KVM: Fix mov cr0 #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>

1 files changed, 3 insertions, 9 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b5e644701cc1..05e9b5dde646 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -425,7 +425,7 @@ out:
         return changed;
 }
 
-static int __kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
+int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 {
         unsigned long old_cr0 = kvm_read_cr0(vcpu);
         unsigned long update_bits = X86_CR0_PG | X86_CR0_WP |
@@ -468,17 +468,11 @@ static int __kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
                 kvm_mmu_reset_context(vcpu);
         return 0;
 }
-
-void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
-{
-        if (__kvm_set_cr0(vcpu, cr0))
-                kvm_inject_gp(vcpu, 0);
-}
 EXPORT_SYMBOL_GPL(kvm_set_cr0);
 
 void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
 {
-        kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
+        (void)kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
 }
 EXPORT_SYMBOL_GPL(kvm_lmsw);
 
@@ -3732,7 +3726,7 @@ static int emulator_set_cr(int cr, unsigned long val, struct kvm_vcpu *vcpu)
 
         switch (cr) {
         case 0:
-                res = __kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val));
+                res = kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val));
                 break;
         case 2:
                 vcpu->arch.cr2 = val;