Re: [PATCH v3 0/5] VMX Capability MSRs

From: Paolo Bonzini
Date: Wed Nov 30 2016 - 06:22:16 EST




On 30/11/2016 03:14, David Matlack wrote:
> This patchset adds support setting the VMX capability MSRs from userspace.
> This is required for migration of nested-capable VMs to different CPUs and
> KVM versions.
>
> Patch 1 generates the non-true VMX MSRs using the true MSRs, which allows
> userspace to skip restoring them.
>
> Patch 2 adds support for restoring the VMX capability MSRs.
>
> Patches 3 and 4 make KVM's emulation of MSR_IA32_VMX_CR{0,4}_FIXED1 more
> accurate.
>
> Patch 5 fixes a bug in emulated VM-entry that came up when testing patches
> 3 and 4.
>
> Changes since v2:
> * Generate CR0_FIXED1 in addition to CR4_FIXED1
> * Generate "non-true" capability MSRs from the "true" versions and remove
> "non-true" MSRs from struct nested_vmx.
> * Disallow restore of CR{0,4}_FIXED1 and "non-true" MSRs since they are
> generated.
>
> 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 (5):
> KVM: nVMX: generate non-true VMX MSRs based on true versions
> KVM: nVMX: support restore of VMX capability MSRs
> KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation
> KVM: nVMX: generate MSR_IA32_CR{0,4}_FIXED1 from guest CPUID
> KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry
>
> arch/x86/include/asm/vmx.h | 31 +++
> arch/x86/kvm/vmx.c | 479 +++++++++++++++++++++++++++++++++++++--------
> 2 files changed, 427 insertions(+), 83 deletions(-)

Just a small nit that can be fixed on applying. Thanks!

Paolo