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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Reto Buerki <reet@codelabs.ch>,
	Liran Alon <liran.alon@oracle.com>
Subject: [PATCH v2 8/8] KVM: x86: Fold decache_cr3() into cache_reg()
Date: Fri, 27 Sep 2019 14:45:23 -0700	[thread overview]
Message-ID: <20190927214523.3376-9-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20190927214523.3376-1-sean.j.christopherson@intel.com>

Handle caching CR3 (from VMX's VMCS) into struct kvm_vcpu via the common
cache_reg() callback and drop the dedicated decache_cr3().  The name
decache_cr3() is somewhat confusing as the caching behavior of CR3
follows that of GPRs, RFLAGS and PDPTRs, (handled via cache_reg()), and
has nothing in common with the caching behavior of CR0/CR4 (whose
decache_cr{0,4}_guest_bits() likely provided the 'decache' verbiage).

Note, this effectively adds a BUG() if KVM attempts to cache CR3 on SVM.
Opportunistically add a WARN_ON_ONCE() in VMX to provide an equivalent
check.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/include/asm/kvm_host.h |  1 -
 arch/x86/kvm/kvm_cache_regs.h   |  2 +-
 arch/x86/kvm/svm.c              |  5 -----
 arch/x86/kvm/vmx/vmx.c          | 15 ++++++---------
 4 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a27f7f6b6b7a..0411dc0a27b0 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1040,7 +1040,6 @@ struct kvm_x86_ops {
 			    struct kvm_segment *var, int seg);
 	void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l);
 	void (*decache_cr0_guest_bits)(struct kvm_vcpu *vcpu);
-	void (*decache_cr3)(struct kvm_vcpu *vcpu);
 	void (*decache_cr4_guest_bits)(struct kvm_vcpu *vcpu);
 	void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
 	void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 9c2bc528800b..f18177cd0030 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -145,7 +145,7 @@ static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
 static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
 {
 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
-		kvm_x86_ops->decache_cr3(vcpu);
+		kvm_x86_ops->cache_reg(vcpu, VCPU_EXREG_CR3);
 	return vcpu->arch.cr3;
 }
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f8ecb6df5106..3102c44c12c6 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2517,10 +2517,6 @@ static void svm_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
 {
 }
 
-static void svm_decache_cr3(struct kvm_vcpu *vcpu)
-{
-}
-
 static void svm_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
 {
 }
@@ -7208,7 +7204,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.get_cpl = svm_get_cpl,
 	.get_cs_db_l_bits = kvm_get_cs_db_l_bits,
 	.decache_cr0_guest_bits = svm_decache_cr0_guest_bits,
-	.decache_cr3 = svm_decache_cr3,
 	.decache_cr4_guest_bits = svm_decache_cr4_guest_bits,
 	.set_cr0 = svm_set_cr0,
 	.set_cr3 = svm_set_cr3,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ed03d0cd1cc8..c84798026e85 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2188,7 +2188,12 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
 		if (enable_ept)
 			ept_save_pdptrs(vcpu);
 		break;
+	case VCPU_EXREG_CR3:
+		if (enable_unrestricted_guest || (enable_ept && is_paging(vcpu)))
+			vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
+		break;
 	default:
+		WARN_ON_ONCE(1);
 		break;
 	}
 }
@@ -2859,13 +2864,6 @@ static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
 	vcpu->arch.cr0 |= vmcs_readl(GUEST_CR0) & cr0_guest_owned_bits;
 }
 
-static void vmx_decache_cr3(struct kvm_vcpu *vcpu)
-{
-	if (enable_unrestricted_guest || (enable_ept && is_paging(vcpu)))
-		vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
-	kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);
-}
-
 static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
 {
 	ulong cr4_guest_owned_bits = vcpu->arch.cr4_guest_owned_bits;
@@ -2910,7 +2908,7 @@ static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
-		vmx_decache_cr3(vcpu);
+		vmx_cache_reg(vcpu, VCPU_EXREG_CR3);
 	if (!(cr0 & X86_CR0_PG)) {
 		/* From paging/starting to nonpaging */
 		exec_controls_setbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
@@ -7792,7 +7790,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.get_cpl = vmx_get_cpl,
 	.get_cs_db_l_bits = vmx_get_cs_db_l_bits,
 	.decache_cr0_guest_bits = vmx_decache_cr0_guest_bits,
-	.decache_cr3 = vmx_decache_cr3,
 	.decache_cr4_guest_bits = vmx_decache_cr4_guest_bits,
 	.set_cr0 = vmx_set_cr0,
 	.set_cr3 = vmx_set_cr3,
-- 
2.22.0


  parent reply	other threads:[~2019-09-27 21:45 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-27 21:45 [PATCH v2 0/8] KVM: x86: nVMX GUEST_CR3 bug fix, and then some Sean Christopherson
2019-09-27 21:45 ` [PATCH v2 1/8] KVM: nVMX: Always write vmcs02.GUEST_CR3 during nested VM-Enter Sean Christopherson
2019-09-27 23:37   ` Jim Mattson
2019-09-27 21:45 ` [PATCH v2 2/8] KVM: VMX: Skip GUEST_CR3 VMREAD+VMWRITE if the VMCS is up-to-date Sean Christopherson
2019-09-27 21:45 ` [PATCH v2 3/8] KVM: VMX: Consolidate to_vmx() usage in RFLAGS accessors Sean Christopherson
2019-09-30  8:48   ` Vitaly Kuznetsov
2019-09-27 21:45 ` [PATCH v2 4/8] KVM: VMX: Optimize vmx_set_rflags() for unrestricted guest Sean Christopherson
2019-09-30  8:57   ` Vitaly Kuznetsov
2019-09-30 15:19     ` Sean Christopherson
2019-09-30 15:55       ` Vitaly Kuznetsov
2019-10-09 10:40   ` Paolo Bonzini
2019-10-09 16:38     ` Sean Christopherson
2019-10-09 20:59       ` Paolo Bonzini
2019-10-09 21:30         ` Sean Christopherson
2019-09-27 21:45 ` [PATCH v2 5/8] KVM: x86: Add WARNs to detect out-of-bounds register indices Sean Christopherson
2019-09-30  9:19   ` Vitaly Kuznetsov
2019-10-09 10:50   ` Paolo Bonzini
2019-10-09 16:36     ` Sean Christopherson
2019-09-27 21:45 ` [PATCH v2 6/8] KVM: x86: Fold 'enum kvm_ex_reg' definitions into 'enum kvm_reg' Sean Christopherson
2019-09-30  9:25   ` Vitaly Kuznetsov
2019-10-09 10:52     ` Paolo Bonzini
2019-10-09 11:27       ` Vitaly Kuznetsov
2019-09-27 21:45 ` [PATCH v2 7/8] KVM: x86: Add helpers to test/mark reg availability and dirtiness Sean Christopherson
2019-09-30  9:32   ` Vitaly Kuznetsov
2019-10-09 11:00     ` Paolo Bonzini
2019-09-27 21:45 ` Sean Christopherson [this message]
2019-09-30 10:58   ` [PATCH v2 8/8] KVM: x86: Fold decache_cr3() into cache_reg() Vitaly Kuznetsov
2019-09-30 15:04     ` Sean Christopherson
2019-09-30 15:27       ` Vitaly Kuznetsov
2019-09-30 15:33         ` Sean Christopherson
2019-10-09 11:03   ` Paolo Bonzini
2019-09-30 10:42 ` [PATCH v2 0/8] KVM: x86: nVMX GUEST_CR3 bug fix, and then some Reto Buerki
2019-10-29 15:03   ` Martin Lucina
2019-10-30  9:09     ` Sean Christopherson

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