Re: [PATCH 0/4] VMX Capability MSRs

From: David Matlack
Date: Mon Nov 28 2016 - 12:45:07 EST


On Wed, Nov 23, 2016 at 3:45 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> On 23/11/2016 02:14, David Matlack wrote:
>> This patchset includes v2 of "KVM: nVMX: support restore of VMX capability
>> MSRs" (patch 1) as well as some additional related patches that came up
>> while preparing v2.
>>
>> Patches 2 and 3 make KVM's emulation of MSR_IA32_VMX_CR{0,4}_FIXED1 more
>> accurate. Patch 4 fixes a bug in emulated VM-entry that came up when
>> testing patches 2 and 3.
>>
>> Changes since v1:
>> * Support restoring less-capable versions of MSR_IA32_VMX_BASIC,
>> MSR_IA32_VMX_CR{0,4}_FIXED{0,1}.
>> * Include VMX_INS_OUTS in MSR_IA32_VMX_BASIC initial value.
>>
>> David Matlack (4):
>> KVM: nVMX: support restore of VMX capability MSRs
>> KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation
>> KVM: nVMX: accurate emulation of MSR_IA32_CR{0,4}_FIXED1
>> KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry
>>
>> arch/x86/include/asm/vmx.h | 31 ++++
>> arch/x86/kvm/vmx.c | 443 +++++++++++++++++++++++++++++++++++++++------
>> 2 files changed, 421 insertions(+), 53 deletions(-)
>>
>
> The main question is whether patches 2-3 actually make
> vmx_restore_fixed0/1_msr unnecessary, otherwise looks great.
>
> It would be nice to have a testcase for patch 4, since it could go in
> independently.

I've got a kvm-unit-test testcase for patches 2-4 but unfortunately it
depends on changes we've made internally to the kvm-unit-tests, and
we're a bit behind on getting those upstreamed.

>
> Paolo