Re: [PATCH v2 0/4] KVM: VMX: enable LBR virtualization

From: Paolo Bonzini
Date: Wed Nov 11 2015 - 10:23:50 EST

On 23/10/2015 11:15, Jian Zhou wrote:
> Changelog in v2:
> (1) move the implementation into vmx.c
> (2) migraton is supported
> (3) add arrays in kvm_vcpu_arch struct to save/restore
> LBR MSRs at vm exit/entry time.
> (4) add a parameter of kvm_intel module to permanently
> disable LBRV
> (5) table of supported CPUs is reorgnized, LBRV
> can be enabled or not according to the guest CPUID
> Jian Zhou (4):
> KVM: X86: Add arrays to save/restore LBR MSRs
> KVM: X86: LBR MSRs of supported CPU types
> KVM: X86: Migration is supported
> KVM: VMX: details of LBR virtualization implementation
> arch/x86/include/asm/kvm_host.h | 26 ++++-
> arch/x86/include/asm/msr-index.h | 26 ++++-
> arch/x86/kvm/vmx.c | 245 +++++++++++++++++++++++++++++++++++++++
> arch/x86/kvm/x86.c | 88 ++++++++++++--
> 4 files changed, 366 insertions(+), 19 deletions(-)

Thanks, this looks better!

The reason why it took me so long to review it, is that I wanted to
understand what happens if you're running this on CPU model x but using
CPU model y for the guest. I still haven't grokked that fully, so I'll
apply your patches locally and play with them.

In the meanwhile, feel free to send v3 with: 1) the tweak I suggested to
patch 3; 2) the fix for the problem that the buildbot reported on patch 1.

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