Messages in this thread Patch in this message | | | Date | Fri, 24 Aug 2012 15:15:14 -0700 | From | tip-bot for Suresh Siddha <> | Subject | [tip:x86/fpu] x86, kvm: use kernel_fpu_begin/end() in kvm_load/ put_guest_fpu() |
| |
Commit-ID: 98700fa647b3572f7fa55485570ab9fc53b91d23 Gitweb: http://git.kernel.org/tip/98700fa647b3572f7fa55485570ab9fc53b91d23 Author: Suresh Siddha <suresh.b.siddha@intel.com> AuthorDate: Fri, 24 Aug 2012 14:12:59 -0700 Committer: H. Peter Anvin <hpa@linux.intel.com> CommitDate: Fri, 24 Aug 2012 14:26:49 -0700
x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
kvm's guest fpu save/restore should be wrapped around kernel_fpu_begin/end(). This will avoid for example taking a DNA in kvm_load_guest_fpu() when it tries to load the fpu immediately after doing unlazy_fpu() on the host side.
More importantly this will prevent the host process fpu from being corrupted.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com Cc: Avi Kivity <avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> --- arch/x86/kvm/x86.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index be6d549..b92cc39 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5954,7 +5954,7 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) */ kvm_put_guest_xcr0(vcpu); vcpu->guest_fpu_loaded = 1; - unlazy_fpu(current); + kernel_fpu_begin(); fpu_restore_checking(&vcpu->arch.guest_fpu); trace_kvm_fpu(1); } @@ -5968,6 +5968,7 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) vcpu->guest_fpu_loaded = 0; fpu_save_init(&vcpu->arch.guest_fpu); + kernel_fpu_end(); ++vcpu->stat.fpu_reload; kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); trace_kvm_fpu(0);
| |