On Wed, Mar 07, 2012 at 09:54:28PM +0800, developer wang wrote:
> Hi,
>
> I want to use qemu (version 1.0) to emulate guest systems with x2APIC
> enabled.
>
> But when I use qemu to emulate CPU's feture "x2APIC", I didn't find
> it in /proc/cpuinfo.
>
x2apic is supported only if kvm is used and only with in kernel irqchip
emulation (which is still not default in qemu upstream IIRC). Try with
qemu-kvm.
> And I saw the source code of qemu.
>
> I only find a single define (#define CPUID_EXE_X2APIC (1<<21) )
>
> but no other places use this this define.
>
> Does this mean qemu now doesn't support to emulate the CPU's feture
> of "x2APIC"?
>
>
>
> Our host machine is running Debian 6, and the host system has x2APIC
> support.
>
> I use the following command to run qemu:
>
> qemu-system-x86_64 -nographic -cpu qemu64,+x2apic -serial
> mon:/dev/tty -hda ~/debian6.qcow2
>
> After the guest (also Debian 6) boots up, I can't see x2apic in /proc/cpuinfo.
>
> Our host machine's CPU features:
>
> model name : Intel(R) Xeon(R) CPU E7- 4850 @ 2.00GHz
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
> pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
> syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts
> rep_good nopl xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64
> monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2
> x2apic popcnt aes lahf_lm ida arat dts tpr_shadow vnmi flexpriority
> ept vpid
>
> The CPU feature from the guest emulated by QEMU:
>
> model name : QEMU Virtual CPU version 1.0,1
> flags : fpu pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx lm up pni cx16
> popcnt hypervisor lahf_lm svm abm sse4a
--
Gleb.
