diff options
| -rw-r--r-- | accel/kvm/kvm-all.c | 87 | ||||
| -rw-r--r-- | accel/kvm/trace-events | 1 | ||||
| -rw-r--r-- | include/sysemu/kvm_int.h | 1 |
3 files changed, 74 insertions, 15 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 905fb844e4..f84413b795 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -69,6 +69,9 @@ #define KVM_GUESTDBG_BLOCKIRQ 0 #endif +/* Default num of memslots to be allocated when VM starts */ +#define KVM_MEMSLOTS_NR_ALLOC_DEFAULT 16 + struct KVMParkedVcpu { unsigned long vcpu_id; int kvm_fd; @@ -165,6 +168,57 @@ void kvm_resample_fd_notify(int gsi) } } +/** + * kvm_slots_grow(): Grow the slots[] array in the KVMMemoryListener + * + * @kml: The KVMMemoryListener* to grow the slots[] array + * @nr_slots_new: The new size of slots[] array + * + * Returns: True if the array grows larger, false otherwise. + */ +static bool kvm_slots_grow(KVMMemoryListener *kml, unsigned int nr_slots_new) +{ + unsigned int i, cur = kml->nr_slots_allocated; + KVMSlot *slots; + + if (nr_slots_new > kvm_state->nr_slots) { + nr_slots_new = kvm_state->nr_slots; + } + + if (cur >= nr_slots_new) { + /* Big enough, no need to grow, or we reached max */ + return false; + } + + if (cur == 0) { + slots = g_new0(KVMSlot, nr_slots_new); + } else { + assert(kml->slots); + slots = g_renew(KVMSlot, kml->slots, nr_slots_new); + /* + * g_renew() doesn't initialize extended buffers, however kvm + * memslots require fields to be zero-initialized. E.g. pointers, + * memory_size field, etc. + */ + memset(&slots[cur], 0x0, sizeof(slots[0]) * (nr_slots_new - cur)); + } + + for (i = cur; i < nr_slots_new; i++) { + slots[i].slot = i; + } + + kml->slots = slots; + kml->nr_slots_allocated = nr_slots_new; + trace_kvm_slots_grow(cur, nr_slots_new); + + return true; +} + +static bool kvm_slots_double(KVMMemoryListener *kml) +{ + return kvm_slots_grow(kml, kml->nr_slots_allocated * 2); +} + unsigned int kvm_get_max_memslots(void) { KVMState *s = KVM_STATE(current_accel()); @@ -193,15 +247,26 @@ unsigned int kvm_get_free_memslots(void) /* Called with KVMMemoryListener.slots_lock held */ static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) { - KVMState *s = kvm_state; + unsigned int n; int i; - for (i = 0; i < s->nr_slots; i++) { + for (i = 0; i < kml->nr_slots_allocated; i++) { if (kml->slots[i].memory_size == 0) { return &kml->slots[i]; } } + /* + * If no free slots, try to grow first by doubling. Cache the old size + * here to avoid another round of search: if the grow succeeded, it + * means slots[] now must have the existing "n" slots occupied, + * followed by one or more free slots starting from slots[n]. + */ + n = kml->nr_slots_allocated; + if (kvm_slots_double(kml)) { + return &kml->slots[n]; + } + return NULL; } @@ -222,10 +287,9 @@ static KVMSlot *kvm_lookup_matching_slot(KVMMemoryListener *kml, hwaddr start_addr, hwaddr size) { - KVMState *s = kvm_state; int i; - for (i = 0; i < s->nr_slots; i++) { + for (i = 0; i < kml->nr_slots_allocated; i++) { KVMSlot *mem = &kml->slots[i]; if (start_addr == mem->start_addr && size == mem->memory_size) { @@ -267,7 +331,7 @@ int kvm_physical_memory_addr_from_host(KVMState *s, void *ram, int i, ret = 0; kvm_slots_lock(); - for (i = 0; i < s->nr_slots; i++) { + for (i = 0; i < kml->nr_slots_allocated; i++) { KVMSlot *mem = &kml->slots[i]; if (ram >= mem->ram && ram < mem->ram + mem->memory_size) { @@ -1071,7 +1135,7 @@ static int kvm_physical_log_clear(KVMMemoryListener *kml, kvm_slots_lock(); - for (i = 0; i < s->nr_slots; i++) { + for (i = 0; i < kml->nr_slots_allocated; i++) { mem = &kml->slots[i]; /* Discard slots that are empty or do not overlap the section */ if (!mem->memory_size || @@ -1715,12 +1779,8 @@ static void kvm_log_sync_global(MemoryListener *l, bool last_stage) /* Flush all kernel dirty addresses into KVMSlot dirty bitmap */ kvm_dirty_ring_flush(); - /* - * TODO: make this faster when nr_slots is big while there are - * only a few used slots (small VMs). - */ kvm_slots_lock(); - for (i = 0; i < s->nr_slots; i++) { + for (i = 0; i < kml->nr_slots_allocated; i++) { mem = &kml->slots[i]; if (mem->memory_size && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { kvm_slot_sync_dirty_pages(mem); @@ -1835,12 +1895,9 @@ void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml, { int i; - kml->slots = g_new0(KVMSlot, s->nr_slots); kml->as_id = as_id; - for (i = 0; i < s->nr_slots; i++) { - kml->slots[i].slot = i; - } + kvm_slots_grow(kml, KVM_MEMSLOTS_NR_ALLOC_DEFAULT); QSIMPLEQ_INIT(&kml->transaction_add); QSIMPLEQ_INIT(&kml->transaction_del); diff --git a/accel/kvm/trace-events b/accel/kvm/trace-events index 82c65fd2ab..e43d18a869 100644 --- a/accel/kvm/trace-events +++ b/accel/kvm/trace-events @@ -36,3 +36,4 @@ kvm_io_window_exit(void) "" kvm_run_exit_system_event(int cpu_index, uint32_t event_type) "cpu_index %d, system_even_type %"PRIu32 kvm_convert_memory(uint64_t start, uint64_t size, const char *msg) "start 0x%" PRIx64 " size 0x%" PRIx64 " %s" kvm_memory_fault(uint64_t start, uint64_t size, uint64_t flags) "start 0x%" PRIx64 " size 0x%" PRIx64 " flags 0x%" PRIx64 +kvm_slots_grow(unsigned int old, unsigned int new) "%u -> %u" diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 17483ff53b..2304537b93 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -46,6 +46,7 @@ typedef struct KVMMemoryListener { MemoryListener listener; KVMSlot *slots; unsigned int nr_used_slots; + unsigned int nr_slots_allocated; int as_id; QSIMPLEQ_HEAD(, KVMMemoryUpdate) transaction_add; QSIMPLEQ_HEAD(, KVMMemoryUpdate) transaction_del; |