diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-02-15 04:14:34 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-02-24 19:59:57 +0300 |
| commit | bb0978d95a551b8181469c4442fd59567c9dd999 (patch) | |
| tree | 0119ed0e4a6f5018403db93c29c60d3dc5fa8e94 | |
| parent | 5c17848134ab1ffb97c4a17a6e25b41390478152 (diff) | |
| download | linux-bb0978d95a551b8181469c4442fd59567c9dd999.tar.xz | |
KVM: x86/xen: Add an #ifdef'd helper to detect writes to Xen MSR
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.
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20250215011437.1203084-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/xen.h | 10 |
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 462a5cd6ac4a..12c60adb7349 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3738,7 +3738,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) * page setup; it could incur locking paths which are not expected * if userspace sets the MSR in an unusual location. */ - if (msr && msr == vcpu->kvm->arch.xen_hvm_config.msr && + if (kvm_xen_is_hypercall_page_msr(vcpu->kvm, msr) && !msr_info->host_initiated) return kvm_xen_write_hypercall_page(vcpu, data); 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; |