diff options
| -rw-r--r-- | accel/kvm/kvm-all.c | 88 |
1 files changed, 50 insertions, 38 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index e06cf3a415..e57492fda5 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2435,6 +2435,55 @@ static int find_kvm_machine_type(MachineState *ms) return type; } +static int kvm_setup_dirty_ring(KVMState *s) +{ + uint64_t dirty_log_manual_caps; + int ret; + + /* + * Enable KVM dirty ring if supported, otherwise fall back to + * dirty logging mode + */ + ret = kvm_dirty_ring_init(s); + if (ret < 0) { + return ret; + } + + /* + * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is not needed when dirty ring is + * enabled. More importantly, KVM_DIRTY_LOG_INITIALLY_SET will assume no + * page is wr-protected initially, which is against how kvm dirty ring is + * usage - kvm dirty ring requires all pages are wr-protected at the very + * beginning. Enabling this feature for dirty ring causes data corruption. + * + * TODO: Without KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 and kvm clear dirty log, + * we may expect a higher stall time when starting the migration. In the + * future we can enable KVM_CLEAR_DIRTY_LOG to work with dirty ring too: + * instead of clearing dirty bit, it can be a way to explicitly wr-protect + * guest pages. + */ + if (!s->kvm_dirty_ring_size) { + dirty_log_manual_caps = + kvm_check_extension(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); + dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | + KVM_DIRTY_LOG_INITIALLY_SET); + s->manual_dirty_log_protect = dirty_log_manual_caps; + if (dirty_log_manual_caps) { + ret = kvm_vm_enable_cap(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, 0, + dirty_log_manual_caps); + if (ret) { + warn_report("Trying to enable capability %"PRIu64" of " + "KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 but failed. " + "Falling back to the legacy mode. ", + dirty_log_manual_caps); + s->manual_dirty_log_protect = 0; + } + } + } + + return 0; +} + static int kvm_init(MachineState *ms) { MachineClass *mc = MACHINE_GET_CLASS(ms); @@ -2454,7 +2503,6 @@ static int kvm_init(MachineState *ms) const KVMCapabilityInfo *missing_cap; int ret; int type; - uint64_t dirty_log_manual_caps; qemu_mutex_init(&kml_slots_lock); @@ -2566,47 +2614,11 @@ static int kvm_init(MachineState *ms) s->coalesced_pio = s->coalesced_mmio && kvm_check_extension(s, KVM_CAP_COALESCED_PIO); - /* - * Enable KVM dirty ring if supported, otherwise fall back to - * dirty logging mode - */ - ret = kvm_dirty_ring_init(s); + ret = kvm_setup_dirty_ring(s); if (ret < 0) { goto err; } - /* - * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is not needed when dirty ring is - * enabled. More importantly, KVM_DIRTY_LOG_INITIALLY_SET will assume no - * page is wr-protected initially, which is against how kvm dirty ring is - * usage - kvm dirty ring requires all pages are wr-protected at the very - * beginning. Enabling this feature for dirty ring causes data corruption. - * - * TODO: Without KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 and kvm clear dirty log, - * we may expect a higher stall time when starting the migration. In the - * future we can enable KVM_CLEAR_DIRTY_LOG to work with dirty ring too: - * instead of clearing dirty bit, it can be a way to explicitly wr-protect - * guest pages. - */ - if (!s->kvm_dirty_ring_size) { - dirty_log_manual_caps = - kvm_check_extension(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); - dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | - KVM_DIRTY_LOG_INITIALLY_SET); - s->manual_dirty_log_protect = dirty_log_manual_caps; - if (dirty_log_manual_caps) { - ret = kvm_vm_enable_cap(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, 0, - dirty_log_manual_caps); - if (ret) { - warn_report("Trying to enable capability %"PRIu64" of " - "KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 but failed. " - "Falling back to the legacy mode. ", - dirty_log_manual_caps); - s->manual_dirty_log_protect = 0; - } - } - } - #ifdef KVM_CAP_VCPU_EVENTS s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS); #endif |