Re: [PATCH v7 0/7] x86/cpu, kvm: Support AMD Automatic IBRS

Sean Christopherson
2023-01-20T01:40:23Z

On Tue, Jan 17, 2023, Borislav Petkov wrote:
> On Mon, Jan 16, 2023 at 05:01:52PM -0600, Kim Phillips wrote:
>
> > Kim Phillips (7):
> > x86/cpu, kvm: Add support for cpuid leaf 80000021/EAX (FeatureExt2Eax)
> > x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature
> > x86/cpu, kvm: Move the LFENCE_RDTSC / LFENCE always serializing
> > feature
> > x86/cpu, kvm: Add the Null Selector Clears Base feature
> > x86/cpu, kvm: Add the SMM_CTL MSR not present feature
> > x86/cpu: Support AMD Automatic IBRS
> > x86/cpu, kvm: Propagate the AMD Automatic IBRS feature to the guest
> >
> > Documentation/admin-guide/hw-vuln/spectre.rst | 6 ++--
> > .../admin-guide/kernel-parameters.txt | 6 ++--
> > arch/x86/include/asm/cpufeature.h | 7 +++--
> > arch/x86/include/asm/cpufeatures.h | 11 +++++--
> > arch/x86/include/asm/disabled-features.h | 3 +-
> > arch/x86/include/asm/msr-index.h | 2 ++
> > arch/x86/include/asm/required-features.h | 3 +-
> > arch/x86/kernel/cpu/amd.c | 2 +-
> > arch/x86/kernel/cpu/bugs.c | 20 ++++++++-----
> > arch/x86/kernel/cpu/common.c | 22 +++++++++-----
> > arch/x86/kvm/cpuid.c | 30 +++++++------------
> > arch/x86/kvm/reverse_cpuid.h | 1 +
> > arch/x86/kvm/svm/svm.c | 3 ++
> > arch/x86/kvm/x86.c | 3 ++
> > 14 files changed, 71 insertions(+), 48 deletions(-)
>
> KVM folks,
>
> I'm going to route this through the tip tree, along with the KVM bits.
>
> Holler if we should do something else to avoid any potential conflicts.

Sorry, completely missed this.

There will be a minor conflict in KVM's reverse_cpuid, but it's trivial to resolve.
I don't anticipate any other conflicts, so taking this through tip does seem like
the best option.

If possible, a new version to fix the bisection issues in patches 2 and 3 would
be nice, but again it's not a big deal. The breakage is very, very minor.