2022-05-23 05:56:07

by Eugenio Perez Martin

Subject: [PATCH 4/4] vdpa_sim: Implement stop vdpa op

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

Signed-off-by: Eugenio Pérez <[email protected]>
---
drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++++++
drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 3 +++
3 files changed, 25 insertions(+)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 50d721072beb..0515cf314bed 100644
--- 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 +506,24 @@ static int vdpasim_reset(struct vdpa_device *vdpa)
return 0;
}

+static int vdpasim_stop(struct vdpa_device *vdpa, bool stop)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ int i;
+
+ spin_lock(&vdpasim->lock);
+ vdpasim->running = !stop;
+ if (vdpasim->running) {
+ /* Check for missed buffers */
+ for (i = 0; i < vdpasim->dev_attr.nvqs; ++i)
+ vdpasim_kick_vq(vdpa, i);
+
+ }
+ 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 +713,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
.get_status = vdpasim_get_status,
.set_status = vdpasim_set_status,
.reset = vdpasim_reset,
+ .stop = vdpasim_stop,
.get_config_size = vdpasim_get_config_size,
.get_config = vdpasim_get_config,
.set_config = vdpasim_set_config,
@@ -726,6 +746,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
.get_status = vdpasim_get_status,
.set_status = vdpasim_set_status,
.reset = vdpasim_reset,
+ .stop = vdpasim_stop,
.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 622782e92239..061986f30911 100644
--- 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_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
index 5125976a4df8..886449e88502 100644
--- 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;

--
2.27.0

2022-05-23 08:52:33

by Stefano Garzarella

Subject: Re: [PATCH 4/4] vdpa_sim: Implement stop vdpa op

On Fri, May 20, 2022 at 07:23:25PM +0200, Eugenio P?rez wrote:
>Implement stop operation for vdpa_sim devices, so vhost-vdpa will offer
>that backend feature and userspace can effectively stop 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).
>
>Signed-off-by: Eugenio P?rez <[email protected]>
>---
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++++++
> drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
> drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 3 +++
> 3 files changed, 25 insertions(+)
>
>diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>index 50d721072beb..0515cf314bed 100644
>--- 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 +506,24 @@ static int vdpasim_reset(struct vdpa_device *vdpa)
> return 0;
> }
>
>+static int vdpasim_stop(struct vdpa_device *vdpa, bool stop)
>+{
>+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>+ int i;
>+
>+ spin_lock(&vdpasim->lock);
>+ vdpasim->running = !stop;
>+ if (vdpasim->running) {
>+ /* Check for missed buffers */
>+ for (i = 0; i < vdpasim->dev_attr.nvqs; ++i)
>+ vdpasim_kick_vq(vdpa, i);
>+
>+ }
>+ 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 +713,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
> .get_status = vdpasim_get_status,
> .set_status = vdpasim_set_status,
> .reset = vdpasim_reset,
>+ .stop = vdpasim_stop,
> .get_config_size = vdpasim_get_config_size,
> .get_config = vdpasim_get_config,
> .set_config = vdpasim_set_config,
>@@ -726,6 +746,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
> .get_status = vdpasim_get_status,
> .set_status = vdpasim_set_status,
> .reset = vdpasim_reset,
>+ .stop = vdpasim_stop,
> .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 622782e92239..061986f30911 100644
>--- 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_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
>index 5125976a4df8..886449e88502 100644
>--- 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;
>+

It would be nice to do the same for vdpa_sim_blk as well.

Thanks,
Stefano

2022-05-23 19:44:17

by Eugenio Perez Martin

Subject: Re: [PATCH 4/4] vdpa_sim: Implement stop vdpa op

On Mon, May 23, 2022 at 10:28 AM Stefano Garzarella <[email protected]> wrote:
>
> On Fri, May 20, 2022 at 07:23:25PM +0200, Eugenio Pérez wrote:
> >Implement stop operation for vdpa_sim devices, so vhost-vdpa will offer
> >that backend feature and userspace can effectively stop 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).
> >
> >Signed-off-by: Eugenio Pérez <[email protected]>
> >---
> > drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++++++
> > drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
> > drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 3 +++
> > 3 files changed, 25 insertions(+)
> >
> >diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> >index 50d721072beb..0515cf314bed 100644
> >--- 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 +506,24 @@ static int vdpasim_reset(struct vdpa_device *vdpa)
> > return 0;
> > }
> >
> >+static int vdpasim_stop(struct vdpa_device *vdpa, bool stop)
> >+{
> >+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> >+ int i;
> >+
> >+ spin_lock(&vdpasim->lock);
> >+ vdpasim->running = !stop;
> >+ if (vdpasim->running) {
> >+ /* Check for missed buffers */
> >+ for (i = 0; i < vdpasim->dev_attr.nvqs; ++i)
> >+ vdpasim_kick_vq(vdpa, i);
> >+
> >+ }
> >+ 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 +713,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
> > .get_status = vdpasim_get_status,
> > .set_status = vdpasim_set_status,
> > .reset = vdpasim_reset,
> >+ .stop = vdpasim_stop,
> > .get_config_size = vdpasim_get_config_size,
> > .get_config = vdpasim_get_config,
> > .set_config = vdpasim_set_config,
> >@@ -726,6 +746,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
> > .get_status = vdpasim_get_status,
> > .set_status = vdpasim_set_status,
> > .reset = vdpasim_reset,
> >+ .stop = vdpasim_stop,
> > .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 622782e92239..061986f30911 100644
> >--- 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_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> >index 5125976a4df8..886449e88502 100644
> >--- 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;
> >+
>
> It would be nice to do the same for vdpa_sim_blk as well.
>

Agree, it will be added in the next revision. If not, blk presents an
invalid backend feature bit.

Thanks!

> Thanks,
> Stefano
>