linux-toradex.git/include/xen/arm, branch master

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/virtio: Optimize the setup of "xen-grant-dma" devices

2022-12-05T11:59:49+00:00

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()->...->xen_is_dt_grant_dma_device()
2. xen_setup_dma_ops()->...->xen_dt_grant_init_backend_domid()
3. xen_virtio_mem_acc()->...->xen_is_dt_grant_dma_device()

With current patch we parse the device-tree only once in
xen_virtio_restricted_mem_acc()->...->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 
Reviewed-by: Xenia Ragiadakou 
Reviewed-by: Stefano Stabellini 
Link: https://lore.kernel.org/r/20221025162004.8501-2-olekstysh@gmail.com
Signed-off-by: Juergen Gross

arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices

2022-06-06T14:07:30+00:00

By assigning xen-grant DMA ops we will restrict memory access for
passed device using Xen grant mappings. This is needed for using any
virtualized device (e.g. virtio) in Xen guests in a safe manner.

Please note, for the virtio devices the XEN_VIRTIO config should
be enabled (it forces ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS).

Signed-off-by: Oleksandr Tyshchenko 
Reviewed-by: Stefano Stabellini 
Link: https://lore.kernel.org/r/1654197833-25362-9-git-send-email-olekstysh@gmail.com
Signed-off-by: Juergen Gross

arm/xen: Introduce xen_setup_dma_ops()

2022-06-06T06:54:33+00:00

This patch introduces new helper and places it in new header.
The helper's purpose is to assign any Xen specific DMA ops in
a single place. For now, we deal with xen-swiotlb DMA ops only.
The one of the subsequent commits in current series will add
xen-grant DMA ops case.

Also re-use the xen_swiotlb_detect() check on Arm32.

Signed-off-by: Oleksandr Tyshchenko 
Reviewed-by: Stefano Stabellini 
[For arm64]
Acked-by: Catalin Marinas 
Link: https://lore.kernel.org/r/1654197833-25362-2-git-send-email-olekstysh@gmail.com
Signed-off-by: Juergen Gross

Merge tag 'for-linus-5.19-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2022-06-04T20:42:53+00:00

Pull more xen updates from Juergen Gross:
 "Two cleanup patches for Xen related code and (more important) an
  update of MAINTAINERS for Xen, as Boris Ostrovsky decided to step
  down"

* tag 'for-linus-5.19-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: replace xen_remap() with memremap()
  MAINTAINERS: Update Xen maintainership
  xen: switch gnttab_end_foreign_access() to take a struct page pointer

xen: replace xen_remap() with memremap()

2022-06-01T05:24:17+00:00

xen_remap() is used to establish mappings for frames not under direct
control of the kernel: for Xenstore and console ring pages, and for
grant pages of non-PV guests.

Today xen_remap() is defined to use ioremap() on x86 (doing uncached
mappings), and ioremap_cache() on Arm (doing cached mappings).

Uncached mappings for those use cases are bad for performance, so they
should be avoided if possible. As all use cases of xen_remap() don't
require uncached mappings (the mapped area is always physical RAM),
a mapping using the standard WB cache mode is fine.

As sparse is flagging some of the xen_remap() use cases to be not
appropriate for iomem(), as the result is not annotated with the
__iomem modifier, eliminate xen_remap() completely and replace all
use cases with memremap() specifying the MEMREMAP_WB caching mode.

xen_unmap() can be replaced with memunmap().

Reported-by: kernel test robot 
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Acked-by: Stefano Stabellini 
Link: https://lore.kernel.org/r/20220530082634.6339-1-jgross@suse.com
Signed-off-by: Juergen Gross

swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm

2022-05-11T17:48:32+00:00

swiotlb-xen uses very different ways to allocate coherent memory on x86
vs arm.  On the former it allocates memory from the page allocator, while
on the later it reuses the dma-direct allocator the handles the
complexities of non-coherent DMA on arm platforms.

Unfortunately the complexities of trying to deal with the two cases in
the swiotlb-xen.c code lead to a bug in the handling of
DMA_ATTR_NO_KERNEL_MAPPING on arm.  With the DMA_ATTR_NO_KERNEL_MAPPING
flag the coherent memory allocator does not actually allocate coherent
memory, but just a DMA handle for some memory that is DMA addressable
by the device, but which does not have to have a kernel mapping.  Thus
dereferencing the return value will lead to kernel crashed and memory
corruption.

Fix this by using the dma-direct allocator directly for arm, which works
perfectly fine because on arm swiotlb-xen is only used when the domain is
1:1 mapped, and then simplifying the remaining code to only cater for the
x86 case with DMA coherent device.

Reported-by: Rahul Singh 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Rahul Singh 
Reviewed-by: Stefano Stabellini 
Tested-by: Rahul Singh

swiotlb: merge swiotlb-xen initialization into swiotlb

2022-04-18T05:21:13+00:00

Reuse the generic swiotlb initialization for xen-swiotlb.  For ARM/ARM64
this works trivially, while for x86 xen_swiotlb_fixup needs to be passed
as the remap argument to swiotlb_init_remap/swiotlb_init_late.

Note that the lower bound of the swiotlb size is changed to the smaller
IO_TLB_MIN_SLABS based value with this patch, but that is fine as the
2MB value used in Xen before was just an optimization and is not the
hard lower bound.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Stefano Stabellini 
Reviewed-by: Konrad Rzeszutek Wilk 
Tested-by: Boris Ostrovsky

xen: allow pv-only hypercalls only with CONFIG_XEN_PV

2021-11-02T13:11:01+00:00

Put the definitions of the hypercalls usable only by pv guests inside
CONFIG_XEN_PV sections.

On Arm two dummy functions related to pv hypercalls can be removed.

While at it remove the no longer supported tmem hypercall definition.

Signed-off-by: Juergen Gross 
Link: https://lore.kernel.org/r/20211028081221.2475-3-jgross@suse.com
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Boris Ostrovsky

xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h

2021-05-14T13:52:05+00:00

Move xen_swiotlb_detect to a static inline function to make it available
to !CONFIG_XEN builds.

CC: boris.ostrovsky@oracle.com
CC: jgross@suse.com
Signed-off-by: Stefano Stabellini 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Juergen Gross 
Link: https://lore.kernel.org/r/20210512201823.1963-1-sstabellini@kernel.org
Signed-off-by: Juergen Gross