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authorChristian Borntraeger <borntraeger@de.ibm.com>2020-04-01 08:37:54 -0400
committerCornelia Huck <cohuck@redhat.com>2020-04-02 17:10:09 +0200
commit5c30ef937f522a65df78dd9f496483fe4fc44d5e (patch)
tree2293a420e0fdddf6779ad2eb5264f651a61cfb5d /hw/s390x/sclp.c
parentedd075ae2baebf64b74e089457af6201362c9343 (diff)
vl/s390x: fixup ram sizes for compat machines
Older QEMU versions did fixup the ram size to match what can be reported via sclp. We need to mimic this behaviour for machine types 4.2 and older to not fail on inbound migration for memory sizes that do not fit. Old machines with proper aligned memory sizes are not affected. Alignment table: VM size (<=) | Alignment -------------------------- 1020M | 1M 2040M | 2M 4080M | 4M 8160M | 8M 16320M | 16M 32640M | 32M 65280M | 64M 130560M | 128M 261120M | 256M 522240M | 512M 1044480M | 1G 2088960M | 2G 4177920M | 4G 8355840M | 8G Suggested action is to replace unaligned -m value with a suitable aligned one or if a change to a newer machine type is possible, use a machine version >= 5.0. A future version might remove the compatibility handling. For machine types >= 5.0 we can simply use an increment size of 1M and use the full range of increment number which allows for all possible memory sizes. The old limitation of having a maximum of 1020 increments was added for standby memory, which we no longer support. With that we can now support even weird memory sizes like 10001234 MB. As we no longer fixup maxram_size as well, make other users use ram_size instead. Keep using maxram_size when setting the maximum ram size in KVM, as that will come in handy in the future when supporting memory hotplug (in contrast, storage keys and storage attributes for hotplugged memory will have to be migrated per RAM block in the future). Fixes: 3a12fc61af5c ("390x/s390-virtio-ccw: use memdev for RAM") Reported-by: Lukáš Doktor <ldoktor@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Igor Mammedov <imammedo@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20200401123754.109602-1-borntraeger@de.ibm.com> [CH: fixed up message on memory size fixup] Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'hw/s390x/sclp.c')
-rw-r--r--hw/s390x/sclp.c17
1 files changed, 5 insertions, 12 deletions
diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index af0bfbc2ec..f0c35aa57a 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -327,27 +327,20 @@ out:
static void sclp_memory_init(SCLPDevice *sclp)
{
MachineState *machine = MACHINE(qdev_get_machine());
+ MachineClass *machine_class = MACHINE_GET_CLASS(qdev_get_machine());
ram_addr_t initial_mem = machine->ram_size;
int increment_size = 20;
/* The storage increment size is a multiple of 1M and is a power of 2.
- * The number of storage increments must be MAX_STORAGE_INCREMENTS or fewer.
+ * For some machine types, the number of storage increments must be
+ * MAX_STORAGE_INCREMENTS or fewer.
* The variable 'increment_size' is an exponent of 2 that can be
* used to calculate the size (in bytes) of an increment. */
- while ((initial_mem >> increment_size) > MAX_STORAGE_INCREMENTS) {
+ while (machine_class->fixup_ram_size != NULL &&
+ (initial_mem >> increment_size) > MAX_STORAGE_INCREMENTS) {
increment_size++;
}
sclp->increment_size = increment_size;
-
- /* The core memory area needs to be aligned with the increment size.
- * In effect, this can cause the user-specified memory size to be rounded
- * down to align with the nearest increment boundary. */
- initial_mem = initial_mem >> increment_size << increment_size;
-
- machine->ram_size = initial_mem;
- machine->maxram_size = initial_mem;
- /* let's propagate the changed ram size into the global variable. */
- ram_size = initial_mem;
}
static void sclp_init(Object *obj)