Re: [PATCH] OvmfPkg/QemuBootOrderLib: drop too strict "/HD(" suffix from vblk prefix

[Jordan Justen <jordan.l.justen@intel.com>]

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

On 2016-09-07 04:42:43, Laszlo Ersek wrote:
> Translating QEMU's virtio-block OpenFirmware device path to a UEFI device
> path prefix was one of the earliest case handled in QemuBootOrderLib. At
> that time, I terminated the translation output (the UEFI devpath prefix)
> with a "/HD(" suffix.
> 
> The intent was for the translation to prefix-match only boot options with
> HD() device path nodes in them, that is, no auto-generated "device level"
> boot options. This was motivated by prioritizing specific boot options
> created by OS installers over auto-generated "device level" options.
> 
> However, practice has shown that:
> 
> - OS installers place their installed boot options first in the boot order
>   anyway,
> 
> - other device types (SATA disks, virtio-scsi disks), where "/HD(" is not
>   appended, work just fine,
> 
> - requiring "/HD(" actually causes problems: after the OS-installed
>   specific boot option has been lost (or purposely removed), the
>   auto-generated "device level" boot option does the right thing (see the
>   Default Boot Behavior under
>   <http://blog.uncooperative.org/blog/2014/02/06/the-efi-system-partition/>).
>   The "/HD(" requirement causes such boot options to be dropped, which
>   prevents "fallback.efi" from running.
> 
> Relax the matching by removing the "/HD(" suffix from the translated
> prefix.
> 
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Fixes: e06a4cd134064590aa1a855ff4b973023279e805
> Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1373812
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
> 
> Notes:
>     Public branch:
>     <https://github.com/lersek/edk2/commits/drop_hdprefix_vblk_v1>
> 
>  OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
> index 86082301a8f5..8cbbdb0568fa 100644
> --- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
> +++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
> @@ -864,29 +864,29 @@ TranslatePciOfwNodes (
>      // OpenFirmware device path (virtio-blk disk):
>      //
>      //   /pci@i0cf8/scsi@6[,3]/disk@0,0
>      //        ^          ^  ^       ^ ^
>      //        |          |  |       fixed
>      //        |          |  PCI function corresponding to disk (optional)
>      //        |          PCI slot holding disk
>      //        PCI root at system bus port, PIO
>      //
>      // UEFI device path prefix:
>      //
> -    //   PciRoot(0x0)/Pci(0x6,0x0)/HD( -- if PCI function is 0 or absent
> -    //   PciRoot(0x0)/Pci(0x6,0x3)/HD( -- if PCI function is present and nonzero
> +    //   PciRoot(0x0)/Pci(0x6,0x0) -- if PCI function is 0 or absent
> +    //   PciRoot(0x0)/Pci(0x6,0x3) -- if PCI function is present and nonzero
>      //
>      Written = UnicodeSPrintAsciiFormat (
>        Translated,
>        *TranslatedSize * sizeof (*Translated), // BufferSize in bytes
> -      "PciRoot(0x%x)%s/Pci(0x%Lx,0x%Lx)/HD(",
> +      "PciRoot(0x%x)%s/Pci(0x%Lx,0x%Lx)",
>        PciRoot,
>        Bridges,
>        PciDevFun[0],
>        PciDevFun[1]
>        );
>    } else if (NumNodes >= FirstNonBridge + 3 &&
>               SubstringEq (OfwNode[FirstNonBridge + 0].DriverName, "scsi") &&
>               SubstringEq (OfwNode[FirstNonBridge + 1].DriverName, "channel") &&
>               SubstringEq (OfwNode[FirstNonBridge + 2].DriverName, "disk")
>               ) {
>      //
> @@ -1109,28 +1109,28 @@ TranslateMmioOfwNodes (
>        SubstringEq (OfwNode[1].DriverName, "disk")) {
>      //
>      // OpenFirmware device path (virtio-blk disk):
>      //
>      //   /virtio-mmio@000000000a003c00/disk@0,0
>      //                ^                     ^ ^
>      //                |                     fixed
>      //                base address of virtio-mmio register block
>      //
>      // UEFI device path prefix:
>      //
> -    //   <VenHwString>/HD(
> +    //   <VenHwString>
>      //
>      Written = UnicodeSPrintAsciiFormat (
>                  Translated,
>                  *TranslatedSize * sizeof (*Translated), // BufferSize in bytes
> -                "%s/HD(",
> +                "%s",
>                  VenHwString
>                  );
>    } else if (NumNodes >= 3 &&
>               SubstringEq (OfwNode[1].DriverName, "channel") &&
>               SubstringEq (OfwNode[2].DriverName, "disk")) {
>      //
>      // OpenFirmware device path (virtio-scsi disk):
>      //
>      //   /virtio-mmio@000000000a003a00/channel@0/disk@2,3
>      //                ^                        ^      ^ ^
>      //                |                        |      | LUN
> -- 
> 2.9.2
>