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-rw-r--r--Documentation/virt/kvm/msr.rst15
-rw-r--r--arch/s390/include/asm/kvm_host.h2
-rw-r--r--arch/x86/include/asm/kvm_host.h3
-rw-r--r--arch/x86/include/uapi/asm/kvm_para.h1
-rw-r--r--arch/x86/kvm/x86.c26
-rw-r--r--virt/kvm/async_pf.c10
6 files changed, 52 insertions, 5 deletions
diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst
index be08df12f31a..9b107889b033 100644
--- a/Documentation/virt/kvm/msr.rst
+++ b/Documentation/virt/kvm/msr.rst
@@ -236,7 +236,9 @@ data:
of these bytes is a token which was previously delivered as 'page not
present' event. The event indicates the page in now available. Guest is
supposed to write '0' to 'token' when it is done handling 'page ready'
- event so the next one can be delivered.
+ event and to write 1' to MSR_KVM_ASYNC_PF_ACK after clearing the location;
+ writing to the MSR forces KVM to re-scan its queue and deliver the next
+ pending notification.
Note, MSR_KVM_ASYNC_PF_INT MSR specifying the interrupt vector for 'page
ready' APF delivery needs to be written to before enabling APF mechanism
@@ -359,3 +361,14 @@ data:
Interrupt vector for asynchnonous 'page ready' notifications delivery.
The vector has to be set up before asynchronous page fault mechanism
is enabled in MSR_KVM_ASYNC_PF_EN.
+
+MSR_KVM_ASYNC_PF_ACK:
+ 0x4b564d07
+
+data:
+ Asynchronous page fault (APF) acknowledgment.
+
+ When the guest is done processing 'page ready' APF event and 'token'
+ field in 'struct kvm_vcpu_pv_apf_data' is cleared it is supposed to
+ write '1' to bit 0 of the MSR, this causes the host to re-scan its queue
+ and check if there are more notifications pending.
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 9d23bde1363b..3d554887794e 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -984,6 +984,8 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
struct kvm_async_pf *work);
+static inline void kvm_arch_async_page_present_queued(struct kvm_vcpu *vcpu) {}
+
void kvm_arch_crypto_clear_masks(struct kvm *kvm);
void kvm_arch_crypto_set_masks(struct kvm *kvm, unsigned long *apm,
unsigned long *aqm, unsigned long *adm);
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2d39571451a0..f345bcf38cfb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -86,6 +86,7 @@
#define KVM_REQ_TLB_FLUSH_CURRENT KVM_ARCH_REQ(26)
#define KVM_REQ_HV_TLB_FLUSH \
KVM_ARCH_REQ_FLAGS(27, KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_APF_READY KVM_ARCH_REQ(28)
#define CR0_RESERVED_BITS \
(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
@@ -775,6 +776,7 @@ struct kvm_vcpu_arch {
u32 host_apf_flags;
unsigned long nested_apf_token;
bool delivery_as_pf_vmexit;
+ bool pageready_pending;
} apf;
/* OSVW MSRs (AMD only) */
@@ -1662,6 +1664,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
struct kvm_async_pf *work);
void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu,
struct kvm_async_pf *work);
+void kvm_arch_async_page_present_queued(struct kvm_vcpu *vcpu);
bool kvm_arch_can_dequeue_async_page_present(struct kvm_vcpu *vcpu);
extern bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn);
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 1d37d616b1fc..7ac20df80ba8 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -51,6 +51,7 @@
#define MSR_KVM_PV_EOI_EN 0x4b564d04
#define MSR_KVM_POLL_CONTROL 0x4b564d05
#define MSR_KVM_ASYNC_PF_INT 0x4b564d06
+#define MSR_KVM_ASYNC_PF_ACK 0x4b564d07
struct kvm_steal_time {
__u64 steal;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e6f3ec5193b2..c9d709a672f3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1248,7 +1248,7 @@ static const u32 emulated_msrs_all[] = {
HV_X64_MSR_TSC_EMULATION_STATUS,
MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
- MSR_KVM_PV_EOI_EN, MSR_KVM_ASYNC_PF_INT,
+ MSR_KVM_PV_EOI_EN, MSR_KVM_ASYNC_PF_INT, MSR_KVM_ASYNC_PF_ACK,
MSR_IA32_TSC_ADJUST,
MSR_IA32_TSCDEADLINE,
@@ -2946,6 +2946,12 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
if (kvm_pv_enable_async_pf_int(vcpu, data))
return 1;
break;
+ case MSR_KVM_ASYNC_PF_ACK:
+ if (data & 0x1) {
+ vcpu->arch.apf.pageready_pending = false;
+ kvm_check_async_pf_completion(vcpu);
+ }
+ break;
case MSR_KVM_STEAL_TIME:
if (unlikely(!sched_info_on()))
@@ -3225,6 +3231,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_KVM_ASYNC_PF_INT:
msr_info->data = vcpu->arch.apf.msr_int_val;
break;
+ case MSR_KVM_ASYNC_PF_ACK:
+ msr_info->data = 0;
+ break;
case MSR_KVM_STEAL_TIME:
msr_info->data = vcpu->arch.st.msr_val;
break;
@@ -8413,6 +8422,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
kvm_hv_process_stimers(vcpu);
if (kvm_check_request(KVM_REQ_APICV_UPDATE, vcpu))
kvm_vcpu_update_apicv(vcpu);
+ if (kvm_check_request(KVM_REQ_APF_READY, vcpu))
+ kvm_check_async_pf_completion(vcpu);
}
if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
@@ -8664,8 +8675,6 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
break;
}
- kvm_check_async_pf_completion(vcpu);
-
if (signal_pending(current)) {
r = -EINTR;
vcpu->run->exit_reason = KVM_EXIT_INTR;
@@ -10555,13 +10564,22 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
trace_kvm_async_pf_ready(work->arch.token, work->cr2_or_gpa);
if (kvm_pv_async_pf_enabled(vcpu) &&
- !apf_put_user_ready(vcpu, work->arch.token))
+ !apf_put_user_ready(vcpu, work->arch.token)) {
+ vcpu->arch.apf.pageready_pending = true;
kvm_apic_set_irq(vcpu, &irq, NULL);
+ }
vcpu->arch.apf.halted = false;
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
}
+void kvm_arch_async_page_present_queued(struct kvm_vcpu *vcpu)
+{
+ kvm_make_request(KVM_REQ_APF_READY, vcpu);
+ if (!vcpu->arch.apf.pageready_pending)
+ kvm_vcpu_kick(vcpu);
+}
+
bool kvm_arch_can_dequeue_async_page_present(struct kvm_vcpu *vcpu)
{
if (!kvm_pv_async_pf_enabled(vcpu))
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 82e53f180a1a..f1e07fae84e9 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -51,6 +51,7 @@ static void async_pf_execute(struct work_struct *work)
unsigned long addr = apf->addr;
gpa_t cr2_or_gpa = apf->cr2_or_gpa;
int locked = 1;
+ bool first;
might_sleep();
@@ -69,10 +70,14 @@ static void async_pf_execute(struct work_struct *work)
kvm_arch_async_page_present(vcpu, apf);
spin_lock(&vcpu->async_pf.lock);
+ first = list_empty(&vcpu->async_pf.done);
list_add_tail(&apf->link, &vcpu->async_pf.done);
apf->vcpu = NULL;
spin_unlock(&vcpu->async_pf.lock);
+ if (!IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC) && first)
+ kvm_arch_async_page_present_queued(vcpu);
+
/*
* apf may be freed by kvm_check_async_pf_completion() after
* this point
@@ -201,6 +206,7 @@ retry_sync:
int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
{
struct kvm_async_pf *work;
+ bool first;
if (!list_empty_careful(&vcpu->async_pf.done))
return 0;
@@ -213,9 +219,13 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
INIT_LIST_HEAD(&work->queue); /* for list_del to work */
spin_lock(&vcpu->async_pf.lock);
+ first = list_empty(&vcpu->async_pf.done);
list_add_tail(&work->link, &vcpu->async_pf.done);
spin_unlock(&vcpu->async_pf.lock);
+ if (!IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC) && first)
+ kvm_arch_async_page_present_queued(vcpu);
+
vcpu->async_pf.queued++;
return 0;
}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-02 04:24:22 +0000