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From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>,
	Sheng Yang <sheng@linux.intel.com>
Cc: kvm@vger.kernel.org
Subject: [PATCH 3/3] KVM: Fix mov cr3 #GP at wrong instruction
Date: Thu, 10 Jun 2010 17:02:16 +0300	[thread overview]
Message-ID: <1276178536-10888-4-git-send-email-avi@redhat.com> (raw)
In-Reply-To: <1276178536-10888-1-git-send-email-avi@redhat.com>

On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.

Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 arch/x86/include/asm/kvm_host.h |    2 +-
 arch/x86/kvm/mmu.c              |    2 +-
 arch/x86/kvm/svm.c              |    4 ++--
 arch/x86/kvm/vmx.c              |    4 ++--
 arch/x86/kvm/x86.c              |   10 ++--------
 5 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f52196d..b127041 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -597,7 +597,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
 		    bool has_error_code, u32 error_code);
 
 int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0);
-void kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3);
+int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3);
 int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);
 void kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8);
 int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 75ddaa1..fcf5555 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3201,7 +3201,7 @@ static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
 
 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
 {
-	kvm_set_cr3(vcpu, vcpu->arch.cr3);
+	(void)kvm_set_cr3(vcpu, vcpu->arch.cr3);
 	return 1;
 }
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6d1616d..f7a6fdc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1963,7 +1963,7 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
 		svm->vmcb->save.cr3 = hsave->save.cr3;
 		svm->vcpu.arch.cr3 = hsave->save.cr3;
 	} else {
-		kvm_set_cr3(&svm->vcpu, hsave->save.cr3);
+		(void)kvm_set_cr3(&svm->vcpu, hsave->save.cr3);
 	}
 	kvm_register_write(&svm->vcpu, VCPU_REGS_RAX, hsave->save.rax);
 	kvm_register_write(&svm->vcpu, VCPU_REGS_RSP, hsave->save.rsp);
@@ -2086,7 +2086,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 		svm->vmcb->save.cr3 = nested_vmcb->save.cr3;
 		svm->vcpu.arch.cr3 = nested_vmcb->save.cr3;
 	} else
-		kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3);
+		(void)kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3);
 
 	/* Guest paging mode is active - reset mmu */
 	kvm_mmu_reset_context(&svm->vcpu);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9d083e9..f15f6bd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3186,8 +3186,8 @@ static int handle_cr(struct kvm_vcpu *vcpu)
 			complete_insn_gp(vcpu, err);
 			return 1;
 		case 3:
-			kvm_set_cr3(vcpu, val);
-			skip_emulated_instruction(vcpu);
+			err = kvm_set_cr3(vcpu, val);
+			complete_insn_gp(vcpu, err);
 			return 1;
 		case 4:
 			err = kvm_set_cr4(vcpu, val);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 60b5154..b31d3fe 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -496,7 +496,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 }
 EXPORT_SYMBOL_GPL(kvm_set_cr4);
 
-static int __kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
+int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
 	if (cr3 == vcpu->arch.cr3 && !pdptrs_changed(vcpu)) {
 		kvm_mmu_sync_roots(vcpu);
@@ -535,12 +535,6 @@ static int __kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 	vcpu->arch.mmu.new_cr3(vcpu);
 	return 0;
 }
-
-void kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
-{
-	if (__kvm_set_cr3(vcpu, cr3))
-		kvm_inject_gp(vcpu, 0);
-}
 EXPORT_SYMBOL_GPL(kvm_set_cr3);
 
 int __kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
@@ -3646,7 +3640,7 @@ static int emulator_set_cr(int cr, unsigned long val, struct kvm_vcpu *vcpu)
 		vcpu->arch.cr2 = val;
 		break;
 	case 3:
-		res = __kvm_set_cr3(vcpu, val);
+		res = kvm_set_cr3(vcpu, val);
 		break;
 	case 4:
 		res = kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val));
-- 
1.7.1


  parent reply	other threads:[~2010-06-10 14:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-10 14:02 [PATCH 0/3] Fix #GP at wrong rip for mov cr instructions Avi Kivity
2010-06-10 14:02 ` [PATCH 1/3] KVM: Fix mov cr0 #GP at wrong instruction Avi Kivity
2010-06-10 14:02 ` [PATCH 2/3] KVM: Fix mov cr4 " Avi Kivity
2010-06-10 14:02 ` Avi Kivity [this message]
2010-06-11 17:09 ` [PATCH 0/3] Fix #GP at wrong rip for mov cr instructions Marcelo Tosatti

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