On Thu, 27 Jun 2019 11:37:59 +0800 Tina Zhang <tina.zhang@xxxxxxxxx> 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@xxxxxxxxx> > --- > 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 */ > }; > > /*