[PATCH v2 1/2] KVM: Introduce pv check helpers

From: Wanpeng Li
Date: Mon Feb 10 2020 - 01:37:45 EST


From: Wanpeng Li <wanpengli@xxxxxxxxxxx>

Introduce some pv check helpers for consistency.

Suggested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
arch/x86/kernel/kvm.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index d817f25..76ea8c4 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -425,7 +425,27 @@ static void __init sev_map_percpu_data(void)
}
}

+static bool pv_tlb_flush_supported(void)
+{
+ return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
+ !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
+ kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
+}
+
#ifdef CONFIG_SMP
+
+static bool pv_ipi_supported(void)
+{
+ return kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI);
+}
+
+static bool pv_sched_yield_supported(void)
+{
+ return (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
+ !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
+ kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
+}
+
#define KVM_IPI_CLUSTER_SIZE (2 * BITS_PER_LONG)

static void __send_ipi_mask(const struct cpumask *mask, int vector)
@@ -619,9 +639,7 @@ static void __init kvm_guest_init(void)
pv_ops.time.steal_clock = kvm_steal_clock;
}

- if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
- !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
- kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
+ if (pv_tlb_flush_supported()) {
pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
pv_ops.mmu.tlb_remove_table = tlb_remove_table;
}
@@ -632,9 +650,7 @@ static void __init kvm_guest_init(void)
#ifdef CONFIG_SMP
smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;
smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
- if (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
- !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
- kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
+ if (pv_sched_yield_supported()) {
smp_ops.send_call_func_ipi = kvm_smp_send_call_func_ipi;
pr_info("KVM setup pv sched yield\n");
}
@@ -700,7 +716,7 @@ static uint32_t __init kvm_detect(void)
static void __init kvm_apic_init(void)
{
#if defined(CONFIG_SMP)
- if (kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI))
+ if (pv_ipi_supported())
kvm_setup_pv_ipi();
#endif
}
@@ -739,9 +755,7 @@ static __init int kvm_setup_pv_tlb_flush(void)
if (!kvm_para_available() || nopv)
return 0;

- if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
- !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
- kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
+ if (pv_tlb_flush_supported()) {
for_each_possible_cpu(cpu) {
zalloc_cpumask_var_node(per_cpu_ptr(&__pv_tlb_mask, cpu),
GFP_KERNEL, cpu_to_node(cpu));
--
2.7.4