@@ -21,6 +21,16 @@
#define S390_MACHINE_CLASS(klass) \
OBJECT_CLASS_CHECK(S390CcwMachineClass, (klass), TYPE_S390_CCW_MACHINE)
+/*
+ * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages
+ * as the dirty bitmap must be managed by bitops that take an int as
+ * position indicator. If we have a guest beyond that we will split off
+ * new subregions. The split must happen on a segment boundary (1MB).
+ */
+#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1)
+#define SEG_MSK (~0xfffffULL)
+#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK)
+
typedef struct S390CcwMachineState {
/*< private >*/
MachineState parent_obj;
@@ -41,4 +41,5 @@ typedef struct KVMMemoryListener {
void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml,
AddressSpace *as, int as_id);
+void kvm_set_max_memslot_size(hwaddr max_slot_size);
#endif
@@ -138,6 +138,7 @@ bool kvm_direct_msi_allowed;
bool kvm_ioeventfd_any_length_allowed;
bool kvm_msi_use_devid;
static bool kvm_immediate_exit;
+static hwaddr kvm_max_slot_size = ~0;
static const KVMCapabilityInfo kvm_required_capabilites[] = {
KVM_CAP_INFO(USER_MEMORY),
@@ -951,6 +952,12 @@ kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list)
return NULL;
}
+void kvm_set_max_memslot_size(hwaddr max_slot_size)
+{
+ g_assert(ROUND_UP(max_slot_size, qemu_real_host_page_size) == max_slot_size);
+ kvm_max_slot_size = max_slot_size;
+}
+
static void kvm_set_phys_mem(KVMMemoryListener *kml,
MemoryRegionSection *section, bool add)
{
@@ -958,7 +965,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
int err;
MemoryRegion *mr = section->mr;
bool writeable = !mr->readonly && !mr->rom_device;
- hwaddr start_addr, size;
+ hwaddr start_addr, size, slot_size;
void *ram;
if (!memory_region_is_ram(mr)) {
@@ -983,41 +990,49 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
kvm_slots_lock(kml);
if (!add) {
- mem = kvm_lookup_matching_slot(kml, start_addr, size);
- if (!mem) {
- goto out;
- }
- if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) {
- kvm_physical_sync_dirty_bitmap(kml, section);
- }
+ do {
+ slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size;
+ mem = kvm_lookup_matching_slot(kml, start_addr, slot_size);
+ if (!mem) {
+ goto out;
+ }
+ if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) {
+ kvm_physical_sync_dirty_bitmap(kml, section);
+ }
- /* unregister the slot */
- g_free(mem->dirty_bmap);
- mem->dirty_bmap = NULL;
- mem->memory_size = 0;
- mem->flags = 0;
- err = kvm_set_user_memory_region(kml, mem, false);
- if (err) {
- fprintf(stderr, "%s: error unregistering slot: %s\n",
- __func__, strerror(-err));
- abort();
- }
+ /* unregister the slot */
+ g_free(mem->dirty_bmap);
+ mem->dirty_bmap = NULL;
+ mem->memory_size = 0;
+ mem->flags = 0;
+ err = kvm_set_user_memory_region(kml, mem, false);
+ if (err) {
+ fprintf(stderr, "%s: error unregistering slot: %s\n",
+ __func__, strerror(-err));
+ abort();
+ }
+ start_addr += slot_size;
+ } while ((size -= slot_size));
goto out;
}
/* register the new slot */
- mem = kvm_alloc_slot(kml);
- mem->memory_size = size;
- mem->start_addr = start_addr;
- mem->ram = ram;
- mem->flags = kvm_mem_flags(mr);
-
- err = kvm_set_user_memory_region(kml, mem, true);
- if (err) {
- fprintf(stderr, "%s: error registering slot: %s\n", __func__,
- strerror(-err));
- abort();
- }
+ do {
+ slot_size = kvm_max_slot_size < size ? kvm_max_slot_size : size;
+ mem = kvm_alloc_slot(kml);
+ mem->memory_size = slot_size;
+ mem->start_addr = start_addr;
+ mem->ram = ram;
+ mem->flags = kvm_mem_flags(mr);
+
+ err = kvm_set_user_memory_region(kml, mem, true);
+ if (err) {
+ fprintf(stderr, "%s: error registering slot: %s\n", __func__,
+ strerror(-err));
+ abort();
+ }
+ start_addr += slot_size;
+ } while ((size -= slot_size));
out:
kvm_slots_unlock(kml);
@@ -151,15 +151,6 @@ static void virtio_ccw_register_hcalls(void)
virtio_ccw_hcall_early_printk);
}
-/*
- * KVM does only support memory slots up to KVM_MEM_MAX_NR_PAGES pages
- * as the dirty bitmap must be managed by bitops that take an int as
- * position indicator. If we have a guest beyond that we will split off
- * new subregions. The split must happen on a segment boundary (1MB).
- */
-#define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1)
-#define SEG_MSK (~0xfffffULL)
-#define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) & SEG_MSK)
static void s390_memory_init(ram_addr_t mem_size)
{
MemoryRegion *sysmem = get_system_memory();
@@ -347,6 +347,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
*/
/* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */
+ kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES);
return 0;
}
Max memslot size supported by kvm on s390 is 8Tb, move logic of splitting RAM on chunks upto 8T to KVM code. This way it will hide KVM specific restrictions in KVM code and won't affect baord level design decisions. Which would allow us to avoid misusing memory_region_allocate_system_memory() API and eventually use a single hostmem backend for guest RAM. Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- patch prepares only KVM side for switching to single RAM memory region other patche will take care of migration issues that improper use of memory_region_allocate_system_memory() introduced --- include/hw/s390x/s390-virtio-ccw.h | 10 ++++ include/sysemu/kvm_int.h | 1 + accel/kvm/kvm-all.c | 77 ++++++++++++++++++------------ hw/s390x/s390-virtio-ccw.c | 9 ---- target/s390x/kvm.c | 1 + 5 files changed, 58 insertions(+), 40 deletions(-)