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| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2012-08-24 14:12:59 -0700 |
|---|---|---|
| committer | Zefan Li <lizefan@huawei.com> | 2015-09-18 09:20:46 +0800 |
| commit | ac573c10cbf023a905dc15c5a2f91887b56ae5a7 (patch) | |
| tree | 77e09a457eb6b4cc6ea0551296eff307142635ee | |
| parent | 7014d74fb26f9adbd5e275f1858c2aae16e35769 (diff) | |
| download | lwn-ac573c10cbf023a905dc15c5a2f91887b56ae5a7.tar.gz lwn-ac573c10cbf023a905dc15c5a2f91887b56ae5a7.zip | |
x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
commit 9c1c3fac53378c9782c18f80107965578d7b7167 upstream.
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>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
| -rw-r--r-- | 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 318a2454366f..55ee4ca517f2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5907,7 +5907,7 @@ 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); } @@ -5921,6 +5921,7 @@ 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); |