diff mbox series

[v3,3/3] vfio/pci: Enable PCI resource mmap() on s390 and remove VFIO_PCI_MMAP

Message ID 20240529-vfio_pci_mmap-v3-3-cd217d019218@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series vfio/pci: s390: Fix issues preventing VFIO_PCI_MMAP=y for s390 and enable it | expand

Commit Message

Niklas Schnelle May 29, 2024, 11:36 a.m. UTC
With the introduction of memory I/O (MIO) instructions enbaled in commit
71ba41c9b1d9 ("s390/pci: provide support for MIO instructions") s390
gained support for direct user-space access to mapped PCI resources.
Even without those however user-space can access mapped PCI resources
via the s390 specific MMIO syscalls. Thus mmap() can and should be
supported on all s390 systems with native PCI. Since VFIO_PCI_MMAP
enablement for s390 would make it unconditionally true and thus
pointless just remove it entirely.

Link: https://lore.kernel.org/all/c5ba134a1d4f4465b5956027e6a4ea6f6beff969.camel@linux.ibm.com/
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/vfio/pci/Kconfig         | 4 ----
 drivers/vfio/pci/vfio_pci_core.c | 3 ---
 2 files changed, 7 deletions(-)

Comments

Alex Williamson June 18, 2024, 3:52 p.m. UTC | #1
On Wed, 29 May 2024 13:36:26 +0200
Niklas Schnelle <schnelle@linux.ibm.com> wrote:

> With the introduction of memory I/O (MIO) instructions enbaled in commit

Nit if there's a respin for the powerpc build, s/enbaled/enabled/

Thanks,
Alex

> 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions") s390
> gained support for direct user-space access to mapped PCI resources.
> Even without those however user-space can access mapped PCI resources
> via the s390 specific MMIO syscalls. Thus mmap() can and should be
> supported on all s390 systems with native PCI. Since VFIO_PCI_MMAP
> enablement for s390 would make it unconditionally true and thus
> pointless just remove it entirely.
> 
> Link: https://lore.kernel.org/all/c5ba134a1d4f4465b5956027e6a4ea6f6beff969.camel@linux.ibm.com/
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
>  drivers/vfio/pci/Kconfig         | 4 ----
>  drivers/vfio/pci/vfio_pci_core.c | 3 ---
>  2 files changed, 7 deletions(-)
> 
> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
> index bf50ffa10bde..c3bcb6911c53 100644
> --- a/drivers/vfio/pci/Kconfig
> +++ b/drivers/vfio/pci/Kconfig
> @@ -7,10 +7,6 @@ config VFIO_PCI_CORE
>  	select VFIO_VIRQFD
>  	select IRQ_BYPASS_MANAGER
>  
> -config VFIO_PCI_MMAP
> -	def_bool y if !S390
> -	depends on VFIO_PCI_CORE
> -
>  config VFIO_PCI_INTX
>  	def_bool y if !S390
>  	depends on VFIO_PCI_CORE
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 0f1ddf2d3ef2..a0e2e2a806d1 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -121,9 +121,6 @@ static void vfio_pci_probe_mmaps(struct vfio_pci_core_device *vdev)
>  
>  		res = &vdev->pdev->resource[bar];
>  
> -		if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
> -			goto no_mmap;
> -
>  		if (!(res->flags & IORESOURCE_MEM))
>  			goto no_mmap;
>  
>
diff mbox series

Patch

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index bf50ffa10bde..c3bcb6911c53 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -7,10 +7,6 @@  config VFIO_PCI_CORE
 	select VFIO_VIRQFD
 	select IRQ_BYPASS_MANAGER
 
-config VFIO_PCI_MMAP
-	def_bool y if !S390
-	depends on VFIO_PCI_CORE
-
 config VFIO_PCI_INTX
 	def_bool y if !S390
 	depends on VFIO_PCI_CORE
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 0f1ddf2d3ef2..a0e2e2a806d1 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -121,9 +121,6 @@  static void vfio_pci_probe_mmaps(struct vfio_pci_core_device *vdev)
 
 		res = &vdev->pdev->resource[bar];
 
-		if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
-			goto no_mmap;
-
 		if (!(res->flags & IORESOURCE_MEM))
 			goto no_mmap;