[libvirt] [PATCH v2 0/7] qemu: support disabling/enabling kvmclock with <timer> elements
Jiri Denemark
jdenemar at redhat.com
Fri Jan 27 16:02:00 UTC 2012
On Fri, Jan 27, 2012 at 14:49:45 +0100, Paolo Bonzini wrote:
> QEMU supports a bunch of CPUID features that are tied to the kvm CPUID
> nodes rather than the processor's. They are "kvmclock", "kvm_nopiodelay",
> "kvm_mmu", "kvm_asyncpf". These are not known to libvirt and their
> CPUID leaf might move if (for example) the Hyper-V extensions are enabled.
> Hence their handling would anyway require some special-casing.
>
> However, among these the most useful is kvmclock; an additional
> "property" of this feature is that a <timer> element is a better model
> than a CPUID feature.
>
> This is what this series does.
>
> Actually, while working on this I noticed that it is quite difficult
> to have round-trip testcases involving -cpu, that can be used with
> both qemuargv2xmltest and qemuxml2argvtest. This is what the first
> five four patches do. The first patch is unrelated. The second patch
> updates the CPU feature map with default CPUs, and is a prerequisite
> for patch 3. That one makes the -cpu parsing code detect the "lm"
> CPU feature, so that the guest arch is correctly set to either
> i686 or x86_64.
>
> The fifth patch is also mostly needed for testing. It notices the
> default models qemu32/qemu64 and does not generate <cpu> elements;
> this happens with "-cpu qemu32,-kvmclock" for example. Then, the
> last two patches actually add the new feature.
>
> Paolo Bonzini (7):
> qemu: parse -enable-kvm
> x86: add kvm32 and kvm64, update qemu64
Two cputests needed to be updated a bit after this 2/7 patch so I squashed
them in, updated the 7/7 commit message as I suggested in the review and
pushed the series.
Jirka
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