linux-kernel - [PATCH v3 5/5] KVM: VMX: Use "illegal GPA" helper for PT/RTIT output base check

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Date:   Thu, 24 Sep 2020 12:42:50 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 5/5] KVM: VMX: Use "illegal GPA" helper for PT/RTIT output base check

Use kvm_vcpu_is_illegal_gpa() to check for a legal GPA when validating a
PT output base instead of open coding a clever, but difficult to read,
variant.  Code readability is far more important than shaving a few uops
in a slow path.

No functional change intended.

Suggested-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 7987de212057..8f1eb5dca794 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1037,7 +1037,7 @@ static inline bool pt_can_write_msr(struct vcpu_vmx *vmx)
 static inline bool pt_output_base_valid(struct kvm_vcpu *vcpu, u64 base)
 {
 	/* The base must be 128-byte aligned and a legal physical address. */
-	return !(base & (~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f));
+	return !kvm_vcpu_is_illegal_gpa(vcpu, base) && !(base & 0x7f);
 }
 
 static inline void pt_load_msr(struct pt_ctx *ctx, u32 addr_range)
-- 
2.28.0