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authorchai wen <chaiw.fnst@cn.fujitsu.com>2013-10-14 22:22:33 +0800
committerGleb Natapov <gleb@redhat.com>2013-10-15 13:43:37 +0300
commitf2e106692d5189303997ad7b96de8d8123aa5613 (patch)
treebe15cad31bc5701570a571b3be04e299bb4ac547 /virt
parenta7efdf6bec34f1a693a926ebd08de6ba6e700dff (diff)
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KVM: Drop FOLL_GET in GUP when doing async page fault
Page pinning is not mandatory in kvm async page fault processing since after async page fault event is delivered to a guest it accesses page once again and does its own GUP. Drop the FOLL_GET flag in GUP in async_pf code, and do some simplifying in check/clear processing. Suggested-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Gu zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: chai wen <chaiw.fnst@cn.fujitsu.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/async_pf.c17
1 files changed, 5 insertions, 12 deletions
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index b197950ac4d5..8631d9c14320 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -56,7 +56,6 @@ void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu)
static void async_pf_execute(struct work_struct *work)
{
- struct page *page = NULL;
struct kvm_async_pf *apf =
container_of(work, struct kvm_async_pf, work);
struct mm_struct *mm = apf->mm;
@@ -68,13 +67,12 @@ static void async_pf_execute(struct work_struct *work)
use_mm(mm);
down_read(&mm->mmap_sem);
- get_user_pages(current, mm, addr, 1, 1, 0, &page, NULL);
+ get_user_pages(current, mm, addr, 1, 1, 0, NULL, NULL);
up_read(&mm->mmap_sem);
unuse_mm(mm);
spin_lock(&vcpu->async_pf.lock);
list_add_tail(&apf->link, &vcpu->async_pf.done);
- apf->page = page;
spin_unlock(&vcpu->async_pf.lock);
/*
@@ -82,7 +80,7 @@ static void async_pf_execute(struct work_struct *work)
* this point
*/
- trace_kvm_async_pf_completed(addr, page, gva);
+ trace_kvm_async_pf_completed(addr, gva);
if (waitqueue_active(&vcpu->wq))
wake_up_interruptible(&vcpu->wq);
@@ -112,8 +110,6 @@ void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
list_entry(vcpu->async_pf.done.next,
typeof(*work), link);
list_del(&work->link);
- if (!is_error_page(work->page))
- kvm_release_page_clean(work->page);
kmem_cache_free(async_pf_cache, work);
}
spin_unlock(&vcpu->async_pf.lock);
@@ -133,14 +129,11 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
list_del(&work->link);
spin_unlock(&vcpu->async_pf.lock);
- if (work->page)
- kvm_arch_async_page_ready(vcpu, work);
+ kvm_arch_async_page_ready(vcpu, work);
kvm_arch_async_page_present(vcpu, work);
list_del(&work->queue);
vcpu->async_pf.queued--;
- if (!is_error_page(work->page))
- kvm_release_page_clean(work->page);
kmem_cache_free(async_pf_cache, work);
}
}
@@ -163,7 +156,7 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
if (!work)
return 0;
- work->page = NULL;
+ work->wakeup_all = false;
work->vcpu = vcpu;
work->gva = gva;
work->addr = gfn_to_hva(vcpu->kvm, gfn);
@@ -203,7 +196,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
if (!work)
return -ENOMEM;
- work->page = KVM_ERR_PTR_BAD_PAGE;
+ work->wakeup_all = true;
INIT_LIST_HEAD(&work->queue); /* for list_del to work */
spin_lock(&vcpu->async_pf.lock);