[PATCH v2 6/7] MdeModulePkg/UefiBootManagerLib: describe VirtIO devices correctly

["David Woodhouse" <dwmw2@infradead.org>]

I know, I said it was Someone Else's Problem. But it annoyed me.

My initial thought was to look for VIRTIO_DEVICE_PROTOCOL on the same
handle but I don't think I can do that if I can't rely on VirtIO being
present in the build. This will do.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
 .../UefiBootManagerLib/BmBootDescription.c    | 34 +++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c b/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
index 06edba8b4d..95adb9a7d3 100644
--- a/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
+++ b/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
@@ -661,6 +661,8 @@ BmGetMiscDescription (
   CHAR16                          *Description;
   EFI_BLOCK_IO_PROTOCOL           *BlockIo;
   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Fs;
+  EFI_PCI_IO_PROTOCOL             *PciIo;
+  PCI_TYPE00                      Pci;
 
   switch (BmDevicePathType (DevicePathFromHandle (Handle))) {
   case BmAcpiFloppyBoot:
@@ -698,9 +700,37 @@ BmGetMiscDescription (
     Status = gBS->HandleProtocol (Handle, &gEfiSimpleFileSystemProtocolGuid, (VOID **) &Fs);
     if (!EFI_ERROR (Status)) {
       Description = L"Non-Block Boot Device";
-    } else {
-      Description = L"Misc Device";
+      break;
+    }
+    Status = gBS->HandleProtocol (Handle, &gEfiPciIoProtocolGuid, (VOID **) &PciIo);
+    if (!EFI_ERROR (Status)) {
+      Status = PciIo->Pci.Read (
+                            PciIo,                        // (protocol, device)
+                                                          // handle
+                            EfiPciIoWidthUint32,          // access width & copy
+                                                          // mode
+                            0,                            // Offset
+                            sizeof Pci / sizeof (UINT32), // Count
+                            &Pci                          // target buffer
+                            );
+      //
+      // If the same node is a Qumranet/Red Hat PCI device, it's VirtIO.
+      //
+      if (!EFI_ERROR (Status) && (Pci.Hdr.VendorId == 0x1AF4))
+        //
+        // Separate checks for legacy/transitional VirtIO vs. Virtio 1.0+
+        //
+        if (((Pci.Hdr.DeviceId >= 0x1000) && (Pci.Hdr.DeviceId <= 0x103F) &&
+             (Pci.Hdr.RevisionID == 0x00)) ||
+            (Pci.Hdr.DeviceId >= 0x1040 && Pci.Hdr.DeviceId <= 0x107F &&
+             Pci.Hdr.RevisionID >= 0x01 && Pci.Device.SubsystemID >= 0x40 &&
+             (Pci.Hdr.Status & EFI_PCI_STATUS_CAPABILITY) != 0)) {
+        Description = L"VirtIO Device";
+        break;
+      }
     }
+
+    Description = L"Misc Device";
     break;
   }
 
-- 
2.21.0