From: Peter Xu <pet...@redhat.com>
Provide a helper kvm_slot_get_dirty_log() to make the function
kvm_physical_sync_dirty_bitmap() clearer. We can even cache the as_id
into KVMSlot when it is created, so that we don't even need to pass it
down every time.
Since at it, remove return value of kvm_physical_sync_dirty_bitmap()
because it should never fail.
Signed-off-by: Peter Xu <pet...@redhat.com>
Message-Id: <20210506160549.130416-5-pet...@redhat.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
accel/kvm/kvm-all.c | 52 +++++++++++++++++++++++-----------------
include/sysemu/kvm_int.h | 2 ++
2 files changed, 32 insertions(+), 22 deletions(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 5bc40fd71b..caaa2a5c98 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -615,6 +615,30 @@ static void kvm_slot_init_dirty_bitmap(KVMSlot *mem)
mem->dirty_bmap = g_malloc0(bitmap_size);
}
+/*
+ * Sync dirty bitmap from kernel to KVMSlot.dirty_bmap, return true if
+ * succeeded, false otherwise
+ */
+static bool kvm_slot_get_dirty_log(KVMState *s, KVMSlot *slot)
+{
+ struct kvm_dirty_log d = {};
+ int ret;
+
+ d.dirty_bitmap = slot->dirty_bmap;
+ d.slot = slot->slot | (slot->as_id << 16);
+ ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d);
+
+ if (ret == -ENOENT) {
+ /* kernel does not have dirty bitmap in this slot */
+ ret = 0;
+ }
+ if (ret) {
+ error_report_once("%s: KVM_GET_DIRTY_LOG failed with %d",
+ __func__, ret);
+ }
+ return ret == 0;
+}
+
/**
* kvm_physical_sync_dirty_bitmap - Sync dirty bitmap from kernel space
*
@@ -626,15 +650,13 @@ static void kvm_slot_init_dirty_bitmap(KVMSlot *mem)
* @kml: the KVM memory listener object
* @section: the memory section to sync the dirty bitmap with
*/
-static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
- MemoryRegionSection *section)
+static void kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
+ MemoryRegionSection *section)
{
KVMState *s = kvm_state;
- struct kvm_dirty_log d = {};
KVMSlot *mem;
hwaddr start_addr, size;
hwaddr slot_size, slot_offset = 0;
- int ret = 0;
size = kvm_align_section(section, &start_addr);
while (size) {
@@ -644,19 +666,10 @@ static int
kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
mem = kvm_lookup_matching_slot(kml, start_addr, slot_size);
if (!mem) {
/* We don't have a slot if we want to trap every access. */
- goto out;
+ return;
}
- d.dirty_bitmap = mem->dirty_bmap;
- d.slot = mem->slot | (kml->as_id << 16);
- ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d);
- if (ret == -ENOENT) {
- /* kernel does not have dirty bitmap in this slot */
- ret = 0;
- } else if (ret < 0) {
- error_report("ioctl KVM_GET_DIRTY_LOG failed: %d", errno);
- goto out;
- } else {
+ if (kvm_slot_get_dirty_log(s, mem)) {
subsection.offset_within_region += slot_offset;
subsection.size = int128_make64(slot_size);
kvm_get_dirty_pages_log_range(&subsection, d.dirty_bitmap);
@@ -666,8 +679,6 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener
*kml,
start_addr += slot_size;
size -= slot_size;
}
-out:
- return ret;
}
/* Alignment requirement for KVM_CLEAR_DIRTY_LOG - 64 pages */
@@ -1179,6 +1190,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
do {
slot_size = MIN(kvm_max_slot_size, size);
mem = kvm_alloc_slot(kml);
+ mem->as_id = kml->as_id;
mem->memory_size = slot_size;
mem->start_addr = start_addr;
mem->ram = ram;
@@ -1221,14 +1233,10 @@ static void kvm_log_sync(MemoryListener *listener,
MemoryRegionSection *section)
{
KVMMemoryListener *kml = container_of(listener, KVMMemoryListener,
listener);
- int r;
kvm_slots_lock();
- r = kvm_physical_sync_dirty_bitmap(kml, section);
+ kvm_physical_sync_dirty_bitmap(kml, section);
kvm_slots_unlock();
- if (r < 0) {
- abort();
- }
}
static void kvm_log_clear(MemoryListener *listener,
diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h
index 1da30e1884..e13075f738 100644
--- a/include/sysemu/kvm_int.h
+++ b/include/sysemu/kvm_int.h
@@ -23,6 +23,8 @@ typedef struct KVMSlot
int old_flags;
/* Dirty bitmap cache for the slot */
unsigned long *dirty_bmap;
+ /* Cache of the address space ID */
+ int as_id;
} KVMSlot;
typedef struct KVMMemoryListener {
--
2.31.1
