[PATCH 04/12] KVM: x86: Add a helper to handle legal GPA with an alignment requirement

From: Sean Christopherson
Date: Wed Feb 03 2021 - 19:03:25 EST


Add a helper to genericize checking for a legal GPA that also must
conform to an arbitrary alignment, and use it in the existing
page_address_valid(). Future patches will replace open coded variants
in VMX and SVM.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/cpuid.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 674d61079f2d..a9d55ab51e3c 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -46,9 +46,15 @@ static inline bool kvm_vcpu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
return !kvm_vcpu_is_legal_gpa(vcpu, gpa);
}

+static inline bool kvm_vcpu_is_legal_aligned_gpa(struct kvm_vcpu *vcpu,
+ gpa_t gpa, gpa_t alignment)
+{
+ return IS_ALIGNED(gpa, alignment) && kvm_vcpu_is_legal_gpa(vcpu, gpa);
+}
+
static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
{
- return PAGE_ALIGNED(gpa) && kvm_vcpu_is_legal_gpa(vcpu, gpa);
+ return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE);
}

struct cpuid_reg {
--
2.30.0.365.g02bc693789-goog