On 10/23/2015 03:08 PM, Igor Mammedov wrote: > On Thu, 22 Oct 2015 22:03:24 +0200 > Matthias Lange <matthias.la...@kernkonzept.com> wrote: > >> This patch appends "ACPI0007" as the HID to each processor object. >> >> Until commit 20843d processor objects used to have a _HID. According >> to the ACPI spec this is not required but removing it breaks systems > Pls answer Michael's question about motivation of this patch. > i.e. what guests it exactly breaks?
It broke the L4Re OS (specifically the mechanism to match ACPI drivers to ACPI devices). However, you can ignore this patch. I decided to change L4Re instead. Best, Matthias. >> which relied on the HID. As it does no harm it is safe to add _HID >> to processor objects and restore the old behaviour. >> >> Signed-off-by: Matthias Lange <matthias.la...@kernkonzept.com> >> --- >> hw/i386/acpi-build.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c >> index 95e0c65..314cd0b 100644 >> --- a/hw/i386/acpi-build.c >> +++ b/hw/i386/acpi-build.c >> @@ -1153,6 +1153,9 @@ build_ssdt(GArray *table_data, GArray *linker, >> for (i = 0; i < acpi_cpus; i++) { >> dev = aml_processor(i, 0, 0, "CP%.02X", i); >> >> + /* for processor objects a _HID is not strictly required, >> however it >> + * does no harm and preserves compatibility with other BIOSes */ >> + aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007"))); > Spec doesn't tell anything about using ACPI0007 with Processor statement, > it's only mentioned in context of Device statement. > >> method = aml_method("_MAT", 0); >> aml_append(method, aml_return(aml_call1("CPMA", aml_int(i)))); >> aml_append(dev, method);