[RFC,v3,1/4] vfio: Define device specific irq type capability

Submitted by Zhang, Tina on June 27, 2019, 3:37 a.m.

Details

Message ID 20190627033802.1663-2-tina.zhang@intel.com
State New
Headers show
Series "Deliver vGPU display vblank event to userspace" ( rev: 1 ) in Intel GVT devel

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Commit Message

Zhang, Tina June 27, 2019, 3:37 a.m.
Cap the number of irqs with fixed indexes and use capability chains
to chain device specific irqs.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
---
 include/uapi/linux/vfio.h | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

Patch hide | download patch | download mbox

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 02bb7ad6e986..600784acc4ac 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -444,11 +444,27 @@  struct vfio_irq_info {
 #define VFIO_IRQ_INFO_MASKABLE		(1 << 1)
 #define VFIO_IRQ_INFO_AUTOMASKED	(1 << 2)
 #define VFIO_IRQ_INFO_NORESIZE		(1 << 3)
+#define VFIO_IRQ_INFO_FLAG_CAPS		(1 << 4) /* Info supports caps */
 	__u32	index;		/* IRQ index */
+	__u32	cap_offset;	/* Offset within info struct of first cap */
 	__u32	count;		/* Number of IRQs within this index */
 };
 #define VFIO_DEVICE_GET_IRQ_INFO	_IO(VFIO_TYPE, VFIO_BASE + 9)
 
+/*
+ * The irq type capability allows irqs unique to a specific device or
+ * class of devices to be exposed.
+ *
+ * The structures below define version 1 of this capability.
+ */
+#define VFIO_IRQ_INFO_CAP_TYPE      3
+
+struct vfio_irq_info_cap_type {
+	struct vfio_info_cap_header header;
+	__u32 type;     /* global per bus driver */
+	__u32 subtype;  /* type specific */
+};
+
 /**
  * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set)
  *
@@ -550,7 +566,8 @@  enum {
 	VFIO_PCI_MSIX_IRQ_INDEX,
 	VFIO_PCI_ERR_IRQ_INDEX,
 	VFIO_PCI_REQ_IRQ_INDEX,
-	VFIO_PCI_NUM_IRQS
+	VFIO_PCI_NUM_IRQS = 5	/* Fixed user ABI, IRQ indexes >=5 use   */
+				/* device specific cap to define content */
 };
 
 /*

Comments

On Thu, 27 Jun 2019 11:37:59 +0800
Tina Zhang <tina.zhang@intel.com> wrote:

> Cap the number of irqs with fixed indexes and use capability chains
> to chain device specific irqs.
> 
> Signed-off-by: Tina Zhang <tina.zhang@intel.com>
> ---
>  include/uapi/linux/vfio.h | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 02bb7ad6e986..600784acc4ac 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -444,11 +444,27 @@ struct vfio_irq_info {
>  #define VFIO_IRQ_INFO_MASKABLE		(1 << 1)
>  #define VFIO_IRQ_INFO_AUTOMASKED	(1 << 2)
>  #define VFIO_IRQ_INFO_NORESIZE		(1 << 3)
> +#define VFIO_IRQ_INFO_FLAG_CAPS		(1 << 4) /* Info supports caps */
>  	__u32	index;		/* IRQ index */
> +	__u32	cap_offset;	/* Offset within info struct of first cap */
>  	__u32	count;		/* Number of IRQs within this index */
>  };


This cannot be inserted into the middle of the structure, it breaks
compatibility with all existing userspace binaries.  I must be added to
the end of the structure.

>  #define VFIO_DEVICE_GET_IRQ_INFO	_IO(VFIO_TYPE, VFIO_BASE + 9)
>  
> +/*
> + * The irq type capability allows irqs unique to a specific device or
> + * class of devices to be exposed.
> + *
> + * The structures below define version 1 of this capability.
> + */
> +#define VFIO_IRQ_INFO_CAP_TYPE      3
> +
> +struct vfio_irq_info_cap_type {
> +	struct vfio_info_cap_header header;
> +	__u32 type;     /* global per bus driver */
> +	__u32 subtype;  /* type specific */
> +};
> +
>  /**
>   * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set)
>   *
> @@ -550,7 +566,8 @@ enum {
>  	VFIO_PCI_MSIX_IRQ_INDEX,
>  	VFIO_PCI_ERR_IRQ_INDEX,
>  	VFIO_PCI_REQ_IRQ_INDEX,
> -	VFIO_PCI_NUM_IRQS
> +	VFIO_PCI_NUM_IRQS = 5	/* Fixed user ABI, IRQ indexes >=5 use   */
> +				/* device specific cap to define content */
>  };
>  
>  /*
Hi,

> +struct vfio_irq_info_cap_type {
> +	struct vfio_info_cap_header header;
> +	__u32 type;     /* global per bus driver */
> +	__u32 subtype;  /* type specific */

Do we really need both type and subtype?

cheers,
  Gerd
> -----Original Message-----
> From: Alex Williamson [mailto:alex.williamson@redhat.com]
> Sent: Thursday, June 27, 2019 12:08 PM
> To: Zhang, Tina <tina.zhang@intel.com>
> Cc: intel-gvt-dev@lists.freedesktop.org; kvm@vger.kernel.org; linux-
> kernel@vger.kernel.org; kraxel@redhat.com; zhenyuw@linux.intel.com; Lv,
> Zhiyuan <zhiyuan.lv@intel.com>; Wang, Zhi A <zhi.a.wang@intel.com>; Tian,
> Kevin <kevin.tian@intel.com>; Yuan, Hang <hang.yuan@intel.com>
> Subject: Re: [RFC PATCH v3 1/4] vfio: Define device specific irq type
> capability
> 
> On Thu, 27 Jun 2019 11:37:59 +0800
> Tina Zhang <tina.zhang@intel.com> wrote:
> 
> > Cap the number of irqs with fixed indexes and use capability chains to
> > chain device specific irqs.
> >
> > Signed-off-by: Tina Zhang <tina.zhang@intel.com>
> > ---
> >  include/uapi/linux/vfio.h | 19 ++++++++++++++++++-
> >  1 file changed, 18 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> > index 02bb7ad6e986..600784acc4ac 100644
> > --- a/include/uapi/linux/vfio.h
> > +++ b/include/uapi/linux/vfio.h
> > @@ -444,11 +444,27 @@ struct vfio_irq_info {
> >  #define VFIO_IRQ_INFO_MASKABLE		(1 << 1)
> >  #define VFIO_IRQ_INFO_AUTOMASKED	(1 << 2)
> >  #define VFIO_IRQ_INFO_NORESIZE		(1 << 3)
> > +#define VFIO_IRQ_INFO_FLAG_CAPS		(1 << 4) /* Info
> supports caps */
> >  	__u32	index;		/* IRQ index */
> > +	__u32	cap_offset;	/* Offset within info struct of first cap */
> >  	__u32	count;		/* Number of IRQs within this index */
> >  };
> 
> 
> This cannot be inserted into the middle of the structure, it breaks
> compatibility with all existing userspace binaries.  I must be added to the end
> of the structure.
Indeed. Thanks.

BR,
Tina
> 
> >  #define VFIO_DEVICE_GET_IRQ_INFO	_IO(VFIO_TYPE, VFIO_BASE +
> 9)
> >
> > +/*
> > + * The irq type capability allows irqs unique to a specific device or
> > + * class of devices to be exposed.
> > + *
> > + * The structures below define version 1 of this capability.
> > + */
> > +#define VFIO_IRQ_INFO_CAP_TYPE      3
> > +
> > +struct vfio_irq_info_cap_type {
> > +	struct vfio_info_cap_header header;
> > +	__u32 type;     /* global per bus driver */
> > +	__u32 subtype;  /* type specific */
> > +};
> > +
> >  /**
> >   * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct
> vfio_irq_set)
> >   *
> > @@ -550,7 +566,8 @@ enum {
> >  	VFIO_PCI_MSIX_IRQ_INDEX,
> >  	VFIO_PCI_ERR_IRQ_INDEX,
> >  	VFIO_PCI_REQ_IRQ_INDEX,
> > -	VFIO_PCI_NUM_IRQS
> > +	VFIO_PCI_NUM_IRQS = 5	/* Fixed user ABI, IRQ indexes >=5
> use   */
> > +				/* device specific cap to define content */
> >  };
> >
> >  /*
> -----Original Message-----

> From: intel-gvt-dev [mailto:intel-gvt-dev-bounces@lists.freedesktop.org] On

> Behalf Of Gerd Hoffmann

> Sent: Thursday, June 27, 2019 2:20 PM

> To: Zhang, Tina <tina.zhang@intel.com>

> Cc: Tian, Kevin <kevin.tian@intel.com>; kvm@vger.kernel.org; linux-

> kernel@vger.kernel.org; zhenyuw@linux.intel.com; Yuan, Hang

> <hang.yuan@intel.com>; alex.williamson@redhat.com; Lv, Zhiyuan

> <zhiyuan.lv@intel.com>; intel-gvt-dev@lists.freedesktop.org; Wang, Zhi A

> <zhi.a.wang@intel.com>

> Subject: Re: [RFC PATCH v3 1/4] vfio: Define device specific irq type

> capability

> 

>   Hi,

> 

> > +struct vfio_irq_info_cap_type {

> > +	struct vfio_info_cap_header header;

> > +	__u32 type;     /* global per bus driver */

> > +	__u32 subtype;  /* type specific */

> 

> Do we really need both type and subtype?

Then, if one device has several irqs, how can we identify them?
Thanks.

BR,
tina
> 

> cheers,

>   Gerd

> 

> _______________________________________________

> intel-gvt-dev mailing list

> intel-gvt-dev@lists.freedesktop.org

> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
On Thu, Jun 27, 2019 at 08:55:21AM +0000, Zhang, Tina wrote:
> 
> 
> > -----Original Message-----
> > From: intel-gvt-dev [mailto:intel-gvt-dev-bounces@lists.freedesktop.org] On
> > Behalf Of Gerd Hoffmann
> > Sent: Thursday, June 27, 2019 2:20 PM
> > To: Zhang, Tina <tina.zhang@intel.com>
> > Cc: Tian, Kevin <kevin.tian@intel.com>; kvm@vger.kernel.org; linux-
> > kernel@vger.kernel.org; zhenyuw@linux.intel.com; Yuan, Hang
> > <hang.yuan@intel.com>; alex.williamson@redhat.com; Lv, Zhiyuan
> > <zhiyuan.lv@intel.com>; intel-gvt-dev@lists.freedesktop.org; Wang, Zhi A
> > <zhi.a.wang@intel.com>
> > Subject: Re: [RFC PATCH v3 1/4] vfio: Define device specific irq type
> > capability
> > 
> >   Hi,
> > 
> > > +struct vfio_irq_info_cap_type {
> > > +	struct vfio_info_cap_header header;
> > > +	__u32 type;     /* global per bus driver */
> > > +	__u32 subtype;  /* type specific */
> > 
> > Do we really need both type and subtype?
> Then, if one device has several irqs, how can we identify them?
> Thanks.

Just assign multiple types?

cheers,
  Gerd