| From 1b385cbdd74aa803e966e01e5fe49490d6044e30 Mon Sep 17 00:00:00 2001 |
| From: Paolo Bonzini <pbonzini@redhat.com> |
| Date: Thu, 27 Feb 2014 22:54:11 +0100 |
| Subject: kvm, vmx: Really fix lazy FPU on nested guest |
| |
| From: Paolo Bonzini <pbonzini@redhat.com> |
| |
| commit 1b385cbdd74aa803e966e01e5fe49490d6044e30 upstream. |
| |
| Commit e504c9098ed6 (kvm, vmx: Fix lazy FPU on nested guest, 2013-11-13) |
| highlighted a real problem, but the fix was subtly wrong. |
| |
| nested_read_cr0 is the CR0 as read by L2, but here we want to look at |
| the CR0 value reflecting L1's setup. In other words, L2 might think |
| that TS=0 (so nested_read_cr0 has the bit clear); but if L1 is actually |
| running it with TS=1, we should inject the fault into L1. |
| |
| The effective value of CR0 in L2 is contained in vmcs12->guest_cr0, use |
| it. |
| |
| Fixes: e504c9098ed6acd9e1079c5e10e4910724ad429f |
| Reported-by: Kashyap Chamarty <kchamart@redhat.com> |
| Reported-by: Stefan Bader <stefan.bader@canonical.com> |
| Tested-by: Kashyap Chamarty <kchamart@redhat.com> |
| Tested-by: Anthoine Bourgeois <bourgeois@bertin.fr> |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/kvm/vmx.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/arch/x86/kvm/vmx.c |
| +++ b/arch/x86/kvm/vmx.c |
| @@ -6644,7 +6644,7 @@ static bool nested_vmx_exit_handled(stru |
| else if (is_page_fault(intr_info)) |
| return enable_ept; |
| else if (is_no_device(intr_info) && |
| - !(nested_read_cr0(vmcs12) & X86_CR0_TS)) |
| + !(vmcs12->guest_cr0 & X86_CR0_TS)) |
| return 0; |
| return vmcs12->exception_bitmap & |
| (1u << (intr_info & INTR_INFO_VECTOR_MASK)); |
