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kvm: halve number of set memory calls for vga 

use the new api to reduce the number of these (expensive)
system calls.

Note: using this API, we should be able to
get rid of vga_dirty_log_xxx APIs. Using them doesn't
affect the performance though because we detects
the log_dirty flag set and ignores the call.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2011-04-06 22:09:54 +03:00
parent 0fd542fb7d
commit 25254bbc4d
1 changed files with 36 additions and 23 deletions
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59
kvm-all.c
View File

@ -245,48 +245,60 @@ err:
/*
* dirty pages logging control
*/
static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr,
ram_addr_t size, int flags, int mask)
static int kvm_mem_flags(KVMState *s, bool log_dirty)
{
return log_dirty ? KVM_MEM_LOG_DIRTY_PAGES : 0;
}
static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty)
{
KVMState *s = kvm_state;
KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
int flags, mask = KVM_MEM_LOG_DIRTY_PAGES;
int old_flags;
if (mem == NULL) {
fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
TARGET_FMT_plx "\n", __func__, phys_addr,
(target_phys_addr_t)(phys_addr + size - 1));
return -EINVAL;
}
old_flags = mem->flags;
flags = (mem->flags & ~mask) | flags;
flags = (mem->flags & ~mask) | kvm_mem_flags(s, 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;
return 0;
}
return kvm_set_user_memory_region(s, mem);
}
static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr,
ram_addr_t size, bool log_dirty)
{
KVMState *s = kvm_state;
KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
if (mem == NULL) {
fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
TARGET_FMT_plx "\n", __func__, phys_addr,
(target_phys_addr_t)(phys_addr + size - 1));
return -EINVAL;
}
return kvm_slot_dirty_pages_log_change(mem, log_dirty);
}
static int kvm_log_start(CPUPhysMemoryClient *client,
target_phys_addr_t phys_addr, ram_addr_t size)
{
return kvm_dirty_pages_log_change(phys_addr, size, KVM_MEM_LOG_DIRTY_PAGES,
KVM_MEM_LOG_DIRTY_PAGES);
return kvm_dirty_pages_log_change(phys_addr, size, true);
}
static int kvm_log_stop(CPUPhysMemoryClient *client,
target_phys_addr_t phys_addr, ram_addr_t size)
{
return kvm_dirty_pages_log_change(phys_addr, size, 0,
KVM_MEM_LOG_DIRTY_PAGES);
return kvm_dirty_pages_log_change(phys_addr, size, false);
}
static int kvm_set_migration_log(int enable)
@ -495,7 +507,7 @@ kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list)
}
static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
ram_addr_t phys_offset)
ram_addr_t phys_offset, bool log_dirty)
{
KVMState *s = kvm_state;
ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
@ -520,7 +532,8 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
(start_addr + size <= mem->start_addr + mem->memory_size) &&
(phys_offset - start_addr == mem->phys_offset - mem->start_addr)) {
/* The new slot fits into the existing one and comes with
* identical parameters - nothing to be done. */
* identical parameters - update flags and done. */
kvm_slot_dirty_pages_log_change(mem, log_dirty);
return;
}
@ -550,7 +563,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
mem->memory_size = old.memory_size;
mem->start_addr = old.start_addr;
mem->phys_offset = old.phys_offset;
mem->flags = 0;
mem->flags = kvm_mem_flags(s, log_dirty);
err = kvm_set_user_memory_region(s, mem);
if (err) {
@ -571,7 +584,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
mem->memory_size = start_addr - old.start_addr;
mem->start_addr = old.start_addr;
mem->phys_offset = old.phys_offset;
mem->flags = 0;
mem->flags = kvm_mem_flags(s, log_dirty);
err = kvm_set_user_memory_region(s, mem);
if (err) {
@ -590,7 +603,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
size_delta = mem->start_addr - old.start_addr;
mem->memory_size = old.memory_size - size_delta;
mem->phys_offset = old.phys_offset + size_delta;
mem->flags = 0;
mem->flags = kvm_mem_flags(s, log_dirty);
err = kvm_set_user_memory_region(s, mem);
if (err) {
@ -613,7 +626,7 @@ static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
mem->memory_size = size;
mem->start_addr = start_addr;
mem->phys_offset = phys_offset;
mem->flags = 0;
mem->flags = kvm_mem_flags(s, log_dirty);
err = kvm_set_user_memory_region(s, mem);
if (err) {
@ -628,7 +641,7 @@ static void kvm_client_set_memory(struct CPUPhysMemoryClient *client,
ram_addr_t size, ram_addr_t phys_offset,
bool log_dirty)
{
kvm_set_phys_mem(start_addr, size, phys_offset);
kvm_set_phys_mem(start_addr, size, phys_offset, log_dirty);
}
static int kvm_client_sync_dirty_bitmap(struct CPUPhysMemoryClient *client,