Mailing List Archive

xen/arch/x86/mm/mem_event.c | 26 ++++++++++++++++++++------
1 files changed, 20 insertions(+), 6 deletions(-)


Don't require a separate domctl to notify the memevent interface that an event
has occured. This domctl can be taxing, particularly when you are scaling
events and paging to many domains across a single system. Instead, we use the
existing event channel to signal when we place something in the ring (as per
normal ring operation).

Signed-off-by: Adin Scannell <adin@scannell.ca>
Signed-off-by: Keir Fraser <keir@xen.org>
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>

diff -r 106296812c3f -r 08a6ea63be98 xen/arch/x86/mm/mem_event.c
--- a/xen/arch/x86/mm/mem_event.c
+++ b/xen/arch/x86/mm/mem_event.c
@@ -37,9 +37,11 @@
#define mem_event_ring_lock(_med) spin_lock(&(_med)->ring_lock)
#define mem_event_ring_unlock(_med) spin_unlock(&(_med)->ring_lock)

-static int mem_event_enable(struct domain *d,
- xen_domctl_mem_event_op_t *mec,
- struct mem_event_domain *med)
+static int mem_event_enable(
+ struct domain *d,
+ xen_domctl_mem_event_op_t *mec,
+ struct mem_event_domain *med,
+ xen_event_channel_notification_t notification_fn)
{
int rc;
struct domain *dom_mem_event = current->domain;
@@ -97,7 +99,7 @@ static int mem_event_enable(struct domai
/* Allocate event channel */
rc = alloc_unbound_xen_event_channel(d->vcpu[0],
current->domain->domain_id,
- NULL);
+ notification_fn);
if ( rc < 0 )
goto err;

@@ -308,6 +310,18 @@ int mem_event_check_ring(struct domain *
return 0;
}

+/* Registered with Xen-bound event channel for incoming notifications. */
+static void mem_paging_notification(struct vcpu *v, unsigned int port)
+{
+ p2m_mem_paging_resume(v->domain);
+}
+
+/* Registered with Xen-bound event channel for incoming notifications. */
+static void mem_access_notification(struct vcpu *v, unsigned int port)
+{
+ p2m_mem_access_resume(v->domain);
+}
+
int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
XEN_GUEST_HANDLE(void) u_domctl)
{
@@ -369,7 +383,7 @@ int mem_event_domctl(struct domain *d, x
if ( p2m->pod.entry_count )
break;

- rc = mem_event_enable(d, mec, med);
+ rc = mem_event_enable(d, mec, med, mem_paging_notification);
}
break;

@@ -408,7 +422,7 @@ int mem_event_domctl(struct domain *d, x
if ( boot_cpu_data.x86_vendor != X86_VENDOR_INTEL )
break;

- rc = mem_event_enable(d, mec, med);
+ rc = mem_event_enable(d, mec, med, mem_access_notification);
}
break;


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