linux-kernel - [PATCH v3 6/8] KVM: x86: introduce kvm_register_clear

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Date:   Mon,  7 Jun 2021 12:02:01 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        linux-kernel@...r.kernel.org (open list),
        linux-doc@...r.kernel.org (open list:DOCUMENTATION),
        Wanpeng Li <wanpengli@...cent.com>,
        Ingo Molnar <mingo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Sean Christopherson <seanjc@...gle.com>,
        Borislav Petkov <bp@...en8.de>, Joerg Roedel <joro@...tes.org>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Jim Mattson <jmattson@...gle.com>,
        Jonathan Corbet <corbet@....net>,
        "H. Peter Anvin" <hpa@...or.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH v3 6/8] KVM: x86: introduce kvm_register_clear_available

Small refactoring that will be used in the next patch.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/kvm_cache_regs.h | 7 +++++++
 arch/x86/kvm/svm/svm.c        | 6 ++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 3db5c42c9ecd..b8559b83c4ca 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -55,6 +55,13 @@ static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
 	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
 }
 
+static inline void kvm_register_clear_available(struct kvm_vcpu *vcpu,
+					       enum kvm_reg reg)
+{
+	__clear_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+	__clear_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
+
 static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
 					   enum kvm_reg reg)
 {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index dfa351e605de..491833ff2495 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3848,10 +3848,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 		vcpu->arch.apf.host_apf_flags =
 			kvm_read_and_reset_apf_flags();
 
-	if (npt_enabled) {
-		vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
-		vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
-	}
+	if (npt_enabled)
+		kvm_register_clear_available(vcpu, VCPU_EXREG_PDPTR);
 
 	/*
 	 * We need to handle MC intercepts here before the vcpu has a chance to
-- 
2.26.3