From: Wanpeng Li <wanpen...@tencent.com>
Enable PV TLB shootdown when !CONFIG_SMP doesn't make sense. Let's move
it inside CONFIG_SMP. In addition, we can avoid alloc __pv_cpu_mask when
!CONFIG_SMP and get rid of 'alloc' variable in kvm_alloc_cpumask.
Signed-off-by: Wanpeng Li <wanpen...@tencent.com>
---
arch/x86/kernel/kvm.c | 79 +++++++++++++++++++++++++--------------------------
1 file changed, 39 insertions(+), 40 deletions(-)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 5e78e01..202e1f0 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -451,6 +451,11 @@ static void __init sev_map_percpu_data(void)
}
}
+
+static DEFINE_PER_CPU(cpumask_var_t, __pv_cpu_mask);
+
+#ifdef CONFIG_SMP
+
static bool pv_tlb_flush_supported(void)
{
return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
@@ -458,10 +463,6 @@ static bool pv_tlb_flush_supported(void)
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
}
-static DEFINE_PER_CPU(cpumask_var_t, __pv_cpu_mask);
-
-#ifdef CONFIG_SMP
-
static bool pv_ipi_supported(void)
{
return kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI);
@@ -574,6 +575,32 @@ static void kvm_smp_send_call_func_ipi(const struct
cpumask *mask)
}
}
+static void kvm_flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info)
+{
+ u8 state;
+ int cpu;
+ struct kvm_steal_time *src;
+ struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
+
+ cpumask_copy(flushmask, cpumask);
+ /*
+ * We have to call flush only on online vCPUs. And
+ * queue flush_on_enter for pre-empted vCPUs
+ */
+ for_each_cpu(cpu, flushmask) {
+ src = &per_cpu(steal_time, cpu);
+ state = READ_ONCE(src->preempted);
+ if ((state & KVM_VCPU_PREEMPTED)) {
+ if (try_cmpxchg(&src->preempted, &state,
+ state | KVM_VCPU_FLUSH_TLB))
+ __cpumask_clear_cpu(cpu, flushmask);
+ }
+ }
+
+ native_flush_tlb_others(flushmask, info);
+}
+
static void __init kvm_smp_prepare_boot_cpu(void)
{
/*
@@ -611,33 +638,16 @@ static int kvm_cpu_down_prepare(unsigned int cpu)
local_irq_enable();
return 0;
}
-#endif
-static void kvm_flush_tlb_others(const struct cpumask *cpumask,
- const struct flush_tlb_info *info)
-{
- u8 state;
- int cpu;
- struct kvm_steal_time *src;
- struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
+#else
- cpumask_copy(flushmask, cpumask);
- /*
- * We have to call flush only on online vCPUs. And
- * queue flush_on_enter for pre-empted vCPUs
- */
- for_each_cpu(cpu, flushmask) {
- src = &per_cpu(steal_time, cpu);
- state = READ_ONCE(src->preempted);
- if ((state & KVM_VCPU_PREEMPTED)) {
- if (try_cmpxchg(&src->preempted, &state,
- state | KVM_VCPU_FLUSH_TLB))
- __cpumask_clear_cpu(cpu, flushmask);
- }
- }
+static bool pv_tlb_flush_supported(void) { return false; }
+static bool pv_ipi_supported(void) { return false; }
+static void kvm_flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info) { }
+static void kvm_setup_pv_ipi(void) { }
- native_flush_tlb_others(flushmask, info);
-}
+#endif
static void __init kvm_guest_init(void)
{
@@ -734,10 +744,8 @@ static uint32_t __init kvm_detect(void)
static void __init kvm_apic_init(void)
{
-#if defined(CONFIG_SMP)
if (pv_ipi_supported())
kvm_setup_pv_ipi();
-#endif
}
static bool __init kvm_msi_ext_dest_id(void)
@@ -797,20 +805,11 @@ arch_initcall(activate_jump_labels);
static __init int kvm_alloc_cpumask(void)
{
int cpu;
- bool alloc = false;
if (!kvm_para_available() || nopv)
return 0;
- if (pv_tlb_flush_supported())
- alloc = true;
-
-#if defined(CONFIG_SMP)
- if (pv_ipi_supported())
- alloc = true;
-#endif
-
- if (alloc)
+ if (pv_tlb_flush_supported() || pv_ipi_supported())
for_each_possible_cpu(cpu) {
zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask,
cpu),
GFP_KERNEL, cpu_to_node(cpu));
--
2.7.4
