linux-toradex.git/include/xen, branch v6.9-rc4

xen: update PV-device interface headers

2024-01-09T10:46:24+00:00

Update the Xen PV-device interface headers in order to avoid undefined
behavior with flexible arrays being defined with one array element.

Reported-by: Pry Mar 
Signed-off-by: Juergen Gross 
Acked-by: Stefano Stabellini 
Link: https://lore.kernel.org/r/20231205115121.11627-1-jgross@suse.com
Signed-off-by: Juergen Gross

xen/events: reduce externally visible helper functions

2023-11-14T08:29:28+00:00

get_evtchn_to_irq() has only one external user while irq_from_evtchn()
provides the same functionality and is exported for a wider user base.
Modify the only external user of get_evtchn_to_irq() to use
irq_from_evtchn() instead and make get_evtchn_to_irq() static.

evtchn_from_irq() and irq_from_virq() have a single external user and
can easily be combined to a new helper irq_evtchn_from_virq() allowing
to drop irq_from_virq() and to make evtchn_from_irq() static.

Signed-off-by: Juergen Gross 
Reviewed-by: Oleksandr Tyshchenko 
Signed-off-by: Juergen Gross

xen/events: remove unused functions

2023-11-13T14:45:20+00:00

There are no users of xen_irq_from_pirq() and xen_set_irq_pending().

Remove those functions.

Signed-off-by: Juergen Gross 
Reviewed-by: Oleksandr Tyshchenko 
Signed-off-by: Juergen Gross

xen: privcmd: Add support for ioeventfd

2023-10-16T13:18:33+00:00

Virtio guests send VIRTIO_MMIO_QUEUE_NOTIFY notification when they need
to notify the backend of an update to the status of the virtqueue. The
backend or another entity, polls the MMIO address for updates to know
when the notification is sent.

It works well if the backend does this polling by itself. But as we move
towards generic backend implementations, we end up implementing this in
a separate user-space program.

Generally, the Virtio backends are implemented to work with the Eventfd
based mechanism. In order to make such backends work with Xen, another
software layer needs to do the polling and send an event via eventfd to
the backend once the notification from guest is received. This results
in an extra context switch.

This is not a new problem in Linux though. It is present with other
hypervisors like KVM, etc. as well. The generic solution implemented in
the kernel for them is to provide an IOCTL call to pass the address to
poll and eventfd, which lets the kernel take care of polling and raise
an event on the eventfd, instead of handling this in user space (which
involves an extra context switch).

This patch adds similar support for xen.

Inspired by existing implementations for KVM, etc..

This also copies ioreq.h header file (only struct ioreq and related
macros) from Xen's source tree (Top commit 5d84f07fe6bf ("xen/pci: drop
remaining uses of bool_t")).

Signed-off-by: Viresh Kumar 
Reviewed-by: Juergen Gross 
Link: https://lore.kernel.org/r/b20d83efba6453037d0c099912813c79c81f7714.1697439990.git.viresh.kumar@linaro.org
Signed-off-by: Juergen Gross

arm/xen: remove lazy mode related definitions

2023-09-19T05:04:49+00:00

include/xen/arm/hypervisor.h contains definitions related to paravirt
lazy mode, which are used nowhere in the code.

All paravirt lazy mode related users are in x86 code, so remove the
definitions on Arm side.

Signed-off-by: Juergen Gross 
Acked-by: Stefano Stabellini 
Link: https://lore.kernel.org/r/20230913113828.18421-2-jgross@suse.com
Signed-off-by: Juergen Gross

xen: simplify evtchn_do_upcall() call maze

2023-09-19T05:04:49+00:00

There are several functions involved for performing the functionality
of evtchn_do_upcall():

- __xen_evtchn_do_upcall() doing the real work
- xen_hvm_evtchn_do_upcall() just being a wrapper for
  __xen_evtchn_do_upcall(), exposed for external callers
- xen_evtchn_do_upcall() calling __xen_evtchn_do_upcall(), too, but
  without any user

Simplify this maze by:

- removing the unused xen_evtchn_do_upcall()
- removing xen_hvm_evtchn_do_upcall() as the only left caller of
  __xen_evtchn_do_upcall(), while renaming __xen_evtchn_do_upcall() to
  xen_evtchn_do_upcall()

Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Juergen Gross

Merge tag 'dma-mapping-6.6-2023-08-29' of git://git.infradead.org/users/hch/dma-mapping

2023-08-30T03:32:10+00:00

Pull dma-maping updates from Christoph Hellwig:

 - allow dynamic sizing of the swiotlb buffer, to cater for secure
   virtualization workloads that require all I/O to be bounce buffered
   (Petr Tesarik)

 - move a declaration to a header (Arnd Bergmann)

 - check for memory region overlap in dma-contiguous (Binglei Wang)

 - remove the somewhat dangerous runtime swiotlb-xen enablement and
   unexport is_swiotlb_active (Christoph Hellwig, Juergen Gross)

 - per-node CMA improvements (Yajun Deng)

* tag 'dma-mapping-6.6-2023-08-29' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: optimize get_max_slots()
  swiotlb: move slot allocation explanation comment where it belongs
  swiotlb: search the software IO TLB only if the device makes use of it
  swiotlb: allocate a new memory pool when existing pools are full
  swiotlb: determine potential physical address limit
  swiotlb: if swiotlb is full, fall back to a transient memory pool
  swiotlb: add a flag whether SWIOTLB is allowed to grow
  swiotlb: separate memory pool data from other allocator data
  swiotlb: add documentation and rename swiotlb_do_find_slots()
  swiotlb: make io_tlb_default_mem local to swiotlb.c
  swiotlb: bail out of swiotlb_init_late() if swiotlb is already allocated
  dma-contiguous: check for memory region overlap
  dma-contiguous: support numa CMA for specified node
  dma-contiguous: support per-numa CMA for all architectures
  dma-mapping: move arch_dma_set_mask() declaration to header
  swiotlb: unexport is_swiotlb_active
  x86: always initialize xen-swiotlb when xen-pcifront is enabling
  xen/pci: add flag for PCI passthrough being possible

xen/evtchn: Remove unused function declaration xen_set_affinity_evtchn()

2023-08-21T07:49:18+00:00

Commit 67473b8194bc ("xen/events: Remove disfunct affinity spreading")
leave this unused declaration.

Signed-off-by: Yue Haibing 
Reviewed-by: Juergen Gross 
Reviewed-by: Rahul Singh 
Link: https://lore.kernel.org/r/20230801145413.40684-1-yuehaibing@huawei.com
Signed-off-by: Juergen Gross

xen/pci: add flag for PCI passthrough being possible

2023-07-31T15:54:27+00:00

When running as a Xen PV guests passed through PCI devices only have a
chance to work if the Xen supplied memory map has some PCI space
reserved.

Add a flag xen_pv_pci_possible which will be set in early boot in case
the memory map has at least one area with the type E820_TYPE_RESERVED.

Signed-off-by: Juergen Gross 
Signed-off-by: Christoph Hellwig

xen/evtchn: Introduce new IOCTL to bind static evtchn

2023-07-26T06:42:34+00:00

Xen 4.17 supports the creation of static evtchns. To allow user space
application to bind static evtchns introduce new ioctl
"IOCTL_EVTCHN_BIND_STATIC". Existing IOCTL doing more than binding
that’s why we need to introduce the new IOCTL to only bind the static
event channels.

Static evtchns to be available for use during the lifetime of the
guest. When the application exits, __unbind_from_irq() ends up being
called from release() file operations because of that static evtchns
are getting closed. To avoid closing the static event channel, add the
new bool variable "is_static" in "struct irq_info" to mark the event
channel static when creating the event channel to avoid closing the
static evtchn.

Also, take this opportunity to remove the open-coded version of the
evtchn close in drivers/xen/evtchn.c file and use xen_evtchn_close().

Signed-off-by: Rahul Singh 
Reviewed-by: Oleksandr Tyshchenko 
Acked-by: Stefano Stabellini 
Link: https://lore.kernel.org/r/ae7329bf1713f83e4aad4f3fa0f316258c40a3e9.1689677042.git.rahul.singh@arm.com
Signed-off-by: Juergen Gross