
                       ^
                      Missing space

> +        break;
> +      }
> +      /* Really no slot, could wait for an event on Dev->EventChannel. */
> +    }
> +  }
> +}
> +
> +VOID
> +XenPvBlockAsyncIo (
> +  IN OUT XEN_BLOCK_FRONT_IO *IoData,
> +  IN     BOOLEAN            IsWrite
> +  )
> +{
> +  XEN_BLOCK_FRONT_DEVICE *Dev = IoData->Dev;
> +  XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
> +  blkif_request_t *Request;
> +  RING_IDX RingIndex;
> +  BOOLEAN Notify;
> +  INT32 NumSegments, Index;
> +  UINTN Start, End;
> +
> +  // Can't io at non-sector-aligned location
> +  ASSERT(!(IoData->Offset & (Dev->MediaInfo.SectorSize - 1)));
> +  // Can't io non-sector-sized amounts
> +  ASSERT(!(IoData->Size & (Dev->MediaInfo.SectorSize - 1)));
> +  // Can't io non-sector-aligned buffer
> +  ASSERT(!((UINTN) IoData->Buffer & (Dev->MediaInfo.SectorSize - 1)));
> +
> +  Start = (UINTN) IoData->Buffer & ~EFI_PAGE_MASK;
> +  End = ((UINTN) IoData->Buffer + IoData->Size + EFI_PAGE_SIZE - 1) & ~EFI_PAGE_MASK;
> +  IoData->NumRef = NumSegments = (End - Start) / EFI_PAGE_SIZE;
> +
> +  ASSERT (NumSegments <= BLKIF_MAX_SEGMENTS_PER_REQUEST);
> +
> +  XenPvBlockWaitSlot (Dev);
> +  RingIndex = Dev->Ring.req_prod_pvt;
> +  Request = RING_GET_REQUEST (&Dev->Ring, RingIndex);
> +
> +  Request->operation = IsWrite ? BLKIF_OP_WRITE : BLKIF_OP_READ;
> +  Request->nr_segments = NumSegments;
> +  Request->handle = Dev->DeviceId;
> +  Request->id = (UINTN) IoData;
> +  Request->sector_number = IoData->Offset / 512;

Offset? Why not just call it 'LBA' instead of Offset?

> +
> +  for (Index = 0; Index < NumSegments; Index++) {
> +    Request->seg[Index].first_sect = 0;
> +    Request->seg[Index].last_sect = EFI_PAGE_SIZE / 512 - 1;
> +  }
> +  Request->seg[0].first_sect = ((UINTN) IoData->Buffer & EFI_PAGE_MASK) / 512;
> +  Request->seg[NumSegments - 1].last_sect =
> +      (((UINTN) IoData->Buffer + IoData->Size - 1) & EFI_PAGE_MASK) / 512;
> +  for (Index = 0; Index < NumSegments; Index++) {
> +    UINTN Data = Start + Index * EFI_PAGE_SIZE;
> +    XenBusIo->GrantAccess (XenBusIo, Dev->DomainId,
> +                           Data >> EFI_PAGE_SHIFT, IsWrite,
> +                           &Request->seg[Index].gref);
> +    IoData->GrantRef[Index] = Request->seg[Index].gref;
> +  }
> +
> +  Dev->Ring.req_prod_pvt = RingIndex + 1;
> +
> +  MemoryFence ();
> +  RING_PUSH_REQUESTS_AND_CHECK_NOTIFY (&Dev->Ring, Notify);
> +
> +  if (Notify) {
> +    XenBusIo->EventChannelNotify (XenBusIo, Dev->EventChannel);
> +  }
> +}
> +
> +EFI_STATUS
> +XenPvBlockIo (
> +  IN OUT XEN_BLOCK_FRONT_IO *IoData,
> +  IN     BOOLEAN            IsWrite
> +  )
> +{
> +  //
> +  // Status value that correspond to an IO in progress.
> +  //
> +  IoData->Status = EFI_ALREADY_STARTED;
> +  XenPvBlockAsyncIo (IoData, IsWrite);
> +
> +  while (IoData->Status == EFI_ALREADY_STARTED) {
> +    XenPvBlockAsyncIoPoll (IoData->Dev);
> +  }
> +
> +  return IoData->Status;
> +}
> +
> +STATIC
> +VOID
> +XenPvBlockPushOperation (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev,
> +  IN UINT8                  Operation,
> +  IN UINT64                 Id
> +  )
> +{
> +  INT32 Index;
> +  blkif_request_t *Request;
> +  BOOLEAN Notify;
> +
> +  XenPvBlockWaitSlot (Dev);
> +  Index = Dev->Ring.req_prod_pvt;
> +  Request = RING_GET_REQUEST(&Dev->Ring, Index);
> +  Request->operation = Operation;
> +  Request->nr_segments = 0;
> +  Request->handle = Dev->DeviceId;
> +  Request->id = Id;
> +  /* Not needed anyway, but the backend will check it */
> +  Request->sector_number = 0;
> +  Dev->Ring.req_prod_pvt = Index + 1;
> +  MemoryFence ();
> +  RING_PUSH_REQUESTS_AND_CHECK_NOTIFY (&Dev->Ring, Notify);
> +  if (Notify) {
> +    XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
> +    XenBusIo->EventChannelNotify (XenBusIo, Dev->EventChannel);
> +  }
> +}
> +
> +VOID

Should you have a comment mentioning that a lock might be needed
by the caller ? So that it won't try to make this call and
also send (or read) data at the same time?

> +XenPvBlockSync (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  )
> +{
> +  if (Dev->MediaInfo.ReadWrite) {
> +    if (Dev->MediaInfo.FeatureBarrier) {
> +      XenPvBlockPushOperation (Dev, BLKIF_OP_WRITE_BARRIER, 0);
> +    }
> +
> +    if (Dev->MediaInfo.FeatureFlushCache) {
> +      XenPvBlockPushOperation (Dev, BLKIF_OP_FLUSH_DISKCACHE, 0);
> +    }
> +  }
> +
> +  /* Note: This won't finish if another thread enqueues requests.  */
> +  while (TRUE) {
> +    XenPvBlockAsyncIoPoll (Dev);
> +    if (RING_FREE_REQUESTS (&Dev->Ring) == RING_SIZE (&Dev->Ring)) {
> +      break;
> +    }
> +  }
> +}
> +
> +VOID
> +XenPvBlockAsyncIoPoll (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  )
> +{
> +  RING_IDX ProducerIndex, ConsumerIndex;
> +  blkif_response_t *Response;
> +  INT32 More;
> +
> +  do {
> +    ProducerIndex = Dev->Ring.sring->rsp_prod;
> +    /* Ensure we see queued responses up to 'ProducerIndex'. */
> +    MemoryFence ();
> +    ConsumerIndex = Dev->Ring.rsp_cons;
> +
> +    while (ConsumerIndex != ProducerIndex) {
> +      XEN_BLOCK_FRONT_IO *IoData = NULL;
> +      INT16 Status;
> +
> +      Response = RING_GET_RESPONSE (&Dev->Ring, ConsumerIndex);
> +
> +      IoData = (VOID *) (UINTN) Response->id;
> +      Status = Response->status;
> +
> +      switch (Response->operation) {
> +      case BLKIF_OP_READ:
> +      case BLKIF_OP_WRITE:
> +        {
> +          INT32 Index;
> +
> +          if (Status != BLKIF_RSP_OKAY) {
> +            DEBUG ((EFI_D_ERROR,
> +                    "XenPvBlk: "
> +                    "%a error %d on %a at offset %p, num bytes %p\n",
> +                    Response->operation == BLKIF_OP_READ ? "read" : "write",
> +                    Status, IoData->Dev->NodeName,
> +                    IoData->Offset,
> +                    IoData->Size));
> +          }
> +
> +          for (Index = 0; Index < IoData->NumRef; Index++) {
> +            Dev->XenBusIo->GrantEndAccess (Dev->XenBusIo, IoData->GrantRef[Index]);
> +          }
> +
> +          break;
> +        }
> +
> +      case BLKIF_OP_WRITE_BARRIER:
> +        if (Status != BLKIF_RSP_OKAY) {
> +          DEBUG ((EFI_D_ERROR, "XenPvBlk: write barrier error %d\n", Status));
> +        }
> +        break;
> +      case BLKIF_OP_FLUSH_DISKCACHE:
> +        if (Status != BLKIF_RSP_OKAY) {
> +          DEBUG ((EFI_D_ERROR, "XenPvBlk: flush error %d\n", Status));
> +        }
> +        break;
> +
> +      default:
> +        DEBUG ((EFI_D_ERROR,
> +                "XenPvBlk: unrecognized block operation %d response (status %d)\n",
> +                Response->operation, Status));
> +        break;
> +      }
> +
> +      Dev->Ring.rsp_cons = ++ConsumerIndex;
> +      if (IoData != NULL) {
> +        IoData->Status = Status ? EFI_DEVICE_ERROR : EFI_SUCCESS;
> +      }
> +      if (Dev->Ring.rsp_cons != ConsumerIndex) {
> +        /* We reentered, we must not continue here */
> +        break;
> +      }
> +    }
> +
> +    RING_FINAL_CHECK_FOR_RESPONSES (&Dev->Ring, More);
> +  } while (More != 0);
> +}
> diff --git a/OvmfPkg/XenPvBlkDxe/BlockFront.h b/OvmfPkg/XenPvBlkDxe/BlockFront.h
> new file mode 100644
> index 0000000..fb60dbd
> --- /dev/null
> +++ b/OvmfPkg/XenPvBlkDxe/BlockFront.h
> @@ -0,0 +1,87 @@
> +#include "XenPvBlkDxe.h"
> +
> +#include <IndustryStandard/Xen/event_channel.h>
> +#include <IndustryStandard/Xen/io/blkif.h>
> +
> +typedef struct _XEN_BLOCK_FRONT_DEVICE XEN_BLOCK_FRONT_DEVICE;
> +typedef struct _XEN_BLOCK_FRONT_IO XEN_BLOCK_FRONT_IO;
> +
> +struct _XEN_BLOCK_FRONT_IO
> +{
> +  XEN_BLOCK_FRONT_DEVICE  *Dev;
> +  UINT8                   *Buffer;
> +  UINTN                   Size;
> +  UINTN                   Offset;
> +
> +  grant_ref_t             GrantRef[BLKIF_MAX_SEGMENTS_PER_REQUEST];
> +  INT32                   NumRef;
> +
> +  EFI_STATUS              Status;
> +};
> +
> +typedef struct
> +{
> +  UINT64    Sectors;
> +  UINT32    SectorSize;
> +  UINT32    VDiskInfo;
> +  BOOLEAN   ReadWrite;
> +  BOOLEAN   CdRom;
> +  BOOLEAN   FeatureBarrier;
> +  BOOLEAN   FeatureFlushCache;
> +} XEN_BLOCK_FRONT_MEDIA_INFO;
> +
> +#define XEN_BLOCK_FRONT_SIGNATURE SIGNATURE_32 ('X', 'p', 'v', 'B')
> +struct _XEN_BLOCK_FRONT_DEVICE {
> +  UINT32                      Signature;
> +  EFI_BLOCK_IO_PROTOCOL       BlockIo;
> +  domid_t                     DomainId;
> +
> +  blkif_front_ring_t          Ring;
> +  grant_ref_t                 RingRef;
> +  evtchn_port_t               EventChannel;
> +  blkif_vdev_t                DeviceId;
> +
> +  CONST CHAR8                 *NodeName;
> +  XEN_BLOCK_FRONT_MEDIA_INFO  MediaInfo;
> +
> +  VOID                        *StateWatchToken;
> +
> +  XENBUS_PROTOCOL             *XenBusIo;
> +};
> +
> +#define XEN_BLOCK_FRONT_FROM_BLOCK_IO(b) \
> +  CR (b, XEN_BLOCK_FRONT_DEVICE, BlockIo, XEN_BLOCK_FRONT_SIGNATURE)
> +
> +EFI_STATUS
> +XenPvBlockFrontInitialization (
> +  IN  XENBUS_PROTOCOL  *XenBusIo,
> +  IN  CONST CHAR8      *NodeName,
> +  OUT XEN_BLOCK_FRONT_DEVICE **DevPtr
> +  );
> +
> +VOID
> +XenPvBlockFrontShutdown (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  );
> +
> +VOID
> +XenPvBlockAsyncIo (
> +  IN OUT XEN_BLOCK_FRONT_IO *IoData,
> +  IN     BOOLEAN            IsWrite
> +  );
> +
> +EFI_STATUS
> +XenPvBlockIo (
> +  IN OUT XEN_BLOCK_FRONT_IO *IoData,
> +  IN     BOOLEAN            IsWrite
> +  );
> +
> +VOID
> +XenPvBlockAsyncIoPoll (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  );
> +
> +VOID
> +XenPvBlockSync (
> +  IN XEN_BLOCK_FRONT_DEVICE *Dev
> +  );
> diff --git a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
> index 00a8a2c..930333f 100644
> --- a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
> +++ b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
> @@ -36,6 +36,8 @@
>  
>  #include "XenPvBlkDxe.h"
>  
> +#include "BlockFront.h"
> +
>  
>  ///
>  /// Driver Binding Protocol instance
> @@ -278,6 +280,7 @@ XenPvBlkDxeDriverBindingStart (
>  {
>    EFI_STATUS Status;
>    XENBUS_PROTOCOL *XenBusIo;
> +  XEN_BLOCK_FRONT_DEVICE *Dev;
>  
>    Status = gBS->OpenProtocol (
>                  ControllerHandle,
> @@ -291,7 +294,17 @@ XenPvBlkDxeDriverBindingStart (
>      return Status;
>    }
>  
> +  Status = XenPvBlockFrontInitialization (XenBusIo, XenBusIo->Node, &Dev);
> +  if (EFI_ERROR (Status)) {
> +    goto CloseProtocol;
> +  }
> +
>    return EFI_SUCCESS;
> +
> +CloseProtocol:
> +  gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,
> +                      This->DriverBindingHandle, ControllerHandle);
> +  return Status;
>  }
>  
>  /**
> diff --git a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
> index aaa809f..619ed8f 100644
> --- a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
> +++ b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
> @@ -50,6 +50,8 @@
>    XenPvBlkDxe.c
>    ComponentName.c
>    ComponentName.h
> +  BlockFront.c
> +  BlockFront.h
>  
>  
>  [LibraryClasses]
> -- 
> Anthony PERARD
> 
> 
> _______________________________________________
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> Xen-devel@lists.xen.org
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