On 21/06/19 23:37, Liran Alon wrote:
> However, during discussion made after merge, it was realised that since QEMU
> commit
> 75d373ef9729 ("target-i386: Disable SVM by default in KVM mode"), an AMD vCPU
> that
> is virtualized by KVM doesn't expose SVM by default, even if you use "-cpu
> host".
> Therefore, it is unlikely that vCPU expose SVM CPUID flag when user is not
> running
> an SVM workload inside guest.
libvirt has "host-model" mode, which constructs a "-cpu
model,+feature,+feature" command line option that matches the host as
good as possible. This lets libvirt check migratability while retaining
a lot of the benefits of "-cpu host", and is the default for OpenStack
for example. I need to check if libvirt adds SVM to this configuration,
if it does the QEMU commit you mention is unfortunately not enough.
Paolo
