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authorPeter Xu <peterx@redhat.com>2021-05-06 12:05:42 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2021-05-26 14:49:45 +0200
commitea776d15adc021a9f38179d27227a7f4d90a8698 (patch)
tree2fe136f7f6556fd13e25cc0cc09fe1a7125de4c7 /accel/kvm
parenta2f77862ffa56b5b0aa9e96fa73620ff751460d5 (diff)
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KVM: Create the KVMSlot dirty bitmap on flag changes
Previously we have two places that will create the per KVMSlot dirty bitmap: 1. When a newly created KVMSlot has dirty logging enabled, 2. When the first log_sync() happens for a memory slot. The 2nd case is lazy-init, while the 1st case is not (which is a fix of what the 2nd case missed). To do explicit initialization of dirty bitmaps, what we're missing is to create the dirty bitmap when the slot changed from not-dirty-track to dirty-track. Do that in kvm_slot_update_flags(). With that, we can safely remove the 2nd lazy-init. This change will be needed for kvm dirty ring because kvm dirty ring does not use the log_sync() interface at all. Also move all the pre-checks into kvm_slot_init_dirty_bitmap(). Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20210506160549.130416-4-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'accel/kvm')
-rw-r--r--accel/kvm/kvm-all.c23
1 files changed, 9 insertions, 14 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index f8980e1..5bc40fd 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -177,6 +177,8 @@ static QemuMutex kml_slots_lock;
#define kvm_slots_lock() qemu_mutex_lock(&kml_slots_lock)
#define kvm_slots_unlock() qemu_mutex_unlock(&kml_slots_lock)
+static void kvm_slot_init_dirty_bitmap(KVMSlot *mem);
+
static inline void kvm_resample_fd_remove(int gsi)
{
KVMResampleFd *rfd;
@@ -500,6 +502,7 @@ static int kvm_slot_update_flags(KVMMemoryListener *kml, KVMSlot *mem,
return 0;
}
+ kvm_slot_init_dirty_bitmap(mem);
return kvm_set_user_memory_region(kml, mem, false);
}
@@ -584,8 +587,12 @@ static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
#define ALIGN(x, y) (((x)+(y)-1) & ~((y)-1))
/* Allocate the dirty bitmap for a slot */
-static void kvm_memslot_init_dirty_bitmap(KVMSlot *mem)
+static void kvm_slot_init_dirty_bitmap(KVMSlot *mem)
{
+ if (!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) || mem->dirty_bmap) {
+ return;
+ }
+
/*
* XXX bad kernel interface alert
* For dirty bitmap, kernel allocates array of size aligned to
@@ -640,11 +647,6 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
goto out;
}
- if (!mem->dirty_bmap) {
- /* Allocate on the first log_sync, once and for all */
- kvm_memslot_init_dirty_bitmap(mem);
- }
-
d.dirty_bitmap = mem->dirty_bmap;
d.slot = mem->slot | (kml->as_id << 16);
ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d);
@@ -1181,14 +1183,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
mem->start_addr = start_addr;
mem->ram = ram;
mem->flags = kvm_mem_flags(mr);
-
- if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) {
- /*
- * Reallocate the bmap; it means it doesn't disappear in
- * middle of a migrate.
- */
- kvm_memslot_init_dirty_bitmap(mem);
- }
+ kvm_slot_init_dirty_bitmap(mem);
err = kvm_set_user_memory_region(kml, mem, true);
if (err) {
fprintf(stderr, "%s: error registering slot: %s\n", __func__,