[edk2-devel] [PATCH 6/7] MdeModulePkg/UefiBootManagerLib: describe VirtIO devices correctly
Laszlo Ersek
lersek at redhat.com
Mon Jun 24 23:16:24 UTC 2019
On 06/22/19 00:31, David Woodhouse wrote:
> 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 at infradead.org>
> ---
> .../UefiBootManagerLib/BmBootDescription.c | 30 +++++++++++++++++--
> 1 file changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c b/MdeModulePkg/Library/UefiBootManagerLib/BmBootDescription.c
> index dd4d160f31..b7d9e98790 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 +700,33 @@ 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
> + );
(1) Can we save some cycles by reading just
PCI_DEVICE_INDEPENDENT_REGION, rather than PCI_TYPE00? It would not
complicate the code either.
> + //
> + // If the same node is a Qumranet/Red Hat PCI device, it's VirtIO.
> + //
> + if (!EFI_ERROR (Status) &&
> + (Pci.Hdr.VendorId == 0x1AF4) &&
> + (Pci.Hdr.DeviceId >= 0x1000) &&
> + (Pci.Hdr.DeviceId <= 0x103F) &&
> + (Pci.Hdr.RevisionID == 0x00)) {
(2) This will match legacy and transitional virtio devices, but not
modern-only virtio devices. (SeaBIOS supports modern-only devices too.)
Please see the check for the latter in Virtio10BindingSupported().
(Admittedly, "Pci.Device.SubsystemID" cannot be determined from
PCI_DEVICE_INDEPENDENT_REGION...)
In general I think this approach is viable; at the worst we might have
to gate the code with a Feature PCD. Let's see what Ray says.
Thanks
Laszlo
> + Description = L"VirtIO Device";
> + break;
> + }
> }
> +
> + Description = L"Misc Device";
> break;
> }
>
>
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#42766): https://edk2.groups.io/g/devel/message/42766
Mute This Topic: https://groups.io/mt/32163533/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-
More information about the edk2-devel-archive
mailing list