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authorWanpeng Li <wanpengli@tencent.com>2018-02-13 09:05:42 +0800
committerRadim Krčmář <rkrcmar@redhat.com>2018-03-06 18:40:45 +0100
commit6beacf74c25711d5ee83412a3abc839af8ce6697 (patch)
treec1d447d139f2783978b2256341d126992656b62d /arch/x86
parentb2798ba0b8769b42f00899b44a538b5fcecb480d (diff)
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KVM: X86: Don't use PV TLB flush with dedicated physical CPUs
vCPUs are very unlikely to get preempted when they are the only task running on a CPU. PV TLB flush is slower that the native flush in that case, so disable it. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/kvm.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index f803e89e0b47..4ccbff63cb86 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -546,6 +546,7 @@ static void __init kvm_guest_init(void)
}
if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
+ !kvm_para_has_hint(KVM_HINTS_DEDICATED) &&
!kvm_para_has_feature(KVM_FEATURE_STEAL_TIME))
pv_mmu_ops.flush_tlb_others = kvm_flush_tlb_others;
@@ -640,6 +641,7 @@ static __init int kvm_setup_pv_tlb_flush(void)
int cpu;
if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
+ !kvm_para_has_hint(KVM_HINTS_DEDICATED) &&
!kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
for_each_possible_cpu(cpu) {
zalloc_cpumask_var_node(per_cpu_ptr(&__pv_tlb_mask, cpu),