diff options
| -rw-r--r-- | hw/arm/virt.c | 1 | ||||
| -rw-r--r-- | hw/block/virtio-blk.c | 6 | ||||
| -rw-r--r-- | hw/core/machine.c | 5 | ||||
| -rw-r--r-- | hw/i386/pc_piix.c | 1 | ||||
| -rw-r--r-- | hw/i386/pc_q35.c | 1 | ||||
| -rw-r--r-- | hw/ppc/spapr.c | 2 | ||||
| -rw-r--r-- | hw/s390x/s390-virtio-ccw.c | 1 | ||||
| -rw-r--r-- | include/hw/boards.h | 3 | ||||
| -rw-r--r-- | include/hw/virtio/virtio-blk.h | 1 | ||||
| -rw-r--r-- | qemu-options.hx | 38 |
10 files changed, 57 insertions, 2 deletions
diff --git a/hw/arm/virt.c b/hw/arm/virt.c index d4bedc2..bf4b1cb 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -2149,6 +2149,7 @@ type_init(machvirt_machine_init); static void virt_machine_4_2_options(MachineClass *mc) { + compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len); } DEFINE_VIRT_MACHINE_AS_LATEST(4, 2) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 4c357d2..d62e637 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -991,7 +991,9 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); } - if (blk_enable_write_cache(s->blk)) { + if (blk_enable_write_cache(s->blk) || + (s->conf.x_enable_wce_if_config_wce && + virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) { virtio_add_feature(&features, VIRTIO_BLK_F_WCE); } if (blk_is_read_only(s->blk)) { @@ -1270,6 +1272,8 @@ static Property virtio_blk_properties[] = { conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS), DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock, conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS), + DEFINE_PROP_BOOL("x-enable-wce-if-config-wce", VirtIOBlock, + conf.x_enable_wce_if_config_wce, true), DEFINE_PROP_END_OF_LIST(), }; diff --git a/hw/core/machine.c b/hw/core/machine.c index 1689ad3..023548b 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -27,6 +27,11 @@ #include "hw/pci/pci.h" #include "hw/mem/nvdimm.h" +GlobalProperty hw_compat_4_2[] = { + { "virtio-blk-device", "x-enable-wce-if-config-wce", "off" }, +}; +const size_t hw_compat_4_2_len = G_N_ELEMENTS(hw_compat_4_2); + GlobalProperty hw_compat_4_1[] = { { "virtio-pci", "x-pcie-flr-init", "off" }, }; diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 1bd70d1..87aced0 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -431,6 +431,7 @@ static void pc_i440fx_4_2_machine_options(MachineClass *m) m->alias = "pc"; m->is_default = 1; pcmc->default_cpu_version = 1; + compat_props_add(m->compat_props, hw_compat_4_2, hw_compat_4_2_len); } DEFINE_I440FX_MACHINE(v4_2, "pc-i440fx-4.2", NULL, diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index 385e5cf..2608cd0 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -354,6 +354,7 @@ static void pc_q35_4_2_machine_options(MachineClass *m) pc_q35_machine_options(m); m->alias = "q35"; pcmc->default_cpu_version = 1; + compat_props_add(m->compat_props, hw_compat_4_2, hw_compat_4_2_len); } DEFINE_Q35_MACHINE(v4_2, "pc-q35-4.2", NULL, diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index e076f60..2ca92f2 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -4496,7 +4496,7 @@ static const TypeInfo spapr_machine_info = { */ static void spapr_machine_4_2_class_options(MachineClass *mc) { - /* Defaults for the latest behaviour inherited from the base class */ + compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len); } DEFINE_SPAPR_MACHINE(4_2, "4.2", true); diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index d3edeef..cb5fe4c 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -645,6 +645,7 @@ static void ccw_machine_4_2_instance_options(MachineState *machine) static void ccw_machine_4_2_class_options(MachineClass *mc) { + compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len); } DEFINE_CCW_MACHINE(4_2, "4.2", true); diff --git a/include/hw/boards.h b/include/hw/boards.h index de45087..24cbeec 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -329,6 +329,9 @@ struct MachineState { } \ type_init(machine_initfn##_register_types) +extern GlobalProperty hw_compat_4_2[]; +extern const size_t hw_compat_4_2_len; + extern GlobalProperty hw_compat_4_1[]; extern const size_t hw_compat_4_1_len; diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index cddcfbe..9c19f5b 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -40,6 +40,7 @@ struct VirtIOBlkConf uint16_t queue_size; uint32_t max_discard_sectors; uint32_t max_write_zeroes_sectors; + bool x_enable_wce_if_config_wce; }; struct VirtIOBlockDataPlane; diff --git a/qemu-options.hx b/qemu-options.hx index 4cf7751..3ff8c4e 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4916,6 +4916,44 @@ access CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB @end example +@item -object iothread,id=@var{id},poll-max-ns=@var{poll-max-ns},poll-grow=@var{poll-grow},poll-shrink=@var{poll-shrink} + +Creates a dedicated event loop thread that devices can be assigned to. This is +known as an IOThread. By default device emulation happens in vCPU threads or +the main event loop thread. This can become a scalability bottleneck. +IOThreads allow device emulation and I/O to run on other host CPUs. + +The @option{id} parameter is a unique ID that will be used to reference this +IOThread from @option{-device ...,iothread=@var{id}}. Multiple devices can be +assigned to an IOThread. Note that not all devices support an +@option{iothread} parameter. + +The @code{query-iothreads} QMP command lists IOThreads and reports their thread +IDs so that the user can configure host CPU pinning/affinity. + +IOThreads use an adaptive polling algorithm to reduce event loop latency. +Instead of entering a blocking system call to monitor file descriptors and then +pay the cost of being woken up when an event occurs, the polling algorithm +spins waiting for events for a short time. The algorithm's default parameters +are suitable for many cases but can be adjusted based on knowledge of the +workload and/or host device latency. + +The @option{poll-max-ns} parameter is the maximum number of nanoseconds to busy +wait for events. Polling can be disabled by setting this value to 0. + +The @option{poll-grow} parameter is the multiplier used to increase the polling +time when the algorithm detects it is missing events due to not polling long +enough. + +The @option{poll-shrink} parameter is the divisor used to decrease the polling +time when the algorithm detects it is spending too long polling without +encountering events. + +The polling parameters can be modified at run-time using the @code{qom-set} command (where @code{iothread1} is the IOThread's @code{id}): + +@example +(qemu) qom-set /objects/iothread1 poll-max-ns 100000 +@end example @end table |