On Thu, Jul 30, 2020 at 06:11:17PM +0200, Philippe Mathieu-Daudé wrote: > On 7/30/20 5:58 PM, Michael S. Tsirkin wrote: > > macOS uses ACPI UIDs to build the DevicePath for NVRAM boot options, > > while OVMF firmware gets them via an internal channel through QEMU. > > Due to a bug in QEMU ACPI currently UEFI firmware and ACPI have > > different values, and this makes the underlying operating system > > unable to report its boot option. > > > > The particular node in question is the primary PciRoot (PCI0 in ACPI), > > which for some reason gets assigned 1 in ACPI UID and 0 in the > > DevicePath. This is due to the _UID assigned to it by build_dsdt in > > hw/i386/acpi-build.c Which does not correspond to the primary PCI > > identifier given by pcibus_num in hw/pci/pci.c > > > > Reference with the device paths, OVMF startup logs, and ACPI table > > dumps (SysReport): > > https://github.com/acidanthera/bugtracker/issues/1050 > > > > In UEFI v2.8, section "10.4.2 Rules with ACPI _HID and _UID" ends with > > the paragraph, > > > > Root PCI bridges will use the plug and play ID of PNP0A03, This will > > be stored in the ACPI Device Path _HID field, or in the Expanded > > ACPI Device Path _CID field to match the ACPI name space. The _UID > > in the ACPI Device Path structure must match the _UID in the ACPI > > name space. > > > > (See especially the last sentence.) > > > > Considering *extra* root bridges / root buses (with bus number > 0), > > QEMU's ACPI generator actually does the right thing; since QEMU commit > > c96d9286a6d7 ("i386/acpi-build: more traditional _UID and _HID for PXB > > root buses", 2015-06-11). > > > > However, the _UID values for root bridge zero (on both i440fx and q35) > > have always been "wrong" (from UEFI perspective), going back in QEMU to > > commit 74523b850189 ("i386: add ACPI table files from seabios", > > 2013-10-14). > > > > Even in SeaBIOS, these _UID values have always been 1; see commit > > a4d357638c57 ("Port rombios32 code from bochs-bios.", 2008-03-08) for > > i440fx, and commit ecbe3fd61511 ("seabios: q35: add dsdt", 2012-12-01) > > for q35. > > > > Suggested-by: Laszlo Ersek <ler...@redhat.com> > > Tested-by: vit9696 <vit9...@protonmail.com> > > Vitaly uses his full name on EDK2 mailing list, so I don't think he'll > have a problem to use it in QEMU too: > Tested-by: Vitaly Cheptsov <vit9...@protonmail.com> > > From: > https://wiki.qemu.org/Contribute/SubmitAPatch#Patch_emails_must_include_a_Signed-off-by:_line > "Please use your real name to sign a patch (not an alias or acronym)."
Right. Tested-by is different though, I don't think we have a problem with anonymous testing. Anyway, updated. > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > > --- > > hw/i386/acpi-build.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > > index b7bcbbbb2a..7a5a8b3521 100644 > > --- a/hw/i386/acpi-build.c > > +++ b/hw/i386/acpi-build.c > > @@ -1497,7 +1497,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, > > dev = aml_device("PCI0"); > > aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03"))); > > aml_append(dev, aml_name_decl("_ADR", aml_int(0))); > > - aml_append(dev, aml_name_decl("_UID", aml_int(1))); > > + aml_append(dev, aml_name_decl("_UID", aml_int(0))); > > aml_append(sb_scope, dev); > > aml_append(dsdt, sb_scope); > > > > @@ -1512,7 +1512,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, > > aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08"))); > > aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03"))); > > aml_append(dev, aml_name_decl("_ADR", aml_int(0))); > > - aml_append(dev, aml_name_decl("_UID", aml_int(1))); > > + aml_append(dev, aml_name_decl("_UID", aml_int(0))); > > aml_append(dev, build_q35_osc_method()); > > aml_append(sb_scope, dev); > > aml_append(dsdt, sb_scope); > >