Searched hist:fe6824d12642b005c69123ecf8631f9b13553f8b (Results 1 – 2 of 2) sorted by relevance
| /openbmc/qemu/include/hw/ppc/ |
| H A D | spapr_drc.h | diff 593080936a06a04eacc589350e3a7ebc02f2ed8e Thu Jun 08 12:27:43 CDT 2017 Laurent Vivier <lvivier@redhat.com> Revert "spapr: fix memory hot-unplugging"
This reverts commit fe6824d12642b005c69123ecf8631f9b13553f8b.
Conflicts hw/ppc/spapr_drc.c, because get_index() has been renamed
spapr_get_index().
This didn't fix the problem. Once the hotplug has been started
some memory is allocated and some structures are allocated.
We don't free it when we ignore the unplug, and we can't because
they can be in use by the kernel.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff fe6824d12642b005c69123ecf8631f9b13553f8b Tue Mar 28 07:09:34 CDT 2017 Laurent Vivier <lvivier@redhat.com> spapr: fix memory hot-unplugging
If, once the kernel has booted, we try to remove a memory
hotplugged while the kernel was not started, QEMU crashes on
an assert:
qemu-system-ppc64: hw/virtio/vhost.c:651:
vhost_commit: Assertion `r >= 0' failed.
...
#4 in vhost_commit
#5 in memory_region_transaction_commit
#6 in pc_dimm_memory_unplug
#7 in spapr_memory_unplug
#8 spapr_machine_device_unplug
#9 in hotplug_handler_unplug
#10 in spapr_lmb_release
#11 in detach
#12 in set_allocation_state
#13 in rtas_set_indicator
...
If we take a closer look to the guest kernel log, we can see when
we try to unplug the memory:
pseries-hotplug-mem: Attempting to hot-add 4 LMB(s)
What happens:
1- The kernel has ignored the memory hotplug event because
it was not started when it was generated.
2- When we hot-unplug the memory,
QEMU starts to remove the memory,
generates an hot-unplug event,
and signals the kernel of the incoming new event
3- as the kernel is started, on the QEMU signal, it reads
the event list, decodes the hotplug event and tries to
finish the hotplugging.
4- QEMU receive the the hotplug notification while it
is trying to hot-unplug the memory. This moves the memory
DRC to an invalid state
This patch prevents this by not allowing to set the allocation
state to USABLE while the DRC is awaiting release.
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1432382
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
|
| /openbmc/qemu/hw/ppc/ |
| H A D | spapr_drc.c | diff 593080936a06a04eacc589350e3a7ebc02f2ed8e Thu Jun 08 12:27:43 CDT 2017 Laurent Vivier <lvivier@redhat.com> Revert "spapr: fix memory hot-unplugging"
This reverts commit fe6824d12642b005c69123ecf8631f9b13553f8b.
Conflicts hw/ppc/spapr_drc.c, because get_index() has been renamed
spapr_get_index().
This didn't fix the problem. Once the hotplug has been started
some memory is allocated and some structures are allocated.
We don't free it when we ignore the unplug, and we can't because
they can be in use by the kernel.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Daniel Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff fe6824d12642b005c69123ecf8631f9b13553f8b Tue Mar 28 07:09:34 CDT 2017 Laurent Vivier <lvivier@redhat.com> spapr: fix memory hot-unplugging
If, once the kernel has booted, we try to remove a memory
hotplugged while the kernel was not started, QEMU crashes on
an assert:
qemu-system-ppc64: hw/virtio/vhost.c:651:
vhost_commit: Assertion `r >= 0' failed.
...
#4 in vhost_commit
#5 in memory_region_transaction_commit
#6 in pc_dimm_memory_unplug
#7 in spapr_memory_unplug
#8 spapr_machine_device_unplug
#9 in hotplug_handler_unplug
#10 in spapr_lmb_release
#11 in detach
#12 in set_allocation_state
#13 in rtas_set_indicator
...
If we take a closer look to the guest kernel log, we can see when
we try to unplug the memory:
pseries-hotplug-mem: Attempting to hot-add 4 LMB(s)
What happens:
1- The kernel has ignored the memory hotplug event because
it was not started when it was generated.
2- When we hot-unplug the memory,
QEMU starts to remove the memory,
generates an hot-unplug event,
and signals the kernel of the incoming new event
3- as the kernel is started, on the QEMU signal, it reads
the event list, decodes the hotplug event and tries to
finish the hotplugging.
4- QEMU receive the the hotplug notification while it
is trying to hot-unplug the memory. This moves the memory
DRC to an invalid state
This patch prevents this by not allowing to set the allocation
state to USABLE while the DRC is awaiting release.
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1432382
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
|