From: luferry <luferry@xxxxxxx> x2apic_eanbled() costs about 200 cycles when guest trigger halt pretty high, pi ops in hotpath Signed-off-by: luferry <luferry@xxxxxxx> --- arch/x86/kvm/vmx/vmx.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d98eac371c0a..e17dbf011e47 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -186,6 +186,8 @@ static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush); static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_cond); static DEFINE_MUTEX(vmx_l1d_flush_mutex); +static int __read_mostly host_x2apic_enabled; + /* Storage for pre module init parameter parsing */ static enum vmx_l1d_flush_state __read_mostly vmentry_l1d_flush_param = VMENTER_L1D_FLUSH_AUTO; @@ -1204,7 +1206,7 @@ static void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu) dest = cpu_physical_id(cpu); - if (x2apic_enabled()) + if (host_x2apic_enabled) new.ndst = dest; else new.ndst = (dest << 8) & 0xFF00; @@ -7151,7 +7153,7 @@ static void __pi_post_block(struct kvm_vcpu *vcpu) dest = cpu_physical_id(vcpu->cpu); - if (x2apic_enabled()) + if (host_x2apic_enabled) new.ndst = dest; else new.ndst = (dest << 8) & 0xFF00; @@ -7221,7 +7223,7 @@ static int pi_pre_block(struct kvm_vcpu *vcpu) */ dest = cpu_physical_id(vcpu->pre_pcpu); - if (x2apic_enabled()) + if (host_x2apic_enabled) new.ndst = dest; else new.ndst = (dest << 8) & 0xFF00; @@ -7804,6 +7806,8 @@ static int __init vmx_init(void) } #endif + host_x2apic_enabled = x2apic_enabled(); + r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx), __alignof__(struct vcpu_vmx), THIS_MODULE); if (r) -- 2.14.1.40.g8e62ba1
