linux-kernel - [PATCH 05/15] KVM: VMX: Add and use X86_CR4_PDPTR_BITS when !enable

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Message-Id: <20211108124407.12187-6-jiangshanlai@gmail.com>
Date:   Mon,  8 Nov 2021 20:43:57 +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 05/15] KVM: VMX: Add and use X86_CR4_PDPTR_BITS when !enable_ept

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

In set_cr4_guest_host_mask(), all cr4 pdptr bits are already set to be
intercepted in an unclear way.

Add X86_CR4_PDPTR_BITS to make it clear and self-documented.

No functionality changed.

Signed-off-by: Lai Jiangshan <laijs@...ux.alibaba.com>
---
 arch/x86/kvm/kvm_cache_regs.h | 1 +
 arch/x86/kvm/vmx/vmx.c        | 4 +++-
 arch/x86/kvm/x86.c            | 4 +---
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 8fe036efa654..592f9eb9753b 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -10,6 +10,7 @@
 	 | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE)
 
 #define X86_CR4_TLB_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP)
+#define X86_CR4_PDPTR_BITS (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP)
 
 #define BUILD_KVM_GPR_ACCESSORS(lname, uname)				      \
 static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 1795702dc6de..d94e51e9c08f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4106,8 +4106,10 @@ void set_cr4_guest_host_mask(struct vcpu_vmx *vmx)
 
 	vcpu->arch.cr4_guest_owned_bits = KVM_POSSIBLE_CR4_GUEST_BITS &
 					  ~vcpu->arch.cr4_guest_rsvd_bits;
-	if (!enable_ept)
+	if (!enable_ept) {
 		vcpu->arch.cr4_guest_owned_bits &= ~X86_CR4_TLB_BITS;
+		vcpu->arch.cr4_guest_owned_bits &= ~X86_CR4_PDPTR_BITS;
+	}
 	if (is_guest_mode(&vmx->vcpu))
 		vcpu->arch.cr4_guest_owned_bits &=
 			~get_vmcs12(vcpu)->cr4_guest_host_mask;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 034c233ea5a1..b92d4241b4d9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1052,8 +1052,6 @@ EXPORT_SYMBOL_GPL(kvm_post_set_cr4);
 int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 {
 	unsigned long old_cr4 = kvm_read_cr4(vcpu);
-	unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE |
-				   X86_CR4_SMEP;
 
 	if (!kvm_is_valid_cr4(vcpu, cr4))
 		return 1;
@@ -1064,7 +1062,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 		if ((cr4 ^ old_cr4) & X86_CR4_LA57)
 			return 1;
 	} else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
-		   && ((cr4 ^ old_cr4) & pdptr_bits)
+		   && ((cr4 ^ old_cr4) & X86_CR4_PDPTR_BITS)
 		   && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
 				   kvm_read_cr3(vcpu)))
 		return 1;
-- 
2.19.1.6.gb485710b