Commit graph

12 commits

Author SHA1 Message Date
Ricardo Cañuelo
5c669c4a4c virtio: kerneldocs fixes and enhancements
Fix variable names in some kerneldocs, naming in others.
Add kerneldocs for struct vring_desc and vring_interrupt.

Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Message-Id: <20220810094004.1250-2-ricardo.canuelo@collabora.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2022-08-16 01:40:24 -04:00
Michael S. Tsirkin
a865e420b9 virtio: force spec specified alignment on types
The ring element addresses are passed between components with different
alignments assumptions. Thus, if guest/userspace selects a pointer and
host then gets and dereferences it, we might need to decrease the
compiler-selected alignment to prevent compiler on the host from
assuming pointer is aligned.

This actually triggers on ARM with -mabi=apcs-gnu - which is a
deprecated configuration, but it seems safer to handle this
generally.

Note that userspace that allocates the memory is actually OK and does
not need to be fixed, but userspace that gets it from guest or another
process does need to be fixed. The later doesn't generally talk to the
kernel so while it might be buggy it's not talking to the kernel in the
buggy way - it's just using the header in the buggy way - so fixing
header and asking userspace to recompile is the best we can do.

I verified that the produced kernel binary on x86 is exactly identical
before and after the change.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2020-06-02 02:45:13 -04:00
Matej Genci
e7c8cc35a6 virtio: add VIRTIO_RING_NO_LEGACY
Add macro to disable legacy vring functions.

Signed-off-by: Matej Genci <matej.genci@nutanix.com>
Link: https://lore.kernel.org/r/20190911124942.243713-1-matej.genci@nutanix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-02 02:45:13 -04:00
Alexey Dobriyan
d6547f2a2c net, uapi: fix -Wpointer-arith warnings
Add casts to fix these warnings:

./usr/include/linux/netfilter_arp/arp_tables.h:200:19: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]
./usr/include/linux/netfilter_bridge/ebtables.h:197:19: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]
./usr/include/linux/netfilter_ipv4/ip_tables.h:223:19: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]
./usr/include/linux/netfilter_ipv6/ip6_tables.h:263:19: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]
./usr/include/linux/tipc_config.h:310:28: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]
./usr/include/linux/tipc_config.h:410:24: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]
./usr/include/linux/virtio_ring.h:170:16: error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]

Those are theoretical probably but kernel doesn't control compiler flags
in userspace.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-04 14:25:17 -07:00
Michael S. Tsirkin
9c0644ee4a virtio: drop internal struct from UAPI
There's no reason to expose struct vring_packed in UAPI - if we do we
won't be able to change or drop it, and it's not part of any interface.

Let's move it to virtio_ring.c

Cc: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-02-05 15:29:48 -05:00
Tiwei Bie
89a9157e12 virtio: add packed ring types and macros
Add types and macros for packed ring.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-26 22:17:39 -08:00
Juergen Gross
ecda85e702 x86/lguest: Remove lguest support
Lguest seems to be rather unused these days. It has seen only patches
ensuring it still builds the last two years and its official state is
"Odd Fixes".

Remove it in order to be able to clean up the paravirt code.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: lguest@lists.ozlabs.org
Cc: rusty@rustcorp.com.au
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-24 09:57:28 +02:00
Thomas Huth
d768f32aec virtio: Fix typecast of pointer in vring_init()
The virtio_ring.h header is used in userspace programs (ie. QEMU),
too. Here we can not assume that sizeof(pointer) is the same as
sizeof(long), e.g. when compiling for Windows, so the typecast in
vring_init() should be done with (uintptr_t) instead of (unsigned long).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-07 14:27:04 +03:00
Stefan Hajnoczi
e412d3a32b virtio: fix typo in vring_need_event() doc comment
Here the "other side" refers to the guest or host.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-01 20:46:32 -07:00
Michael S. Tsirkin
b28e0506fa virtio_ring: document alignment requirements
Host needs to know vring element alignment requirements:
simply doing alignof on structures doesn't work reliably: on some
platforms gcc has alignof(uint32_t) == 2.

Add macros for alignment as specified in virtio 1.0 cs01,
export them to userspace as well.

Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-29 10:54:54 +02:00
Michael S. Tsirkin
eef960a043 virtio: memory access APIs
virtio 1.0 makes all memory structures LE, so
we need APIs to conditionally do a byteswap on BE
architectures.

To make it easier to check code statically,
add virtio specific types for multi-byte integers
in memory.

Add low level wrappers that do a byteswap conditionally, these will be
useful e.g. for vhost.  Add high level wrappers that
query device endian-ness and act accordingly.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 12:05:24 +02:00
David Howells
607ca46e97 UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-13 10:46:48 +01:00