Re: [PATCH v6 12/20] vfio: move VFIO PCI macros to common header

From: Alex Williamson <alex.williamson@redhat.com>
To: Dave Jiang <dave.jiang@intel.com>
Cc: kwankhede@nvidia.com, tglx@linutronix.de, vkoul@kernel.org,
	jgg@mellanox.com, megha.dey@intel.com, jacob.jun.pan@intel.com,
	ashok.raj@intel.com, yi.l.liu@intel.com, baolu.lu@intel.com,
	kevin.tian@intel.com, sanjay.k.kumar@intel.com,
	tony.luck@intel.com, dan.j.williams@intel.com,
	eric.auger@redhat.com, pbonzini@redhat.com,
	dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org
Subject: Re: [PATCH v6 12/20] vfio: move VFIO PCI macros to common header
Date: Thu, 3 Jun 2021 21:47:31 -0600	[thread overview]
Message-ID: <20210603214731.1631a480.alex.williamson@redhat.com> (raw)
In-Reply-To: <162164281969.261970.17759783730654052269.stgit@djiang5-desk3.ch.intel.com>

On Fri, 21 May 2021 17:20:19 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> Move some VFIO_PCI macros to a common header as they will be shared between
> mdev and vfio_pci.

No, this is the current implementation of vfio-pci, it's specifically
not meant to be a standard.  Each vfio device driver is free to expose
regions on the device file descriptor as they wish.  If you want to use
a 40-bit implementation as well, great, but it should not be imposed as
a standard.  Thanks,

Alex

> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/vfio/pci/vfio_pci_private.h |    6 ------
>  include/linux/vfio.h                |    6 ++++++
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
> index a17943911fcb..e644f981509c 100644
> --- a/drivers/vfio/pci/vfio_pci_private.h
> +++ b/drivers/vfio/pci/vfio_pci_private.h
> @@ -18,12 +18,6 @@
>  #ifndef VFIO_PCI_PRIVATE_H
>  #define VFIO_PCI_PRIVATE_H
>  
> -#define VFIO_PCI_OFFSET_SHIFT   40
> -
> -#define VFIO_PCI_OFFSET_TO_INDEX(off)	(off >> VFIO_PCI_OFFSET_SHIFT)
> -#define VFIO_PCI_INDEX_TO_OFFSET(index)	((u64)(index) << VFIO_PCI_OFFSET_SHIFT)
> -#define VFIO_PCI_OFFSET_MASK	(((u64)(1) << VFIO_PCI_OFFSET_SHIFT) - 1)
> -
>  /* Special capability IDs predefined access */
>  #define PCI_CAP_ID_INVALID		0xFF	/* default raw access */
>  #define PCI_CAP_ID_INVALID_VIRT		0xFE	/* default virt access */
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 3b372fa57ef4..ed5ca027eb49 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -15,6 +15,12 @@
>  #include <linux/poll.h>
>  #include <uapi/linux/vfio.h>
>  
> +#define VFIO_PCI_OFFSET_SHIFT   40
> +
> +#define VFIO_PCI_OFFSET_TO_INDEX(off)	((off) >> VFIO_PCI_OFFSET_SHIFT)
> +#define VFIO_PCI_INDEX_TO_OFFSET(index)	((u64)(index) << VFIO_PCI_OFFSET_SHIFT)
> +#define VFIO_PCI_OFFSET_MASK	(((u64)(1) << VFIO_PCI_OFFSET_SHIFT) - 1)
> +
>  struct vfio_device {
>  	struct device *dev;
>  	const struct vfio_device_ops *ops;
> 
> 