From: Cornelia Huck <cohuck@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>, David Airlie <airlied@linux.ie>,
Tony Krowiak <akrowiak@linux.ibm.com>,
Alex Williamson <alex.williamson@redhat.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Jonathan Corbet <corbet@lwn.net>, Daniel Vetter <daniel@ffwll.ch>,
Diana Craciun <diana.craciun@oss.nxp.com>,
dri-devel@lists.freedesktop.org,
Eric Auger <eric.auger@redhat.com>,
Eric Farman <farman@linux.ibm.com>,
Harald Freudenberger <freude@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
intel-gfx@lists.freedesktop.org,
intel-gvt-dev@lists.freedesktop.org,
Jani Nikula <jani.nikula@linux.intel.com>,
Jason Herne <jjherne@linux.ibm.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
kvm@vger.kernel.org, Kirti Wankhede <kwankhede@nvidia.com>,
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Matthew Rosato <mjrosato@linux.ibm.com>,
Peter Oberparleiter <oberpar@linux.ibm.com>,
Halil Pasic <pasic@linux.ibm.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Vineeth Vijayan <vneethv@linux.ibm.com>,
Zhi Wang <zhi.a.wang@intel.com>
Cc: "Raj, Ashok" <ashok.raj@intel.com>,
Christoph Hellwig <hch@lst.de>,
Leon Romanovsky <leonro@nvidia.com>,
Max Gurtovoy <mgurtovoy@nvidia.com>,
Yishai Hadas <yishaih@nvidia.com>,
Zhenyu Wang <zhenyuw@linux.intel.com>
Subject: Re: [Intel-gfx] [PATCH v4 09/14] vfio/pci: Change vfio_pci_try_bus_reset() to use the dev_set
Date: Wed, 11 Aug 2021 12:14:56 +0200 [thread overview]
Message-ID: <87wnosuw2n.fsf@redhat.com> (raw)
In-Reply-To: <9-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com>
On Thu, Aug 05 2021, Jason Gunthorpe <jgg@nvidia.com> wrote:
> vfio_pci_try_bus_reset() is triggering a reset of the entire_dev set if
> any device within it has accumulated a needs_reset. This reset can only be
> done once all of the drivers operating the PCI devices to be reset are in
> a known safe state.
>
> Make this clearer by directly operating on the dev_set instead of the
> vfio_pci_device. Rename the function to vfio_pci_dev_set_try_reset().
>
> Use the device list inside the dev_set to check that all drivers are in a
> safe state instead of working backwards from the pci_device.
>
> The dev_set->lock directly prevents devices from joining/leaving the set,
> or changing their state, which further implies the pci_device cannot
> change drivers or that the vfio_device be freed, eliminating the need for
> get/put's.
>
> If a pci_device to be reset is not in the dev_set then the reset cannot be
> used as we can't know what the state of that driver is. Directly measure
> this by checking that every pci_device is in the dev_set - which
> effectively proves that VFIO drivers are attached to everything.
>
> Remove the odd interaction around vfio_pci_set_power_state() - have the
> only caller avoid its redundant vfio_pci_set_power_state() instead of
> avoiding it inside vfio_pci_dev_set_try_reset().
>
> This restructuring corrects a call to pci_dev_driver() without holding the
> device_lock() and removes a hard wiring to &vfio_pci_driver.
>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
> drivers/vfio/pci/vfio_pci.c | 182 +++++++++++++++++-------------------
> 1 file changed, 86 insertions(+), 96 deletions(-)
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
next prev parent reply other threads:[~2021-08-11 10:15 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-06 1:18 [Intel-gfx] [PATCH v4 00/14] Provide core infrastructure for managing open/release Jason Gunthorpe
2021-08-06 1:18 ` [Intel-gfx] [PATCH v4 01/14] vfio/samples: Remove module get/put Jason Gunthorpe
2021-08-08 8:54 ` Max Gurtovoy
2021-08-06 1:18 ` [Intel-gfx] [PATCH v4 02/14] vfio/mbochs: Fix missing error unwind of mbochs_used_mbytes Jason Gunthorpe
2021-08-11 9:17 ` Cornelia Huck
2021-08-06 1:18 ` [Intel-gfx] [PATCH v4 03/14] vfio: Introduce a vfio_uninit_group_dev() API call Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 04/14] vfio: Provide better generic support for open/release vfio_device_ops Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 05/14] vfio/samples: Delete useless open/close Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 06/14] vfio/fsl: Move to the device set infrastructure Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 07/14] vfio/platform: Use open_device() instead of open coding a refcnt scheme Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 08/14] vfio/pci: Move to the device set infrastructure Jason Gunthorpe
2021-08-11 9:35 ` Cornelia Huck
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 09/14] vfio/pci: Change vfio_pci_try_bus_reset() to use the dev_set Jason Gunthorpe
2021-08-10 8:26 ` Christoph Hellwig
2021-08-11 10:14 ` Cornelia Huck [this message]
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 10/14] vfio/pci: Reorganize VFIO_DEVICE_PCI_HOT_RESET to use the device set Jason Gunthorpe
2021-08-11 10:33 ` Cornelia Huck
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 11/14] vfio/mbochs: Fix close when multiple device FDs are open Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 12/14] vfio/ap, ccw: Fix open/close " Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 13/14] vfio/gvt: " Jason Gunthorpe
2021-08-06 1:19 ` [Intel-gfx] [PATCH v4 14/14] vfio: Remove struct vfio_device_ops open/release Jason Gunthorpe
2021-08-11 10:35 ` Cornelia Huck
2021-08-06 1:52 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for Provide core infrastructure for managing open/release (rev9) Patchwork
2021-08-06 2:22 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork
2021-08-11 22:08 ` [Intel-gfx] [PATCH v4 00/14] Provide core infrastructure for managing open/release Alex Williamson
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