Re: [Qemu-devel] X86 CPU topology broken in qemu ?

[Bharata B Rao]

On Wed, Aug 17, 2011 at 10:55 AM, Bharata B Rao <address@hidden> wrote:
> Hi,
>
> I see that x86 CPU topology inside VM is not showing up as specified.
> With some debugging, I found out that the root cause for this: qemu is
> not enumerating the apic ids correctly for vcpus. I made the below
> hackish change to get it working.  Has anybody else seen this problem
> ?  This patch is on qemu-kvm-0.14.1. Using 2.6.39 for guest.
>
> ***************************
> Fix apic id enumeration
>
> apic id returned to guest kernel in ebx for cpuid(function=1) depends on
> CPUX86State->cpuid_apic_id which gets populated after the cpuid information
> is cached in the host kernel.
>
> Fix this by setting cpuid_apic_id before cpuid information is passed to
> the host kernel.

Going by the lack of response I assume not many people are using - smp
option with sockets, cores and threads specified explicitly ?

Or is it that I hit a corner case and not using the -smp option
correctly enough ?

Regards,
Bharata.