4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paolo Bonzini pbonzini@redhat.com
commit cd28325249a1ca0d771557ce823e0308ad629f98 upstream
This lets userspace read the MSR_IA32_ARCH_CAPABILITIES and check that all requested features are available on the host.
Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: David Woodhouse dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1015,6 +1015,7 @@ static unsigned num_emulated_msrs; static u32 msr_based_features[] = { MSR_F10H_DECFG, MSR_IA32_UCODE_REV, + MSR_IA32_ARCH_CAPABILITIES, };
static unsigned int num_msr_based_features; @@ -1023,7 +1024,8 @@ static int kvm_get_msr_feature(struct kv { switch (msr->index) { case MSR_IA32_UCODE_REV: - rdmsrl(msr->index, msr->data); + case MSR_IA32_ARCH_CAPABILITIES: + rdmsrl_safe(msr->index, &msr->data); break; default: if (kvm_x86_ops->get_msr_feature(msr))