linux-kernel - [PATCH 09/15] KVM: SVM: Remove the unneeded code to mark available for CR3

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Date:   Mon,  8 Nov 2021 20:44:01 +0800
From:   Lai Jiangshan <jiangshanlai@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     Lai Jiangshan <laijs@...ux.alibaba.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>
Subject: [PATCH 09/15] KVM: SVM: Remove the unneeded code to mark available for CR3

From: Lai Jiangshan <laijs@...ux.alibaba.com>

VCPU_EXREG_CR3 is never cleared from vcpu->arch.regs_avail in SVM so
marking available for CR3 is mere an NOP, just remove it.

And it is not required to mark it dirty since VCPU_EXREG_CR3 is neither
never cleared from vcpu->arch.regs_dirty and SVM doesn't use the dirty
information of VCPU_EXREG_CR3.

Signed-off-by: Lai Jiangshan <laijs@...ux.alibaba.com>
---
 arch/x86/kvm/svm/nested.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 13a58722e097..2d88ff584d61 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -444,7 +444,6 @@ static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,
 		kvm_mmu_new_pgd(vcpu, cr3);
 
 	vcpu->arch.cr3 = cr3;
-	kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);
 
 	/* Re-initialize the MMU, e.g. to pick up CR4 MMU role changes. */
 	kvm_init_mmu(vcpu);
-- 
2.19.1.6.gb485710b