From: Wanpeng Li <[email protected]> IPI shorthand is supported now by linux apic/x2apic driver, switch to IPI shorthand for all excluding self and all including self destination shorthand in kvm guest, to avoid splitting the target mask into serveral PV IPI hypercalls.
Cc: Thomas Gleixner <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: Nadav Amit <[email protected]> Signed-off-by: Wanpeng Li <[email protected]> --- Note: rebase against tip tree's x86/apic branch arch/x86/kernel/kvm.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index b7f34fe..87b73b8 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -34,7 +34,9 @@ #include <asm/hypervisor.h> #include <asm/tlb.h> +static struct apic orig_apic; static int kvmapf = 1; +DECLARE_STATIC_KEY_FALSE(apic_use_ipi_shorthand); static int __init parse_no_kvmapf(char *arg) { @@ -507,12 +509,18 @@ static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector) static void kvm_send_ipi_allbutself(int vector) { - kvm_send_ipi_mask_allbutself(cpu_online_mask, vector); + if (static_branch_likely(&apic_use_ipi_shorthand)) + orig_apic.send_IPI_allbutself(vector); + else + kvm_send_ipi_mask_allbutself(cpu_online_mask, vector); } static void kvm_send_ipi_all(int vector) { - __send_ipi_mask(cpu_online_mask, vector); + if (static_branch_likely(&apic_use_ipi_shorthand)) + orig_apic.send_IPI_allbutself(vector); + else + __send_ipi_mask(cpu_online_mask, vector); } /* @@ -520,6 +528,8 @@ static void kvm_send_ipi_all(int vector) */ static void kvm_setup_pv_ipi(void) { + orig_apic = *apic; + apic->send_IPI_mask = kvm_send_ipi_mask; apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself; apic->send_IPI_allbutself = kvm_send_ipi_allbutself; -- 2.7.4
