kvm: remove special handling of DIRTY_MEMORY_MIGRATION in the dirty log mask

One recent example is commit 4cc856f (kvm-all: Sync dirty-bitmap from
kvm before kvm destroy the corresponding dirty_bitmap, 2015-04-02).
Another performance problem is that KVM keeps tracking dirty pages
after a failed live migration, which causes bad performance due to
disallowing huge page mapping.

Thanks to the previous patch, KVM can now stop hooking into
log_global_start/stop.  This simplifies the KVM code noticeably.

Reported-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reported-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2015-03-23 10:57:21 +01:00
parent 6f6a5ef3e4
commit 1bfbac4ee1

View file

@ -83,7 +83,6 @@ struct KVMState
struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
bool coalesced_flush_in_progress;
int broken_set_mem_region;
int migration_log;
int vcpu_events;
int robust_singlestep;
int debugregs;
@ -234,9 +233,6 @@ static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot)
mem.guest_phys_addr = slot->start_addr;
mem.userspace_addr = (unsigned long)slot->ram;
mem.flags = slot->flags;
if (s->migration_log) {
mem.flags |= KVM_MEM_LOG_DIRTY_PAGES;
}
if (slot->memory_size && mem.flags & KVM_MEM_READONLY) {
/* Set the slot size to 0 before setting the slot to the desired
@ -317,10 +313,6 @@ static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty)
mem->flags = flags;
/* If nothing changed effectively, no need to issue ioctl */
if (s->migration_log) {
flags |= KVM_MEM_LOG_DIRTY_PAGES;
}
if (flags == old_flags) {
return 0;
}
@ -375,31 +367,6 @@ static void kvm_log_stop(MemoryListener *listener,
}
}
static int kvm_set_migration_log(bool enable)
{
KVMState *s = kvm_state;
KVMSlot *mem;
int i, err;
s->migration_log = enable;
for (i = 0; i < s->nr_slots; i++) {
mem = &s->slots[i];
if (!mem->memory_size) {
continue;
}
if (!!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) == enable) {
continue;
}
err = kvm_set_user_memory_region(s, mem);
if (err) {
return err;
}
}
return 0;
}
/* get kvm's dirty pages bitmap and update qemu's */
static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
unsigned long *bitmap)
@ -671,8 +638,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)
KVMSlot *mem, old;
int err;
MemoryRegion *mr = section->mr;
bool log_dirty =
memory_region_get_dirty_log_mask(mr) & ~(1 << DIRTY_MEMORY_MIGRATION);
bool log_dirty = memory_region_get_dirty_log_mask(mr) != 0;
bool writeable = !mr->readonly && !mr->rom_device;
bool readonly_flag = mr->readonly || memory_region_is_romd(mr);
hwaddr start_addr = section->offset_within_address_space;
@ -724,7 +690,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)
old = *mem;
if ((mem->flags & KVM_MEM_LOG_DIRTY_PAGES) || s->migration_log) {
if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) {
kvm_physical_sync_dirty_bitmap(section);
}
@ -853,22 +819,6 @@ static void kvm_log_sync(MemoryListener *listener,
}
}
static void kvm_log_global_start(struct MemoryListener *listener)
{
int r;
r = kvm_set_migration_log(1);
assert(r >= 0);
}
static void kvm_log_global_stop(struct MemoryListener *listener)
{
int r;
r = kvm_set_migration_log(0);
assert(r >= 0);
}
static void kvm_mem_ioeventfd_add(MemoryListener *listener,
MemoryRegionSection *section,
bool match_data, uint64_t data,
@ -944,8 +894,6 @@ static MemoryListener kvm_memory_listener = {
.log_start = kvm_log_start,
.log_stop = kvm_log_stop,
.log_sync = kvm_log_sync,
.log_global_start = kvm_log_global_start,
.log_global_stop = kvm_log_global_stop,
.eventfd_add = kvm_mem_ioeventfd_add,
.eventfd_del = kvm_mem_ioeventfd_del,
.coalesced_mmio_add = kvm_coalesce_mmio_region,