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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2010-11-01 14:01:29 +0100 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-01-12 11:28:52 +0200 |
| commit | 2eec73437487aa690882cafddca6e4d93df46f26 (patch) | |
| tree | 07dc35deb31d99607eac676e38215abe3996ce65 /arch | |
| parent | aac8763697c6b7aa133abe8092a25154960e9a0c (diff) | |
| download | linux-2eec73437487aa690882cafddca6e4d93df46f26.tar.gz linux-2eec73437487aa690882cafddca6e4d93df46f26.tar.bz2 linux-2eec73437487aa690882cafddca6e4d93df46f26.zip | |
KVM: x86: Avoid issuing wbinvd twice
Micro optimization to avoid calling wbinvd twice on the CPU that has to
emulate it. As we might be preempted between smp_call_function_many and
the local wbinvd, the cache might be filled again so that real work
could be done uselessly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/x86.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 35f82f2c66f6..c10135bc0f2f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4007,13 +4007,15 @@ int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu) return X86EMUL_CONTINUE; if (kvm_x86_ops->has_wbinvd_exit()) { - preempt_disable(); + int cpu = get_cpu(); + + cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask); smp_call_function_many(vcpu->arch.wbinvd_dirty_mask, wbinvd_ipi, NULL, 1); - preempt_enable(); + put_cpu(); cpumask_clear(vcpu->arch.wbinvd_dirty_mask); - } - wbinvd(); + } else + wbinvd(); return X86EMUL_CONTINUE; } EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd); |