Using pread/pwrite or io_submit has the advantage of eliminating the
bounce buffer, but drops the SCSI status.  This keeps the guest from
seeing unit attention codes, as well as statuses such as RESERVATION
CONFLICT.  Because we know scsi-block operates on an SBC device we can
still use the DMA helpers with SG_IO; just remember to patch the CDBs
if the transfer is split into multiple segments.

This means that scsi-block will always use the thread-pool unfortunately,
instead of respecting aio=native.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commonize all the checks for canceled requests and errors.  The next patch
will add another case to check for, in order to handle passthrough commands.

There is no semantic change here; the only nontrivial modification is in
scsi_write_do_fua, where cancellation has been checked earlier by both
callers.  Thus, the check is replaced with an assertion.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

scsi-block will be able to do FUA just by passing the request through
to the LUN (which is also more efficient); there is no need to emulate
it like we do for scsi-disk.

Add a new method to distinguish this.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

These are replacements for blk_aio_readv and blk_aio_writev that allow
customization of the data path.  They reuse the DMA helpers' DMAIOFunc
callback type, so that the same function can be used in either the
QEMUSGList or the bounce-buffered case.

This customization will be needed in the next patch to do zero-copy
SG_IO on scsi-block.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This will be the place to add DMAIOFuncs in the next patch.  There
are also a couple DeviceClass members that can be moved to the
abstract class's initialization function.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Since Xen will correctly handle accesses to unimplemented I/O ports (by
returning all 1's for reads and ignoring writes) there is no need for
QEMU to register backgroud I/O sections.

This patch therefore adds checks to xen_io_add/del so that sections with
memory-region ops pointing at 'unassigned_io_ops' are ignored.
Signed-off-by: NPaul Durrant <paul.durrant@citrix.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1462811480-16295-1-git-send-email-paul.durrant@citrix.com>
Acked-by: NAnthony PERARD <anthony.perard@citrix.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Over time, some differences between QEMU and Linux atomics are getting
smoothed.  In particular, Linux grew atomic_fetch_or (and in general
the differences regarding RMW operations were not described accurately)
and smp_load_acquire/smp_store_release.  Also, set_mb was renamed to
smp_store_mb().  Include these changes in the documentation.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Currently we emit a consume-load in atomic_rcu_read.  Because of
limitations in current compilers, this is overkill for non-Alpha hosts
and it is only useful to make Thread Sanitizer work.

This patch leaves the consume-load in atomic_rcu_read when
compiling with Thread Sanitizer enabled, and resorts to a
relaxed load + smp_read_barrier_depends otherwise.

On an RMO host architecture, such as aarch64, the performance
improvement of this change is easily measurable. For instance,
qht-bench performs an atomic_rcu_read on every lookup. Performance
before and after applying this patch:

$ tests/qht-bench -d 5 -n 1
Before: 9.78 MT/s
After:  10.96 MT/s
Signed-off-by: NEmilio G. Cota <cota@braap.org>
Message-Id: <1464120374-8950-4-git-send-email-cota@braap.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

For correctness, smp_read_barrier_depends() is only required to
emit a barrier on Alpha hosts. However, we are currently emitting
a consume fence unconditionally, and most compilers currently treat
consume and acquire fences as equivalent.

Fix it by keeping the consume fence if we're compiling with Thread
Sanitizer, since this might help prevent false warnings. Otherwise,
only emit the barrier for Alpha hosts. Note that we still guarantee
that smp_read_barrier_depends() is a compiler barrier.
Signed-off-by: NEmilio G. Cota <cota@braap.org>
Message-Id: <1464120374-8950-3-git-send-email-cota@braap.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Recently Linux did a mass conversion of its atomic_read/set calls
so that they at least are READ/WRITE_ONCE. See Linux's commit
62e8a325 ("atomic, arch: Audit atomic_{read,set}()"). It seems though
that their documentation hasn't been updated to reflect this.

The appended updates our documentation to reflect the change, which
means there is effectively no difference between our atomic_read/set
and the current Linux implementation.

While at it, fix the statement that a barrier is implied by
atomic_read/set, which is incorrect. Volatile/atomic semantics prevent
transformations pertaining the variable they apply to; this, however,
has no effect on surrounding statements like barriers do. For more
details on this, see:
  https://gcc.gnu.org/onlinedocs/gcc/Volatiles.htmlSigned-off-by: NEmilio G. Cota <cota@braap.org>
Message-Id: <1464120374-8950-2-git-send-email-cota@braap.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The usage of INT_MAX in this function confuses Coverity.  I think
the defect is bogus, however there is no protection against
getting more than sizeof(s->inpkt) bytes from the character device
backend.

Rewrite the function to only fill in as much data as needed from
buf into s->inpkt.  The plen variable is replaced by a simple
state machine and there is no need anymore to shift contents to
the beginning of s->inpkt.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

at least in the path via virtio-blk the maximum size is not
restricted.

Cc: qemu-stable@nongnu.org
Signed-off-by: NPeter Lieven <pl@kamp.de>
Message-Id: <1464080368-29584-1-git-send-email-pl@kamp.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

While doing MegaRAID SAS controller command frame lookup, routine
'megasas_lookup_frame' uses 'read_queue_head' value as an index
into 'frames[MEGASAS_MAX_FRAMES=2048]' array. Limit its value
within array bounds to avoid any OOB access.
Reported-by: NLi Qiang <liqiang6-s@360.cn>
Signed-off-by: NPrasad J Pandit <pjp@fedoraproject.org>
Message-Id: <1464179110-18593-1-git-send-email-ppandit@redhat.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When reading MegaRAID SAS controller configuration via MegaRAID
Firmware Interface(MFI) commands, routine megasas_dcmd_cfg_read
uses an uninitialised local data buffer. Initialise this buffer
to avoid stack information leakage.
Reported-by: NLi Qiang <liqiang6-s@360.cn>
Signed-off-by: NPrasad J Pandit <pjp@fedoraproject.org>
Message-Id: <1464178304-12831-1-git-send-email-ppandit@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When setting MegaRAID SAS controller properties via MegaRAID
Firmware Interface(MFI) commands, a user supplied size parameter
is used to set property value. Use appropriate size value to avoid
OOB access issues.
Reported-by: NLi Qiang <liqiang6-s@360.cn>
Signed-off-by: NPrasad J Pandit <pjp@fedoraproject.org>
Message-Id: <1464172291-2856-2-git-send-email-ppandit@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The LSI SAS1068 Host Bus Adapter emulator in Qemu, periodically
looks for requests and fetches them. A loop doing that in
mptsas_fetch_requests() could run infinitely if 's->state' was
not operational. Move check to avoid such a loop.
Reported-by: NLi Qiang <liqiang6-s@360.cn>
Signed-off-by: NPrasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
Message-Id: <1464077264-25473-1-git-send-email-ppandit@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Vmware Paravirtual SCSI emulation uses command descriptors to
process SCSI commands. These descriptors come with their ring
buffers. A guest could set the ring buffer size to an arbitrary
value leading to OOB access issue. Add check to avoid it.
Reported-by: NLi Qiang <liqiang6-s@360.cn>
Signed-off-by: NPrasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
Message-Id: <1464000485-27041-1-git-send-email-ppandit@redhat.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Reviewed-by: NDmitry Fleytman <dmitry@daynix.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The source has moved to the Linux kernel tree.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Similar to commit df7b97ff, we are mishandling clients that
give an unaligned NBD_CMD_TRIM request, and potentially
trimming bytes that occur before their request; which in turn
can cause potential unintended data loss (unlikely in
practice, since most clients are sane and issue aligned trim
requests).  However, while we fixed read and write by switching
to the byte interfaces of blk_, we don't yet have a byte
interface for discard.  On the other hand, trim is advisory, so
rounding the user's request to simply ignore the first and last
unaligned sectors (or the entire request, if it is sub-sector
in length) is just fine.

CC: qemu-stable@nongnu.org
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1464173965-9694-1-git-send-email-eblake@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

drop the qemu_char_get_next_serial and use chardev prop instead
Signed-off-by: Nxiaoqiang zhao <zxq_yx_007@163.com>
Message-Id: <1464158344-12266-6-git-send-email-zxq_yx_007@163.com>
Tested-by: NMichael Walle <michael@walle.cc>
Acked-by: NMichael Walle <michael@walle.cc>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

* Drop the old SysBus init function and use instance_init
* Call qemu_chr_add_handlers in the realize callback
* Use qdev chardev prop instead of qemu_char_get_next_serial
* Add lm32_uart_create function to create lm32 uart device
Signed-off-by: Nxiaoqiang zhao <zxq_yx_007@163.com>
Message-Id: <1464158344-12266-5-git-send-email-zxq_yx_007@163.com>
Tested-by: NMichael Walle <michael@walle.cc>
Acked-by: NMichael Walle <michael@walle.cc>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

* Drop the old SysBus init function
* Call qemu_chr_add_handlers in the realize callback
* Use qdev chardev prop instead of qemu_char_get_next_serial
Signed-off-by: Nxiaoqiang zhao <zxq_yx_007@163.com>
Message-Id: <1464158344-12266-4-git-send-email-zxq_yx_007@163.com>
Tested-by: NMichael Walle <michael@walle.cc>
Acked-by: NMichael Walle <michael@walle.cc>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

* Drop the old SysBus init function and use instance_init
* Call qemu_chr_add_handlers in the realize callback
* Use qdev chardev prop instead of qemu_char_get_next_serial
* Add etraxfs_ser_create function to create etraxfs serial device
Signed-off-by: Nxiaoqiang zhao <zxq_yx_007@163.com>
Message-Id: <1464158344-12266-3-git-send-email-zxq_yx_007@163.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

* Drop the old SysBus init function and use instance_init
* Call qemu_chr_add_handlers in the realize callback
Signed-off-by: Nxiaoqiang zhao <zxq_yx_007@163.com>
Message-Id: <1464158344-12266-2-git-send-email-zxq_yx_007@163.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This reverts commit 5b5660ad,
as it breaks the UEFI guest firmware (known as ArmVirtPkg or AAVMF)
running in the "virt" machine type of "qemu-system-aarch64":

Contrary to the commit message, (a->mr == b->mr) does *not* imply
that (a->romd_mode == b->romd_mode): the pflash device model calls
memory_region_rom_device_set_romd() -- for switching between the above
modes --, and that function changes mr->romd_mode but the current
AddressSpaceDispatch's FlatRange keeps the old value.  Therefore
region_del/region_add are not called on the KVM MemoryListener.
Reported-by: NDrew Jones <drjones@redhat.com>
Tested-by: NDrew Jones <drjones@redhat.com>
Analyzed-by: NLaszlo Ersek <lersek@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

linux-user pull request v2 for may 2016

# gpg: Signature made Fri 27 May 2016 12:51:10 BST using RSA key ID DE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg:                 aka "Riku Voipio <riku.voipio@linaro.org>"

* remotes/riku/tags/pull-linux-user-20160527: (38 commits)
  linux-user,target-ppc: fix use of MSR_LE
  linux-user/signal.c: Use s390 target space address instead of host space
  linux-user/signal.c: Use target address instead of host address for microblaze restorer
  linux-user/signal.c: Generate opcode data for restorer in setup_rt_frame
  linux-user: arm: Remove ARM_cpsr and similar #defines
  linux-user: Use direct syscalls for setuid(), etc
  linux-user: x86_64: Don't use 16-bit UIDs
  linux-user: Use g_try_malloc() in do_msgrcv()
  linux-user: Handle msgrcv error case correctly
  linux-user: Handle negative values in timespec conversion
  linux-user: Use safe_syscall for futex syscall
  linux-user: Use safe_syscall for pselect, select syscalls
  linux-user: Use safe_syscall for execve syscall
  linux-user: Use safe_syscall for wait system calls
  linux-user: Use safe_syscall for open and openat system calls
  linux-user: Use safe_syscall for read and write system calls
  linux-user: Provide safe_syscall for fixing races between signals and syscalls
  linux-user: Add debug code to exercise restarting system calls
  linux-user: Support for restarting system calls for Microblaze targets
  linux-user: Set r14 on exit from microblaze syscall
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

setup_frame()/setup_rt_frame()/restore_user_regs() are using
MSR_LE as the similar kernel functions do: as a bitmask.

But in QEMU, MSR_LE is a bit position, so change this
accordingly.

The previous code was doing nothing as MSR_LE is 0,
and "env->msr &= ~MSR_LE" doesn't change the value of msr.

And yes, a user process can change its endianness,
see linux kernel commit:

    fab5db9 [PATCH] powerpc: Implement support for setting little-endian mode via prctl

and prctl(2): PR_SET_ENDIAN, PR_GET_ENDIAN
Reviewed-by: NThomas Huth <huth@tuxfamily.org>
Signed-off-by: NLaurent Vivier <laurent@vivier.eu>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

The return address is in target space, so the restorer address needs to
be target space, too.
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NLaurent Vivier <laurent@vivier.eu>

The return address is in target space, so the restorer address needs to
be target space, too.
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NLaurent Vivier <laurent@vivier.eu>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

Original implementation uses do_rt_sigreturn directly in host space,
when a guest program is in unwind procedure in guest space, it will get
an incorrect restore address, then causes unwind failure.

Also cleanup the original incorrect indentation.
Reviewed-by: NLaurent Vivier <laurent@vivier.eu>
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

The #defines of ARM_cpsr and friends in linux-user/arm/target-syscall.h
can clash with versions in the system headers if building on an
ARM or AArch64 build (though this seems to be dependent on the version
of the system headers). The QEMU defines are not very useful (it's
not clear that they're intended for use with the target_pt_regs struct
rather than (say) the CPUARMState structure) and we only use them in one
function in elfload.c anyway. So just remove the #defines and directly
access regs->uregs[].
Reported-by: NChristopher Covington <cov@codeaurora.org>
Tested-by: NChristopher Covington <cov@codeaurora.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

On Linux the setuid(), setgid(), etc system calls have different semantics
from the libc functions. The libc functions follow POSIX and update the
credentials for all threads in the process; the system calls update only
the thread which makes the call. (This impedance mismatch is worked around
in libc by signalling all threads to tell them to do a syscall, in a
byzantine and fragile way; see http://ewontfix.com/17/.)

Since in linux-user we are trying to emulate the system call semantics,
we must implement all these syscalls to directly call the underlying
host syscall, rather than calling the host libc function.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

The 64-bit x86 syscall ABI uses 32-bit UIDs; only define
USE_UID16 for 32-bit x86.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

In do_msgrcv() we want to allocate a message buffer, whose size
is passed to us by the guest. That means we could legitimately
fail, so use g_try_malloc() and handle the error case, in the same
way that do_msgsnd() does.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

The msgrcv ABI is a bit odd -- the msgsz argument is a size_t, which is
unsigned, but it must fail EINVAL if the value is negative when cast
to a long. We were incorrectly passing the value through an
"unsigned int", which meant that if the guest was 32-bit longs and
the host was 64-bit longs an input of 0xffffffff (which should trigger
EINVAL) would simply be passed to the host msgrcv() as 0xffffffff,
where it does not cause the host kernel to reject it.
Follow the same approach as do_msgsnd() in using a ssize_t and
doing the check for negative values by hand, so we correctly fail
in this corner case.

This fixes the msgrcv03 Linux Test Project test case, which otherwise
hangs.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

In a struct timespec, both fields are signed longs. Converting
them from guest to host with code like
    host_ts->tv_sec = tswapal(target_ts->tv_sec);
mishandles negative values if the guest has 32-bit longs and
the host has 64-bit longs because tswapal()'s return type is
abi_ulong: the assignment will zero-extend into the host long
type rather than sign-extending it.

Make the conversion routines use __get_user() and __set_user()
instead: this automatically picks up the signedness of the
field type and does the correct kind of sign or zero extension.
It also handles the possibility that the target struct is not
sufficiently aligned for the host's requirements.

In particular, this fixes a hang when running the Linux Test Project
mq_timedsend01 and mq_timedreceive01 tests: one of the test cases
sets the timeout to -1 and expects an EINVAL failure, but we were
setting a very long timeout instead.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

Use the safe_syscall wrapper for the futex syscall.

In particular, this fixes hangs when using programs that link
against the Boehm garbage collector, including the Mono runtime.

(We don't change the sys_futex() call in the implementation of
the exit syscall, because as the FIXME comment there notes
that should be handled by disabling signals, since we can't
easily back out if the futex were to return ERESTARTSYS.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

Use the safe_syscall wrapper for the pselect and select syscalls.
Since not every architecture has the select syscall, we now
have to implement select in terms of pselect, which means doing
timeval<->timespec conversion.

(Five years on from the initial patch that added pselect support
to QEMU and a decade after pselect6 went into the kernel, it seems
safe to not try to support hosts with header files which don't
define __NR_pselect6.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

Wrap execve() in the safe-syscall handling. Although execve() is not
an interruptible syscall, it is a special case: if we allow a signal
to happen before we make the host$ syscall then we will 'lose' it,
because at the point of execve the process leaves QEMU's control.  So
we use the safe syscall wrapper to ensure that we either take the
signal as a guest signal, or else it does not happen before the
execve completes and makes it the other program's problem.

The practical upshot is that without this SIGTERM could fail to
terminate the process.
Signed-off-by: NTimothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-25-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: expanded commit message to explain in more detail why this is
 needed, and add comment about it too]
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>

Use safe_syscall for waitpid, waitid and wait4 syscalls. Note that this
change allows us to implement support for waitid's fifth (rusage) argument
in future; for the moment we ignore it as we have done up til now.
Signed-off-by: NTimothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-18-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: Adjust to new safe_syscall convention. Add fifth waitid syscall argument
 (which isn't present in the libc interface but is in the syscall ABI)]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>