Commit 3dad5682 authored by Xie Yongji's avatar Xie Yongji Committed by Michael S. Tsirkin

virtio-vdpa: Support interrupt affinity spreading mechanism

To support interrupt affinity spreading mechanism,
this makes use of group_cpus_evenly() to create
an irq callback affinity mask for each virtqueue
of vdpa device. Then we will unify set_vq_affinity
callback to pass the affinity to the vdpa device driver.
Signed-off-by: default avatarXie Yongji <xieyongji@bytedance.com>
Message-Id: <20230323053043.35-4-xieyongji@bytedance.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
parent 1d246927
......@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/group_cpus.h>
#include <linux/virtio.h>
#include <linux/vdpa.h>
#include <linux/virtio_config.h>
......@@ -272,6 +273,66 @@ static void virtio_vdpa_del_vqs(struct virtio_device *vdev)
virtio_vdpa_del_vq(vq);
}
static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
{
affd->nr_sets = 1;
affd->set_size[0] = affvecs;
}
static struct cpumask *
create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd)
{
unsigned int affvecs = 0, curvec, usedvecs, i;
struct cpumask *masks = NULL;
if (nvecs > affd->pre_vectors + affd->post_vectors)
affvecs = nvecs - affd->pre_vectors - affd->post_vectors;
if (!affd->calc_sets)
affd->calc_sets = default_calc_sets;
affd->calc_sets(affd, affvecs);
if (!affvecs)
return NULL;
masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
if (!masks)
return NULL;
/* Fill out vectors at the beginning that don't need affinity */
for (curvec = 0; curvec < affd->pre_vectors; curvec++)
cpumask_setall(&masks[curvec]);
for (i = 0, usedvecs = 0; i < affd->nr_sets; i++) {
unsigned int this_vecs = affd->set_size[i];
int j;
struct cpumask *result = group_cpus_evenly(this_vecs);
if (!result) {
kfree(masks);
return NULL;
}
for (j = 0; j < this_vecs; j++)
cpumask_copy(&masks[curvec + j], &result[j]);
kfree(result);
curvec += this_vecs;
usedvecs += this_vecs;
}
/* Fill out vectors at the end that don't need affinity */
if (usedvecs >= affvecs)
curvec = affd->pre_vectors + affvecs;
else
curvec = affd->pre_vectors + usedvecs;
for (; curvec < nvecs; curvec++)
cpumask_setall(&masks[curvec]);
return masks;
}
static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
......@@ -282,9 +343,15 @@ static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
struct irq_affinity default_affd = { 0 };
struct cpumask *masks;
struct vdpa_callback cb;
int i, err, queue_idx = 0;
masks = create_affinity_masks(nvqs, desc ? desc : &default_affd);
if (!masks)
return -ENOMEM;
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
......@@ -298,6 +365,7 @@ static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
err = PTR_ERR(vqs[i]);
goto err_setup_vq;
}
ops->set_vq_affinity(vdpa, i, &masks[i]);
}
cb.callback = virtio_vdpa_config_cb;
......
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