Re: [PATCH v3 09/23] OvmfPkg/VirtioLib: add function to map VRING

[Laszlo Ersek <lersek@redhat.com>]

There's one trivial omission in this patch, wrt. the previous review
comments:

On 08/23/17 14:22, Brijesh Singh wrote:
> Add functions to map the ring buffer with BusMasterCommonBuffer so that

(1) s/functions/a function/

I'll fix it up before I push the initial subsequence.

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

Thanks!
Laszlo

> ring can be accessed by both guest and hypervisor.
> 
> 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/Include/Library/VirtioLib.h   | 26 +++++++++++
>  OvmfPkg/Library/VirtioLib/VirtioLib.c | 45 ++++++++++++++++++++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/OvmfPkg/Include/Library/VirtioLib.h b/OvmfPkg/Include/Library/VirtioLib.h
> index 40c51a2b3305..3d9314b3acaf 100644
> --- a/OvmfPkg/Include/Library/VirtioLib.h
> +++ b/OvmfPkg/Include/Library/VirtioLib.h
> @@ -62,6 +62,32 @@ VirtioRingInit (
>  
>  /**
>  
> +  Map the ring buffer so that it can be accessed equally by both guest
> +  and hypervisor.
> +
> +  @param[in]      VirtIo          The virtio device instance.
> +
> +  @param[in]      Ring            The virtio ring to map.
> +
> +  @param[out]     RingBaseShift   A resulting translation offset, to be
> +                                  passed to VirtIo->SetQueueAddress().
> +
> +  @param[out]     Mapping         A resulting token to pass to
> +                                  VirtIo->UnmapSharedBuffer().
> +
> +  @return         Status code from VirtIo->MapSharedBuffer()
> +**/
> +EFI_STATUS
> +EFIAPI
> +VirtioRingMap (
> +  IN  VIRTIO_DEVICE_PROTOCOL *VirtIo,
> +  IN  VRING                  *Ring,
> +  OUT UINT64                 *RingBaseShift,
> +  OUT VOID                   **Mapping
> +  );
> +
> +/**
> +
>    Tear down the internal resources of a configured virtio ring.
>  
>    The caller is responsible to stop the host from using this ring before
> diff --git a/OvmfPkg/Library/VirtioLib/VirtioLib.c b/OvmfPkg/Library/VirtioLib/VirtioLib.c
> index 8bc5b9aea4fc..535635ac0ba8 100644
> --- a/OvmfPkg/Library/VirtioLib/VirtioLib.c
> +++ b/OvmfPkg/Library/VirtioLib/VirtioLib.c
> @@ -505,3 +505,48 @@ Failed:
>    VirtIo->UnmapSharedBuffer (VirtIo, MapInfo);
>    return EFI_OUT_OF_RESOURCES;
>  }
> +
> +/**
> +
> +  Map the ring buffer so that it can be accessed equally by both guest
> +  and hypervisor.
> +
> +  @param[in]      VirtIo          The virtio device instance.
> +
> +  @param[in]      Ring            The virtio ring to map.
> +
> +  @param[out]     RingBaseShift   A resulting translation offset, to be
> +                                  passed to VirtIo->SetQueueAddress().
> +
> +  @param[out]     Mapping         A resulting token to pass to
> +                                  VirtIo->UnmapSharedBuffer().
> +
> +  @return         Status code from VirtIo->MapSharedBuffer()
> +**/
> +EFI_STATUS
> +EFIAPI
> +VirtioRingMap (
> +  IN  VIRTIO_DEVICE_PROTOCOL *VirtIo,
> +  IN  VRING                  *Ring,
> +  OUT UINT64                 *RingBaseShift,
> +  OUT VOID                   **Mapping
> +  )
> +{
> +  EFI_STATUS            Status;
> +  EFI_PHYSICAL_ADDRESS  DeviceAddress;
> +
> +  Status = VirtioMapAllBytesInSharedBuffer (
> +             VirtIo,
> +             VirtioOperationBusMasterCommonBuffer,
> +             Ring->Base,
> +             EFI_PAGES_TO_SIZE (Ring->NumPages),
> +             &DeviceAddress,
> +             Mapping
> +             );
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
> +  *RingBaseShift = DeviceAddress - (UINT64)(UINTN)Ring->Base;
> +  return EFI_SUCCESS;
> +}
>