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Diffstat (limited to 'virt/kvm/async_pf.c')
-rw-r--r--virt/kvm/async_pf.c56
1 files changed, 31 insertions, 25 deletions
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 15e5b037f92d..9bfe1d6f6529 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();
@@ -59,20 +60,24 @@ static void async_pf_execute(struct work_struct *work)
* mm and might be done in another context, so we must
* access remotely.
*/
- down_read(&mm->mmap_sem);
- get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL,
+ mmap_read_lock(mm);
+ get_user_pages_remote(mm, addr, 1, FOLL_WRITE, NULL, NULL,
&locked);
if (locked)
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
if (IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC))
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
@@ -80,8 +85,7 @@ static void async_pf_execute(struct work_struct *work)
trace_kvm_async_pf_completed(addr, cr2_or_gpa);
- if (swq_has_sleeper(&vcpu->wq))
- swake_up_one(&vcpu->wq);
+ __kvm_vcpu_wake_up(vcpu);
mmput(mm);
kvm_put_kvm(vcpu->kvm);
@@ -135,7 +139,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
struct kvm_async_pf *work;
while (!list_empty_careful(&vcpu->async_pf.done) &&
- kvm_arch_can_inject_async_page_present(vcpu)) {
+ kvm_arch_can_dequeue_async_page_present(vcpu)) {
spin_lock(&vcpu->async_pf.lock);
work = list_first_entry(&vcpu->async_pf.done, typeof(*work),
link);
@@ -152,15 +156,21 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
}
}
-int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
- unsigned long hva, struct kvm_arch_async_pf *arch)
+/*
+ * Try to schedule a job to handle page fault asynchronously. Returns 'true' on
+ * success, 'false' on failure (page fault has to be handled synchronously).
+ */
+bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
+ unsigned long hva, struct kvm_arch_async_pf *arch)
{
struct kvm_async_pf *work;
if (vcpu->async_pf.queued >= ASYNC_PF_PER_VCPU)
- return 0;
+ return false;
- /* setup delayed work */
+ /* Arch specific code should not do async PF in this case */
+ if (unlikely(kvm_is_error_hva(hva)))
+ return false;
/*
* do alloc nowait since if we are going to sleep anyway we
@@ -168,7 +178,7 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
*/
work = kmem_cache_zalloc(async_pf_cache, GFP_NOWAIT | __GFP_NOWARN);
if (!work)
- return 0;
+ return false;
work->wakeup_all = false;
work->vcpu = vcpu;
@@ -179,29 +189,21 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
mmget(work->mm);
kvm_get_kvm(work->vcpu->kvm);
- /* this can't really happen otherwise gfn_to_pfn_async
- would succeed */
- if (unlikely(kvm_is_error_hva(work->addr)))
- goto retry_sync;
-
INIT_WORK(&work->work, async_pf_execute);
- if (!schedule_work(&work->work))
- goto retry_sync;
list_add_tail(&work->queue, &vcpu->async_pf.queue);
vcpu->async_pf.queued++;
- kvm_arch_async_page_not_present(vcpu, work);
- return 1;
-retry_sync:
- kvm_put_kvm(work->vcpu->kvm);
- mmput(work->mm);
- kmem_cache_free(async_pf_cache, work);
- return 0;
+ work->notpresent_injected = kvm_arch_async_page_not_present(vcpu, work);
+
+ schedule_work(&work->work);
+
+ return true;
}
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;
@@ -214,9 +216,13 @@ 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;
}