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authorBrijesh Singh <brijesh.singh@amd.com>2017-08-23 06:57:18 -0400
committerLaszlo Ersek <lersek@redhat.com>2017-08-25 10:42:19 +0200
commitfef6becb55355c2f6cf0a99f6e7e564d3165ee49 (patch)
tree4a053f610e193a3b93976cf1240b266a6e9b6329 /OvmfPkg/Library/VirtioLib
parent60ee56295fb672bf5a324d4016582c88facb2ecf (diff)
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OvmfPkg/VirtioLib: add function to map VRING
Add a function to map the ring buffer with BusMasterCommonBuffer so that 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> [lersek@redhat.com: fix typo in commit message] Reviewed-by: Laszlo Ersek <lersek@redhat.com> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'OvmfPkg/Library/VirtioLib')
-rw-r--r--OvmfPkg/Library/VirtioLib/VirtioLib.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/OvmfPkg/Library/VirtioLib/VirtioLib.c b/OvmfPkg/Library/VirtioLib/VirtioLib.c
index 78405c7..84acfe6 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;
+}