diff options
Diffstat (limited to 'accel/kvm/kvm-all.c')
| -rw-r--r-- | accel/kvm/kvm-all.c | 131 |
1 files changed, 95 insertions, 36 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 905fb844e4..801cff16a5 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -69,6 +69,11 @@ #define KVM_GUESTDBG_BLOCKIRQ 0 #endif +/* Default num of memslots to be allocated when VM starts */ +#define KVM_MEMSLOTS_NR_ALLOC_DEFAULT 16 +/* Default max allowed memslots if kernel reported nothing */ +#define KVM_MEMSLOTS_NR_MAX_DEFAULT 32 + struct KVMParkedVcpu { unsigned long vcpu_id; int kvm_fd; @@ -165,11 +170,62 @@ 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_max) { + nr_slots_new = kvm_state->nr_slots_max; + } + + 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()); - return s->nr_slots; + return s->nr_slots_max; } unsigned int kvm_get_free_memslots(void) @@ -183,25 +239,36 @@ unsigned int kvm_get_free_memslots(void) if (!s->as[i].ml) { continue; } - used_slots = MAX(used_slots, s->as[i].ml->nr_used_slots); + used_slots = MAX(used_slots, s->as[i].ml->nr_slots_used); } kvm_slots_unlock(); - return s->nr_slots - used_slots; + return s->nr_slots_max - used_slots; } /* 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 +289,9 @@ 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 +333,7 @@ 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 +1137,7 @@ 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 || @@ -1450,7 +1516,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, } start_addr += slot_size; size -= slot_size; - kml->nr_used_slots--; + kml->nr_slots_used--; } while (size); return; } @@ -1489,7 +1555,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, ram_start_offset += slot_size; ram += slot_size; size -= slot_size; - kml->nr_used_slots++; + kml->nr_slots_used++; } while (size); } @@ -1715,12 +1781,8 @@ 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 +1897,9 @@ 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); @@ -2545,26 +2604,14 @@ static int kvm_init(MachineState *ms) goto err; } - kvm_supported_memory_attributes = kvm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES); - kvm_guest_memfd_supported = - kvm_check_extension(s, KVM_CAP_GUEST_MEMFD) && - kvm_check_extension(s, KVM_CAP_USER_MEMORY2) && - (kvm_supported_memory_attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE); - kvm_immediate_exit = kvm_check_extension(s, KVM_CAP_IMMEDIATE_EXIT); - s->nr_slots = kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS); + s->nr_slots_max = kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS); /* If unspecified, use the default value */ - if (!s->nr_slots) { - s->nr_slots = 32; + if (!s->nr_slots_max) { + s->nr_slots_max = KVM_MEMSLOTS_NR_MAX_DEFAULT; } - s->nr_as = kvm_check_extension(s, KVM_CAP_MULTI_ADDRESS_SPACE); - if (s->nr_as <= 1) { - s->nr_as = 1; - } - s->as = g_new0(struct KVMAs, s->nr_as); - type = find_kvm_machine_type(ms); if (type < 0) { ret = -EINVAL; @@ -2578,6 +2625,12 @@ static int kvm_init(MachineState *ms) s->vmfd = ret; + s->nr_as = kvm_vm_check_extension(s, KVM_CAP_MULTI_ADDRESS_SPACE); + if (s->nr_as <= 1) { + s->nr_as = 1; + } + s->as = g_new0(struct KVMAs, s->nr_as); + /* check the vcpu limits */ soft_vcpus_limit = kvm_recommended_vcpus(s); hard_vcpus_limit = kvm_max_vcpus(s); @@ -2630,7 +2683,7 @@ static int kvm_init(MachineState *ms) } kvm_readonly_mem_allowed = - (kvm_check_extension(s, KVM_CAP_READONLY_MEM) > 0); + (kvm_vm_check_extension(s, KVM_CAP_READONLY_MEM) > 0); kvm_resamplefds_allowed = (kvm_check_extension(s, KVM_CAP_IRQFD_RESAMPLE) > 0); @@ -2664,6 +2717,12 @@ static int kvm_init(MachineState *ms) goto err; } + kvm_supported_memory_attributes = kvm_vm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES); + kvm_guest_memfd_supported = + kvm_check_extension(s, KVM_CAP_GUEST_MEMFD) && + kvm_check_extension(s, KVM_CAP_USER_MEMORY2) && + (kvm_supported_memory_attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE); + if (s->kernel_irqchip_split == ON_OFF_AUTO_AUTO) { s->kernel_irqchip_split = mc->default_kernel_irqchip_split ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; } |