Re: [PATCH] hw/i386/acpi: Set PCAT_COMPAT bit only when pic is not disabled

[Michael S. Tsirkin]

On Tue, Apr 02, 2024 at 04:25:16AM -0400, Xiaoyao Li wrote:
> Set MADT.FLAGS[bit 0].PCAT_COMPAT based on x86ms->pic.
> 
> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>

Please include more info in the commit log:
what is the behaviour you observe, why it is wrong,
how does the patch fix it, what is guest behaviour
before and after.

The commit log and the subject should not repeat
what the diff already states.

> ---
>  hw/i386/acpi-common.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/acpi-common.c b/hw/i386/acpi-common.c
> index 20f19269da40..0cc2919bb851 100644
> --- a/hw/i386/acpi-common.c
> +++ b/hw/i386/acpi-common.c
> @@ -107,7 +107,9 @@ void acpi_build_madt(GArray *table_data, BIOSLinker 
> *linker,
>      acpi_table_begin(&table, table_data);
>      /* Local APIC Address */
>      build_append_int_noprefix(table_data, APIC_DEFAULT_ADDRESS, 4);
> -    build_append_int_noprefix(table_data, 1 /* PCAT_COMPAT */, 4); /* Flags 
> */
> +    /* Flags. bit 0: PCAT_COMPAT */
> +    build_append_int_noprefix(table_data,
> +                              x86ms->pic != ON_OFF_AUTO_OFF ? 1 : 0 , 4);
>  
>      for (i = 0; i < apic_ids->len; i++) {
>          pc_madt_cpu_entry(i, apic_ids, table_data, false);
> -- 
> 2.34.1