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 3e81532c01cb809c66ed0d4bcd71116e222be32c..225b7f5d8be353c16dbcbeb98790f2486ab943a8 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 622782e922391c217c690b98459b8e272a443175..061986f30911a73f9b3fd2d3f47a79e926f23bb1 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 dde965a826bbe8130bea1ebe318659ec1b9af81c..ba253f8bce32d658d24a9625a427bdc04da13137 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 5125976a4df87c7c71557bca89cc776e3a5c84bc..886449e885026ab2b7ee1e4ca3681bb59edf2cbd 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;