| Message ID | 20240521-vfio_pci_mmap-v1-3-2f6315e0054e@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | vfio/pci: s390: Fix issues preventing VFIO_PCI_MMAP=y for s390 and enable it | expand |
On Tue, May 21, 2024 at 02:14:59PM +0200, Niklas Schnelle wrote: > 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 VFIO_PCI_MMAP can be enabled > on all s390 systems with native PCI allowing vfio-pci user-space > applications direct access to mapped resources. > > Link: https://lore.kernel.org/all/c5ba134a1d4f4465b5956027e6a4ea6f6beff969.camel@linux.ibm.com/ > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> > --- > drivers/vfio/pci/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig > index 15821a2d77d2..814aa0941d61 100644 > --- a/drivers/vfio/pci/Kconfig > +++ b/drivers/vfio/pci/Kconfig > @@ -8,7 +8,7 @@ config VFIO_PCI_CORE > select IRQ_BYPASS_MANAGER > > config VFIO_PCI_MMAP > - def_bool y if !S390 > + def_bool y > depends on VFIO_PCI_CORE Should we just purge this kconfig entirely? It is never meaningfully n now? Jason
On Wed, 2024-05-22 at 20:20 -0300, Jason Gunthorpe wrote: > On Tue, May 21, 2024 at 02:14:59PM +0200, Niklas Schnelle wrote: > > 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 VFIO_PCI_MMAP can be enabled > > on all s390 systems with native PCI allowing vfio-pci user-space > > applications direct access to mapped resources. > > > > Link: https://lore.kernel.org/all/c5ba134a1d4f4465b5956027e6a4ea6f6beff969.camel@linux.ibm.com/ > > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> > > --- > > drivers/vfio/pci/Kconfig | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig > > index 15821a2d77d2..814aa0941d61 100644 > > --- a/drivers/vfio/pci/Kconfig > > +++ b/drivers/vfio/pci/Kconfig > > @@ -8,7 +8,7 @@ config VFIO_PCI_CORE > > select IRQ_BYPASS_MANAGER > > > > config VFIO_PCI_MMAP > > - def_bool y if !S390 > > + def_bool y > > depends on VFIO_PCI_CORE > > Should we just purge this kconfig entirely? It is never meaningfully n now? > > Jason Makes sense to me. Will change this for v2. I'll also add a Suggested- by for you if that's okay, should probably have been in this version already. Thanks, Niklas
diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig index 15821a2d77d2..814aa0941d61 100644 --- a/drivers/vfio/pci/Kconfig +++ b/drivers/vfio/pci/Kconfig @@ -8,7 +8,7 @@ config VFIO_PCI_CORE select IRQ_BYPASS_MANAGER config VFIO_PCI_MMAP - def_bool y if !S390 + def_bool y depends on VFIO_PCI_CORE config VFIO_PCI_INTX
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 VFIO_PCI_MMAP can be enabled on all s390 systems with native PCI allowing vfio-pci user-space applications direct access to mapped resources. Link: https://lore.kernel.org/all/c5ba134a1d4f4465b5956027e6a4ea6f6beff969.camel@linux.ibm.com/ Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> --- drivers/vfio/pci/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)