[v1] rust: pci: add abstractions for SR-IOV capability

[PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs

Posted by Peter Colberg 2 months, 3 weeks ago

From: John Hubbard <jhubbard@nvidia.com>

Add a method to check if a PCI device is a Virtual Function (VF) created
through Single Root I/O Virtualization (SR-IOV).

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Peter Colberg <pcolberg@redhat.com>
---
This patch was originally part of the series "rust: pci: expose
is_virtfn() and reject VFs in nova-core" and modified as follows:
- Replace true -> `true` in doc comment.
- Shorten description and omit justification specific to nova-core.

Link: https://lore.kernel.org/rust-for-linux/20250930220759.288528-2-jhubbard@nvidia.com/
---
 rust/kernel/pci.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 82e128431f080fde78a06dc5c284ab12739e747e..c20b8daeb7aadbef9f6ecfc48c972436efac9a08 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -409,6 +409,12 @@ pub fn resource_start(&self, bar: u32) -> Result<bindings::resource_size_t> {
         Ok(unsafe { bindings::pci_resource_start(self.as_raw(), bar.try_into()?) })
     }
 
+    /// Returns `true` if this device is a Virtual Function (VF).
+    pub fn is_virtfn(&self) -> bool {
+        // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
+        unsafe { (*self.as_raw()).is_virtfn() != 0 }
+    }
+
     /// Returns the size of the given PCI BAR resource.
     pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {
         if !Bar::index_is_valid(bar) {

-- 
2.51.1

Re: [PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs

Posted by Joel Fernandes 2 months ago

On Wed, Nov 19, 2025 at 05:19:05PM -0500, Peter Colberg wrote:
> From: John Hubbard <jhubbard@nvidia.com>
> 
> Add a method to check if a PCI device is a Virtual Function (VF) created
> through Single Root I/O Virtualization (SR-IOV).
> 
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> Reviewed-by: Alistair Popple <apopple@nvidia.com>
> Signed-off-by: Peter Colberg <pcolberg@redhat.com>
> ---
> This patch was originally part of the series "rust: pci: expose
> is_virtfn() and reject VFs in nova-core" and modified as follows:
> - Replace true -> `true` in doc comment.
> - Shorten description and omit justification specific to nova-core.
> 
> Link: https://lore.kernel.org/rust-for-linux/20250930220759.288528-2-jhubbard@nvidia.com/
> ---
>  rust/kernel/pci.rs | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
> index 82e128431f080fde78a06dc5c284ab12739e747e..c20b8daeb7aadbef9f6ecfc48c972436efac9a08 100644
> --- a/rust/kernel/pci.rs
> +++ b/rust/kernel/pci.rs
> @@ -409,6 +409,12 @@ pub fn resource_start(&self, bar: u32) -> Result<bindings::resource_size_t> {
>          Ok(unsafe { bindings::pci_resource_start(self.as_raw(), bar.try_into()?) })
>      }
>  
> +    /// Returns `true` if this device is a Virtual Function (VF).
> +    pub fn is_virtfn(&self) -> bool {

Add #[inline] here and to `is_physfn()` similar to other methods in this struct?

With that,

Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>

thanks,

 - Joel


> +        // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
> +        unsafe { (*self.as_raw()).is_virtfn() != 0 }
> +    }
> +
>      /// Returns the size of the given PCI BAR resource.
>      pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {
>          if !Bar::index_is_valid(bar) {
> 
> -- 
> 2.51.1
>

Re: [PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs

Posted by Peter Colberg 2 months ago

On Sun, Dec 07, 2025 at 01:28:19AM -0500, Joel Fernandes wrote:
> On Wed, Nov 19, 2025 at 05:19:05PM -0500, Peter Colberg wrote:
> > From: John Hubbard <jhubbard@nvidia.com>
> > 
> > Add a method to check if a PCI device is a Virtual Function (VF) created
> > through Single Root I/O Virtualization (SR-IOV).
> > 
> > Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> > Reviewed-by: Alistair Popple <apopple@nvidia.com>
> > Signed-off-by: Peter Colberg <pcolberg@redhat.com>
> > ---
> > This patch was originally part of the series "rust: pci: expose
> > is_virtfn() and reject VFs in nova-core" and modified as follows:
> > - Replace true -> `true` in doc comment.
> > - Shorten description and omit justification specific to nova-core.
> > 
> > Link: https://lore.kernel.org/rust-for-linux/20250930220759.288528-2-jhubbard@nvidia.com/
> > ---
> >  rust/kernel/pci.rs | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
> > index 82e128431f080fde78a06dc5c284ab12739e747e..c20b8daeb7aadbef9f6ecfc48c972436efac9a08 100644
> > --- a/rust/kernel/pci.rs
> > +++ b/rust/kernel/pci.rs
> > @@ -409,6 +409,12 @@ pub fn resource_start(&self, bar: u32) -> Result<bindings::resource_size_t> {
> >          Ok(unsafe { bindings::pci_resource_start(self.as_raw(), bar.try_into()?) })
> >      }
> >  
> > +    /// Returns `true` if this device is a Virtual Function (VF).
> > +    pub fn is_virtfn(&self) -> bool {
> 
> Add #[inline] here and to `is_physfn()` similar to other methods in this struct?

Thanks for your review! Where should the line be drawn for #[inline]?

Should these be #[inline] as well and why (not)?

- Device::num_vf()
- Device<Core>::enable_sriov()
- Device<Core>::disable_sriov()

Why is Device<Core>::enable_device_mem() not #[inline], while
Device<Core>::set_master() is [1]? Is the former an oversight?

[1] https://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git/tree/rust/kernel/pci.rs?id=67a454e6b1c604555c04501c77b7fedc5d98a779#n433

Thanks,
Peter

> 
> With that,
> 
> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
> 
> thanks,
> 
>  - Joel
> 
> 
> > +        // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
> > +        unsafe { (*self.as_raw()).is_virtfn() != 0 }
> > +    }
> > +
> >      /// Returns the size of the given PCI BAR resource.
> >      pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {
> >          if !Bar::index_is_valid(bar) {
> > 
> > -- 
> > 2.51.1
> > 
>

Re: [PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs

Posted by kernel test robot 2 months, 2 weeks ago

Hi Peter,

kernel test robot noticed the following build errors:

[auto build test ERROR on e4addc7cc2dfcc19f1c8c8e47f3834b22cb21559]

url:    https://github.com/intel-lab-lkp/linux/commits/Peter-Colberg/rust-pci-add-is_virtfn-to-check-for-VFs/20251120-062302
base:   e4addc7cc2dfcc19f1c8c8e47f3834b22cb21559
patch link:    https://lore.kernel.org/r/20251119-rust-pci-sriov-v1-1-883a94599a97%40redhat.com
patch subject: [PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs
config: um-randconfig-001-20251121 (https://download.01.org/0day-ci/archive/20251121/202511211008.jgLuTcrQ-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9e9fe08b16ea2c4d9867fb4974edf2a3776d6ece)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251121/202511211008.jgLuTcrQ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511211008.jgLuTcrQ-lkp@intel.com/

All errors (new ones prefixed by >>):

>> error[E0599]: no method named `is_virtfn` found for struct `bindings::pci_dev` in the current scope
   --> rust/kernel/pci.rs:415:35
   |
   415 |         unsafe { (*self.as_raw()).is_virtfn() != 0 }
   |                                   ^^^^^^^^^ method not found in `pci_dev`

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs

Posted by Peter Colberg 2 months, 2 weeks ago

On Fri, Nov 21, 2025 at 11:00:32AM +0800, kernel test robot wrote:
> Hi Peter,
> 
> kernel test robot noticed the following build errors:

This appears to be a generic issue with UML, unrelated to this series.

https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/CONFIG_UML.20maybe.20broken.3F/with/558611169

Thanks,
Peter

> 
> [auto build test ERROR on e4addc7cc2dfcc19f1c8c8e47f3834b22cb21559]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Peter-Colberg/rust-pci-add-is_virtfn-to-check-for-VFs/20251120-062302
> base:   e4addc7cc2dfcc19f1c8c8e47f3834b22cb21559
> patch link:    https://lore.kernel.org/r/20251119-rust-pci-sriov-v1-1-883a94599a97%40redhat.com
> patch subject: [PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs
> config: um-randconfig-001-20251121 (https://download.01.org/0day-ci/archive/20251121/202511211008.jgLuTcrQ-lkp@intel.com/config)
> compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9e9fe08b16ea2c4d9867fb4974edf2a3776d6ece)
> rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251121/202511211008.jgLuTcrQ-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202511211008.jgLuTcrQ-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
> >> error[E0599]: no method named `is_virtfn` found for struct `bindings::pci_dev` in the current scope
>    --> rust/kernel/pci.rs:415:35
>    |
>    415 |         unsafe { (*self.as_raw()).is_virtfn() != 0 }
>    |                                   ^^^^^^^^^ method not found in `pci_dev`
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>