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)." > 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); >
