On Wed, Feb 16, 2022 at 6:48 PM Alexandru Elisei
<alexandru.elisei@xxxxxxx> wrote:
>
> Hi,
>
> Would you mind rewording the commit subject to:
>
> x86: Set the correct APIC ID
>
> On Wed, Feb 16, 2022 at 12:38:34PM +0800, Muchun Song wrote:
> > When I boot kernel, the dmesg will print the following message:
> ^^^^^^^^^^^^^^^^^^
>
> Would you mind replacing that with "When kvmtool boots a kernel, [..]"?
Will do.
>
> >
> > [Firmware Bug]: CPU1: APIC id mismatch. Firmware: 1 APIC: 30
> >
> > Fix this by setting up correct initial_apicid to cpu_id.
>
> Thank you for fixing this. I've always wanted to fix that error, but I didn't
> know enough about the x86 architecture.
>
> >
> > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> > ---
> > x86/cpuid.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/x86/cpuid.c b/x86/cpuid.c
> > index c3b67d9..aa213d5 100644
> > --- a/x86/cpuid.c
> > +++ b/x86/cpuid.c
> > @@ -8,7 +8,7 @@
> >
> > #define MAX_KVM_CPUID_ENTRIES 100
> >
> > -static void filter_cpuid(struct kvm_cpuid2 *kvm_cpuid)
> > +static void filter_cpuid(struct kvm_cpuid2 *kvm_cpuid, int cpu_id)
> > {
> > unsigned int signature[3];
> > unsigned int i;
> > @@ -28,6 +28,8 @@ static void filter_cpuid(struct kvm_cpuid2 *kvm_cpuid)
> > entry->edx = signature[2];
> > break;
> > case 1:
> > + entry->ebx &= ~(0xff << 24);
> > + entry->ebx |= cpu_id << 24;
> > /* Set X86_FEATURE_HYPERVISOR */
> > if (entry->index == 0)
> > entry->ecx |= (1 << 31);
> > @@ -80,7 +82,7 @@ void kvm_cpu__setup_cpuid(struct kvm_cpu *vcpu)
> > if (ioctl(vcpu->kvm->sys_fd, KVM_GET_SUPPORTED_CPUID, kvm_cpuid) < 0)
> > die_perror("KVM_GET_SUPPORTED_CPUID failed");
> >
> > - filter_cpuid(kvm_cpuid);
> > + filter_cpuid(kvm_cpuid, vcpu->cpu_id);
>
> Tested it and it works:
>
> Tested-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
>
Thanks.
