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-rw-r--r--Documentation/virtual/kvm/cpuid.txt4
-rw-r--r--arch/x86/include/uapi/asm/kvm_para.h2
-rw-r--r--arch/x86/kernel/kvm.c47
3 files changed, 53 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
index 3c65feb83010..dcab6dc11e3b 100644
--- a/Documentation/virtual/kvm/cpuid.txt
+++ b/Documentation/virtual/kvm/cpuid.txt
@@ -54,6 +54,10 @@ KVM_FEATURE_PV_UNHALT || 7 || guest checks this feature bit
|| || before enabling paravirtualized
|| || spinlock support.
------------------------------------------------------------------------------
+KVM_FEATURE_PV_TLB_FLUSH || 9 || guest checks this feature bit
+ || || before enabling paravirtualized
+ || || tlb flush.
+------------------------------------------------------------------------------
KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side
|| || per-cpu warps are expected in
|| || kvmclock.
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 15685bd22faa..7a2ade4aa235 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -25,6 +25,7 @@
#define KVM_FEATURE_STEAL_TIME 5
#define KVM_FEATURE_PV_EOI 6
#define KVM_FEATURE_PV_UNHALT 7
+#define KVM_FEATURE_PV_TLB_FLUSH 9
/* The last 8 bits are used to indicate how to interpret the flags field
* in pvclock structure. If no bits are set, all flags are ignored.
@@ -52,6 +53,7 @@ struct kvm_steal_time {
};
#define KVM_VCPU_PREEMPTED (1 << 0)
+#define KVM_VCPU_FLUSH_TLB (1 << 1)
#define KVM_CLOCK_PAIRING_WALLCLOCK 0
struct kvm_clock_pairing {
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 6610b92fc6a5..4e37d1a851a6 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -498,6 +498,34 @@ static void __init kvm_apf_trap_init(void)
update_intr_gate(X86_TRAP_PF, async_page_fault);
}
+static DEFINE_PER_CPU(cpumask_var_t, __pv_tlb_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_tlb_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_guest_init(void)
{
int i;
@@ -517,6 +545,9 @@ static void __init kvm_guest_init(void)
pv_time_ops.steal_clock = kvm_steal_clock;
}
+ if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH))
+ pv_mmu_ops.flush_tlb_others = kvm_flush_tlb_others;
+
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
apic_set_eoi_write(kvm_guest_apic_eoi_write);
@@ -598,6 +629,22 @@ static __init int activate_jump_labels(void)
}
arch_initcall(activate_jump_labels);
+static __init int kvm_setup_pv_tlb_flush(void)
+{
+ int cpu;
+
+ if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH)) {
+ for_each_possible_cpu(cpu) {
+ zalloc_cpumask_var_node(per_cpu_ptr(&__pv_tlb_mask, cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+ }
+ pr_info("KVM setup pv remote TLB flush\n");
+ }
+
+ return 0;
+}
+arch_initcall(kvm_setup_pv_tlb_flush);
+
#ifdef CONFIG_PARAVIRT_SPINLOCKS
/* Kick a cpu by its apicid. Used to wake up a halted vcpu */