From c95b4437da6832f3bef9129de897cc7a8334ea8e Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 26 Jun 2020 09:22:43 +0200 Subject: [PATCH] virtio-mem: Allow notifiers for size changes We want to send qapi events in case the size of a virtio-mem device changes. This allows upper layers to always know how much memory is actually currently consumed via a virtio-mem device. Unfortuantely, we have to report the id of our proxy device. Let's provide an easy way for our proxy device to register, so it can send the qapi events. Piggy-backing on the notifier infrastructure (although we'll only ever have one notifier registered) seems to be an easy way. Reviewed-by: Dr. David Alan Gilbert Cc: "Michael S. Tsirkin" Cc: "Dr. David Alan Gilbert" Cc: Igor Mammedov Signed-off-by: David Hildenbrand Message-Id: <20200626072248.78761-17-david@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio-mem.c | 21 ++++++++++++++++++++- include/hw/virtio/virtio-mem.h | 5 +++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index 2d6f3061a6..6b5551515d 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -184,6 +184,7 @@ static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa, } else { vmem->size -= size; } + notifier_list_notify(&vmem->size_change_notifiers, &vmem->size); return VIRTIO_MEM_RESP_ACK; } @@ -242,7 +243,10 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem) return -EBUSY; } bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size); - vmem->size = 0; + if (vmem->size) { + vmem->size = 0; + notifier_list_notify(&vmem->size_change_notifiers, &vmem->size); + } virtio_mem_resize_usable_region(vmem, vmem->requested_size, true); return 0; @@ -561,6 +565,18 @@ static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp) return &vmem->memdev->mr; } +static void virtio_mem_add_size_change_notifier(VirtIOMEM *vmem, + Notifier *notifier) +{ + notifier_list_add(&vmem->size_change_notifiers, notifier); +} + +static void virtio_mem_remove_size_change_notifier(VirtIOMEM *vmem, + Notifier *notifier) +{ + notifier_remove(notifier); +} + static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name, void *opaque, Error **errp) { @@ -668,6 +684,7 @@ static void virtio_mem_instance_init(Object *obj) VirtIOMEM *vmem = VIRTIO_MEM(obj); vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE; + notifier_list_init(&vmem->size_change_notifiers); object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size, NULL, NULL, NULL); @@ -705,6 +722,8 @@ static void virtio_mem_class_init(ObjectClass *klass, void *data) vmc->fill_device_info = virtio_mem_fill_device_info; vmc->get_memory_region = virtio_mem_get_memory_region; + vmc->add_size_change_notifier = virtio_mem_add_size_change_notifier; + vmc->remove_size_change_notifier = virtio_mem_remove_size_change_notifier; } static const TypeInfo virtio_mem_info = { diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h index 6981096f7c..b74c77cd42 100644 --- a/include/hw/virtio/virtio-mem.h +++ b/include/hw/virtio/virtio-mem.h @@ -64,6 +64,9 @@ typedef struct VirtIOMEM { /* block size and alignment */ uint64_t block_size; + + /* notifiers to notify when "size" changes */ + NotifierList size_change_notifiers; } VirtIOMEM; typedef struct VirtIOMEMClass { @@ -73,6 +76,8 @@ typedef struct VirtIOMEMClass { /* public */ void (*fill_device_info)(const VirtIOMEM *vmen, VirtioMEMDeviceInfo *vi); MemoryRegion *(*get_memory_region)(VirtIOMEM *vmem, Error **errp); + void (*add_size_change_notifier)(VirtIOMEM *vmem, Notifier *notifier); + void (*remove_size_change_notifier)(VirtIOMEM *vmem, Notifier *notifier); } VirtIOMEMClass; #endif -- 2.11.0