virtio: support setting memory region based host notifier

This patch introduces the support for setting memory region
based host notifiers for virtio device. This is helpful when
using a hardware accelerator for a virtio device, because
hardware heavily depends on the notification, this will allow
the guest driver in the VM to notify the hardware directly.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Tiwei Bie 2018-04-12 23:12:30 +08:00 committed by Michael S. Tsirkin
parent 1f3a4519b1
commit 6f80e6170e
4 changed files with 39 additions and 0 deletions

View File

@ -1037,6 +1037,27 @@ assign_error:
return r;
}
static int virtio_pci_set_host_notifier_mr(DeviceState *d, int n,
MemoryRegion *mr, bool assign)
{
VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
int offset;
if (n >= VIRTIO_QUEUE_MAX || !virtio_pci_modern(proxy) ||
virtio_pci_queue_mem_mult(proxy) != memory_region_size(mr)) {
return -1;
}
if (assign) {
offset = virtio_pci_queue_mem_mult(proxy) * n;
memory_region_add_subregion_overlap(&proxy->notify.mr, offset, mr, 1);
} else {
memory_region_del_subregion(&proxy->notify.mr, mr);
}
return 0;
}
static void virtio_pci_vmstate_change(DeviceState *d, bool running)
{
VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
@ -2652,6 +2673,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
k->has_extra_state = virtio_pci_has_extra_state;
k->query_guest_notifiers = virtio_pci_query_guest_notifiers;
k->set_guest_notifiers = virtio_pci_set_guest_notifiers;
k->set_host_notifier_mr = virtio_pci_set_host_notifier_mr;
k->vmstate_change = virtio_pci_vmstate_change;
k->pre_plugged = virtio_pci_pre_plugged;
k->device_plugged = virtio_pci_device_plugged;

View File

@ -2454,6 +2454,19 @@ EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
return &vq->host_notifier;
}
int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
MemoryRegion *mr, bool assign)
{
BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
if (k->set_host_notifier_mr) {
return k->set_host_notifier_mr(qbus->parent, n, mr, assign);
}
return -1;
}
void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name)
{
g_free(vdev->bus_name);

View File

@ -52,6 +52,8 @@ typedef struct VirtioBusClass {
bool (*has_extra_state)(DeviceState *d);
bool (*query_guest_notifiers)(DeviceState *d);
int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
int (*set_host_notifier_mr)(DeviceState *d, int n,
MemoryRegion *mr, bool assign);
void (*vmstate_change)(DeviceState *d, bool running);
/*
* Expose the features the transport layer supports before

View File

@ -239,6 +239,8 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
void virtio_queue_notify(VirtIODevice *vdev, int n);
uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
MemoryRegion *mr, bool assign);
int virtio_set_status(VirtIODevice *vdev, uint8_t val);
void virtio_reset(void *opaque);
void virtio_update_irq(VirtIODevice *vdev);