Mem event interface improvements

PATCH Applied Andres Lagar-Cavilla 3 participants 11 messages Dec 5, 2011 – Dec 6, 2011

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Andres Lagar-Cavilla

author

2011-12-05 15:11 UTC #0 lore raw

PATCH 1/1 Mem event interface improvements

In this patch series we add a series of improevements to the memory event interface. Namely:
- Allow batched consumption of multiple outstanding responses
- Signal Xen to consume responses solely with an event channel kick
- Extra flag to tag events generated byforeign-domains
- Allow placing dummy domains in the ring, to keep it in sync if a state transition does not require an explicit response.

All these changes are orthogonal to the outstanding proposals for enhancing ring management.

Signed-off-by Andres Lagar-Cavilla <[email protected]>

Signed-off-by Adin Scannell <[email protected]>

Signed-off-by Keir Fraser <[email protected]>

 xen/arch/x86/mm/mem_event.c     |   6 +++
 xen/include/public/mem_event.h  |   1 +
 xen/arch/ia64/vmx/vmx_init.c    |   2 +-
 xen/arch/x86/hvm/hvm.c          |   7 ++-
 xen/arch/x86/mm/mem_event.c     |   3 +-
 xen/common/event_channel.c      |  75 +++++++++++++++++++++++++++++++---------
 xen/include/xen/event.h         |   5 ++-
 xen/include/xen/sched.h         |   2 +-
 xen/arch/x86/mm/mem_event.c     |  26 ++++++++++---
 xen/arch/x86/mm/mem_event.c     |  10 ++++-
 xen/arch/x86/mm/mem_sharing.c   |  13 +++---
 xen/arch/x86/mm/p2m.c           |  52 ++++++++++++++-------------
 xen/include/asm-x86/mem_event.h |   2 +-
 xen/arch/x86/mm/mem_sharing.c   |   2 +
 xen/arch/x86/mm/p2m.c           |   4 ++
 xen/include/public/mem_event.h  |   7 +++
 16 files changed, 154 insertions(+), 63 deletions(-)

Andres Lagar-Cavilla

author

2011-12-05 15:12 UTC #1 lore raw

PATCH 1/1 Flag events caused by foreign domains

 xen/arch/x86/mm/mem_event.c    |  6 ++++++
 xen/include/public/mem_event.h |  1 +
 2 files changed, 7 insertions(+), 0 deletions(-)

Add a new flag for mem events, as consumers might need to discriminate foreign domain-caused from guest-caused events. The vcpu field of an event is bogus from a consumer p.o.v. for foreign domain-caused events.

Also assert that we shouldn't be pausing foreign vcpus.

Signed-off-by Andres Lagar-Cavilla <andres@lagarcavilla>

xen/arch/x86/mm/mem_event.c +6 -0

diff -r 8ad7af68e017 -r 2a4ec2e2ae36 xen/arch/x86/mm/mem_event.c
@@ -143,6 +143,12 @@ void mem_event_put_request(struct domain
     front_ring = &med->front_ring;
     req_prod = front_ring->req_prod_pvt;
 
+    if ( current->domain != d )
+    {
+        req->flags |= MEM_EVENT_FLAG_FOREIGN;
+        ASSERT( !(req->flags & MEM_EVENT_FLAG_VCPU_PAUSED) );
+    }
+
     /* Copy request */
     memcpy(RING_GET_REQUEST(front_ring, req_prod), req, sizeof(*req));
     req_prod++;

xen/include/public/mem_event.h +1 -0

diff -r 8ad7af68e017 -r 2a4ec2e2ae36 xen/include/public/mem_event.h
@@ -39,6 +39,7 @@
 #define MEM_EVENT_FLAG_VCPU_PAUSED  (1 << 0)
 #define MEM_EVENT_FLAG_DROP_PAGE    (1 << 1)
 #define MEM_EVENT_FLAG_EVICT_FAIL   (1 << 2)
+#define MEM_EVENT_FLAG_FOREIGN      (1 << 3)
 
 /* Reasons for the memory event request */
 #define MEM_EVENT_REASON_UNKNOWN     0    /* typical reason */

Andres Lagar-Cavilla

author

2011-12-05 15:12 UTC #2 lore raw

PATCH 1/1 Create a generic callback mechanism for Xen-bound event channels

In reply to Andres Lagar-Cavilla

 xen/arch/ia64/vmx/vmx_init.c |   2 +-
 xen/arch/x86/hvm/hvm.c       |   7 ++-
 xen/arch/x86/mm/mem_event.c  |   3 +-
 xen/common/event_channel.c   |  75 ++++++++++++++++++++++++++++++++++---------
 xen/include/xen/event.h      |   5 ++-
 xen/include/xen/sched.h      |   2 +-
 6 files changed, 70 insertions(+), 24 deletions(-)

For event channels for which Xen is the consumer, there currently is a single action. With this patch, we allow event channel creators to specify a generic callback (or no callback). Because the expectation is that there will be few callbacks, they are stored in a small table.

Signed-off-by Adin Scannell <[email protected]>

Signed-off-by Keir Fraser <[email protected]>

Signed-off-by Andres Lagar-Cavilla <[email protected]>

xen/arch/ia64/vmx/vmx_init.c +1 -1

diff -r 2a4ec2e2ae36 -r 4c19931b40d5 xen/arch/ia64/vmx/vmx_init.c
@@ -377,7 +377,7 @@ vmx_vcpu_initialise(struct vcpu *v)
 {
 	struct vmx_ioreq_page *iorp = &v->domain->arch.hvm_domain.ioreq;
 
-	int rc = alloc_unbound_xen_event_channel(v, 0);
+	int rc = alloc_unbound_xen_event_channel(v, 0, NULL);
 	if (rc < 0)
 		return rc;
 	v->arch.arch_vmx.xen_port = rc;

xen/arch/x86/hvm/hvm.c +4 -3

diff -r 2a4ec2e2ae36 -r 4c19931b40d5 xen/arch/x86/hvm/hvm.c
@@ -979,7 +979,7 @@ int hvm_vcpu_initialise(struct vcpu *v)
         goto fail3;
 
     /* Create ioreq event channel. */
-    rc = alloc_unbound_xen_event_channel(v, 0);
+    rc = alloc_unbound_xen_event_channel(v, 0, NULL);
     if ( rc < 0 )
         goto fail4;

@@ -989,7 +989,7 @@ int hvm_vcpu_initialise(struct vcpu *v)
     if ( v->vcpu_id == 0 )
     {
         /* Create bufioreq event channel. */
-        rc = alloc_unbound_xen_event_channel(v, 0);
+        rc = alloc_unbound_xen_event_channel(v, 0, NULL);
         if ( rc < 0 )
             goto fail2;
         v->domain->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_EVTCHN] = rc;

@@ -3561,7 +3561,8 @@ long do_hvm_op(unsigned long op, XEN_GUE
                 for_each_vcpu ( d, v )
                 {
                     int old_port, new_port;
-                    new_port = alloc_unbound_xen_event_channel(v, a.value);
+                    new_port = alloc_unbound_xen_event_channel(
+                        v, a.value, NULL);
                     if ( new_port < 0 )
                     {
                         rc = new_port;

xen/arch/x86/mm/mem_event.c +2 -1

diff -r 2a4ec2e2ae36 -r 4c19931b40d5 xen/arch/x86/mm/mem_event.c
@@ -93,7 +93,8 @@ static int mem_event_enable(struct domai
 
     /* Allocate event channel */
     rc = alloc_unbound_xen_event_channel(d->vcpu[0],
-                                         current->domain->domain_id);
+                                         current->domain->domain_id,
+                                         NULL);
     if ( rc < 0 )
         goto err;

xen/common/event_channel.c +58 ~~-17~~

141 lines not on this page · raw message

xen/include/xen/event.h +4 -1

diff -r 2a4ec2e2ae36 -r 4c19931b40d5 xen/include/xen/event.h
@@ -51,8 +51,11 @@ int evtchn_unmask(unsigned int port);
 void evtchn_move_pirqs(struct vcpu *v);
 
 /* Allocate/free a Xen-attached event channel port. */
+typedef void (*xen_event_channel_notification_t)(
+    struct vcpu *v, unsigned int port);
 int alloc_unbound_xen_event_channel(
-    struct vcpu *local_vcpu, domid_t remote_domid);
+    struct vcpu *local_vcpu, domid_t remote_domid,
+    xen_event_channel_notification_t notification_fn);
 void free_xen_event_channel(
     struct vcpu *local_vcpu, int port);

xen/include/xen/sched.h +1 -1

diff -r 2a4ec2e2ae36 -r 4c19931b40d5 xen/include/xen/sched.h
@@ -47,7 +47,7 @@ struct evtchn
 #define ECS_VIRQ         5 /* Channel is bound to a virtual IRQ line.        */
 #define ECS_IPI          6 /* Channel is bound to a virtual IPI line.        */
     u8  state;             /* ECS_* */
-    u8  consumer_is_xen;   /* Consumed by Xen or by guest? */
+    u8  xen_consumer;      /* Consumer in Xen, if any? (0 = send to guest) */
     u16 notify_vcpu_id;    /* VCPU for local delivery notification */
     union {
         struct {

Andres Lagar-Cavilla

author

2011-12-05 15:12 UTC #3 lore raw

PATCH 1/1 Allow memevent responses to be signaled via the event channel

In reply to Andres Lagar-Cavilla

 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 <[email protected]>

Signed-off-by Keir Fraser <[email protected]>

Signed-off-by Andres Lagar-Cavilla <[email protected]>

xen/arch/x86/mm/mem_event.c +20 -6

diff -r 4c19931b40d5 -r 22b05954f754 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;

@@ -94,7 +96,7 @@ 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;

@@ -233,6 +235,18 @@ int mem_event_check_ring(struct domain *
     return ring_full;
 }
 
+/* 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)
 {

@@ -294,7 +308,7 @@ 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;

@@ -333,7 +347,7 @@ 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;

Andres Lagar-Cavilla

author

2011-12-05 15:12 UTC #4 lore raw

PATCH 1/1 Consume multiple mem event responses off the ring

In reply to Andres Lagar-Cavilla

 xen/arch/x86/mm/mem_event.c     |  10 +++++++-
 xen/arch/x86/mm/mem_sharing.c   |  13 +++++----
 xen/arch/x86/mm/p2m.c           |  52 +++++++++++++++++++++-------------------
 xen/include/asm-x86/mem_event.h |   2 +-
 4 files changed, 44 insertions(+), 33 deletions(-)

Signed-off-by Andres Lagar-Cavilla <[email protected]>

Signed-off-by Adin Scannell <[email protected]>

xen/arch/x86/mm/mem_event.c +9 -1

diff -r 22b05954f754 -r c71f4c5b42f0 xen/arch/x86/mm/mem_event.c
@@ -166,7 +166,7 @@ void mem_event_put_request(struct domain
     notify_via_xen_event_channel(d, med->xen_port);
 }
 
-void mem_event_get_response(struct mem_event_domain *med, mem_event_response_t *rsp)
+int mem_event_get_response(struct mem_event_domain *med, mem_event_response_t *rsp)
 {
     mem_event_front_ring_t *front_ring;
     RING_IDX rsp_cons;

@@ -176,6 +176,12 @@ void mem_event_get_response(struct mem_e
     front_ring = &med->front_ring;
     rsp_cons = front_ring->rsp_cons;
 
+    if ( !RING_HAS_UNCONSUMED_RESPONSES(front_ring) )
+    {
+        mem_event_ring_unlock(med);
+        return 0;
+    }
+
     /* Copy response */
     memcpy(rsp, RING_GET_RESPONSE(front_ring, rsp_cons), sizeof(*rsp));
     rsp_cons++;

@@ -185,6 +191,8 @@ void mem_event_get_response(struct mem_e
     front_ring->sring->rsp_event = rsp_cons + 1;
 
     mem_event_ring_unlock(med);
+
+    return 1;
 }
 
 void mem_event_unpause_vcpus(struct domain *d)

xen/arch/x86/mm/mem_sharing.c +7 -6

diff -r 22b05954f754 -r c71f4c5b42f0 xen/arch/x86/mm/mem_sharing.c
@@ -300,12 +300,13 @@ int mem_sharing_sharing_resume(struct do
 {
     mem_event_response_t rsp;
 
-    /* Get request off the ring */
-    mem_event_get_response(&d->mem_event->share, &rsp);
-
-    /* Unpause domain/vcpu */
-    if( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
-        vcpu_unpause(d->vcpu[rsp.vcpu_id]);
+    /* Get all requests off the ring */
+    while ( mem_event_get_response(&d->mem_event->share, &rsp) )
+    {
+        /* Unpause domain/vcpu */
+        if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
+            vcpu_unpause(d->vcpu[rsp.vcpu_id]);
+    }
 
     return 0;
 }

xen/arch/x86/mm/p2m.c +27 ~~-25~~

69 lines not on this page · raw message

xen/include/asm-x86/mem_event.h +1 -1

diff -r 22b05954f754 -r c71f4c5b42f0 xen/include/asm-x86/mem_event.h
@@ -29,7 +29,7 @@ void mem_event_mark_and_pause(struct vcp
 int mem_event_check_ring(struct domain *d, struct mem_event_domain *med);
 void mem_event_put_req_producers(struct mem_event_domain *med);
 void mem_event_put_request(struct domain *d, struct mem_event_domain *med, mem_event_request_t *req);
-void mem_event_get_response(struct mem_event_domain *med, mem_event_response_t *rsp);
+int mem_event_get_response(struct mem_event_domain *med, mem_event_response_t *rsp);
 void mem_event_unpause_vcpus(struct domain *d);
 
 int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,

Andres Lagar-Cavilla

author

2011-12-05 15:12 UTC #5 lore raw

PATCH 1/1 Ignore memory events with an obviously invalid gfn

In reply to Andres Lagar-Cavilla

 xen/arch/x86/mm/mem_sharing.c  |  2 ++
 xen/arch/x86/mm/p2m.c          |  4 ++++
 xen/include/public/mem_event.h |  7 +++++++
 3 files changed, 13 insertions(+), 0 deletions(-)

Ring semantics require that for every request, a response be put. This allows consumer to place a dummy response if need be.

Signed-off-by Andres Lagar-Cavilla <[email protected]>

xen/arch/x86/mm/mem_sharing.c +2 -0

diff -r c71f4c5b42f0 -r 790cd814bee8 xen/arch/x86/mm/mem_sharing.c
@@ -303,6 +303,8 @@ int mem_sharing_sharing_resume(struct do
     /* Get all requests off the ring */
     while ( mem_event_get_response(&d->mem_event->share, &rsp) )
     {
+        if ( DUMMY_MEM_EVENT_RSP(&rsp) )
+            continue;
         /* Unpause domain/vcpu */
         if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
             vcpu_unpause(d->vcpu[rsp.vcpu_id]);

xen/arch/x86/mm/p2m.c +4 -0

diff -r c71f4c5b42f0 -r 790cd814bee8 xen/arch/x86/mm/p2m.c
@@ -1069,6 +1069,8 @@ void p2m_mem_paging_resume(struct domain
     /* Pull all responses off the ring */
     while( mem_event_get_response(&d->mem_event->paging, &rsp) )
     {
+        if ( DUMMY_MEM_EVENT_RSP(&rsp) )
+            continue;
         /* Fix p2m entry if the page was not dropped */
         if ( !(rsp.flags & MEM_EVENT_FLAG_DROP_PAGE) )
         {

@@ -1177,6 +1179,8 @@ void p2m_mem_access_resume(struct domain
     /* Pull all responses off the ring */
     while( mem_event_get_response(&d->mem_event->access, &rsp) )
     {
+        if ( DUMMY_MEM_EVENT_RSP(&rsp) )
+            continue;
         /* Unpause domain */
         if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
             vcpu_unpause(d->vcpu[rsp.vcpu_id]);

xen/include/public/mem_event.h +7 -0

diff -r c71f4c5b42f0 -r 790cd814bee8 xen/include/public/mem_event.h
@@ -76,6 +76,13 @@ typedef struct mem_event_st {
 
 DEFINE_RING_TYPES(mem_event, mem_event_request_t, mem_event_response_t);
 
+#define INVALID_RSP_GFN -1UL
+
+#define DUMMY_MEM_EVENT_RSP(_r)         ((_r)->gfn == INVALID_RSP_GFN)
+#define MAKE_MEM_EVENT_RSP_DUMMY(_r)    ((_r)->gfn = INVALID_RSP_GFN)
+#define DECLARE_DUMMY_MEM_EVENT_RSP(_name) \
+    mem_event_response_t _name = { .gfn = INVALID_RSP_GFN }
+
 #endif
 
 /*

Tim Deegan

2011-12-05 16:01 UTC #6 lore raw

Re: [PATCH 5 of 5] Ignore memory events with an obviously invalid gfn

Quoted 13 lines · Andres Lagar-Cavilla

 xen/arch/x86/mm/mem_sharing.c  |  2 ++
 xen/arch/x86/mm/p2m.c          |  4 ++++
 xen/include/public/mem_event.h |  7 +++++++
 3 files changed, 13 insertions(+), 0 deletions(-)
Ring semantics require that for every request, a response be put. This allows consumer to place a dummy response if need be.
diff -r c71f4c5b42f0 -r 790cd814bee8 xen/include/public/mem_event.h

xen/include/public/mem_event.h typedef struct mem_event_st { · line 80

Quoted 5 lines

xen/include/public/mem_event.h +2 -0

@@ -76,6 +76,13 @@ typedef struct mem_event_st {
 
 DEFINE_RING_TYPES(mem_event, mem_event_request_t, mem_event_response_t);
 
+#define INVALID_RSP_GFN -1UL
+

On a 32-bit system this doesn't do what you want.

Actually, can you use a flag for this, please? Wedging it into the gfn field seems a bit of a hack, and we have plenty of flag bits left.

Tim.

Quoted 13 lines

xen/include/public/mem_event.h +5 -0
+#define DUMMY_MEM_EVENT_RSP(_r)         ((_r)->gfn == INVALID_RSP_GFN)
+#define MAKE_MEM_EVENT_RSP_DUMMY(_r)    ((_r)->gfn = INVALID_RSP_GFN)
+#define DECLARE_DUMMY_MEM_EVENT_RSP(_name) \
+    mem_event_response_t _name = { .gfn = INVALID_RSP_GFN }
+
 #endif
 
 /*
_______________________________________________
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http://lists.xensource.com/xen-devel

Andres Lagar-Cavilla

author

2011-12-05 16:20 UTC #7 lore raw

Re: [PATCH 5 of 5] Ignore memory events with an obviously invalid gfn

Quoted 23 lines

Quoted 13 lines · Andres Lagar-Cavilla
 xen/arch/x86/mm/mem_sharing.c  |  2 ++
 xen/arch/x86/mm/p2m.c          |  4 ++++
 xen/include/public/mem_event.h |  7 +++++++
 3 files changed, 13 insertions(+), 0 deletions(-)
Ring semantics require that for every request, a response be put. This allows consumer to place a dummy response if need be.
diff -r c71f4c5b42f0 -r 790cd814bee8 xen/include/public/mem_event.h
xen/include/public/mem_event.h typedef struct mem_event_st { · line 81
Quoted 6 lines
xen/include/public/mem_event.h +2 -0
@@ -76,6 +76,13 @@ typedef struct mem_event_st {
 
 DEFINE_RING_TYPES(mem_event, mem_event_request_t,
 mem_event_response_t);
 
+#define INVALID_RSP_GFN -1UL
+
On a 32-bit system this doesn't do what you want.

Quoted 4 lines

Actually, can you use a flag for this, please? Wedging it into the gfn field seems a bit of a hack, and we have plenty of flag bits left.
Tim.

Good point, here it is:

# HG changeset patch
# Parent c71f4c5b42f0c7cc04e4ae758c8ab775305f2c6a Ignore memory events with an obviously invalid gfn.

Ring semantics require that for every request, a response be put. This allows consumer to place a dummy response if need be.

Signed-off-by Andres Lagar-Cavilla <[email protected]>

xen/arch/x86/mm/mem_sharing.c +2 -0

diff -r c71f4c5b42f0 xen/arch/x86/mm/mem_sharing.c
@@ -303,6 +303,8 @@ int mem_sharing_sharing_resume(struct do
     /* Get all requests off the ring */
     while ( mem_event_get_response(&d->mem_event->share, &rsp) )
     {
+        if ( DUMMY_MEM_EVENT_RSP(&rsp) )
+            continue;
         /* Unpause domain/vcpu */
         if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
             vcpu_unpause(d->vcpu[rsp.vcpu_id]);

xen/arch/x86/mm/p2m.c +4 -0

diff -r c71f4c5b42f0 xen/arch/x86/mm/p2m.c
@@ -1069,6 +1069,8 @@ void p2m_mem_paging_resume(struct domain
     /* Pull all responses off the ring */
     while( mem_event_get_response(&d->mem_event->paging, &rsp) )
     {
+        if ( DUMMY_MEM_EVENT_RSP(&rsp) )
+            continue;
         /* Fix p2m entry if the page was not dropped */
         if ( !(rsp.flags & MEM_EVENT_FLAG_DROP_PAGE) )
         {

@@ -1177,6 +1179,8 @@ void p2m_mem_access_resume(struct domain
     /* Pull all responses off the ring */
     while( mem_event_get_response(&d->mem_event->access, &rsp) )
     {
+        if ( DUMMY_MEM_EVENT_RSP(&rsp) )
+            continue;
         /* Unpause domain */
         if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
             vcpu_unpause(d->vcpu[rsp.vcpu_id]);

xen/include/public/mem_event.h +8 -0

diff -r c71f4c5b42f0 xen/include/public/mem_event.h
@@ -40,6 +40,7 @@
 #define MEM_EVENT_FLAG_DROP_PAGE    (1 << 1)
 #define MEM_EVENT_FLAG_EVICT_FAIL   (1 << 2)
 #define MEM_EVENT_FLAG_FOREIGN      (1 << 3)
+#define MEM_EVENT_FLAG_DUMMY        (1 << 4)
 
 /* Reasons for the memory event request */
 #define MEM_EVENT_REASON_UNKNOWN     0    /* typical reason */

@@ -76,6 +77,13 @@ typedef struct mem_event_st {
 
 DEFINE_RING_TYPES(mem_event, mem_event_request_t, mem_event_response_t);
 
+#define DUMMY_MEM_EVENT_RSP(_r)             \
+        ((_r)->flags & MEM_EVENT_FLAG_DUMMY)
+#define MAKE_MEM_EVENT_RSP_DUMMY(_r)        \
+        ((_r)->flags |= MEM_EVENT_FLAG_DUMMY)
+#define DECLARE_DUMMY_MEM_EVENT_RSP(_name)  \
+    mem_event_response_t _name = { .flags = MEM_EVENT_FLAG_DUMMY }
+
 #endif
 
 /*

Olaf Hering

2011-12-06 12:23 UTC #8 lore raw

In reply to Andres Lagar-Cavilla

Quoted 7 lines · Andres Lagar-Cavilla

In this patch series we add a series of improevements to the memory event interface. Namely:
- Allow batched consumption of multiple outstanding responses
- Signal Xen to consume responses solely with an event channel kick
- Extra flag to tag events generated byforeign-domains
- Allow placing dummy domains in the ring, to keep it in sync if a state transition does not require an explicit response.

Assuming that these patches have been tested, I'm ok with them.

Olaf

Tim Deegan

Applied

2011-12-06 20:15 UTC #9 lore raw

In reply to Andres Lagar-Cavilla

Quoted 7 lines · Andres Lagar-Cavilla

In this patch series we add a series of improevements to the memory event interface. Namely:
- Allow batched consumption of multiple outstanding responses
- Signal Xen to consume responses solely with an event channel kick
- Extra flag to tag events generated byforeign-domains
- Allow placing dummy domains in the ring, to keep it in sync if a state transition does not require an explicit response.

Applied, thanks. I stripped out the 'MEM_EVENT_RSP' macros from patch 5, as they didn't seem useful now that it's just a flag, so you might have to fix up your client code to match.

Cheers,

Tim.

Andres Lagar-Cavilla

author

2011-12-06 20:39 UTC #10 lore raw

Quoted 9 lines

Quoted 7 lines · Andres Lagar-Cavilla
In this patch series we add a series of improevements to the memory event interface. Namely:
- Allow batched consumption of multiple outstanding responses
- Signal Xen to consume responses solely with an event channel kick
- Extra flag to tag events generated byforeign-domains
- Allow placing dummy domains in the ring, to keep it in sync if a state transition does not require an explicit response.

Quoted 7 lines

Applied, thanks. I stripped out the 'MEM_EVENT_RSP' macros from patch 5, as they didn't seem useful now that it's just a flag, so you might have to fix up your client code to match.
Cheers,
Tim.

Thanks! no biggie about macros
Andres

Quoted 2 lines