* [PATCH] vfio: Depend on MMU
@ 2021-03-05 1:30 Jason Gunthorpe
2021-03-05 8:46 ` Cornelia Huck
0 siblings, 1 reply; 7+ messages in thread
From: Jason Gunthorpe @ 2021-03-05 1:30 UTC (permalink / raw)
To: Alex Williamson, kvm; +Cc: Cornelia Huck
VFIO_IOMMU_TYPE1 does not compile with !MMU:
../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
So require it.
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/vfio/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index 90c0525b1e0cf4..67d0bf4efa1606 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -22,7 +22,7 @@ config VFIO_VIRQFD
menuconfig VFIO
tristate "VFIO Non-Privileged userspace driver framework"
select IOMMU_API
- select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
+ select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
help
VFIO provides a framework for secure userspace device drivers.
See Documentation/driver-api/vfio.rst for more details.
--
2.30.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] vfio: Depend on MMU
2021-03-05 1:30 [PATCH] vfio: Depend on MMU Jason Gunthorpe
@ 2021-03-05 8:46 ` Cornelia Huck
2021-03-05 23:11 ` Jason Gunthorpe
2021-03-08 17:59 ` Alex Williamson
0 siblings, 2 replies; 7+ messages in thread
From: Cornelia Huck @ 2021-03-05 8:46 UTC (permalink / raw)
To: Jason Gunthorpe; +Cc: Alex Williamson, kvm
On Thu, 4 Mar 2021 21:30:03 -0400
Jason Gunthorpe <jgg@nvidia.com> wrote:
> VFIO_IOMMU_TYPE1 does not compile with !MMU:
>
> ../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
> ../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
>
> So require it.
>
> Suggested-by: Cornelia Huck <cohuck@redhat.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
> drivers/vfio/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> index 90c0525b1e0cf4..67d0bf4efa1606 100644
> --- a/drivers/vfio/Kconfig
> +++ b/drivers/vfio/Kconfig
> @@ -22,7 +22,7 @@ config VFIO_VIRQFD
> menuconfig VFIO
> tristate "VFIO Non-Privileged userspace driver framework"
> select IOMMU_API
> - select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
> + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
> help
> VFIO provides a framework for secure userspace device drivers.
> See Documentation/driver-api/vfio.rst for more details.
Actually, I'm wondering how much sense vfio makes on !MMU at all? (And
maybe just merge this with your patch that switches IOMMU_API from a
depend to a select, because that is the change that makes the MMU
dependency required?)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] vfio: Depend on MMU
2021-03-05 8:46 ` Cornelia Huck
@ 2021-03-05 23:11 ` Jason Gunthorpe
2021-03-08 18:14 ` Cornelia Huck
2021-03-08 17:59 ` Alex Williamson
1 sibling, 1 reply; 7+ messages in thread
From: Jason Gunthorpe @ 2021-03-05 23:11 UTC (permalink / raw)
To: Cornelia Huck; +Cc: Alex Williamson, kvm
On Fri, Mar 05, 2021 at 09:46:49AM +0100, Cornelia Huck wrote:
> On Thu, 4 Mar 2021 21:30:03 -0400
> Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> > VFIO_IOMMU_TYPE1 does not compile with !MMU:
> >
> > ../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
> > ../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
> >
> > So require it.
> >
> > Suggested-by: Cornelia Huck <cohuck@redhat.com>
> > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > drivers/vfio/Kconfig | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> > index 90c0525b1e0cf4..67d0bf4efa1606 100644
> > +++ b/drivers/vfio/Kconfig
> > @@ -22,7 +22,7 @@ config VFIO_VIRQFD
> > menuconfig VFIO
> > tristate "VFIO Non-Privileged userspace driver framework"
> > select IOMMU_API
> > - select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
> > + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
> > help
> > VFIO provides a framework for secure userspace device drivers.
> > See Documentation/driver-api/vfio.rst for more details.
>
> Actually, I'm wondering how much sense vfio makes on !MMU at all? (And
> maybe just merge this with your patch that switches IOMMU_API from a
> depend to a select, because that is the change that makes the MMU
> dependency required?)
Why does changing depend to select affect MMU vs !MMU? Am I missing
something?
It looks like IOMMU_API can be turned with ARM !MMU here, for
instance:
config MSM_IOMMU
bool "MSM IOMMU Support"
depends on ARM
depends on ARCH_MSM8X60 || ARCH_MSM8960 || COMPILE_TEST
select IOMMU_API
Generally with !MMU I try to ignore it as much as possible unless
things don't compile, as I have no idea what people use it for :)
Jason
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] vfio: Depend on MMU
2021-03-05 23:11 ` Jason Gunthorpe
@ 2021-03-08 18:14 ` Cornelia Huck
2021-03-08 18:23 ` Jason Gunthorpe
0 siblings, 1 reply; 7+ messages in thread
From: Cornelia Huck @ 2021-03-08 18:14 UTC (permalink / raw)
To: Jason Gunthorpe; +Cc: Alex Williamson, kvm
On Fri, 5 Mar 2021 19:11:41 -0400
Jason Gunthorpe <jgg@nvidia.com> wrote:
> On Fri, Mar 05, 2021 at 09:46:49AM +0100, Cornelia Huck wrote:
> > On Thu, 4 Mar 2021 21:30:03 -0400
> > Jason Gunthorpe <jgg@nvidia.com> wrote:
> >
> > > VFIO_IOMMU_TYPE1 does not compile with !MMU:
> > >
> > > ../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
> > > ../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
> > >
> > > So require it.
> > >
> > > Suggested-by: Cornelia Huck <cohuck@redhat.com>
> > > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > > drivers/vfio/Kconfig | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> > > index 90c0525b1e0cf4..67d0bf4efa1606 100644
> > > +++ b/drivers/vfio/Kconfig
> > > @@ -22,7 +22,7 @@ config VFIO_VIRQFD
> > > menuconfig VFIO
> > > tristate "VFIO Non-Privileged userspace driver framework"
> > > select IOMMU_API
> > > - select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
> > > + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
> > > help
> > > VFIO provides a framework for secure userspace device drivers.
> > > See Documentation/driver-api/vfio.rst for more details.
> >
> > Actually, I'm wondering how much sense vfio makes on !MMU at all? (And
> > maybe just merge this with your patch that switches IOMMU_API from a
> > depend to a select, because that is the change that makes the MMU
> > dependency required?)
>
> Why does changing depend to select affect MMU vs !MMU? Am I missing
> something?
>
> It looks like IOMMU_API can be turned with ARM !MMU here, for
> instance:
>
> config MSM_IOMMU
> bool "MSM IOMMU Support"
> depends on ARM
> depends on ARCH_MSM8X60 || ARCH_MSM8960 || COMPILE_TEST
> select IOMMU_API
But that one is sitting under a menu depending on MMU, isn't it?
>
> Generally with !MMU I try to ignore it as much as possible unless
> things don't compile, as I have no idea what people use it for :)
>
> Jason
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] vfio: Depend on MMU
2021-03-08 18:14 ` Cornelia Huck
@ 2021-03-08 18:23 ` Jason Gunthorpe
0 siblings, 0 replies; 7+ messages in thread
From: Jason Gunthorpe @ 2021-03-08 18:23 UTC (permalink / raw)
To: Cornelia Huck; +Cc: Alex Williamson, kvm
On Mon, Mar 08, 2021 at 07:14:21PM +0100, Cornelia Huck wrote:
> On Fri, 5 Mar 2021 19:11:41 -0400
> Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> > On Fri, Mar 05, 2021 at 09:46:49AM +0100, Cornelia Huck wrote:
> > > On Thu, 4 Mar 2021 21:30:03 -0400
> > > Jason Gunthorpe <jgg@nvidia.com> wrote:
> > >
> > > > VFIO_IOMMU_TYPE1 does not compile with !MMU:
> > > >
> > > > ../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
> > > > ../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
> > > >
> > > > So require it.
> > > >
> > > > Suggested-by: Cornelia Huck <cohuck@redhat.com>
> > > > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > > > drivers/vfio/Kconfig | 2 +-
> > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> > > > index 90c0525b1e0cf4..67d0bf4efa1606 100644
> > > > +++ b/drivers/vfio/Kconfig
> > > > @@ -22,7 +22,7 @@ config VFIO_VIRQFD
> > > > menuconfig VFIO
> > > > tristate "VFIO Non-Privileged userspace driver framework"
> > > > select IOMMU_API
> > > > - select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
> > > > + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
> > > > help
> > > > VFIO provides a framework for secure userspace device drivers.
> > > > See Documentation/driver-api/vfio.rst for more details.
> > >
> > > Actually, I'm wondering how much sense vfio makes on !MMU at all? (And
> > > maybe just merge this with your patch that switches IOMMU_API from a
> > > depend to a select, because that is the change that makes the MMU
> > > dependency required?)
> >
> > Why does changing depend to select affect MMU vs !MMU? Am I missing
> > something?
> >
> > It looks like IOMMU_API can be turned with ARM !MMU here, for
> > instance:
> >
> > config MSM_IOMMU
> > bool "MSM IOMMU Support"
> > depends on ARM
> > depends on ARCH_MSM8X60 || ARCH_MSM8960 || COMPILE_TEST
> > select IOMMU_API
>
> But that one is sitting under a menu depending on MMU, isn't it?
Yep.
Still, I'd keep the two ideas as two patches - order this one first.
Jason
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] vfio: Depend on MMU
2021-03-05 8:46 ` Cornelia Huck
2021-03-05 23:11 ` Jason Gunthorpe
@ 2021-03-08 17:59 ` Alex Williamson
2021-03-08 18:12 ` Cornelia Huck
1 sibling, 1 reply; 7+ messages in thread
From: Alex Williamson @ 2021-03-08 17:59 UTC (permalink / raw)
To: Cornelia Huck; +Cc: Jason Gunthorpe, kvm
On Fri, 5 Mar 2021 09:46:49 +0100
Cornelia Huck <cohuck@redhat.com> wrote:
> On Thu, 4 Mar 2021 21:30:03 -0400
> Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> > VFIO_IOMMU_TYPE1 does not compile with !MMU:
> >
> > ../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
> > ../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
> >
> > So require it.
> >
> > Suggested-by: Cornelia Huck <cohuck@redhat.com>
> > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > ---
> > drivers/vfio/Kconfig | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> > index 90c0525b1e0cf4..67d0bf4efa1606 100644
> > --- a/drivers/vfio/Kconfig
> > +++ b/drivers/vfio/Kconfig
> > @@ -22,7 +22,7 @@ config VFIO_VIRQFD
> > menuconfig VFIO
> > tristate "VFIO Non-Privileged userspace driver framework"
> > select IOMMU_API
> > - select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
> > + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
> > help
> > VFIO provides a framework for secure userspace device drivers.
> > See Documentation/driver-api/vfio.rst for more details.
>
> Actually, I'm wondering how much sense vfio makes on !MMU at all? (And
> maybe just merge this with your patch that switches IOMMU_API from a
> depend to a select, because that is the change that makes the MMU
> dependency required?)
We do have the no-iommu code in vfio, potentially it's useful for !MMU,
I guess. It seems a little arbitrary to remove it without a known
breakage at this point. Thanks,
Alex
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] vfio: Depend on MMU
2021-03-08 17:59 ` Alex Williamson
@ 2021-03-08 18:12 ` Cornelia Huck
0 siblings, 0 replies; 7+ messages in thread
From: Cornelia Huck @ 2021-03-08 18:12 UTC (permalink / raw)
To: Alex Williamson; +Cc: Jason Gunthorpe, kvm
On Mon, 8 Mar 2021 10:59:13 -0700
Alex Williamson <alex.williamson@redhat.com> wrote:
> On Fri, 5 Mar 2021 09:46:49 +0100
> Cornelia Huck <cohuck@redhat.com> wrote:
>
> > On Thu, 4 Mar 2021 21:30:03 -0400
> > Jason Gunthorpe <jgg@nvidia.com> wrote:
> >
> > > VFIO_IOMMU_TYPE1 does not compile with !MMU:
> > >
> > > ../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
> > > ../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]
> > >
> > > So require it.
> > >
> > > Suggested-by: Cornelia Huck <cohuck@redhat.com>
> > > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > > ---
> > > drivers/vfio/Kconfig | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> > > index 90c0525b1e0cf4..67d0bf4efa1606 100644
> > > --- a/drivers/vfio/Kconfig
> > > +++ b/drivers/vfio/Kconfig
> > > @@ -22,7 +22,7 @@ config VFIO_VIRQFD
> > > menuconfig VFIO
> > > tristate "VFIO Non-Privileged userspace driver framework"
> > > select IOMMU_API
> > > - select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
> > > + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
> > > help
> > > VFIO provides a framework for secure userspace device drivers.
> > > See Documentation/driver-api/vfio.rst for more details.
> >
> > Actually, I'm wondering how much sense vfio makes on !MMU at all? (And
> > maybe just merge this with your patch that switches IOMMU_API from a
> > depend to a select, because that is the change that makes the MMU
> > dependency required?)
>
> We do have the no-iommu code in vfio, potentially it's useful for !MMU,
> I guess. It seems a little arbitrary to remove it without a known
> breakage at this point. Thanks,
>
> Alex
Well, in practice, I think we had an implicit dependency on MMU before
(everything selecting IOMMU_API depended on MMU.) If we think !MMU
would be useful for the no-iommu use case, we can certainly restrict
the dependency to VFIO_IOMMU_TYPE1.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-03-08 18:24 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2021-03-05 1:30 [PATCH] vfio: Depend on MMU Jason Gunthorpe
2021-03-05 8:46 ` Cornelia Huck
2021-03-05 23:11 ` Jason Gunthorpe
2021-03-08 18:14 ` Cornelia Huck
2021-03-08 18:23 ` Jason Gunthorpe
2021-03-08 17:59 ` Alex Williamson
2021-03-08 18:12 ` Cornelia Huck
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