diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 67f6a40b5e93a2f9b19ae4be197ba150a083b6a0..31d0ca8de02f784bd7d4f4d44c6f6af95e05558d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -801,6 +801,7 @@ config KVM_GUEST
depends on PARAVIRT
select PARAVIRT_CLOCK
select ARCH_CPUIDLE_HALTPOLL
+ select X86_HV_CALLBACK_VECTOR
default y
---help---
This option enables various optimizations for running under the KVM
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index a5eed844e948bd853fbb22428a0c3d76d306c80b..e0d1938c041518095be21b7eca0af74a6e3548b2 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1475,6 +1475,11 @@ BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR,
#endif /* CONFIG_HYPERV */
+#ifdef CONFIG_KVM_GUEST
+BUILD_INTERRUPT3(kvm_async_pf_vector, HYPERVISOR_CALLBACK_VECTOR,
+ kvm_async_pf_intr)
+#endif
+
SYM_CODE_START(page_fault)
ASM_CLAC
pushl $do_page_fault
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index eead1e2bebd5c12f1bda7539760ae728b268a09b..cd8af69dd9ff5449335deb12842402534bc82838 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1190,6 +1190,11 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
acrn_hv_callback_vector acrn_hv_vector_handler
#endif
+#ifdef CONFIG_KVM_GUEST
+apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
+ kvm_async_pf_vector kvm_async_pf_intr
+#endif
+
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=IST_INDEX_DB ist_offset=DB_STACK_OFFSET
idtentry int3 do_int3 has_error_code=0 create_gap=1
idtentry stack_segment do_stack_segment has_error_code=1
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 57fd1966c4ea9a4063215e8d1d2f0690b7681066..bbc43e5411d95a5e6ceff3544b9eff533a62f50a 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -4,6 +4,7 @@
#include <asm/processor.h>
#include <asm/alternative.h>
+#include <linux/interrupt.h>
#include <uapi/asm/kvm_para.h>
extern void kvmclock_init(void);
@@ -104,6 +105,12 @@ static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token)
return false;
}
+extern __visible void kvm_async_pf_vector(void);
+#ifdef CONFIG_TRACING
+#define trace_kvm_async_pf_vector kvm_async_pf_vector
+#endif
+__visible void __irq_entry kvm_async_pf_intr(struct pt_regs *regs);
+
#ifdef CONFIG_PARAVIRT_SPINLOCKS
void __init kvm_spinlock_init(void);
#else /* !CONFIG_PARAVIRT_SPINLOCKS */
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 7e6403a8d8610f1816de20a636f8d21799e1cd3d..3a0115e8d880617becad69ba5312152b1a5d3c5c 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -233,15 +233,10 @@ NOKPROBE_SYMBOL(kvm_read_and_reset_apf_flags);
bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
{
- u32 reason = kvm_read_and_reset_apf_flags();
+ u32 flags = kvm_read_and_reset_apf_flags();
- switch (reason) {
- case KVM_PV_REASON_PAGE_NOT_PRESENT:
- case KVM_PV_REASON_PAGE_READY:
- break;
- default:
+ if (!flags)
return false;
- }
/*
* If the host managed to inject an async #PF into an interrupt
@@ -251,19 +246,38 @@ bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
if (unlikely(!(regs->flags & X86_EFLAGS_IF)))
panic("Host injected async #PF in interrupt disabled region\n");
- if (reason == KVM_PV_REASON_PAGE_NOT_PRESENT) {
+ if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) {
if (unlikely(!(user_mode(regs))))
panic("Host injected async #PF in kernel mode\n");
/* Page is swapped out by the host. */
kvm_async_pf_task_wait_schedule(token);
- } else {
+ return true;
+ }
+
+ WARN_ONCE(1, "Unexpected async PF flags: %x\n", flags);
+ return true;
+}
+NOKPROBE_SYMBOL(__kvm_handle_async_pf);
+
+__visible void __irq_entry kvm_async_pf_intr(struct pt_regs *regs)
+{
+ u32 token;
+
+ entering_ack_irq();
+
+ inc_irq_stat(irq_hv_callback_count);
+
+ if (__this_cpu_read(apf_reason.enabled)) {
+ token = __this_cpu_read(apf_reason.token);
rcu_irq_enter();
kvm_async_pf_task_wake(token);
rcu_irq_exit();
+ __this_cpu_write(apf_reason.token, 0);
+ wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
}
- return true;
+
+ exiting_irq();
}
-NOKPROBE_SYMBOL(__kvm_handle_async_pf);
static void __init paravirt_ops_setup(void)
{
@@ -308,17 +322,19 @@ static notrace void kvm_guest_apic_eoi_write(u32 reg, u32 val)
static void kvm_guest_cpu_init(void)
{
- if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
- u64 pa;
+ if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
+ u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
WARN_ON_ONCE(!static_branch_likely(&kvm_async_pf_enabled));
pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
- pa |= KVM_ASYNC_PF_ENABLED;
+ pa |= KVM_ASYNC_PF_ENABLED | KVM_ASYNC_PF_DELIVERY_AS_INT;
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_VMEXIT))
pa |= KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
+ wrmsrl(MSR_KVM_ASYNC_PF_INT, HYPERVISOR_CALLBACK_VECTOR);
+
wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
__this_cpu_write(apf_reason.enabled, 1);
pr_info("KVM setup async PF for cpu %d\n", smp_processor_id());
@@ -643,8 +659,10 @@ static void __init kvm_guest_init(void)
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
apic_set_eoi_write(kvm_guest_apic_eoi_write);
- if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf)
+ if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
static_branch_enable(&kvm_async_pf_enabled);
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, kvm_async_pf_vector);
+ }
#ifdef CONFIG_SMP
smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;