vdpa_sim: Implement suspend vdpa op

Implement suspend operation for vdpa_sim devices, so vhost-vdpa will
offer that backend feature and userspace can effectively suspend the
device.

This is a must before get virtqueue indexes (base) for live migration,
since the device could modify them after userland gets them. There are
individual ways to perform that action for some devices
(VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no
way to perform it for any vhost device (and, in particular, vhost-vdpa).

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20220810171512.2343333-5-eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 3e81532..225b7f5 100644 (file)
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -107,6 +107,7 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim)
        for (i = 0; i < vdpasim->dev_attr.nas; i++)
                vhost_iotlb_reset(&vdpasim->iommu[i]);
 
+       vdpasim->running = true;
        spin_unlock(&vdpasim->iommu_lock);
 
        vdpasim->features = 0;
@@ -505,6 +506,17 @@ static int vdpasim_reset(struct vdpa_device *vdpa)
        return 0;
 }
 
+static int vdpasim_suspend(struct vdpa_device *vdpa)
+{
+       struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+       spin_lock(&vdpasim->lock);
+       vdpasim->running = false;
+       spin_unlock(&vdpasim->lock);
+
+       return 0;
+}
+
 static size_t vdpasim_get_config_size(struct vdpa_device *vdpa)
 {
        struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
@@ -694,6 +706,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
        .get_status             = vdpasim_get_status,
        .set_status             = vdpasim_set_status,
        .reset                  = vdpasim_reset,
+       .suspend                = vdpasim_suspend,
        .get_config_size        = vdpasim_get_config_size,
        .get_config             = vdpasim_get_config,
        .set_config             = vdpasim_set_config,
@@ -726,6 +739,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
        .get_status             = vdpasim_get_status,
        .set_status             = vdpasim_set_status,
        .reset                  = vdpasim_reset,
+       .suspend                = vdpasim_suspend,
        .get_config_size        = vdpasim_get_config_size,
        .get_config             = vdpasim_get_config,
        .set_config             = vdpasim_set_config,

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h
index 622782e..061986f 100644 (file)
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.h
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h
@@ -66,6 +66,7 @@ struct vdpasim {
        u32 generation;
        u64 features;
        u32 groups;
+       bool running;
        /* spinlock to synchronize iommu table */
        spinlock_t iommu_lock;
 };

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
index dde965a..ba253f8 100644 (file)
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -213,6 +213,9 @@ static void vdpasim_blk_work(struct work_struct *work)
        if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
                goto out;
 
+       if (!vdpasim->running)
+               goto out;
+
        for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) {
                struct vdpasim_virtqueue *vq = &vdpasim->vqs[i];
                int reqs = 0;

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
index 5125976..886449e 100644 (file)
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
@@ -154,6 +154,9 @@ static void vdpasim_net_work(struct work_struct *work)
 
        spin_lock(&vdpasim->lock);
 
+       if (!vdpasim->running)
+               goto out;
+
        if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
                goto out;