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: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ea8c319cdffcb84ef83f98d1437126a11265f13b..c2813d658f3e865f77d02b04d0da1ce2008f6a2d 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -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);

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4706a936e36f49c6b17e3d8992cacc84487fb636..aa98fca03ed7a6d104e91b0ae783a84397ffe498 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -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;
 }
 

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6d1616d47c54c8499a7f8fd326b72d3c05e1e4f8..f7a6fdcf8ef35eb58bccc37d2a9837157779a79c 100644 (file)
--- 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 f64d65dc38c65aef39a6b74c48aadba2f4f45376..345a35470511abbc8b94280956c2c388bbfc64a2 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -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);

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ed3af15d4404a8bb21de1a45602e81032a9d5b0b..795999e1ac196fb4b664d25c181478c13b7a9c50 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -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));