From e504c9098ed6acd9e1079c5e10e4910724ad429f Mon Sep 17 00:00:00 2001 From: Anthoine Bourgeois Date: Wed, 13 Nov 2013 11:45:37 +0100 Subject: [PATCH] kvm, vmx: Fix lazy FPU on nested guest If a nested guest does a NM fault but its CR0 doesn't contain the TS flag (because it was already cleared by the guest with L1 aid) then we have to activate FPU ourselves in L0 and then continue to L2. If TS flag is set then we fallback on the previous behavior, forward the fault to L1 if it asked for. Signed-off-by: Anthoine Bourgeois Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e293a62a11d6..b2fe1c252f35 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6643,6 +6643,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) return 0; else if (is_page_fault(intr_info)) return enable_ept; + else if (is_no_device(intr_info) && + !(nested_read_cr0(vmcs12) & X86_CR0_TS)) + return 0; return vmcs12->exception_bitmap & (1u << (intr_info & INTR_INFO_VECTOR_MASK)); case EXIT_REASON_EXTERNAL_INTERRUPT: -- 2.34.1