Messages in this thread | | | Date | Wed, 1 Feb 2023 09:36:44 -0700 | From | Alex Williamson <> | Subject | Re: [PATCH v7 1/5] vfio/migration: Add debugfs to live migration driver |
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On Wed, 1 Feb 2023 11:20:08 +0800 liulongfang <liulongfang@huawei.com> wrote:
> On 2023/1/27 3:27, Alex Williamson wrote: > > On Fri, 20 Jan 2023 11:29:26 +0800 > > Longfang Liu <liulongfang@huawei.com> wrote: > > > >> There are multiple devices, software and operational steps involved > >> in the process of live migration. An error occurred on any node may > >> cause the live migration operation to fail. > >> This complex process makes it very difficult to locate and analyze > >> the cause when the function fails. > >> > >> In order to quickly locate the cause of the problem when the > >> live migration fails, I added a set of debugfs to the vfio > >> live migration driver. > >> > >> +------------------------------------------+ > >> | | > >> | | > >> | QEMU | > >> | | > >> | | > >> +-----+-------------------------+----------+ > >> | ^ | ^ > >> v | v | > >> +-----+--+ +-----+--+ > >> | src VF | | dst VF | > >> +-+------+ +-+------+ > >> | ^ | ^ > >> v | v | > >> +-------+-+------+ +-------+-+------+ > >> |Debugfs|state | |Debugfs|state | > >> +-------+--------+ +-------+--------+ > >> | debug_root | | debug_root | > >> +-------+--------+ +-------+--------+ > >> > >> The entire debugfs directory will be based on the definition of > >> the CONFIG_DEBUG_FS macro. If this macro is not enabled, the > >> interfaces in vfio_pci_debugfs.h will be empty definitions, > >> and the creation and initialization of the debugfs directory > >> will not be executed. > >> > >> debugfs will create a public root directory "vfio_mig" file. > >> then create a "debug_root" file for each live migration VF device. > > > > s/VF // In practice it may be VFs, but I don't think we want to > > artificially imply that the device must be a VF. In fact, I'm not sure > > Yes, the description should be modified here, and it should not be limited > to only support VF. > > > why any of this code lives in vfio/pci/ vs vfio/, there's nothing PCI > > specific here. Why isn't all of this done in vfio_main to be shared > > with both pci and non-pci vfio drivers and devices? > > > > Combined with your observations below, I think it is more appropriate to > create a "vfio-pci" directory here, because the current live migration > function is still used on pci devices. > > For non-pci devices, if there is a device that needs to add debugfs, > then it can create a similar directory.
But live migration itself is not specific to vfio-pci, it's device agnostic. We'd certainly expect to see mdev devices supporting migration in the near term. Thanks,
Alex
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