[PATCH] hyper-v: allow access to vmbus from userspace driver

[PATCH] hyper-v: allow access to vmbus from userspace driver

[Stephen Hemminger]

Brocade is submitting a hyper-v driver for DPDK <dev@dpdk.org>
but this driver needs a hook in the hyper-v bus layer
to allow the additional hv_uio driver to access the shared vmbus
pages. The hv_uio driver lives in DPDK (like igb_uio) and provides
userspace access to raw network packets.

Signed-off-by: Stas Egorov <segorov@mirantis.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

---
 drivers/hv/connection.c |   20 +++++++++++++++++---
 include/linux/hyperv.h  |    3 +++
 2 files changed, 20 insertions(+), 3 deletions(-)

--- a/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
+++ b/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
@@ -64,6 +64,21 @@ static __u32 vmbus_get_next_version(__u3
 	}
 }
 
+static const uuid_le HV_NET_GUID = {
+	.b = {
+		0x63, 0x51, 0x61, 0xf8, 0x3e, 0xdf, 0xc5, 0x46,
+		0x91, 0x3f, 0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e
+	}
+};
+
+void vmbus_get_pages(unsigned long *int_page, unsigned long monitor_pages[2])
+{
+	*int_page = (unsigned long)vmbus_connection.int_page;
+	monitor_pages[0] = (unsigned long)vmbus_connection.monitor_pages[0];
+	monitor_pages[1] = (unsigned long)vmbus_connection.monitor_pages[1];
+}
+EXPORT_SYMBOL_GPL(vmbus_get_pages);
+
 static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 					__u32 version)
 {
@@ -347,7 +362,8 @@ static void process_chn_event(u32 relid)
 			else
 				bytes_to_read = 0;
 		} while (read_state && (bytes_to_read != 0));
-	} else {
+	} else if (!memcmp(&channel->device_obj->dev_type, &HV_NET_GUID,
+			   sizeof(uuid_le))) {
 		pr_err("no channel callback for relid - %u\n", relid);
 	}
 
--- a/include/linux/hyperv.h	2015-02-03 10:58:51.751752450 -0800
+++ b/include/linux/hyperv.h	2015-02-03 10:58:51.751752450 -0800
@@ -868,6 +868,9 @@ extern int vmbus_recvpacket_raw(struct v
 
 extern void vmbus_ontimer(unsigned long data);
 
+extern void vmbus_get_pages(unsigned long *int_page,
+			    unsigned long monitor_pages[2]);
+
 /* Base driver object */
 struct hv_driver {
 	const char *name;

RE: [PATCH] hyper-v: allow access to vmbus from userspace driver

[KY Srinivasan]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Tuesday, February 3, 2015 11:04 AM
> To: KY Srinivasan; Haiyang Zhang
> Cc: devel@linuxdriverproject.org; netdev@vger.kernel.org
> Subject: [PATCH] hyper-v: allow access to vmbus from userspace driver
> 
> Brocade is submitting a hyper-v driver for DPDK <dev@dpdk.org> but this
> driver needs a hook in the hyper-v bus layer to allow the additional hv_uio
> driver to access the shared vmbus pages. The hv_uio driver lives in DPDK (like
> igb_uio) and provides userspace access to raw network packets.
> 
> Signed-off-by: Stas Egorov <segorov@mirantis.com>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> 
> ---
>  drivers/hv/connection.c |   20 +++++++++++++++++---
>  include/linux/hyperv.h  |    3 +++
>  2 files changed, 20 insertions(+), 3 deletions(-)
> 
> --- a/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
> +++ b/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
> @@ -64,6 +64,21 @@ static __u32 vmbus_get_next_version(__u3
>  	}
>  }
> 
> +static const uuid_le HV_NET_GUID = {
> +	.b = {
> +		0x63, 0x51, 0x61, 0xf8, 0x3e, 0xdf, 0xc5, 0x46,
> +		0x91, 0x3f, 0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e
> +	}
> +};
> +

We already have this guid defined in linux/hyperv.h; look at HV_NIC_GUID.
 
> +void vmbus_get_pages(unsigned long *int_page, unsigned long
> +monitor_pages[2]) {
> +	*int_page = (unsigned long)vmbus_connection.int_page;
> +	monitor_pages[0] = (unsigned
> long)vmbus_connection.monitor_pages[0];
> +	monitor_pages[1] = (unsigned
> long)vmbus_connection.monitor_pages[1];
> +}
> +EXPORT_SYMBOL_GPL(vmbus_get_pages);
> +
>  static int vmbus_negotiate_version(struct vmbus_channel_msginfo
> *msginfo,
>  					__u32 version)
>  {
> @@ -347,7 +362,8 @@ static void process_chn_event(u32 relid)
>  			else
>  				bytes_to_read = 0;
>  		} while (read_state && (bytes_to_read != 0));
> -	} else {
> +	} else if (!memcmp(&channel->device_obj->dev_type,
> &HV_NET_GUID,
> +			   sizeof(uuid_le))) {
>  		pr_err("no channel callback for relid - %u\n", relid);
>  	}

I am not sure this message is all that useful. We may just get rid of the message.
If we get rid of this message, we can significantly simplify.

> 
> --- a/include/linux/hyperv.h	2015-02-03 10:58:51.751752450 -0800
> +++ b/include/linux/hyperv.h	2015-02-03 10:58:51.751752450 -0800
> @@ -868,6 +868,9 @@ extern int vmbus_recvpacket_raw(struct v
> 
>  extern void vmbus_ontimer(unsigned long data);
> 
> +extern void vmbus_get_pages(unsigned long *int_page,
> +			    unsigned long monitor_pages[2]);
> +
>  /* Base driver object */
>  struct hv_driver {
>  	const char *name;

Thanks,

K. Y

RE: [PATCH] hyper-v: allow access to vmbus from userspace driver

[KY Srinivasan]

> -----Original Message-----
> From: devel [mailto:driverdev-devel-bounces@linuxdriverproject.org] On
> Behalf Of KY Srinivasan
> Sent: Tuesday, February 3, 2015 11:24 AM
> To: Stephen Hemminger; Haiyang Zhang
> Cc: devel@linuxdriverproject.org; netdev@vger.kernel.org
> Subject: RE: [PATCH] hyper-v: allow access to vmbus from userspace driver
> 
> 
> 
> > -----Original Message-----
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Tuesday, February 3, 2015 11:04 AM
> > To: KY Srinivasan; Haiyang Zhang
> > Cc: devel@linuxdriverproject.org; netdev@vger.kernel.org
> > Subject: [PATCH] hyper-v: allow access to vmbus from userspace driver
> >
> > Brocade is submitting a hyper-v driver for DPDK <dev@dpdk.org> but
> > this driver needs a hook in the hyper-v bus layer to allow the
> > additional hv_uio driver to access the shared vmbus pages. The hv_uio
> > driver lives in DPDK (like
> > igb_uio) and provides userspace access to raw network packets.
> >
> > Signed-off-by: Stas Egorov <segorov@mirantis.com>
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> >
> > ---
> >  drivers/hv/connection.c |   20 +++++++++++++++++---
> >  include/linux/hyperv.h  |    3 +++
> >  2 files changed, 20 insertions(+), 3 deletions(-)
> >
> > --- a/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
> > +++ b/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
> > @@ -64,6 +64,21 @@ static __u32 vmbus_get_next_version(__u3
> >  	}
> >  }
> >
> > +static const uuid_le HV_NET_GUID = {
> > +	.b = {
> > +		0x63, 0x51, 0x61, 0xf8, 0x3e, 0xdf, 0xc5, 0x46,
> > +		0x91, 0x3f, 0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e
> > +	}
> > +};
> > +
> 
> We already have this guid defined in linux/hyperv.h; look at HV_NIC_GUID.
> 
> > +void vmbus_get_pages(unsigned long *int_page, unsigned long
> > +monitor_pages[2]) {
> > +	*int_page = (unsigned long)vmbus_connection.int_page;
> > +	monitor_pages[0] = (unsigned
> > long)vmbus_connection.monitor_pages[0];
> > +	monitor_pages[1] = (unsigned
> > long)vmbus_connection.monitor_pages[1];
> > +}
> > +EXPORT_SYMBOL_GPL(vmbus_get_pages);

vmbus_get_pages() is too generic. Perhaps vmbus_get_monitor_pages() may be a better
name for this function.

Regards,

K. Y

Re: hyper-v: allow access to vmbus from userspace driver

[Thomas Monjalon]

Hi Stephen,

2015-02-03 11:03, stephen hemminger:
> Brocade is submitting a hyper-v driver for DPDK <dev@dpdk.org>
> but this driver needs a hook in the hyper-v bus layer
> to allow the additional hv_uio driver to access the shared vmbus
> pages. The hv_uio driver lives in DPDK (like igb_uio) and provides
> userspace access to raw network packets.
> 
> Signed-off-by: Stas Egorov <segorov@mirantis.com>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

The hyper-v driver for DPDK has not been sent yet to
	http://dpdk.org/dev/patchwork
but it would be interesting to better explain this uio mapping.

Thanks
-- 
Thomas


> --- a/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
> +++ b/drivers/hv/connection.c	2015-02-03 10:58:51.751752450 -0800
> @@ -64,6 +64,21 @@ static __u32 vmbus_get_next_version(__u3
>  	}
>  }
>  
> +static const uuid_le HV_NET_GUID = {
> +	.b = {
> +		0x63, 0x51, 0x61, 0xf8, 0x3e, 0xdf, 0xc5, 0x46,
> +		0x91, 0x3f, 0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e
> +	}
> +};
> +
> +void vmbus_get_pages(unsigned long *int_page, unsigned long monitor_pages[2])
> +{
> +	*int_page = (unsigned long)vmbus_connection.int_page;
> +	monitor_pages[0] = (unsigned long)vmbus_connection.monitor_pages[0];
> +	monitor_pages[1] = (unsigned long)vmbus_connection.monitor_pages[1];
> +}
> +EXPORT_SYMBOL_GPL(vmbus_get_pages);
> +
>  static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
>  					__u32 version)
>  {
> @@ -347,7 +362,8 @@ static void process_chn_event(u32 relid)
>  			else
>  				bytes_to_read = 0;
>  		} while (read_state && (bytes_to_read != 0));
> -	} else {
> +	} else if (!memcmp(&channel->device_obj->dev_type, &HV_NET_GUID,
> +			   sizeof(uuid_le))) {
>  		pr_err("no channel callback for relid - %u\n", relid);
>  	}
>  
> --- a/include/linux/hyperv.h	2015-02-03 10:58:51.751752450 -0800
> +++ b/include/linux/hyperv.h	2015-02-03 10:58:51.751752450 -0800
> @@ -868,6 +868,9 @@ extern int vmbus_recvpacket_raw(struct v
>  
>  extern void vmbus_ontimer(unsigned long data);
>  
> +extern void vmbus_get_pages(unsigned long *int_page,
> +			    unsigned long monitor_pages[2]);
> +
>  /* Base driver object */
>  struct hv_driver {
>  	const char *name;