@@ -176,7 +176,7 @@ static void qemu_s390_skeys_init(Object *obj)
QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
MachineState *machine = MACHINE(qdev_get_machine());
- skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
+ skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE;
skeys->keydata = g_malloc0(skeys->key_count);
}
@@ -85,7 +85,7 @@ static int kvm_s390_stattrib_set_stattr(S390StAttribState *sa,
{
KVMS390StAttribState *sas = KVM_S390_STATTRIB(sa);
MachineState *machine = MACHINE(qdev_get_machine());
- unsigned long max = machine->maxram_size / TARGET_PAGE_SIZE;
+ unsigned long max = machine->ram_size / TARGET_PAGE_SIZE;
if (start_gfn + count > max) {
error_report("Out of memory bounds when setting storage attributes");
@@ -104,7 +104,7 @@ static void kvm_s390_stattrib_synchronize(S390StAttribState *sa)
{
KVMS390StAttribState *sas = KVM_S390_STATTRIB(sa);
MachineState *machine = MACHINE(qdev_get_machine());
- unsigned long max = machine->maxram_size / TARGET_PAGE_SIZE;
+ unsigned long max = machine->ram_size / TARGET_PAGE_SIZE;
/* We do not need to reach the maximum buffer size allowed */
unsigned long cx, len = KVM_S390_SKEYS_MAX / 2;
int r;
@@ -327,7 +327,7 @@ out:
static void sclp_memory_init(SCLPDevice *sclp)
{
MachineState *machine = MACHINE(qdev_get_machine());
- ram_addr_t initial_mem = machine->ram_size;
+ uint64_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.
@@ -339,15 +339,17 @@ static void sclp_memory_init(SCLPDevice *sclp)
}
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. */
+ /*
+ * The core memory area needs to be aligned to the increment size. In
+ * case it's not aligned, bail out.
+ */
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;
+ if (initial_mem != machine->ram_size) {
+ error_report("RAM size not aligned to storage increments."
+ " Possible aligned RAM size: %" PRIu64 " MB",
+ initial_mem / MiB);
+ exit(1);
+ }
}
static void sclp_init(Object *obj)
Historically, we fixed up the RAM size (rounded it down), to fit into storage increments (maximum number of storage increments is 1020). Since commit 3a12fc61af5c ("390x/s390-virtio-ccw: use memdev for RAM"), we no longer consider the fixed-up size when allcoating the RAM block - which will break migration. Let's simply drop that manual fixup code and let the user supply sane RAM sizes. This will bail out early when trying to migrate (and make an existing guest with e.g., 12345 MB non-migratable), but maybe we should have rejected such RAM sizes right from the beginning. One can consider it a BUG that we don't supply what the user asked for. 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). This fixes (or rather rejects early): 1. Migrating older QEMU to upstream QEMU (e.g., with "-m 1235M"), as the RAM block size changed. 2. Migrating upstream QEMU to upstream QEMU (e.g., with "-m 1235M"), as we receive storage attributes for memory we don't expect (as we fixed up ram_size and maxram_size). Note that a migration from older QEMU is still possible - the migration target has to be started with the properly (down) aligned size (e.g., "-m 1234M" instead of "-m 1235M"). The following table can be used to write a conversion script to automate migration in environments where this is relevant. 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 Fixes: 3a12fc61af5c ("390x/s390-virtio-ccw: use memdev for RAM") Reported-by: Lukáš Doktor <ldoktor@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- v1 -> v2: - Don't use global ram_size - Add more details how migration from older QEMU can still work, along with a table. --- hw/s390x/s390-skeys.c | 2 +- hw/s390x/s390-stattrib-kvm.c | 4 ++-- hw/s390x/sclp.c | 20 +++++++++++--------- 3 files changed, 14 insertions(+), 12 deletions(-)