linux-kernel - [PATCH v2 2/6] KVM: x86/mmu: only zap EPT when guest CR0

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Message-Id: <20230509135110.1664-1-yan.y.zhao@intel.com>
Date:   Tue,  9 May 2023 21:51:10 +0800
From:   Yan Zhao <yan.y.zhao@...el.com>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     pbonzini@...hat.com, seanjc@...gle.com,
        Yan Zhao <yan.y.zhao@...el.com>
Subject: [PATCH v2 2/6] KVM: x86/mmu: only zap EPT when guest CR0_CD changes

Call new helper kvm_zap_gfn_for_memtype() to skip zap mmu if EPT is not
enabled.

Guest CR0_CD value will affect memory type of EPT leaf entry with
noncoherent DMA present. But mmu zap is not necessary if EPT is not
enabled.

Suggested-by: Chao Gao <chao.gao@...el.com>
Signed-off-by: Yan Zhao <yan.y.zhao@...el.com>
---
 arch/x86/kvm/x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e7f78fe79b32..ed1e3939bd05 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -942,7 +942,7 @@ void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned lon
 	if (((cr0 ^ old_cr0) & X86_CR0_CD) &&
 	    kvm_arch_has_noncoherent_dma(vcpu->kvm) &&
 	    !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
-		kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
+		kvm_zap_gfn_for_memtype(vcpu->kvm, gpa_to_gfn(0), gpa_to_gfn(~0ULL));
 }
 EXPORT_SYMBOL_GPL(kvm_post_set_cr0);
 
-- 
2.17.1