gwj / at91sam9263 · Commits

Commit bd8367761236cd5c435598aeb2f1b8240c09b059

Authored by Alexander Graf
Committed by Anthony Liguori
1 parent 16415335

Fake dirty loggin when it's not there 

Some KVM platforms don't support dirty logging yet, like IA64 and PPC,
so in order to still have screen updates on those, we need to fake it.

This patch just tells the getter function for dirty bitmaps, that all
pages within a slot are dirty when the slot has dirty logging enabled.

That way we can implement dirty logging on those platforms sometime when
it drags down performance, but share the rest of the code with dirty
logging capable platforms.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Inline Side-by-side
Showing 1 changed file with 12 additions and 1 deletions
kvm-all.c
  View file @bd83677
... ... @@ -300,6 +300,7 @@ int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
300 300 KVMDirtyLog d;
301 301 KVMSlot *mem;
302 302 int ret = 0;
  303 + int r;
303 304  
304 305 d.dirty_bitmap = NULL;
305 306 while (start_addr < end_addr) {
... ... @@ -308,6 +309,11 @@ int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
308 309 break;
309 310 }
310 311  
  312 + /* We didn't activate dirty logging? Don't care then. */
  313 + if(!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES)) {
  314 + continue;
  315 + }
  316 +
311 317 size = ((mem->memory_size >> TARGET_PAGE_BITS) + 7) / 8;
312 318 if (!d.dirty_bitmap) {
313 319 d.dirty_bitmap = qemu_malloc(size);
... ... @@ -319,7 +325,8 @@ int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
319 325  
320 326 d.slot = mem->slot;
321 327  
322   - if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
  328 + r = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d);
  329 + if (r == -EINVAL) {
323 330 dprintf("ioctl failed %d\n", errno);
324 331 ret = -1;
325 332 break;
... ... @@ -335,6 +342,10 @@ int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
335 342  
336 343 if ((bitmap[word] >> bit) & 1) {
337 344 cpu_physical_memory_set_dirty(addr);
  345 + } else if (r < 0) {
  346 + /* When our KVM implementation doesn't know about dirty logging
  347 + * we can just assume it's always dirty and be fine. */
  348 + cpu_physical_memory_set_dirty(addr);
338 349 }
339 350 }
340 351 start_addr = phys_addr;
... ...