Add a helper to detect writes to the Xen hypercall page MSR, and provide a
stub for CONFIG_KVM_XEN=n to optimize out the check for kernels built
without Xen support.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 2 +-
arch/x86/kvm/xen.h | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b2d9a16fd4d3..f13d9d3f7c60 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3733,7 +3733,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
u32 msr = msr_info->index;
u64 data = msr_info->data;
- if (msr && msr == vcpu->kvm->arch.xen_hvm_config.msr)
+ if (kvm_xen_is_hypercall_page_msr(vcpu->kvm, msr))
return kvm_xen_write_hypercall_page(vcpu, data);
switch (msr) {
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index f5841d9000ae..e92e06926f76 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -56,6 +56,11 @@ static inline bool kvm_xen_msr_enabled(struct kvm *kvm)
kvm->arch.xen_hvm_config.msr;
}
+static inline bool kvm_xen_is_hypercall_page_msr(struct kvm *kvm, u32 msr)
+{
+ return msr && msr == kvm->arch.xen_hvm_config.msr;
+}
+
static inline bool kvm_xen_hypercall_enabled(struct kvm *kvm)
{
return static_branch_unlikely(&kvm_xen_enabled.key) &&
@@ -124,6 +129,11 @@ static inline bool kvm_xen_msr_enabled(struct kvm *kvm)
return false;
}
+static inline bool kvm_xen_is_hypercall_page_msr(struct kvm *kvm, u32 msr)
+{
+ return false;
+}
+
static inline bool kvm_xen_hypercall_enabled(struct kvm *kvm)
{
return false;
--
2.48.1.362.g079036d154-goog
