KVM: VMX: do not overwrite uptodate vcpu->arch.cr3 on KVM_SET_SREGS

Only decache guest CR3 value if vcpu->arch.cr3 is stale.
Fixes loadvm with live guest.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Markus Schade <markus.schade@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4c3fa0f67469..d48ec60ea421 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2047,7 +2047,8 @@ static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
                                         unsigned long cr0,
                                         struct kvm_vcpu *vcpu)
 {
-        vmx_decache_cr3(vcpu);
+        if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+                vmx_decache_cr3(vcpu);
         if (!(cr0 & X86_CR0_PG)) {
                 /* From paging/starting to nonpaging */
                 vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,