Re: [libvirt] [PATCH 2/5] Introduce SMM feature
On 01.08.2016 21:10, Laszlo Ersek wrote:
On 08/01/16 19:05, Gerd Hoffmann wrote:
> Hi,
>
>> If it does, then the host kernel should be 4.4 or later. (If we want to
>> capture version numbers, then for each minor release, the latest patch
>> level should be required: 4.4.16, 4.5.7, 4.6.5, 4.7.0, because there
>> have been a number of KVM tweaks and stable backports for SMM support.)
>
> Better check /dev/kvm for the KVM_CAP_X86_SMM capability, otherwise the
> rhel-7 kernel is out even though smm is backported.
>
> Probably libvirt already has checks for other caps so it should be easy.
The problem is that KVM_CAP_X86_SMM does not guarantee that all the
tricky bugfixes are present in the host kernel.
Moreover, libvirt does not validate nor check guest kernel. And the only
/dev/kvm/ caps we check are:
KVM_CAP_IOMMU - to see if legacy PCI passthrough works
KVM_CAP_PPC_SMT -
KVM_CAP_MAX_VCPUS -
KVM_CAP_NR_VCPUS - for some vCPUs counts
I don't think libvirt should check for KVM_CAP_x86_SMM. I mean, if we go
down the rabbit hole, libvirt would have to check everything. The buck
has to stop somewhere.
Michal