Re: [PATCH] vhost-test: Make vhost/test.c work

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, May 08, 2013 at 03:14:58PM +0800, Asias He wrote:
> On Tue, May 07, 2013 at 02:22:32PM +0300, Michael S. Tsirkin wrote:
> > On Tue, May 07, 2013 at 02:52:45PM +0800, Asias He wrote:
> > > Fix it by:
> > > 1) switching to use the new device specific fields per vq
> > > 2) not including vhost.c, instead make vhost-test.ko depend on vhost.ko.
> > 
> > Please split this up.
> > 1. make test work for 3.10
> > 2. make test work for 3.11
> > 
> > thanks!
> 
> okay.
> 
> > > ---
> > >  drivers/vhost/test.c | 37 +++++++++++++++++++++++++------------
> > >  1 file changed, 25 insertions(+), 12 deletions(-)
> > > 
> > > diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
> > > index 1ee45bc..dc526eb 100644
> > > --- a/drivers/vhost/test.c
> > > +++ b/drivers/vhost/test.c
> > > @@ -18,7 +18,7 @@
> > >  #include <linux/slab.h>
> > >  
> > >  #include "test.h"
> > > -#include "vhost.c"
> > > +#include "vhost.h"
> > >  
> > >  /* Max number of bytes transferred before requeueing the job.
> > >   * Using this limit prevents one virtqueue from starving others. */
> > > @@ -29,16 +29,20 @@ enum {
> > >  	VHOST_TEST_VQ_MAX = 1,
> > >  };
> > >  
> > > +struct vhost_test_virtqueue {
> > > +	struct vhost_virtqueue vq;
> > > +};
> > > +
> > 
> > This isn't needed or useful. Drop above change pls and patch
> > size will shrink.
> 
> The difference is:
> 
>  drivers/vhost/test.c | 23 ++++++++++++++++-------
>  1 file changed, 16 insertions(+), 7 deletions(-)
> 
>  drivers/vhost/test.c | 35 ++++++++++++++++++++++++-----------
>  1 file changed, 24 insertions(+), 11 deletions(-)
> 
> which is not significant.

I did it like this:
 test.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)


> So, I think it is better to code the same way as we do in vhost-net and
> vhost-scsi which makes the device specific usage more consistent.
> 
> > >  struct vhost_test {
> > >  	struct vhost_dev dev;
> > > -	struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
> > > +	struct vhost_test_virtqueue vqs[VHOST_TEST_VQ_MAX];
> > >  };
> > >  
> > >  /* Expects to be always run from workqueue - which acts as
> > >   * read-size critical section for our kind of RCU. */
> > >  static void handle_vq(struct vhost_test *n)
> > >  {
> > > -	struct vhost_virtqueue *vq = &n->dev.vqs[VHOST_TEST_VQ];
> > > +	struct vhost_virtqueue *vq = n->dev.vqs[VHOST_TEST_VQ];
> > >  	unsigned out, in;
> > >  	int head;
> > >  	size_t len, total_len = 0;
> > > @@ -101,15 +105,23 @@ static void handle_vq_kick(struct vhost_work *work)
> > >  static int vhost_test_open(struct inode *inode, struct file *f)
> > >  {
> > >  	struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
> > > +	struct vhost_virtqueue **vqs;
> > >  	struct vhost_dev *dev;
> > >  	int r;
> > >  
> > >  	if (!n)
> > >  		return -ENOMEM;
> > >  
> > > +	vqs = kmalloc(VHOST_TEST_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
> > > +	if (!vqs) {
> > > +		kfree(n);
> > > +		return -ENOMEM;
> > > +	}
> > > +
> > >  	dev = &n->dev;
> > > -	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
> > > -	r = vhost_dev_init(dev, n->vqs, VHOST_TEST_VQ_MAX);
> > > +	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ].vq;
> > > +	n->vqs[VHOST_TEST_VQ].vq.handle_kick = handle_vq_kick;
> > > +	r = vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX);
> > >  	if (r < 0) {
> > >  		kfree(n);
> > >  		return r;
> > > @@ -135,12 +147,12 @@ static void *vhost_test_stop_vq(struct vhost_test *n,
> > >  
> > >  static void vhost_test_stop(struct vhost_test *n, void **privatep)
> > >  {
> > > -	*privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
> > > +	*privatep = vhost_test_stop_vq(n, &n->vqs[VHOST_TEST_VQ].vq);
> > >  }
> > >  
> > >  static void vhost_test_flush_vq(struct vhost_test *n, int index)
> > >  {
> > > -	vhost_poll_flush(&n->dev.vqs[index].poll);
> > > +	vhost_poll_flush(&n->vqs[index].vq.poll);
> > >  }
> > >  
> > >  static void vhost_test_flush(struct vhost_test *n)
> > > @@ -159,6 +171,7 @@ static int vhost_test_release(struct inode *inode, struct file *f)
> > >  	/* We do an extra flush before freeing memory,
> > >  	 * since jobs can re-queue themselves. */
> > >  	vhost_test_flush(n);
> > > +	kfree(n->dev.vqs);
> > >  	kfree(n);
> > >  	return 0;
> > >  }
> > > @@ -179,14 +192,14 @@ static long vhost_test_run(struct vhost_test *n, int test)
> > >  
> > >  	for (index = 0; index < n->dev.nvqs; ++index) {
> > >  		/* Verify that ring has been setup correctly. */
> > > -		if (!vhost_vq_access_ok(&n->vqs[index])) {
> > > +		if (!vhost_vq_access_ok(&n->vqs[index].vq)) {
> > >  			r = -EFAULT;
> > >  			goto err;
> > >  		}
> > >  	}
> > >  
> > >  	for (index = 0; index < n->dev.nvqs; ++index) {
> > > -		vq = n->vqs + index;
> > > +		vq = &n->vqs[index].vq;
> > >  		mutex_lock(&vq->mutex);
> > >  		priv = test ? n : NULL;
> > >  
> > > @@ -195,7 +208,7 @@ static long vhost_test_run(struct vhost_test *n, int test)
> > >  						    lockdep_is_held(&vq->mutex));
> > >  		rcu_assign_pointer(vq->private_data, priv);
> > >  
> > > -		r = vhost_init_used(&n->vqs[index]);
> > > +		r = vhost_init_used(&n->vqs[index].vq);
> > >  
> > >  		mutex_unlock(&vq->mutex);
> > >  
> > > @@ -268,14 +281,14 @@ static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
> > >  			return -EFAULT;
> > >  		return vhost_test_run(n, test);
> > >  	case VHOST_GET_FEATURES:
> > > -		features = VHOST_NET_FEATURES;
> > > +		features = VHOST_FEATURES;
> > >  		if (copy_to_user(featurep, &features, sizeof features))
> > >  			return -EFAULT;
> > >  		return 0;
> > >  	case VHOST_SET_FEATURES:
> > >  		if (copy_from_user(&features, featurep, sizeof features))
> > >  			return -EFAULT;
> > > -		if (features & ~VHOST_NET_FEATURES)
> > > +		if (features & ~VHOST_FEATURES)
> > >  			return -EOPNOTSUPP;
> > >  		return vhost_test_set_features(n, features);
> > >  	case VHOST_RESET_OWNER:
> > > -- 
> > > 1.8.1.4
> 
> -- 
> Asias