Commit 2390218b authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Fix mov cr3 #GP at wrong instruction 



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: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent a83b29c6

arch/x86/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -598,7 +598,7 @@ 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);

arch/x86/kvm/mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -3203,7 +3203,7 @@ 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;

}

arch/x86/kvm/svm.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/vmx.c

+2 −2
Original line number Diff line number Diff line
@@ -3185,8 +3185,8 @@ 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);

arch/x86/kvm/x86.c

+2 −8
Original line number Diff line number Diff line
@@ -565,7 +565,7 @@ 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);
@@ -604,12 +604,6 @@ 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)
@@ -3726,7 +3720,7 @@ 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));