KVM: SVM: set NM intercept when enabling CR0.TS in the guest

Explicitly enable the NM intercept in svm_set_cr0 if we enable TS in the guest
copy of CR0 for lazy FPU switching. This fixes guest SMP with Linux under SVM.
Without that patch Linux deadlocks or panics right after trying to boot the
other CPUs.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 511628916c4b..d71daabbb51b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -792,8 +792,10 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
         vcpu->arch.cr0 = cr0;
         cr0 |= X86_CR0_PG | X86_CR0_WP;
         cr0 &= ~(X86_CR0_CD | X86_CR0_NW);
-        if (!vcpu->fpu_active)
+        if (!vcpu->fpu_active) {
+                svm->vmcb->control.intercept_exceptions |= (1 << NM_VECTOR);
                 cr0 |= X86_CR0_TS;
+        }
         svm->vmcb->save.cr0 = cr0;
 }