Re: [RFC PATCH v3 11/19] Implement qmp and hmp commands for notification lists
Hi,
On Fri, Sep 21, 2012 at 04:03:26PM -0600, Eric Blake wrote:
On 09/21/2012 05:17 AM, Vasilis Liaskovitis wrote:
Guest can respond to ACPI hotplug events e.g. with _EJ or _OST method.
This patch implements a tail queue to store guest notifications for memory
hot-add and hot-remove requests.
Guest responses for memory hotplug command on a per-dimm basis can be
detected
with the new hmp command info memhp or the new qmp command query-memhp
Naming doesn't match the QMP code.
will fix.
Examples:
(qemu) device_add dimm,id=ram0
These notification items should probably be part of migration state (not yet
implemented).
In the case of libvirt driving migration, you already said in 10/19 that
libvirt has to start the destination with the populated=on|off fields
correct for each dimm according to the state it was in at the time the
That patch actually alleviates this restriction for the off-on direction i.e.
it allows for the target-VM to not have its args updated for dimm hot-add.
(e.g. Let's say the source was started with a dimm, initialy off. The dimm is
hot-plugged, and then migrated . WIth patch 10/19, the populated arg doesn't
have to be updated on the target)
The other direction (off-on) still needs correct arg change.
If libvirt/management layers guarantee the dimm arguments are correctly changed,
I don't see that we need 10/19 patch eventually.
What I think is needed is another hmp/qmp command, that will report
which dimms are on/off at any given time e.g.
(monitor) info memory-hotplug
dimm0: off
dimm1: on
...
dimmN: off
This can be used on the source by libvirt / other layers to find out the
populated dimms, and construct the correct command line on the destination.
Does this make sense to you?
The current patch only deals with success/failure event notifications (not
on-off state of dimms) and should probably be renamed to
query-memory-hotplug-events.
host started the update. Can the host hot unplug memory after migration
has started?
Good testcase. I would rather not allow any hotplug operations while the
migration
is happening.
What do we do with pci hotplug during migration currently? I found a discussion
dating from a year ago, suggesting the same as the simplest solution, but I
don't know what's currently implemented.
http://lists.nongnu.org/archive/html/qemu-devel/2011-07/msg01204.html
+
+##
+# @MemHpInfo:
+#
+# Information about status of a memory hotplug command
+#
+# @dimm: the Dimm associated with the result
+#
+# @result: the result of the hotplug command
+#
+# Since: 1.3
+#
+##
+{ 'type': 'MemHpInfo',
+ 'data': {'dimm': 'str', 'request': 'str', 'result': 'str'} }
Should 'result' be a bool (true for success, false for still pending) or
an enum, instead of a free-form string? Likewise, isn't 'request' going
to be exactly one of two values (plug or unplug)?
agreed with 'request'.
For 'result' it is also a boolean, but with 'success' and 'failure' (rather than
'pending'). Items are only queued when the guest has given us a definite _OST
or _EJ result wich is either success or fail. If an operation is pending,
nothing
is queued here.
Perhaps queueing pending operations also has a usecase, but this isn't addressed
in this patch.
thanks,
- Vasilis
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[RFC PATCH v3 11/19] Implement qmp and hmp commands for notification lists
Guest can respond to ACPI hotplug events e.g. with _EJ or _OST method.
This patch implements a tail queue to store guest notifications for memory
hot-add and hot-remove requests.
Guest responses for memory hotplug command on a per-dimm basis can be detected
with the new hmp command info memhp or the new qmp command query-memhp
Examples:
(qemu) device_add dimm,id=ram0
(qemu) info memory-hotplug
dimm: ram0 hot-add success
or
dimm: ram0 hot-add failure
(qemu) device_del ram3
(qemu) info memory-hotplug
dimm: ram3 hot-remove success
or
dimm: ram3 hot-remove failure
Results are removed from the queue once read.
This patch only queues _EJ events that signal hot-remove success.
For _OST event queuing, which cover the hot-remove failure and
hot-add success/failure cases, the _OST patches in this series are are also
needed.
These notification items should probably be part of migration state (not yet
implemented).
Signed-off-by: Vasilis Liaskovitis vasilis.liaskovi...@profitbricks.com
---
hmp-commands.hx |2 +
hmp.c| 17 ++
hmp.h|1 +
hw/dimm.c| 62 +-
hw/dimm.h|2 +-
monitor.c|7 ++
qapi-schema.json | 26 ++
qmp-commands.hx | 37
8 files changed, 152 insertions(+), 2 deletions(-)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index ed67e99..cfb1b67 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1462,6 +1462,8 @@ show device tree
show qdev device model list
@item info roms
show roms
+@item info memory-hotplug
+show memory-hotplug
@end table
ETEXI
diff --git a/hmp.c b/hmp.c
index ba6fbd3..4b3d63d 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1168,3 +1168,20 @@ void hmp_screen_dump(Monitor *mon, const QDict *qdict)
qmp_screendump(filename, err);
hmp_handle_error(mon, err);
}
+
+void hmp_info_memory_hotplug(Monitor *mon)
+{
+MemHpInfoList *info;
+MemHpInfoList *item;
+MemHpInfo *dimm;
+
+info = qmp_query_memory_hotplug(NULL);
+for (item = info; item; item = item-next) {
+dimm = item-value;
+monitor_printf(mon, dimm: %s %s %s\n, dimm-dimm,
+dimm-request, dimm-result);
+dimm-dimm = NULL;
+}
+
+qapi_free_MemHpInfoList(info);
+}
diff --git a/hmp.h b/hmp.h
index 48b9c59..986705a 100644
--- a/hmp.h
+++ b/hmp.h
@@ -73,5 +73,6 @@ void hmp_getfd(Monitor *mon, const QDict *qdict);
void hmp_closefd(Monitor *mon, const QDict *qdict);
void hmp_send_key(Monitor *mon, const QDict *qdict);
void hmp_screen_dump(Monitor *mon, const QDict *qdict);
+void hmp_info_memory_hotplug(Monitor *mon);
#endif
diff --git a/hw/dimm.c b/hw/dimm.c
index 288b997..fbd93a8 100644
--- a/hw/dimm.c
+++ b/hw/dimm.c
@@ -65,6 +65,7 @@ static void dimm_bus_initfn(Object *obj)
DimmBus *bus = DIMM_BUS(obj);
QTAILQ_INIT(bus-dimmconfig_list);
QTAILQ_INIT(bus-dimmlist);
+QTAILQ_INIT(bus-dimm_hp_result_queue);
QTAILQ_FOREACH_SAFE(dimm_cfg, dimmconfig_list, nextdimmcfg,
next_dimm_cfg) {
QTAILQ_REMOVE(dimmconfig_list, dimm_cfg, nextdimmcfg);
@@ -236,20 +237,78 @@ void dimm_notify(uint32_t idx, uint32_t event)
{
DimmBus *bus = main_memory_bus;
DimmDevice *s;
+DimmConfig *slotcfg;
+struct dimm_hp_result *result;
+
s = dimm_find_from_idx(idx);
assert(s != NULL);
+result = g_malloc0(sizeof(*result));
+slotcfg = dimmcfg_find_from_name(DEVICE(s)-id);
+result-dimmname = slotcfg-name;
switch(event) {
case DIMM_REMOVE_SUCCESS:
dimm_depopulate(s);
-qdev_simple_unplug_cb((DeviceState*)s);
QTAILQ_REMOVE(bus-dimmlist, s, nextdimm);
+qdev_simple_unplug_cb((DeviceState*)s);
+QTAILQ_INSERT_TAIL(bus-dimm_hp_result_queue, result, next);
break;
default:
+g_free(result);
break;
}
}
+MemHpInfoList *qmp_query_memory_hotplug(Error **errp)
+{
+DimmBus *bus = main_memory_bus;
+MemHpInfoList *head = NULL, *cur_item = NULL, *info;
+struct dimm_hp_result *item, *nextitem;
+
+QTAILQ_FOREACH_SAFE(item, bus-dimm_hp_result_queue, next, nextitem) {
+
+info = g_malloc0(sizeof(*info));
+info-value = g_malloc0(sizeof(*info-value));
+info-value-dimm = g_malloc0(sizeof(char) * 32);
+info-value-request = g_malloc0(sizeof(char) * 16);
+info-value-result = g_malloc0(sizeof(char) * 16);
+switch (item-ret) {
+case DIMM_REMOVE_SUCCESS:
+strcpy(info-value-request, hot-remove);
+strcpy(info-value-result, success);
+break;
+case DIMM_REMOVE_FAIL:
+strcpy(info-value-request, hot-remove);
+strcpy(info-value-result, failure);
+break;
+case DIMM_ADD_SUCCESS:
+strcpy(info-value-request, hot-add);
+
Re: [RFC PATCH v3 11/19] Implement qmp and hmp commands for notification lists
On 09/21/2012 05:17 AM, Vasilis Liaskovitis wrote:
Guest can respond to ACPI hotplug events e.g. with _EJ or _OST method.
This patch implements a tail queue to store guest notifications for memory
hot-add and hot-remove requests.
Guest responses for memory hotplug command on a per-dimm basis can be detected
with the new hmp command info memhp or the new qmp command query-memhp
Naming doesn't match the QMP code.
Examples:
(qemu) device_add dimm,id=ram0
These notification items should probably be part of migration state (not yet
implemented).
In the case of libvirt driving migration, you already said in 10/19 that
libvirt has to start the destination with the populated=on|off fields
correct for each dimm according to the state it was in at the time the
host started the update. Can the host hot unplug memory after migration
has started?
+
+##
+# @MemHpInfo:
+#
+# Information about status of a memory hotplug command
+#
+# @dimm: the Dimm associated with the result
+#
+# @result: the result of the hotplug command
+#
+# Since: 1.3
+#
+##
+{ 'type': 'MemHpInfo',
+ 'data': {'dimm': 'str', 'request': 'str', 'result': 'str'} }
Should 'result' be a bool (true for success, false for still pending) or
an enum, instead of a free-form string? Likewise, isn't 'request' going
to be exactly one of two values (plug or unplug)?
--
Eric Blake ebl...@redhat.com+1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
