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| author | Paolo Bonzini <pbonzini@redhat.com> | 2014-02-27 22:54:11 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-06 22:06:18 -0800 |
| commit | 92cb6f3c5533832aa70a7dc9326ef21270169583 (patch) | |
| tree | 65b86d7844f0b48d272a3018c8aa76223df0c5ba | |
| parent | 74e1995da649f4669741dbb19cf5cffa5690a241 (diff) | |
| download | lwn-92cb6f3c5533832aa70a7dc9326ef21270169583.tar.gz lwn-92cb6f3c5533832aa70a7dc9326ef21270169583.zip | |
kvm, vmx: Really fix lazy FPU on nested guest
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>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index da7837e1349d..dcc4de3ee57a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6644,7 +6644,7 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) 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)); |