<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/xen, branch v6.3-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2023-02-24T20:58:55+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-24T20:58:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a93e884edf61f9debc9ca61ef9e545f0394ab666'/>
<id>a93e884edf61f9debc9ca61ef9e545f0394ab666</id>
<content type='text'>
Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.3-rc1.

  There's a lot of changes this development cycle, most of the work
  falls into two different categories:

   - fw_devlink fixes and updates. This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.

   - driver core changes to work to make struct bus_type able to be
     moved into read-only memory (i.e. const) The recent work with Rust
     has pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only
     making things safer overall. This is the contuation of that work
     (started last release with kobject changes) in moving struct
     bus_type to be constant. We didn't quite make it for this release,
     but the remaining patches will be finished up for the release after
     this one, but the groundwork has been laid for this effort.

  Other than that we have in here:

   - debugfs memory leak fixes in some subsystems

   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.

   - cacheinfo rework and fixes

   - Other tiny fixes, full details are in the shortlog

  All of these have been in linux-next for a while with no reported
  problems"

[ Geert Uytterhoeven points out that that last sentence isn't true, and
  that there's a pending report that has a fix that is queued up - Linus ]

* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
  debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
  OPP: fix error checking in opp_migrate_dentry()
  debugfs: update comment of debugfs_rename()
  i3c: fix device.h kernel-doc warnings
  dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
  driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
  Revert "driver core: add error handling for devtmpfs_create_node()"
  Revert "devtmpfs: add debug info to handle()"
  Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
  driver core: cpu: don't hand-override the uevent bus_type callback.
  devtmpfs: remove return value of devtmpfs_delete_node()
  devtmpfs: add debug info to handle()
  driver core: add error handling for devtmpfs_create_node()
  driver core: bus: update my copyright notice
  driver core: bus: add bus_get_dev_root() function
  driver core: bus: constify bus_unregister()
  driver core: bus: constify some internal functions
  driver core: bus: constify bus_get_kset()
  driver core: bus: constify bus_register/unregister_notifier()
  driver core: remove private pointer from struct bus_type
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.3-rc1.

  There's a lot of changes this development cycle, most of the work
  falls into two different categories:

   - fw_devlink fixes and updates. This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.

   - driver core changes to work to make struct bus_type able to be
     moved into read-only memory (i.e. const) The recent work with Rust
     has pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only
     making things safer overall. This is the contuation of that work
     (started last release with kobject changes) in moving struct
     bus_type to be constant. We didn't quite make it for this release,
     but the remaining patches will be finished up for the release after
     this one, but the groundwork has been laid for this effort.

  Other than that we have in here:

   - debugfs memory leak fixes in some subsystems

   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.

   - cacheinfo rework and fixes

   - Other tiny fixes, full details are in the shortlog

  All of these have been in linux-next for a while with no reported
  problems"

[ Geert Uytterhoeven points out that that last sentence isn't true, and
  that there's a pending report that has a fix that is queued up - Linus ]

* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
  debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
  OPP: fix error checking in opp_migrate_dentry()
  debugfs: update comment of debugfs_rename()
  i3c: fix device.h kernel-doc warnings
  dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
  driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
  Revert "driver core: add error handling for devtmpfs_create_node()"
  Revert "devtmpfs: add debug info to handle()"
  Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
  driver core: cpu: don't hand-override the uevent bus_type callback.
  devtmpfs: remove return value of devtmpfs_delete_node()
  devtmpfs: add debug info to handle()
  driver core: add error handling for devtmpfs_create_node()
  driver core: bus: update my copyright notice
  driver core: bus: add bus_get_dev_root() function
  driver core: bus: constify bus_unregister()
  driver core: bus: constify some internal functions
  driver core: bus: constify bus_get_kset()
  driver core: bus: constify bus_register/unregister_notifier()
  driver core: remove private pointer from struct bus_type
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: Allow platform PCI interrupt to be shared</title>
<updated>2023-02-13T05:53:20+00:00</updated>
<author>
<name>David Woodhouse</name>
<email>dwmw@amazon.co.uk</email>
</author>
<published>2023-01-18T12:22:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3e8cd711c3da6c3d724076048038cd666bdbb2b5'/>
<id>3e8cd711c3da6c3d724076048038cd666bdbb2b5</id>
<content type='text'>
When we don't use the per-CPU vector callback, we ask Xen to deliver event
channel interrupts as INTx on the PCI platform device. As such, it can be
shared with INTx on other PCI devices.

Set IRQF_SHARED, and make it return IRQ_HANDLED or IRQ_NONE according to
whether the evtchn_upcall_pending flag was actually set. Now I can share
the interrupt:

 11:         82          0   IO-APIC  11-fasteoi   xen-platform-pci, ens4

Drop the IRQF_TRIGGER_RISING. It has no effect when the IRQ is shared,
and besides, the only effect it was having even beforehand was to trigger
a debug message in both I/OAPIC and legacy PIC cases:

[    0.915441] genirq: No set_type function for IRQ 11 (IO-APIC)
[    0.951939] genirq: No set_type function for IRQ 11 (XT-PIC)

Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/f9a29a68d05668a3636dd09acd94d970269eaec6.camel@infradead.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When we don't use the per-CPU vector callback, we ask Xen to deliver event
channel interrupts as INTx on the PCI platform device. As such, it can be
shared with INTx on other PCI devices.

Set IRQF_SHARED, and make it return IRQ_HANDLED or IRQ_NONE according to
whether the evtchn_upcall_pending flag was actually set. Now I can share
the interrupt:

 11:         82          0   IO-APIC  11-fasteoi   xen-platform-pci, ens4

Drop the IRQF_TRIGGER_RISING. It has no effect when the IRQ is shared,
and besides, the only effect it was having even beforehand was to trigger
a debug message in both I/OAPIC and legacy PIC cases:

[    0.915441] genirq: No set_type function for IRQ 11 (IO-APIC)
[    0.951939] genirq: No set_type function for IRQ 11 (XT-PIC)

Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/f9a29a68d05668a3636dd09acd94d970269eaec6.camel@infradead.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: make struct bus_type.uevent() take a const *</title>
<updated>2023-01-27T12:45:52+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-01-11T11:30:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2a81ada32f0e584fc0c943e0d3a8c9f4fae411d6'/>
<id>2a81ada32f0e584fc0c943e0d3a8c9f4fae411d6</id>
<content type='text'>
The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen/xenbus: move to_xenbus_device() to use container_of_const()</title>
<updated>2023-01-27T12:45:50+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-01-11T11:30:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c6e8418521a8fd2068ade2c6a1514315c99cc717'/>
<id>c6e8418521a8fd2068ade2c6a1514315c99cc717</id>
<content type='text'>
The driver core is changing to pass some pointers as const, so move
to_xenbus_device() to use container_of_const() to handle this change.

to_xenbus_device() now properly keeps the const-ness of the pointer passed
into it, while as before it could be lost.

Cc: Stefano Stabellini &lt;sstabellini@kernel.org&gt;
Cc: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt;
Cc: xen-devel@lists.xenproject.org
Acked-by: Juergen Gross &lt;jgross@suse.com&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20230111113018.459199-15-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The driver core is changing to pass some pointers as const, so move
to_xenbus_device() to use container_of_const() to handle this change.

to_xenbus_device() now properly keeps the const-ness of the pointer passed
into it, while as before it could be lost.

Cc: Stefano Stabellini &lt;sstabellini@kernel.org&gt;
Cc: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt;
Cc: xen-devel@lists.xenproject.org
Acked-by: Juergen Gross &lt;jgross@suse.com&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20230111113018.459199-15-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: make remove callback of xen driver void returned</title>
<updated>2022-12-15T15:06:10+00:00</updated>
<author>
<name>Dawei Li</name>
<email>set_pte_at@outlook.com</email>
</author>
<published>2022-12-13T15:46:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7cffcade57a429667447c4f41d8414bbcf1b3aaa'/>
<id>7cffcade57a429667447c4f41d8414bbcf1b3aaa</id>
<content type='text'>
Since commit fc7a6209d571 ("bus: Make remove callback return void")
forces bus_type::remove be void-returned, it doesn't make much sense for
any bus based driver implementing remove callbalk to return non-void to
its caller.

This change is for xen bus based drivers.

Acked-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Dawei Li &lt;set_pte_at@outlook.com&gt;
Link: https://lore.kernel.org/r/TYCP286MB23238119AB4DF190997075C9CAE39@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit fc7a6209d571 ("bus: Make remove callback return void")
forces bus_type::remove be void-returned, it doesn't make much sense for
any bus based driver implementing remove callbalk to return non-void to
its caller.

This change is for xen bus based drivers.

Acked-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Dawei Li &lt;set_pte_at@outlook.com&gt;
Link: https://lore.kernel.org/r/TYCP286MB23238119AB4DF190997075C9CAE39@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: fix xen.h build for CONFIG_XEN_PVH=y</title>
<updated>2022-12-05T11:59:49+00:00</updated>
<author>
<name>Jani Nikula</name>
<email>jani.nikula@intel.com</email>
</author>
<published>2022-11-23T13:10:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=11987fbeaae78f2fc01ce9eb3f5a0eec382b4282'/>
<id>11987fbeaae78f2fc01ce9eb3f5a0eec382b4282</id>
<content type='text'>
For CONFIG_XEN_PVH=y, xen.h uses bool before the type is known. Include
&lt;linux/types.h&gt; earlier.

Signed-off-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20221123131057.3864183-1-jani.nikula@intel.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For CONFIG_XEN_PVH=y, xen.h uses bool before the type is known. Include
&lt;linux/types.h&gt; earlier.

Signed-off-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20221123131057.3864183-1-jani.nikula@intel.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen/virtio: Optimize the setup of "xen-grant-dma" devices</title>
<updated>2022-12-05T11:59:49+00:00</updated>
<author>
<name>Oleksandr Tyshchenko</name>
<email>oleksandr_tyshchenko@epam.com</email>
</author>
<published>2022-10-25T16:20:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=035e3a4321f73c352b6408ec2153fa5bc3feb459'/>
<id>035e3a4321f73c352b6408ec2153fa5bc3feb459</id>
<content type='text'>
This is needed to avoid having to parse the same device-tree
several times for a given device.

For this to work we need to install the xen_virtio_restricted_mem_acc
callback in Arm's xen_guest_init() which is same callback as x86's
PV and HVM modes already use and remove the manual assignment in
xen_setup_dma_ops(). Also we need to split the code to initialize
backend_domid into a separate function.

Prior to current patch we parsed the device-tree three times:
1. xen_setup_dma_ops()-&gt;...-&gt;xen_is_dt_grant_dma_device()
2. xen_setup_dma_ops()-&gt;...-&gt;xen_dt_grant_init_backend_domid()
3. xen_virtio_mem_acc()-&gt;...-&gt;xen_is_dt_grant_dma_device()

With current patch we parse the device-tree only once in
xen_virtio_restricted_mem_acc()-&gt;...-&gt;xen_dt_grant_init_backend_domid()

Other benefits are:
- Not diverge from x86 when setting up Xen grant DMA ops
- Drop several global functions

Signed-off-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt;
Reviewed-by: Xenia Ragiadakou &lt;burzalodowa@gmail.com&gt;
Reviewed-by: Stefano Stabellini &lt;sstabellini@kernel.org&gt;
Link: https://lore.kernel.org/r/20221025162004.8501-2-olekstysh@gmail.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is needed to avoid having to parse the same device-tree
several times for a given device.

For this to work we need to install the xen_virtio_restricted_mem_acc
callback in Arm's xen_guest_init() which is same callback as x86's
PV and HVM modes already use and remove the manual assignment in
xen_setup_dma_ops(). Also we need to split the code to initialize
backend_domid into a separate function.

Prior to current patch we parsed the device-tree three times:
1. xen_setup_dma_ops()-&gt;...-&gt;xen_is_dt_grant_dma_device()
2. xen_setup_dma_ops()-&gt;...-&gt;xen_dt_grant_init_backend_domid()
3. xen_virtio_mem_acc()-&gt;...-&gt;xen_is_dt_grant_dma_device()

With current patch we parse the device-tree only once in
xen_virtio_restricted_mem_acc()-&gt;...-&gt;xen_dt_grant_init_backend_domid()

Other benefits are:
- Not diverge from x86 when setting up Xen grant DMA ops
- Drop several global functions

Signed-off-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt;
Reviewed-by: Xenia Ragiadakou &lt;burzalodowa@gmail.com&gt;
Reviewed-by: Stefano Stabellini &lt;sstabellini@kernel.org&gt;
Link: https://lore.kernel.org/r/20221025162004.8501-2-olekstysh@gmail.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen/virtio: enable grant based virtio on x86</title>
<updated>2022-10-10T12:31:26+00:00</updated>
<author>
<name>Juergen Gross</name>
<email>jgross@suse.com</email>
</author>
<published>2022-08-29T11:26:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=61367688f1fb07678b1d865a0ce9364f5267a896'/>
<id>61367688f1fb07678b1d865a0ce9364f5267a896</id>
<content type='text'>
Use an x86-specific virtio_check_mem_acc_cb() for Xen in order to setup
the correct DMA ops.

Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Reviewed-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt; # common code
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use an x86-specific virtio_check_mem_acc_cb() for Xen in order to setup
the correct DMA ops.

Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Reviewed-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt; # common code
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/xen: Add support for HVMOP_set_evtchn_upcall_vector</title>
<updated>2022-08-12T09:28:21+00:00</updated>
<author>
<name>Jane Malalane</name>
<email>jane.malalane@citrix.com</email>
</author>
<published>2022-07-29T07:04:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b1c3497e604ddccea5af4071831ed0e4680fb35e'/>
<id>b1c3497e604ddccea5af4071831ed0e4680fb35e</id>
<content type='text'>
Implement support for the HVMOP_set_evtchn_upcall_vector hypercall in
order to set the per-vCPU event channel vector callback on Linux and
use it in preference of HVM_PARAM_CALLBACK_IRQ.

If the per-VCPU vector setup is successful on BSP, use this method
for the APs. If not, fallback to the global vector-type callback.

Also register callback_irq at per-vCPU event channel setup to trick
toolstack to think the domain is enlightened.

Suggested-by: "Roger Pau Monné" &lt;roger.pau@citrix.com&gt;
Signed-off-by: Jane Malalane &lt;jane.malalane@citrix.com&gt;
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Link: https://lore.kernel.org/r/20220729070416.23306-1-jane.malalane@citrix.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Implement support for the HVMOP_set_evtchn_upcall_vector hypercall in
order to set the per-vCPU event channel vector callback on Linux and
use it in preference of HVM_PARAM_CALLBACK_IRQ.

If the per-VCPU vector setup is successful on BSP, use this method
for the APs. If not, fallback to the global vector-type callback.

Also register callback_irq at per-vCPU event channel setup to trick
toolstack to think the domain is enlightened.

Suggested-by: "Roger Pau Monné" &lt;roger.pau@citrix.com&gt;
Signed-off-by: Jane Malalane &lt;jane.malalane@citrix.com&gt;
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Link: https://lore.kernel.org/r/20220729070416.23306-1-jane.malalane@citrix.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: don't require virtio with grants for non-PV guests</title>
<updated>2022-08-01T05:43:03+00:00</updated>
<author>
<name>Juergen Gross</name>
<email>jgross@suse.com</email>
</author>
<published>2022-06-22T06:38:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=251e90e7e346a23742b90e2c4db19d322e071d99'/>
<id>251e90e7e346a23742b90e2c4db19d322e071d99</id>
<content type='text'>
Commit fa1f57421e0b ("xen/virtio: Enable restricted memory access using
Xen grant mappings") introduced a new requirement for using virtio
devices: the backend now needs to support the VIRTIO_F_ACCESS_PLATFORM
feature.

This is an undue requirement for non-PV guests, as those can be operated
with existing backends without any problem, as long as those backends
are running in dom0.

Per default allow virtio devices without grant support for non-PV
guests.

On Arm require VIRTIO_F_ACCESS_PLATFORM for devices having been listed
in the device tree to use grants.

Add a new config item to always force use of grants for virtio.

Fixes: fa1f57421e0b ("xen/virtio: Enable restricted memory access using Xen grant mappings")
Reported-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Reviewed-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt;
Tested-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt; # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini &lt;sstabellini@kernel.org&gt;
Link: https://lore.kernel.org/r/20220622063838.8854-4-jgross@suse.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit fa1f57421e0b ("xen/virtio: Enable restricted memory access using
Xen grant mappings") introduced a new requirement for using virtio
devices: the backend now needs to support the VIRTIO_F_ACCESS_PLATFORM
feature.

This is an undue requirement for non-PV guests, as those can be operated
with existing backends without any problem, as long as those backends
are running in dom0.

Per default allow virtio devices without grant support for non-PV
guests.

On Arm require VIRTIO_F_ACCESS_PLATFORM for devices having been listed
in the device tree to use grants.

Add a new config item to always force use of grants for virtio.

Fixes: fa1f57421e0b ("xen/virtio: Enable restricted memory access using Xen grant mappings")
Reported-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Reviewed-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt;
Tested-by: Oleksandr Tyshchenko &lt;oleksandr_tyshchenko@epam.com&gt; # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini &lt;sstabellini@kernel.org&gt;
Link: https://lore.kernel.org/r/20220622063838.8854-4-jgross@suse.com
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
