in case of hot-remove failure on a guest that does not implement _OST, the dimm bitmaps in qemu and Seabios show the dimm as unplugged, but the dimm is still present on the qdev/memory bus. To avoid this inconsistency, we set the dimm state to active/hot-plugged on a reset of the associated acpi_pm device. This way the dimm is still active after a VM reboot and dimm visibility has always the same behaviour, regardless of _OST support in the guest.
Signed-off-by: Vasilis Liaskovitis vasilis.liaskovitis@profitbricks.com --- hw/acpi_piix4.c | 1 + hw/dimm.c | 20 ++++++++++++++++++++ hw/dimm.h | 1 + 3 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c index f7220d4..8bf58a6 100644 --- a/hw/acpi_piix4.c +++ b/hw/acpi_piix4.c @@ -373,6 +373,7 @@ static void piix4_reset(void *opaque) pci_conf[0x5B] = 0x02; } piix4_update_hotplug(s); + dimm_state_sync(); }
static void piix4_powerdown(void *opaque, int irq, int power_failing) diff --git a/hw/dimm.c b/hw/dimm.c index 1521462..b993668 100644 --- a/hw/dimm.c +++ b/hw/dimm.c @@ -182,6 +182,26 @@ static DimmDevice *dimm_find_from_idx(uint32_t idx) return NULL; }
+void dimm_state_sync(void) +{ + DimmBus *bus = main_memory_bus; + DimmDevice *slot; + + /* if a hot-remove operation is pending on reset, it means the hot-remove + * operation has failed, but the guest hasn't notified us e.g. because the + * guest does not provide _OST notifications. The device is still present on + * the dimmbus, but the qemu and Seabios dimm bitmaps show this device as + * unplugged. To avoid this inconsistency, we set the dimm bits to active + * i.e. hot-plugged for each dimm present on the dimmbus. + */ + QTAILQ_FOREACH(slot, &bus->dimmlist, nextdimm) { + if (slot->pending == DIMM_REMOVE_PENDING) { + if (bus->dimm_revert) + bus->dimm_revert(bus->dimm_hotplug_qdev, slot, 0); + } + } +} + /* used to create a dimm device, only on incoming migration of a hotplugged * RAMBlock */ diff --git a/hw/dimm.h b/hw/dimm.h index a6c6e6f..ce091fe 100644 --- a/hw/dimm.h +++ b/hw/dimm.h @@ -95,5 +95,6 @@ void main_memory_bus_create(Object *parent); void dimm_config_create(char *id, uint64_t size, uint64_t node, uint32_t dimm_idx, uint32_t populated); uint64_t get_hp_memory_total(void); +void dimm_state_sync(void);
#endif