Commit 6f80e617 authored by Tiwei Bie's avatar Tiwei Bie Committed by Michael S. Tsirkin
Browse files

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: default avatarTiwei Bie <tiwei.bie@intel.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 1f3a4519

hw/virtio/virtio-pci.c

+22 −0
Original line number Diff line number Diff line
@@ -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;

hw/virtio/virtio.c

+13 −0
Original line number Diff line number Diff line
@@ -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);

include/hw/virtio/virtio-bus.h

+2 −0
Original line number Diff line number Diff line
@@ -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

include/hw/virtio/virtio.h

+2 −0
Original line number Diff line number Diff line
@@ -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);