diff mbox series

[2/2] tools/virtio: Add hints when module is not installed

Message ID 20230926050021.717-2-liming.wu@jaguarmicro.com (mailing list archive)
State Superseded
Headers show
Series [1/2] tools/virtio: Add dma sync api for virtio test | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Liming Wu Sept. 26, 2023, 5 a.m. UTC
From: Liming Wu <liming.wu@jaguarmicro.com>

Need to insmod vhost_test.ko before run virtio_test.
Give some hints to users.

Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
---
 tools/virtio/virtio_test.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Michael S. Tsirkin Sept. 27, 2023, 3:20 p.m. UTC | #1
On Tue, Sep 26, 2023 at 01:00:20PM +0800, liming.wu@jaguarmicro.com wrote:
> From: Liming Wu <liming.wu@jaguarmicro.com>
> 
> Need to insmod vhost_test.ko before run virtio_test.
> Give some hints to users.
> 
> Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
> ---
>  tools/virtio/virtio_test.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
> index 028f54e6854a..ce2c4d93d735 100644
> --- a/tools/virtio/virtio_test.c
> +++ b/tools/virtio/virtio_test.c
> @@ -135,6 +135,10 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
>  	dev->buf = malloc(dev->buf_size);
>  	assert(dev->buf);
>  	dev->control = open("/dev/vhost-test", O_RDWR);
> +
> +	if (dev->control < 0)
> +		fprintf(stderr, "Install vhost_test module" \
> +		"(./vhost_test/vhost_test.ko) firstly\n");

Thanks!

things to improve:

firstly -> first
add space before (
End sentence with a dot
align "" on the two lines

>  	assert(dev->control >= 0);
>  	r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
>  	assert(r >= 0);
> -- 
> 2.34.1
Jason Wang Oct. 8, 2023, 4:35 a.m. UTC | #2
On Tue, Sep 26, 2023 at 1:00 PM <liming.wu@jaguarmicro.com> wrote:
>
> From: Liming Wu <liming.wu@jaguarmicro.com>
>
> Need to insmod vhost_test.ko before run virtio_test.
> Give some hints to users.
>
> Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
> ---
>  tools/virtio/virtio_test.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
> index 028f54e6854a..ce2c4d93d735 100644
> --- a/tools/virtio/virtio_test.c
> +++ b/tools/virtio/virtio_test.c
> @@ -135,6 +135,10 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
>         dev->buf = malloc(dev->buf_size);
>         assert(dev->buf);
>         dev->control = open("/dev/vhost-test", O_RDWR);
> +
> +       if (dev->control < 0)
> +               fprintf(stderr, "Install vhost_test module" \
> +               "(./vhost_test/vhost_test.ko) firstly\n");

There should be many other reasons to fail for open().

Let's use strerror()?

Thanks


>         assert(dev->control >= 0);
>         r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
>         assert(r >= 0);
> --
> 2.34.1
>
Liming Wu Oct. 9, 2023, 2:44 a.m. UTC | #3
> -----Original Message-----
> From: Jason Wang <jasowang@redhat.com>
> Sent: Sunday, October 8, 2023 12:36 PM
> To: Liming Wu <liming.wu@jaguarmicro.com>
> Cc: Michael S . Tsirkin <mst@redhat.com>; kvm@vger.kernel.org;
> virtualization@lists.linux-foundation.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; 398776277@qq.com
> Subject: Re: [PATCH 2/2] tools/virtio: Add hints when module is not installed
> 
> On Tue, Sep 26, 2023 at 1:00 PM <liming.wu@jaguarmicro.com> wrote:
> >
> > From: Liming Wu <liming.wu@jaguarmicro.com>
> >
> > Need to insmod vhost_test.ko before run virtio_test.
> > Give some hints to users.
> >
> > Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
> > ---
> >  tools/virtio/virtio_test.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
> > index 028f54e6854a..ce2c4d93d735 100644
> > --- a/tools/virtio/virtio_test.c
> > +++ b/tools/virtio/virtio_test.c
> > @@ -135,6 +135,10 @@ static void vdev_info_init(struct vdev_info* dev,
> unsigned long long features)
> >         dev->buf = malloc(dev->buf_size);
> >         assert(dev->buf);
> >         dev->control = open("/dev/vhost-test", O_RDWR);
> > +
> > +       if (dev->control < 0)
> > +               fprintf(stderr, "Install vhost_test module" \
> > +               "(./vhost_test/vhost_test.ko) firstly\n");
> 
> There should be many other reasons to fail for open().
> 
> Let's use strerror()?
Yes,  Thanks for the review. 
Please rechecked the code as follow:
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -135,6 +135,11 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
        dev->buf = malloc(dev->buf_size);
        assert(dev->buf);
        dev->control = open("/dev/vhost-test", O_RDWR);
+
+       if (dev->control == NULL)
+               fprintf(stderr,
+                       "%s: Check whether vhost_test.ko is installed.\n",
+                       strerror(errno));
        assert(dev->control >= 0);
        r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
        assert(r >= 0);
 
Thanks
Michael S. Tsirkin Oct. 9, 2023, 10:52 a.m. UTC | #4
On Mon, Oct 09, 2023 at 02:44:55AM +0000, Liming Wu wrote:
> 
> 
> > -----Original Message-----
> > From: Jason Wang <jasowang@redhat.com>
> > Sent: Sunday, October 8, 2023 12:36 PM
> > To: Liming Wu <liming.wu@jaguarmicro.com>
> > Cc: Michael S . Tsirkin <mst@redhat.com>; kvm@vger.kernel.org;
> > virtualization@lists.linux-foundation.org; netdev@vger.kernel.org; linux-
> > kernel@vger.kernel.org; 398776277@qq.com
> > Subject: Re: [PATCH 2/2] tools/virtio: Add hints when module is not installed
> > 
> > On Tue, Sep 26, 2023 at 1:00 PM <liming.wu@jaguarmicro.com> wrote:
> > >
> > > From: Liming Wu <liming.wu@jaguarmicro.com>
> > >
> > > Need to insmod vhost_test.ko before run virtio_test.
> > > Give some hints to users.
> > >
> > > Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
> > > ---
> > >  tools/virtio/virtio_test.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > > diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
> > > index 028f54e6854a..ce2c4d93d735 100644
> > > --- a/tools/virtio/virtio_test.c
> > > +++ b/tools/virtio/virtio_test.c
> > > @@ -135,6 +135,10 @@ static void vdev_info_init(struct vdev_info* dev,
> > unsigned long long features)
> > >         dev->buf = malloc(dev->buf_size);
> > >         assert(dev->buf);
> > >         dev->control = open("/dev/vhost-test", O_RDWR);
> > > +
> > > +       if (dev->control < 0)
> > > +               fprintf(stderr, "Install vhost_test module" \
> > > +               "(./vhost_test/vhost_test.ko) firstly\n");
> > 
> > There should be many other reasons to fail for open().
> > 
> > Let's use strerror()?
> Yes,  Thanks for the review. 
> Please rechecked the code as follow:
> --- a/tools/virtio/virtio_test.c
> +++ b/tools/virtio/virtio_test.c
> @@ -135,6 +135,11 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
>         dev->buf = malloc(dev->buf_size);
>         assert(dev->buf);
>         dev->control = open("/dev/vhost-test", O_RDWR);
> +
> +       if (dev->control == NULL)


???
Why are you comparing a file descriptor to NULL?

> +               fprintf(stderr,
> +                       "%s: Check whether vhost_test.ko is installed.\n",
> +                       strerror(errno));


No, do not suggest checking unconditionally this is just wasting user's
time.  You would have to check the exact errno value. You will either
get ENOENT or ENODEV if module is not loaded. Other errors indicate
other problems.  And what matters is whether it's loaded, not installed
- vhost_test.ko will not get auto-loaded even if installed.


>         assert(dev->control >= 0);
>         r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
>         assert(r >= 0);
>  
> Thanks
> 

In short, I am not applying this patch. If you really want to make
things a bit easier in case of errors, replace all assert r >= 0 with
a macro that prints out strerror(errno), that should be enough.
Maybe print file/line number too while we are at it.
diff mbox series

Patch

diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index 028f54e6854a..ce2c4d93d735 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -135,6 +135,10 @@  static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
 	dev->buf = malloc(dev->buf_size);
 	assert(dev->buf);
 	dev->control = open("/dev/vhost-test", O_RDWR);
+
+	if (dev->control < 0)
+		fprintf(stderr, "Install vhost_test module" \
+		"(./vhost_test/vhost_test.ko) firstly\n");
 	assert(dev->control >= 0);
 	r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
 	assert(r >= 0);