Add some notes on the parts needed to use ivshmem devices: more specifically,
explain the purpose of an ivshmem server and the basic concept to use the
ivshmem devices in guests.
Move some parts of the documentation and re-organise it.
Signed-off-by: David Marchand <david.marchand@6wind.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
As pointed out on the ML by Andrew Jones, glibc no longer permits
creating POSIX shm on hugetlbfs directly. When given a hugetlbfs path,
create a shareable file there.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
In practice, the number of VM is limited to MAXUINT16 in ivshmem, so use
the same limit on the server (removes a theorical infinite loop)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
When using ivshmem devices, notifications between guests can be sent as
interrupts using a ivshmem-server (typical use described in documentation).
The client is provided as a debug tool.
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Signed-off-by: David Marchand <david.marchand@6wind.com>
[fix a valgrind warning, option and server_close() segvs, extra server
headers includes, getopt() return type, out-of-tree build, use qemu
event_notifier instead of eventfd, fix x86/osx warnings - Marc-André]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
The number of eventfd that can be handled per peer is limited by the
number of vectors. Return an error when receiving too many of them.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
The terms 'guest' and 'peer' are used sometime interchangeably which may
be confusing. Instead, use 'peer' for the remote instances of ivshmem
clients, and 'guest' for the local VM.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
The server should not change the shm, and this isn't handled by qemu and
we should should verify this in qemu.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
The test whether the chardev is an AF_UNIX socket rejects
"-chardev socket,id=chr0,path=/tmp/foo,server,nowait -device
ivshmem,chardev=chr0", but fails to explain why.
Use an explicit error on why a chardev may be rejected.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
max_peer isn't really useful, it tracks the maximum received VM id, but
that quickly matches nb_peers, the size of the peers array. Since VM
come and go, there might be sparse peers so it doesn't help much in
general to have this value around.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
It simplifies a bit the code to allocate the array when setting the
number of peers instead of lazily when receiving the first vector.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Set the number of peers and array allocation in a single place. Rename
to better reflect the function content.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Limit the maximum number of peers to MAXUINT16. This is more realistic
and better matches the limit of the doorbell register.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Use the latest qemu device modeling API, in particular, convert to
realize to fix the error handling; right now a botched device_add
ivhsmem command kills the VM.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Make a new function fifo_update_and_get() that can be reused by other
functions (in next commits).
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
If the fifo has 0 bytes, and the read is of size 1, the call to
fifo8_push_all() will copy off boundary data.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
ivshmem_read() only reads sizeof(long) from the input buffer. Accepting
more could lead to fifo8 abort() on 32bit systems if fifo is not empty.
A following patch will change the protocol to 64-bit little-endian
instead.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
If a chardev is allowed to be created outside of QMP, then it must be
also possible to free it. This is useful for ivshmem that creates
chardev anonymously and must be able to free them.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
ivshmem doesn't actually require kvm, so enable it when POSIX is
enabled. (it is required however when ioeventfd is enabled)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
X86 queue, 2015-10-23
# gpg: Signature made Fri 23 Oct 2015 16:30:58 BST using RSA key ID 984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
* remotes/ehabkost/tags/x86-pull-request:
vl: trivial: minor tweaks to a max-cpu error msg
target-i386: Use 1UL for bit shift
target-i386: Add DE to TCG_FEATURES
target-i386: Ensure always-1 bits on DR6 can't be cleared
target-i386: Check CR4[DE] for processing DR4/DR5
target-i386: Handle I/O breakpoints
target-i386: Optimize setting dr[0-3]
target-i386: Move hw_*breakpoint_* functions
target-i386: Ensure bit 10 on DR7 is never cleared
target-i386: Re-introduce optimal breakpoint removal
target-i386: Introduce cpu_x86_update_dr7
target-i386: Disable cache info passthrough by default
target-i386: allow any alignment for SMBASE
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Fix undefined behavior detected by clang runtime check:
qemu/target-i386/cpu.c:1494:15: runtime error:
left shift of 1 by 31 places cannot be represented in type 'int'
While doing that, add extra parenthesis for clarity.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Now DE is supported by TCG so it can be enabled in CPUID bits.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Bits 4-11 and 16-31 on DR6 are documented as always 1, so ensure they
can't be cleared by software.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Introduce helper_get_dr so that we don't have to put CR4[DE]
into the scarce HFLAGS resource. At the same time, rename
helper_movl_drN_T0 to helper_set_dr and set the helper flags.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
If the debug register is not enabled, we need
do nothing besides update the register.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Bit 10 of DR7 is documented as always set to 1, so ensure that's
always the case.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Before the last patch, we had an efficient loop that disabled
local breakpoints on task switch. Re-add that, but in a more
general way that handles changes to the global enable bits too.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This moves the last of the iteration over breakpoints into
the bpt_helper.c file. This also allows us to make several
breakpoint functions static.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
