Repetitive ioctls makes vdpa devices initialization and startup slow. This patch is to cache Virtio status, features, and config. Testing with vdpa-sim-net as my vdpa device, the numbers of ioctl is reduced from 47 to 37.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1579 Signed-off-by: Shao-Chien Chiang <ray90...@gmail.com> --- hw/virtio/vhost-vdpa.c | 44 +++++++++++++++++++++++----------- include/hw/virtio/vhost-vdpa.h | 3 +++ 2 files changed, 33 insertions(+), 14 deletions(-) diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index bc6bad23d5..1fccd151cf 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -343,21 +343,17 @@ static int vhost_vdpa_call(struct vhost_dev *dev, unsigned long int request, int ret; assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA); - ret = ioctl(fd, request, arg); return ret < 0 ? -errno : ret; } static int vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status) { - uint8_t s; + struct vhost_vdpa *v = dev->opaque; + uint8_t s = v->status; int ret; trace_vhost_vdpa_add_status(dev, status); - ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &s); - if (ret < 0) { - return ret; - } s |= status; @@ -374,6 +370,7 @@ static int vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status) if (!(s & status)) { return -EIO; } + v->status = s; return 0; } @@ -436,8 +433,15 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp) dev->opaque = opaque ; v->listener = vhost_vdpa_memory_listener; v->msg_type = VHOST_IOTLB_MSG_V2; + v->config = NULL; + v->features = dev->features; vhost_vdpa_init_svq(dev, v); + ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &v->status); + if (ret) { + return ret; + } + error_propagate(&dev->migration_blocker, v->migration_blocker); if (!vhost_vdpa_first_dev(dev)) { return 0; @@ -456,6 +460,7 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp) return ret; } vhost_svq_valid_features(features, &dev->migration_blocker); + v->features = features; } /* @@ -602,6 +607,7 @@ static int vhost_vdpa_cleanup(struct vhost_dev *dev) vhost_vdpa_svq_cleanup(dev); dev->opaque = NULL; + g_free(v->config); return 0; } @@ -718,6 +724,7 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev) ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status); trace_vhost_vdpa_reset_device(dev, status); v->suspended = false; + v->status = 0; return ret; } @@ -767,6 +774,7 @@ static int vhost_vdpa_set_config(struct vhost_dev *dev, const uint8_t *data, uint32_t offset, uint32_t size, uint32_t flags) { + struct vhost_vdpa *v = dev->opaque; struct vhost_vdpa_config *config; int ret; unsigned long config_size = offsetof(struct vhost_vdpa_config, buf); @@ -776,6 +784,10 @@ static int vhost_vdpa_set_config(struct vhost_dev *dev, const uint8_t *data, config->off = offset; config->len = size; memcpy(config->buf, data, size); + if (v->config != NULL) { + assert(size + offset <= v->config->len); + memcpy(v->config->buf + offset, data, size); + } if (trace_event_get_state_backends(TRACE_VHOST_VDPA_SET_CONFIG) && trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_CONFIG)) { vhost_vdpa_dump_config(dev, data, size); @@ -788,17 +800,19 @@ static int vhost_vdpa_set_config(struct vhost_dev *dev, const uint8_t *data, static int vhost_vdpa_get_config(struct vhost_dev *dev, uint8_t *config, uint32_t config_len, Error **errp) { - struct vhost_vdpa_config *v_config; + struct vhost_vdpa *v = dev->opaque; unsigned long config_size = offsetof(struct vhost_vdpa_config, buf); int ret; trace_vhost_vdpa_get_config(dev, config, config_len); - v_config = g_malloc(config_len + config_size); - v_config->len = config_len; - v_config->off = 0; - ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_CONFIG, v_config); - memcpy(config, v_config->buf, config_len); - g_free(v_config); + if (v->config == NULL) { + v->config = g_malloc(config_len + config_size); + v->config->len = config_len; + v->config->off = 0; + ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_CONFIG, v->config); + } + assert(config_len <= v->config->len); + memcpy(config, v->config->buf, config_len); if (trace_event_get_state_backends(TRACE_VHOST_VDPA_GET_CONFIG) && trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_CONFIG)) { vhost_vdpa_dump_config(dev, config, config_len); @@ -1294,8 +1308,10 @@ static int vhost_vdpa_set_vring_call(struct vhost_dev *dev, static int vhost_vdpa_get_features(struct vhost_dev *dev, uint64_t *features) { - int ret = vhost_vdpa_get_dev_features(dev, features); + struct vhost_vdpa *v = dev->opaque; + int ret = 0; + *features = v->features; if (ret == 0) { /* Add SVQ logging capabilities */ *features |= BIT_ULL(VHOST_F_LOG_ALL); diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h index c278a2a8de..c1505a21ec 100644 --- a/include/hw/virtio/vhost-vdpa.h +++ b/include/hw/virtio/vhost-vdpa.h @@ -39,6 +39,9 @@ typedef struct vhost_vdpa { MemoryListener listener; struct vhost_vdpa_iova_range iova_range; uint64_t acked_features; + uint64_t features; + uint8_t status; + struct vhost_vdpa_config *config; bool shadow_vqs_enabled; /* Vdpa must send shadow addresses as IOTLB key for data queues, not GPA */ bool shadow_data; -- 2.25.1
