From: Leon Romanovsky <leon@kernel.org>
To: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: netdev@vger.kernel.org,
Jesse Brandeburg <jesse.brandeburg@intel.com>,
intel-wired-lan@lists.osuosl.org,
Mateusz Polchlopek <mateusz.polchlopek@intel.com>,
Tony Nguyen <anthony.l.nguyen@intel.com>
Subject: Re: [Intel-wired-lan] [PATCH iwl-next] ice: store VF's pci_dev ptr in ice_vf
Date: Fri, 18 Aug 2023 21:20:59 +0300 [thread overview]
Message-ID: <20230818182059.GZ22185@unreal> (raw)
In-Reply-To: <c1f65aa1-3e20-9e21-1994-1190bf0086b7@intel.com>
On Fri, Aug 18, 2023 at 02:20:51PM +0200, Przemek Kitszel wrote:
> On 8/16/23 16:31, Leon Romanovsky wrote:
> > On Wed, Aug 16, 2023 at 04:54:54AM -0400, Przemek Kitszel wrote:
> > > Extend struct ice_vf by vfdev.
> > > Calculation of vfdev falls more nicely into ice_create_vf_entries().
> > >
> > > Caching of vfdev enables simplification of ice_restore_all_vfs_msi_state().
> >
> > I see that old code had access to pci_dev * of VF without any locking
> > from concurrent PCI core access. How is it protected? How do you make
> > sure that vfdev is valid?
> >
> > Generally speaking, it is rarely good idea to cache VF pci_dev pointers
> > inside driver.
> >
> > Thanks
>
> Overall, I do agree that ice driver, as a whole, has room for improvement in
> terms of synchronization, objects lifetime, and similar.
>
> In this particular case, I don't see any reason of PCI reconfiguration
> during VF lifetime, but likely I'm missing something?
You are caching VF pointer in PF, and you are subjected to PF lifetime
and not VF lifetime.
Thanks
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next prev parent reply other threads:[~2023-08-18 18:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-16 8:54 [Intel-wired-lan] [PATCH iwl-next] ice: store VF's pci_dev ptr in ice_vf Przemek Kitszel
2023-08-16 14:31 ` Leon Romanovsky
2023-08-18 12:20 ` Przemek Kitszel
2023-08-18 18:20 ` Leon Romanovsky [this message]
2023-08-21 10:48 ` Przemek Kitszel
2023-08-21 11:01 ` Leon Romanovsky
2023-08-22 20:46 ` Keller, Jacob E
2023-08-23 9:55 ` Leon Romanovsky
2023-08-17 7:54 ` kernel test robot
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