From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: David Woodhouse <dwmw@amazon.co.uk>,
KarimAllah Ahmed <karahmed@amazon.de>
Subject: [PATCH] KVM: VMX: expose the host's ARCH_CAPABILITIES MSR to userspace
Date: Sat, 24 Feb 2018 01:52:26 +0100 [thread overview]
Message-ID: <1519433546-33879-1-git-send-email-pbonzini@redhat.com> (raw)
Use the new MSR feature framework to expose the ARCH_CAPABILITIES MSR to
userspace. This way, userspace can access the capabilities even if it
does not have the permissions to read MSRs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx.c | 12 +++++++++++-
arch/x86/kvm/x86.c | 1 +
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 130fca0ea1bf..99689061e11e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3228,7 +3228,17 @@ static inline bool vmx_feature_control_msr_valid(struct kvm_vcpu *vcpu,
static int vmx_get_msr_feature(struct kvm_msr_entry *msr)
{
- return 1;
+ switch (msr->index) {
+ case MSR_IA32_ARCH_CAPABILITIES:
+ if (!boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
+ return 1;
+ rdmsrl(msr->index, msr->data);
+ break;
+ default:
+ return 1;
+ }
+
+ return 0;
}
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 54b4ed55945b..e9a8cc9e3b2b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1054,6 +1054,7 @@ bool kvm_rdpmc(struct kvm_vcpu *vcpu)
* can be used by a hypervisor to validate requested CPU features.
*/
static u32 msr_based_features[] = {
+ MSR_IA32_ARCH_CAPABILITIES,
MSR_F10H_DECFG,
};
--
1.8.3.1
next reply other threads:[~2018-02-24 0:52 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-24 0:52 Paolo Bonzini [this message]
2018-02-26 22:13 ` [PATCH] KVM: VMX: expose the host's ARCH_CAPABILITIES MSR to userspace Konrad Rzeszutek Wilk
2018-02-26 22:23 ` Konrad Rzeszutek Wilk
2018-03-01 21:39 ` Radim Krčmář
2018-03-02 9:36 ` Paolo Bonzini
2018-03-02 21:42 ` Radim Krčmář
2018-03-07 11:53 ` Paolo Bonzini
2018-03-07 14:56 ` Radim Krčmář
2018-03-07 15:10 ` Paolo Bonzini
2018-03-07 15:39 ` Radim Krčmář
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