Commit Graph
100 Commits
Author SHA1 Message Date
Markus Armbruster 7ea7d36e34 error: Fix error_printf() calls lacking newlines
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-08-08 09:01:27 +02:00
Markus Armbruster fea1c0999a vfio: Use error_report() instead of error_printf() for errors
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-4-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-08-08 09:01:18 +02:00
Markus Armbruster a47eb01098 checkpatch: Fix newline detection in error_setg() & friends
Commit 5d596c2's regexp assumes the error message string is the first
argument.  Correct for error_report(), wrong for all the others.
Relax the regexp to match newline in anywhere.  This might cause
additional false positives.

While there, update the list of error_reporting functions.

Cc: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-08-08 09:01:08 +02:00
Markus Armbruster df3c286c53 error: Strip trailing '\n' from error string arguments (again)
Commit 9af9e0f, 6daf194d, be62a2eb and 312fd5f got rid of a bunch, but
they keep coming back.  checkpatch.pl tries to flag them since commit
5d596c2, but it's not very good at it.  Offenders tracked down with
Coccinelle script scripts/coccinelle/err-bad-newline.cocci, an updated
version of the script from commit 312fd5f.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1470224274-31522-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-08-08 09:00:44 +02:00
Markus Armbruster e061fa3ca9 fw_cfg: Make base type "fw_cfg" abstract
Missed when commit 5712db6 split off "fw_cfg_io" and "fw_cfg_mem".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1469777353-9383-1-git-send-email-armbru@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-03 18:44:57 +02:00
Markus Armbruster 82751a32be cris: Fix broken header guard in hw/cris/boot.h
Found with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:20:46 +02:00
Markus Armbruster 175de52487 Clean up decorations and whitespace around header guards
Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:20:46 +02:00
Markus Armbruster 2a6a4076e1 Clean up ill-advised or unusual header guards
Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:20:46 +02:00
Markus Armbruster 965379b455 libdecnumber: Don't error out on decNumberLocal.h re-inclusion
decNumberLocal.h errors out when it's included with its header guard
defined.  This catches multiple inclusions.

Drop that.  Including it multiple times is safe, and the compiler can
do it efficiently.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 6031a51f1d libdecnumber: Don't fool around with guards to avoid #include
Some libdecnumber headers avoid including decNumber.h or decContext.h
again by checking their header guards.  Don't.  Including them
multiple times is safe, and the compiler can do it efficiently.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 121d07125b Clean up header guards that don't match their file name
Header guard symbols should match their file name to make guard
collisions less likely.  Offenders found with
scripts/clean-header-guards.pl -vn.

Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 85aad98a0e Drop Emacs local variables lists redundant with .dir-locals.el
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 20668fdebd spapr_pci: Include spapr.h instead of playing games with #error
include/hw/pci-host/spapr.h needs hw/ppc/spapr.h.  It checks whether
its header guard is defined, and errors out if it isn't.

Playing games with some other header's guard symbol is not a good
idea.  Just include the frackin' header already.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 14e54f8ecf tcg: Clean up tcg-target.h header guards
These use guard symbols like TCG_TARGET_$target.
scripts/clean-header-guards.pl doesn't like them because they don't
match their file name (they should, to make guard collisions less
likely).

Clean them up: use guard symbol $target_TCG_TARGET_H for
tcg/$target/tcg-target.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 1b3c4fdf30 linux-user: Fix broken header guard in syscall_defs.h
Found with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 59e96bcbf9 linux-user: Clean up hostdep.h header guards
These headers all use QEMU_HOSTDEP_H as header guard symbol.  Reuse of
the same guard symbol in multiple headers is okay as long as they
cannot be included together.

Since we can avoid guard symbol reuse easily, do so: use guard symbol
$target_HOSTDEP_H for linux-user/host/$target/hostdep.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 3500385697 linux-user: Clean up target_structs.h header guards
These headers all use TARGET_STRUCTS_H as header guard symbol.  Reuse
of the same guard symbol in multiple headers is okay as long as they
cannot be included together.

Since we can avoid guard symbol reuse easily, do so: use guard symbol
$target_TARGET_STRUCTS_H for linux-user/$target/target_structs.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 9c93ae13a4 linux-user: Clean up target_signal.h header guards
These headers all use TARGET_SIGNAL_H as header guard symbol.  Reuse
of the same guard symbol in multiple headers is okay as long as they
cannot be included together.

Since we can avoid guard symbol reuse easily, do so: use guard symbol
$target_TARGET_SIGNAL_H for linux-user/$target/target_signal.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 55c5063c61 linux-user: Clean up target_cpu.h header guards
These headers all use TARGET_CPU_H as header guard symbol.  Reuse of
the same guard symbol in multiple headers is okay as long as they
cannot be included together.

Since we can avoid guard symbol reuse easily, do so: use guard symbol
$target_TARGET_CPU_H for linux-user/$target/target_cpu.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 3622634bc6 linux-user: Clean up target_syscall.h header guards
Some of them use guard symbol TARGET_SYSCALL_H, but we also have
CRIS_SYSCALL_H, MICROBLAZE_SYSCALLS_H, TILEGX_SYSCALLS_H and
__UC32_SYSCALL_H__.  They all upset scripts/clean-header-guards.pl.

Reuse of the same guard symbol TARGET_SYSCALL_H in multiple headers is
okay as long as they cannot be included together.  The script can't
tell, so it warns.

The script dislikes the other guard symbols, too.  They don't match
their file name (they should, to make guard collisions less likely),
and __UC32_SYSCALL_H__ is a reserved identifier.

Clean them all up: use guard symbol $target_TARGET_SYSCALL_H for
linux-user/$target/target_sycall.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 07f5a25875 target-*: Clean up cpu.h header guards
Most of them use guard symbols like CPU_$target_H, but we also have
__MIPS_CPU_H__ and __TRICORE_CPU_H__.  They all upset
scripts/clean-header-guards.pl.

The script dislikes CPU_$target_H because they don't match their file
name (they should, to make guard collisions less likely).  The others
are reserved identifiers.

Clean them all up: use guard symbol $target_CPU_H for
target-$target/cpu.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 2dbc4ebc17 scripts: New clean-header-guards.pl
The conventional way to ensure a header can be included multiple times
is to bracket it like this:

    #ifndef HEADER_NAME_H
    #define HEADER_NAME_H
    ...
    #endif

where HEADER_NAME_H is a symbol unique to this header.

The endif may be optionally decorated like this:

    #endif /* HEADER_NAME_H */

Unconventional ways present in our code:

* Identifiers reserved for any use:
    #define _FILEOP_H

* Lowercase (bad idea for object-like macros):
    #define __linux_video_vga_h__

* Roundabout ways to say the same thing (and hide from grep):
    #if !defined(__PPC_MAC_H__)
    #endif /* !defined(__PPC_MAC_H__) */

* Redundant values:
    #define HW_ALPHA_H 1

* Funny redundant values:
    # define PXA_H                 "pxa.h"

* Decorations with bangs:

    #endif /* !QEMU_ARM_GIC_INTERNAL_H */

  The negation actually makes sense, but almost all our header guard
  #endif decorations don't negate.

* Useless decorations:

   #endif  /* audio.h */

Header guards are not the place to show off creativity.  This script
normalizes them to the conventional way, and cleans up whitespace
while there.  It warns when it renames guard symbols, and explains how
to find occurences of these symbols that may have to be updated
manually.

Another issue is use of the same guard symbol in multiple headers.
That's okay only for headers that cannot be used together, such as the
*-user/*/target_syscall.h.  This script can't tell, so it warns when
it sees a reuse.

The script also warns when preprocessing a header with its guard
symbol defined produces anything but whitespace.

The next commits will put the script to use.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster a9c94277f0 Use #include "..." for our own headers, <...> for others
Tracked down with an ugly, brittle and probably buggy Perl script.

Also move includes converted to <...> up so they get included before
ours where that's obviously okay.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Markus Armbruster 58eeb83cc7 log: Permit -dfilter 0..0xffffffffffffffff
Works fine since the previous commit fixed the underlying range data
type.  Of course it filters out nothing, but so does
0..1,2..0xffffffffffffffff, and we don't bother rejecting that either.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-04 16:49:33 +03:00
Markus Armbruster 6dd726a2bf range: Replace internal representation of Range
Range represents a range as follows.  Member @start is the inclusive
lower bound, member @end is the exclusive upper bound.  Zero @end is
special: if @start is also zero, the range is empty, else @end is to
be interpreted as 2^64.  No other empty ranges may occur.

The range [0,2^64-1] cannot be represented.  If you try to create it
with range_set_bounds1(), you get the empty range instead.  If you try
to create it with range_set_bounds() or range_extend(), assertions
fail.  Before range_set_bounds() existed, the open-coded creation
usually got you the empty range instead.  Open deathtrap.

Moreover, the code dealing with the janus-faced @end is too clever by
half.

Dumb this down to a more pedestrian representation: members @lob and
@upb are inclusive lower and upper bounds.  The empty range is encoded
as @lob = 1, @upb = 0.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-04 16:49:33 +03:00
Markus Armbruster a0efbf1660 range: Eliminate direct Range member access
Users of struct Range mess liberally with its members, which makes
refactoring hard.  Create a set of methods, and convert all users to
call them instead of accessing members.  The methods have carefully
worded contracts, and use assertions to check them.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-04 16:49:33 +03:00
Markus Armbruster 58e19e6e79 log: Clean up misuse of Range for -dfilter
Range encodes an integer interval [a,b] as { begin = a, end = b + 1 },
where a \in [0,2^64-1] and b \in [1,2^64].  Thus, zero end is to be
interpreted as 2^64.

The implementation of -dfilter (commit 3514552) uses Range
differently: it encodes [a,b] as { begin = a, end = b }.  The code
works, but it contradicts the specification of Range in range.h.

Switch to the specified representation.  Since it can't represent
[0,UINT64_MAX], we have to reject that now.  Add a test for it.

While we're rejecting anyway: observe that we reject -dfilter LOB..UPB
where LOB > UPB when UPB is zero, but happily create an empty Range
when it isn't.  Reject it then, too, and add a test for it.

While there, add a positive test for the problematic upper bound
UINT64_MAX.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-04 16:49:33 +03:00
Markus Armbruster 01c9742d9d pc: Eliminate PcPciInfo
PcPciInfo has two (ill-named) members: Range w32 is the PCI hole, and
w64 is the PCI64 hole.

Three users:

* I440FXState and MCHPCIState have a member PcPciInfo pci_info, but
  only pci_info.w32 is actually used.  This is confusing.  Replace by
  Range pci_hole.

* acpi_build() uses auto PcPciInfo pci_info to forward both PCI holes
  from acpi_get_pci_info() to build_dsdt().  Replace by two variables
  Range pci_hole, pci_hole64.  Rename acpi_get_pci_info() to
  acpi_get_pci_holes().

PcPciInfo is now unused; drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
2016-07-04 14:52:10 +03:00
Markus Armbruster 97a83ec3a9 piix: Set I440FXState member pci_info.w32 in one place
Range pci_info.w32 records the location of the PCI hole.

It's initialized to empty when QOM zeroes I440FXState.  That's a fine
value for a still unknown PCI hole.

i440fx_init() sets pci_info.w32.begin = below_4g_mem_size.  Changes
the PCI hole from empty to [below_4g_mem_size, UINT64_MAX].  That's a
bogus value.

i440fx_pcihost_initfn() sets pci_info.end = IO_APIC_DEFAULT_ADDRESS.
Since i440fx_init() ran already, this changes the PCI hole to
[below_4g_mem_size, IO_APIC_DEFAULT_ADDRESS-1].  That's the correct
value.

Setting the bounds of the PCI hole in two separate places is
confusing, and begs the question whether the bogus intermediate value
could be used by something, or what would happen if we somehow managed
to realize an i440FX device without having run the board init function
i440fx_init() first.

Avoid the confusion by setting the (constant) upper bound along with
the lower bound in i440fx_init().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
2016-07-04 14:50:59 +03:00
Markus Armbruster 297e8005f8 MAINTAINERS: Remove Blue Swirl leftovers
Blue hasn't been active in the QEMU project for a long time.  Drop his
last MAINTAINERS entries.

As per Paolo's recommendation, downgrade status of "BSD user" from
Maintained to Orphan since the FreeBSD guys effectively forked it, and
"SPARC target" from Maintained to Odd Fixes, since we still have the
overall TCG maintainer looking after it.

I'm leaving Checkpatch's status at Odd Fixes.  Calling it Maintained
wouldn't be wrong, but I'm not comfortable upgrading it while nobody
is willing to have his name nailed to the thing.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-30 13:34:49 +01:00
Markus Armbruster daa76aa416 log: Fix qemu_set_log_filename() error handling
When qemu_set_log_filename() detects an invalid file name, it reports
an error, closes the log file (if any), and starts logging to stderr
(unless daemonized or nothing is being logged).

This is wrong.  Asking for an invalid log file on the command line
should be fatal.  Asking for one in the monitor should fail without
messing up an existing logfile.

Fix by converting qemu_set_log_filename() to Error.  Pass it
&error_fatal, except for hmp_logfile report errors.

This also permits testing without a subprocess, so do that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1466011636-6112-4-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-20 16:39:08 +02:00
Markus Armbruster bd6fee9f12 log: Fix qemu_set_dfilter_ranges() error reporting
g_error() is not an acceptable way to report errors to the user:

    $ qemu-system-x86_64 -dfilter 1000+0

    ** (process:17187): ERROR **: Failed to parse range in: 1000+0
    Trace/breakpoint trap (core dumped)

g_assert() isn't, either:

    $ qemu-system-x86_64 -dfilter 1000x+64
    **
    ERROR:/work/armbru/qemu/util/log.c:180:qemu_set_dfilter_ranges: assertion failed: (e == range_op)
    Aborted (core dumped)

Convert qemu_set_dfilter_ranges() to Error.  Rework its deeply nested
control flow.  Touch up the error messages.  Call it with
&error_fatal.

This also permits testing without a subprocess, so do that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1466011636-6112-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-20 16:38:31 +02:00
Markus Armbruster 2ec62faea2 log: Plug memory leak on multiple -dfilter
-dfilter overwrites any previous filter.  The overwritten filter is
leaked.  Leaks since the beginning (commit 3514552, v2.6.0).  Free it
properly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1466011636-6112-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-20 16:38:14 +02:00
Markus Armbruster da002526ac vl: Error messages need to go to stderr, fix some
We print a few fatal error messages to stdout instead of stderr.
Reproducer:

    $ qemu-system-x86_64 -g 1024x768
    Option g not supported for this target
    $ qemu-system-x86_64 -g 1024x768 >/dev/null

Fix by printing them with error_report().  This also improves the messages.
The above one becomes

    qemu-system-x86_64: -g 1024x768: Option not supported for this target

Reported-by: Tobi {github.com/tobimensch}
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1464683498-28779-1-git-send-email-armbru@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
2016-06-20 16:36:29 +02:00
Markus Armbruster 679dd415bb spapr_pci: Drop cannot_instantiate_with_device_add_yet=false
It's become redundant since it was added in commit 09aa9a5 "spapr-pci:
enable adding PHB via -device".

Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2016-06-07 10:17:45 +10:00
Markus Armbruster b72fe9e690 migration/qjson: Drop gratuitous use of QOM
All the use of QOM buys us here is the ability to destroy the thing
with object_unref(OBJECT(vmdesc)).  Not worth the notational overhead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1462380558-2030-3-git-send-email-armbru@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-23 14:16:12 +05:30
Markus Armbruster 17b74b9867 migration: Move qjson.[ch] to migration/
Type QJSON lets you build JSON text.  Its interface mirrors (a subset
of) abstract JSON syntax.

QAPI output visitors also produce JSON text.  They assert their
preconditions and invariants, and therefore abort on incorrect use.

Contrastingly, QJSON does *not* detect incorrect use.  It happily
produces invalid JSON then.  This is what migration wants.

QJSON was designed for migration, and migration is its only user.
Move it to migration/ for proper coverage by MAINTAINERS, and to deter
accidental use outside migration.

[Pointed out by Eric: QJSON was added in commits 0457d07..b174257
 -- Amit]

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1462380558-2030-2-git-send-email-armbru@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-23 14:16:09 +05:30
Markus Armbruster 7337468385 tests/string-input-visitor: Add negative integer tests
Add two negative tests, one for int and one for int16List.  The latter
exposes a bug: nonsensical input results in an empty list instead of
an error.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461325048-14122-1-git-send-email-armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-22-git-send-email-eblake@redhat.com>
2016-05-12 09:47:55 +02:00
Markus Armbruster 51b9b478cc qom: -object error messages lost location, restore it
qemu_opts_foreach() runs its callback with the error location set to
the option's location.  Any errors the callback reports use the
option's location automatically.

Commit 90998d5 moved the actual error reporting from "inside"
qemu_opts_foreach() to after it.  Here's a typical hunk:

	 if (qemu_opts_foreach(qemu_find_opts("object"),
    -                          object_create,
    -                          object_create_initial, NULL)) {
    +                          user_creatable_add_opts_foreach,
    +                          object_create_initial, &err)) {
    +        error_report_err(err);
	     exit(1);
	 }

Before, object_create() reports from within qemu_opts_foreach(), using
the option's location.  Afterwards, we do it after
qemu_opts_foreach(), using whatever location happens to be current
there.  Commonly a "none" location.

This is because Error objects don't have location information.
Problematic.

Reproducer:

    $ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar
    qemu-system-x86_64: Property '.foo' not found

Note no location.  This commit restores it:

    qemu-system-x86_64: -object secret,id=foo,foo=bar: Property '.foo' not found

Note that the qemu_opts_foreach() bug just fixed could mask the bug
here: if the location it leaves dangling hasn't been clobbered, yet,
it's the correct one.

Reported-by: Eric Blake <eblake@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-4-git-send-email-armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Paragraph on Error added to commit message]
2016-04-28 08:19:36 +02:00
Markus Armbruster d9d3aaea0b replay: Fix dangling location bug in replay_configure()
replay_configure() pushes and pops a Location with automatic storage
duration.  Except it fails to pop when -icount parameter "rr" isn't
given.  cur_loc then points to unused stack space, and will most
likely get clobbered in short order.

Clobbered cur_loc can make loc_pop() and error_print_loc() crash or
report bogus locations.

Broken in commit 890ad55.

I didn't take the time to find a reproducer.

Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
2016-04-28 08:19:20 +02:00
Markus Armbruster 37f32349ea QemuOpts: Fix qemu_opts_foreach() dangling location regression
qemu_opts_foreach() pushes and pops a Location with automatic storage
duration.  Except it fails to pop when @func() returns non-zero.
cur_loc then points to unused stack space, and will most likely get
clobbered in short order.

Clobbered cur_loc can make loc_pop() and error_print_loc() crash or
report bogus locations.

Affects several qemu command line options as well as qemu-img,
qemu-io, qemu-nbd -object, and blkdebug's configuration file.

Broken in commit a4c7367, v2.4.0.

Reproducer:
    $ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar

main() reports "Property '.foo' not found" like this:

    if (qemu_opts_foreach(qemu_find_opts("object"),
                          user_creatable_add_opts_foreach,
                          object_create_delayed, &err)) {
        error_report_err(err);
        exit(1);
    }

cur_loc then points to where qemu_opts_foreach()'s Location used to
be, i.e. unused stack space.  With optimization, this Location doesn't
get clobbered for me, and also happens to be the correct location.
Without optimization, it does get clobbered in a way that makes
error_report_err() report no location.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-04-28 08:18:56 +02:00
Markus Armbruster 63d3145aad fw_cfg: Adopt /opt/RFQDN convention
FW CFG's primary user is QEMU, which uses it to expose configuration
information (in the widest sense) to Firmware.  Thus the name FW CFG.

FW CFG can also be used by others for their own purposes.  QEMU is
merely acting as transport then.  Names starting with opt/ are
reserved for such uses.  There is no provision, however, to guide safe
sharing among different such users.

Fix that, loosely following QMP precedence: names should start with
opt/RFQDN/, where RFQDN is a reverse fully qualified domain name you
control.

Based on a more ambitious patch from Michael Tsirkin.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Gabriel L. Somlo <somlo@cmu.edu>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Gabriel Somlo <somlo@cmu.edu>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2016-04-19 16:09:50 +02:00
Markus Armbruster 7136fc1da2 include/crypto: Include qapi-types.h or qemu/bswap.h instead of qemu-common.h
qemu-common.h should only be included by .c files.  Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."

Several include/crypto/ headers include qemu-common.h, but either need
just qapi-types.h from it, or qemu/bswap.h, or nothing at all.  Replace or
drop the include accordingly.  tests/test-crypto-secret.c now misses
qemu/module.h, so include it there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster bd36a618cc isa: Move DMA_transfer_handler from qemu-common.h to hw/isa/isa.h
DMA_transfer_handler is actually an ISA thing, and as such has no
business in qemu-common.h.  Move it to hw/isa/isa.h, and rename it to
IsaDmaTransferHandler.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster 8a98ecada3 Move ParallelIOArg from qemu-common.h to sysemu/char.h
ParallelIOArg is shared between just qemu-char.c and
hw/char/parallel.c, and as such has no business in qemu-common.h.
Move it to sysemu/char.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster e07e540aaa Move QEMU_ALIGN_*() from qemu-common.h to qemu/osdep.h
qemu-common.h should only be included by .c files.  Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."

One of the reasons for headers to include it is QEMU_ALIGN_UP() and
QEMU_ALIGN_DOWN().  Move them next to ROUND_UP() in qemu/osdep.h, to
facilitate removing these ill-advised includes later on.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster a813963216 Move HOST_LONG_BITS from qemu-common.h to qemu/osdep.h
qemu-common.h should only be included by .c files.  Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."

One of the reasons for headers to include it is HOST_LONG_BITS.  Move
that to its more natural home qemu/osdep.h, to facilitate removing
these ill-advised includes later on.

This also lets us use HOST_LONG_BITS in bswap.h instead of duplicating
its definition there to avoid cyclic inclusion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster a7c4d9c7ca hw/pci/pci.h: Don't include qemu-common.h
qemu-common.h should only be included by .c files.  Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."

hw/pci/pci.h includes qemu-common.h, but its users only need pcibus_t
and PCIHostDeviceAddress from it.  Move them to hw/pci/pci.h and drop
the ill-advised include.  Include hw/pci/pci.h where the moved stuff
is now missing.  Except we can't in target-i386/kvm_i386.h, because
that would break the i386-linux-user compile.  Add
PCIHostDeviceAddress to qemu/typedefs.h instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster 0137fdc094 include/hw/hw.h: Don't include qemu-common.h
qemu-common.h should only be included by .c files.  Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."

hw/hw.h includes qemu-common.h, but its users generally need only
hw_error() and qemu/module.h from it.  Move the former to hw/hw.h,
include the latter there, and drop the ill-advised include.
hw/misc/cbus.c now misses hw_error(), so include hw/hw.h there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster daf015ef5a include/qemu/iov.h: Don't include qemu-common.h
qemu-common.h should only be included by .c files.  Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."

qemu/iov.h includes qemu-common.h for QEMUIOVector stuff.  Move all
that to qemu/iov.h and drop the ill-advised include.  Include
qemu/iov.h where the QEMUIOVector stuff is now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster 6f061ea10f fw_cfg: Split fw_cfg_keys.h off fw_cfg.h
Much of fw_cfg.h's contents is #ifndef NO_QEMU_PROTOS.  This lets a
few places include it without satisfying the dependencies of the
suppressed code.  If you somehow include it with NO_QEMU_PROTOS, any
future includes are ignored.  Unnecessarily unclean.

Move the stuff not under NO_QEMU_PROTOS into its own header
fw_cfg_keys.h, and include it as appropriate.  Tidy up the moved code
to please checkpatch.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster c80f6e9caa Clean up includes some more
Manually drop redundant includes that scripts/clean-includes misses,
e.g. because they're hidden in generator programs, or they use the
wrong kind of delimiter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster 14b6d44d47 Use scripts/clean-includes to drop redundant qemu/typedefs.h
Re-run scripts/clean-includes to apply the previous commit's
corrections and updates.  Besides redundant qemu/typedefs.h, this only
finds a redundant config-host.h include in ui/egl-helpers.c.  No idea
how that escaped the previous runs.

Some manual whitespace trimming around dropped includes squashed in.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Markus Armbruster a335c6f204 contrib/ivshmem-server: Print "not for production" warning
The code is okay for illustrating how things work and for testing, but
its error handling make it unfit for production use.  Print a warning
to protect the innocent.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-41-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster 62a830b688 ivshmem: Require master to have ID zero
Migration with ivshmem needs to be carefully orchestrated to work.
Exactly one peer (the "master") migrates to the destination, all other
peers need to unplug (and disconnect), migrate, plug back (and
reconnect).  This is sort of documented in qemu-doc.

If peers connect on the destination before migration completes, the
shared memory can get messed up.  This isn't documented anywhere.  Fix
that in qemu-doc.

To avoid messing up register IVPosition on migration, the server must
assign the same ID on source and destination.  ivshmem-spec.txt leaves
ID assignment unspecified, however.

Amend ivshmem-spec.txt to require the first client to receive ID zero.
The example ivshmem-server complies: it always assigns the first
unused ID.

For a bit of additional safety, enforce ID zero for the master.  This
does nothing when we're not using a server, because the ID is zero for
all peers then.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-40-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster 13fd2cb689 ivshmem: Drop ivshmem property x-memdev
Use ivshmem-plain instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-39-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster ddc8528443 ivshmem: Clean up after the previous commit
Move code to more sensible places.  Use the opportunity to reorder and
document IVShmemState members.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-38-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster 5400c02b90 ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem
ivshmem can be configured with and without interrupt capability
(a.k.a. "doorbell").  The two configurations have largely disjoint
options, which makes for a confusing (and badly checked) user
interface.  Moreover, the device can't tell the guest whether its
doorbell is enabled.

Create two new device models ivshmem-plain and ivshmem-doorbell, and
deprecate the old one.

Changes from ivshmem:

* PCI revision is 1 instead of 0.  The new revision is fully backwards
  compatible for guests.  Guests may elect to require at least
  revision 1 to make sure they're not exposed to the funny "no shared
  memory, yet" state.

* Property "role" replaced by "master".  role=master becomes
  master=on, role=peer becomes master=off.  Default is off instead of
  auto.

* Property "use64" is gone.  The new devices always have 64 bit BARs.

Changes from ivshmem to ivshmem-plain:

* The Interrupt Pin register in PCI config space is zero (does not use
  an interrupt pin) instead of one (uses INTA).

* Property "x-memdev" is renamed to "memdev".

* Properties "shm" and "size" are gone.  Use property "memdev"
  instead.

* Property "msi" is gone.  The new device can't have MSI-X capability.
  It can't interrupt anyway.

* Properties "ioeventfd" and "vectors" are gone.  They're meaningless
  without interrupts anyway.

Changes from ivshmem to ivshmem-doorbell:

* Property "msi" is gone.  The new device always has MSI-X capability.

* Property "ioeventfd" defaults to on instead of off.

* Property "size" is gone.  The new device can only map all the shared
  memory received from the server.

Guests can easily find out whether the device is configured for
interrupts by checking for MSI-X capability.

Note: some code added in sub-optimal places to make the diff easier to
review.  The next commit will move it to more sensible places.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-37-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster 2a845da736 ivshmem: Replace int role_val by OnOffAuto master
In preparation of making it a qdev property.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-36-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster 55e8a15435 qdev: New DEFINE_PROP_ON_OFF_AUTO
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-35-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster 8baeb22bfc ivshmem: Inline check_shm_size() into its only caller
Improve the error messages while there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-34-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster c2d8019cd7 ivshmem: Simplify memory regions for BAR 2 (shared memory)
ivshmem_realize() puts the shared memory region in a container region.
Used to be necessary to permit delayed mapping of the shared memory.
However, we recently moved to synchronous mapping, in "ivshmem:
Receive shared memory synchronously in realize()" and the commit
following it.  The container is redundant since then.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-33-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster 5503e28504 ivshmem: Implement shm=... with a memory backend
ivshmem has its very own code to create and map shared memory.
Replace that with an implicitly created memory backend.  Reduces the
number of ways we create BAR 2 from three to two.

The memory-backend-file is currently available only with CONFIG_LINUX,
so this adds a second Linuxism to ivshmem (the other one is eventfd).
Should we ever need to make it portable to systems where
memory-backend-file can't be made to serve, we could create a
memory-backend-shmem that allocates memory with shm_open().

Bonus fix: shared memory files are now created with permissions 0655
instead of 0777.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-32-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster 08183c20b8 ivshmem: Tighten check of property "size"
If size_t is narrower than 64 bits, passing uint64_t ivshmem_size to
mmap() truncates.  Reject such sizes.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-31-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster ee276391a3 ivshmem: Simplify how we cope with short reads from server
Short reads from a UNIX domain sockets are exceedingly unlikely when
the other side always sends eight bytes and we always read eight
bytes.  We cope with them anyway.  However, the code doing that is
rather convoluted.  Dumb it down radically.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-30-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster ba5970a178 ivshmem: Drop the hackish test for UNIX domain chardev
The chardev must be capable of transmitting SCM_RIGHTS ancillary
messages.  We check it by comparing CharDriverState member filename to
"unix:".  That's almost as brittle as it is disgusting.

When the actual transmission all happened asynchronously, this check
was all we could do in realize(), and thus better than nothing.  But
now we receive at least one SCM_RIGHTS synchronously in realize(),
it's not worth its keep anymore.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-29-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster a3feb08639 ivshmem: Rely on server sending the ID right after the version
The protocol specification (ivshmem-spec.txt, formerly
ivshmem_device_spec.txt) has always required the ID message to be sent
right at the beginning, and ivshmem-server has always complied.  The
device, however, accepts it out of order.  If an interrupt setup
arrived before it, though, it would be misinterpreted as connect
notification.  Fix the latent bug by relying on the spec and
ivshmem-server's actual behavior.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-28-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster 1309cf448a ivshmem: Propagate errors through ivshmem_recv_setup()
This kills off the funny state described in the previous commit.

Simplify ivshmem_io_read() accordingly, and update documentation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-27-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster 3a55fc0f24 ivshmem: Receive shared memory synchronously in realize()
When configured for interrupts (property "chardev" given), we receive
the shared memory from an ivshmem server.  We do so asynchronously
after realize() completes, by setting up callbacks with
qemu_chr_add_handlers().

Keeping server I/O out of realize() that way avoids delays due to a
slow server.  This is probably relevant only for hot plug.

However, this funny "no shared memory, yet" state of the device also
causes a raft of issues that are hard or impossible to work around:

* The guest is exposed to this state: when we enter and leave it its
  shared memory contents is apruptly replaced, and device register
  IVPosition changes.

  This is a known issue.  We document that guests should not access
  the shared memory after device initialization until the IVPosition
  register becomes non-negative.

  For cold plug, the funny state is unlikely to be visible in
  practice, because we normally receive the shared memory long before
  the guest gets around to mess with the device.

  For hot plug, the timing is tighter, but the relative slowness of
  PCI device configuration has a good chance to hide the funny state.

  In either case, guests complying with the documented procedure are
  safe.

* Migration becomes racy.

  If migration completes before the shared memory setup completes on
  the source, shared memory contents is silently lost.  Fortunately,
  migration is rather unlikely to win this race.

  If the shared memory's ramblock arrives at the destination before
  shared memory setup completes, migration fails.

  There is no known way for a management application to wait for
  shared memory setup to complete.

  All you can do is retry failed migration.  You can improve your
  chances by leaving more time between running the destination QEMU
  and the migrate command.

  To mitigate silent memory loss, you need to ensure the server
  initializes shared memory exactly the same on source and
  destination.

  These issues are entirely undocumented so far.

I'd expect the server to be almost always fast enough to hide these
issues.  But then rare catastrophic races are in a way the worst kind.

This is way more trouble than I'm willing to take from any device.
Kill the funny state by receiving shared memory synchronously in
realize().  If your hot plug hangs, go kill your ivshmem server.

For easier review, this commit only makes the receive synchronous, it
doesn't add the necessary error propagation.  Without that, the funny
state persists.  The next commit will do that, and kill it off for
real.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-26-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster 9db51b4d64 ivshmem: Plug leaks on unplug, fix peer disconnect
close_peer_eventfds() cleans up three things: ioeventfd triggers if
they exist, eventfds, and the array to store them.

Commit 98609cd (v1.2.0) fixed it not to clean up ioeventfd triggers
when they don't exist (property ioeventfd=off, which is the default).
Unfortunately, the fix also made it skip cleanup of the eventfds and
the array then.  This is a memory and file descriptor leak on unplug.

Additionally, the reset of nb_eventfds is skipped.  Doesn't matter on
unplug.  On peer disconnect, however, this permanently wedges the
interrupt vectors used for that peer's ID.  The eventfds stay behind,
but aren't connected to a peer anymore.  When the ID gets recycled for
a new peer, the new peer's eventfds get assigned to vectors after the
old ones.  Commonly, the device's number of vectors matches the
server's, so the new ones get dropped with a "Too many eventfd
received" message.  Interrupts either don't work (common case) or go
to the wrong vector.

Fix by narrowing the conditional to just the ioeventfd trigger
cleanup.

While there, move the "invalid" peer check to the only caller where it
can actually happen, and tighten it to reject own ID.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-25-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster ca0b7566cc ivshmem: Disentangle ivshmem_read()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-24-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster cd9953f720 ivshmem: Simplify rejection of invalid peer ID from server
ivshmem_read() processes server messages.  These are 64 bit signed
integers.  -1 is shared memory setup, 16 bit unsigned is a peer ID,
anything else is invalid.

ivshmem_read() rejects invalid negative messages right away, silently.

Invalid positive messages get rejected only in resize_peers(), and
ivshmem_read() then prints the rather cryptic message "failed to
resize peers array".

Extend the first check to cover all invalid messages, make it report
"server sent invalid message", and drop the second check.

Now resize_peers() can't fail anymore; simplify.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-23-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster 3c27969b3e ivshmem: Assert interrupts are set up once
An interrupt is set up when the interrupt's file descriptor is
received.  Each message applies to the next interrupt vector.
Therefore, each vector cannot be set up more than once.

ivshmem_add_kvm_msi_virq() half-heartedly tries not to rely on this by
doing nothing then, but that's not going to recover from this error
should it become possible in the future.  watch_vector_notifier()
doesn't even try.

Simply assert what is the case, so we get alerted if we ever screw it
up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-22-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster 2d1d422d11 ivshmem: Leave INTx alone when using MSI-X
The ivshmem device can either use MSI-X or legacy INTx for interrupts.

With MSI-X enabled, peer interrupt events trigger an MSI as they
should.  But software can still raise INTx via interrupt status and
mask register in BAR 0.  This is explicitly prohibited by PCI Local
Bus Specification Revision 3.0, section 6.8.3.3:

    While enabled for MSI or MSI-X operation, a function is prohibited
    from using its INTx# pin (if implemented) to request service (MSI,
    MSI-X, and INTx# are mutually exclusive).

Fix the device model to leave INTx alone when using MSI-X.

Document that we claim to use INTx in config space even when we don't.
Unlike other devices, ivshmem does *not* use INTx when configured for
MSI-X and MSI-X isn't enabled by software.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-21-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster 082751e82b ivshmem: Clean up MSI-X conditions
There are three predicates related to MSI-X:

* ivshmem_has_feature(s, IVSHMEM_MSI) is true unless the non-MSI-X
  variant of the device is selected with msi=off.

* msix_present() is true when the device has the PCI capability MSI-X.
  It's initially false, and becomes true during successful realize of
  the MSI-X variant of the device.  Thus, it's the same as
  ivshmem_has_feature(s, IVSHMEM_MSI) for realized devices.

* msix_enabled() is true when msix_present() is true and guest software
  has enabled MSI-X.

Code that differs between the non-MSI-X and the MSI-X variant of the
device needs to be guarded by ivshmem_has_feature(s, IVSHMEM_MSI) or
by msix_present(), except the latter works only for realized devices.

Code that depends on whether MSI-X is in use needs to be guarded with
msix_enabled().

Code review led me to two minor messes:

* ivshmem_vector_notify() calls msix_notify() even when
  !msix_enabled(), unlike most other MSI-X-capable devices.  As far as
  I can tell, msix_notify() does nothing when !msix_enabled().  Add
  the guard anyway.

* Most callers of ivshmem_use_msix() guard it with
  ivshmem_has_feature(s, IVSHMEM_MSI).  Not necessary, because
  ivshmem_use_msix() does nothing when !msix_present().  That's
  ivshmem's only use of msix_present(), though.  Guard it
  consistently, and drop the now redundant msix_present() check.
  While there, rename ivshmem_use_msix() to ivshmem_msix_vector_use().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-20-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster 434ad76db5 ivshmem: Clean up register callbacks
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-19-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster d855e27565 ivshmem: Failed realize() can leave migration blocker behind
If pci_ivshmem_realize() fails after it created its migration blocker,
the blocker is left in place.  Fix that by creating it last.

Likewise, if it fails after it called fifo8_create(), it leaks fifo
memory.  Fix that the same way.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-18-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster 9cf70c5225 ivshmem: Fix harmless misuse of Error
We reuse errp after passing it host_memory_backend_get_memory().  If
both host_memory_backend_get_memory() and the reuse set an error, the
reuse will fail the assertion in error_setv().  Fortunately,
host_memory_backend_get_memory() can't fail.

Pass it &error_abort to make our assumption explicit, and to get the
assertion failure in the right place should it become invalid.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-17-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster 71c265816d ivshmem: Don't destroy the chardev on version mismatch
Yes, the chardev is commonly useless after we read a bad version from
it, but destroying it is inappropriate anyway: the user created it, so
the user should be able to hold on to it as long as he likes.  We
don't destroy it on other errors.  Screwed up in commit 5105b1d.

Stop reading instead.

Also note QEMU's behavior in ivshmem-spec.txt.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-16-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster c20fc0c3ee ivshmem: Drop ivshmem_event() stub
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-15-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster e64befe929 ivshmem: Clean up after commit 9940c32
IVShmemState member eventfd_chr is useless since commit 9940c32.  Drop
it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-14-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster a4fa93bf20 ivshmem: Compile debug prints unconditionally to prevent bit-rot
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-13-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster 97553976dd ivshmem: Add missing newlines to debug printfs
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-12-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster fdee2025dd ivshmem: Rewrite specification document
This started as an attempt to update ivshmem_device_spec.txt for
clarity, accuracy and completeness while working on its code, and
quickly became a full rewrite.  Since the diff would be useless
anyway, I'm using the opportunity to rename the file to
ivshmem-spec.txt.

I tried hard to ensure the new text contradicts neither the old text
nor the code.  If the new text contradicts the old text but not the
code, it's probably a bug in the old text.  If the new text
contradicts both, its probably a bug in the new text.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-11-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster 41b65e5eda ivshmem-test: Improve test cases /ivshmem/server-*
Document missing test: behavior with MSI-X present but not enabled.

For MSI-X, we test and clear the interrupt pending bit before testing
the interrupt.  For INTx, we only clear.  Change to test and clear for
consistency.

Test MSI-X vector 1 in addition to vector 0.

Improve comments.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-10-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster 14c5d49ab3 ivshmem-test: Clean up wait for devices to become operational
test_ivshmem_server() waits until the first byte in BAR 2 contains the
0x42 we put into shared memory.  Works because the byte reads zero
until the device maps the shared memory gotten from the server.

Check the IVPosition register instead: it's initially -1, and becomes
non-negative right when the device maps the share memory, so no
change, just cleaner, because it's what guest software is supposed to
do.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-9-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster 4958fe5d3c ivshmem-test: Improve test case /ivshmem/single
Test state of registers after reset.

Test reading Interrupt Status clears it.

Test (invalid) read of Doorbell.

Add more comments.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-8-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster 998261726a tests/libqos/pci-pc: Fix qpci_pc_iomap() to map BARs aligned
qpci_pc_iomap() maps BARs one after the other, without padding.  This
is wrong.  PCI Local Bus Specification Revision 3.0, 6.2.5.1. Address
Maps: "all address spaces used are a power of two in size and are
naturally aligned".  That's because the size of a BAR is given by the
number of address bits the device decodes, and the BAR needs to be
mapped at a multiple of that size to ensure the address decoding
works.

Fix qpci_pc_iomap() accordingly.  This takes care of a FIXME in
ivshmem-test.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-7-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster 330b58368c event_notifier: Make event_notifier_init_fd() #ifdef CONFIG_EVENTFD
Event notifiers are designed for eventfd(2).  They can fall back to
pipes, but according to Paolo, event_notifier_init_fd() really
requires the real thing, and should therefore be under #ifdef
CONFIG_EVENTFD.  Do that.

Its only user is ivshmem, which is currently CONFIG_POSIX.  Narrow it
to CONFIG_EVENTFD.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-6-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster ad4929384b qemu-doc: Fix ivshmem huge page example
Option parameter "share" is missing.  Without it, you get a *private*
mmap(), which defeats ivshmem's purpose pretty thoroughly ;)

While there, switch to the conventional mountpoint of hugetlbfs
/dev/hugepages.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-5-git-send-email-armbru@redhat.com>
2016-03-18 17:34:55 +01:00
Markus Armbruster 3625c739ea ivshmem-server: Don't overload POSIX shmem and file name
Option -m NAME is interpreted as directory name if we can statfs() it
and its on hugetlbfs.  Else it's interpreted as POSIX shared memory
object name.  This is nuts.

Always interpret -m as directory.  Create new -M for POSIX shared
memory.  Last of -m or -M wins.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-4-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-18 17:34:40 +01:00
Markus Armbruster e3ad72965a ivshmem-server: Fix and clean up command line help
Burying error messages in ~20 lines of usage help is bad form.  Print
a single line pointing to -h instead.

Print -h help to stdout rather than stderr.  Fix default of -p.  Clean
up the help text a bit.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-3-git-send-email-armbru@redhat.com>
2016-03-18 17:34:40 +01:00
Markus Armbruster 3be5cc2324 target-ppc: Document TOCTTOU in hugepage support
The code to find the minimum page size is is vulnerable to TOCTTOU.
Added in commit 2d103aa "target-ppc: fix hugepage support when using
memory-backend-file" (v2.4.0).  Since I can't fix it myself right now,
add a FIXME comment.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-2-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-18 17:34:21 +01:00
Markus Armbruster e1fb647199 exec: Fix memory allocation when memory path isn't on hugetlbfs
gethugepagesize() works reliably only when its argument is on
hugetlbfs.  When it's not, it returns the filesystem's "optimal
transfer block size", which may or may not be the actual page size
you'll get when you mmap().

If the value is too small or not a power of two, we fail
qemu_ram_mmap()'s assertions.  These were added in commit 794e8f3
(v2.5.0).  The bug's impact before that is currently unknown.  Seems
fairly unlikely at least when the normal page size is 4KiB.

Else, if the value is too large, we align more strictly than
necessary.

gethugepagesize() goes back to commit c902760 (v0.13).  That commit
clearly intended gethugepagesize() to be used on hugetlbfs only.  Not
only was it named accordingly, it also printed a warning when used on
anything else.  However, the commit neglected to spell out the
restriction in user documentation of -mem-path.

Commit bfc2a1a (v2.5.0) dropped the warning as bogus "because QEMU
functions perfectly well with the path on a regular tmpfs filesystem".
It sure does when you're sufficiently lucky.  In my testing, I was
lucky, too.

Fix by switching to qemu_fd_getpagesize().  Rename the variable
holding its result from hpagesize to page_size.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1457378754-21649-3-git-send-email-armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-15 18:23:33 +01:00
Markus Armbruster fd97fd4408 exec: Fix memory allocation when memory path names new file
Commit 8d31d6b extended file_ram_alloc() to accept file names in
addition to directory names.  Even though it passes O_CREAT to open(),
it actually works only for existing files.  Reproducer adapted from
the commit's qemu-doc.texi update:

    $ qemu-system-x86_64 -object memory-backend-file,size=2M,mem-path=/dev/hugepages/my-shmem-file,id=mb1
    qemu-system-x86_64: -object memory-backend-file,size=2M,mem-path=/dev/hugepages/my-shmem-file,id=mb1: failed to get page size of file /dev/hugepages/my-shmem-file: No such file or directory

This is because we first get the page size for @path, then open the
actual file.  Unwise even before the flawed commit, because the
directory could change in between, invalidating the page size.
Unlikely to bite in practice.

Rearrange the code to create the file (if necessary) before getting
its page size.  Carefully avoid TOCTTOU conditions with a method
suggested by Paolo Bonzini.

While there, replace "hugepages" by "guest RAM" in error messages,
because host memory backends can be used for purposes other than huge
pages, e.g. /dev/shm/ shared memory.  Help text of -mem-path agrees.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1457378754-21649-2-git-send-email-armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-15 18:23:33 +01:00
Markus Armbruster 7580f231cf vl: Clean up machine selection in main().
We set machine_class to the default first, and update it to the real
one later.  Any use of machine_class in between is almost certainly
wrong (there are no such uses right now).  Set it once and for all
instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
2016-02-19 13:46:44 +01:00
Markus Armbruster 59d9e84cc9 qapi-visit: Unify struct and union visit
gen_visit_union() is now just like gen_visit_struct().  Rename
it to gen_visit_object(), use it for structs, and drop
gen_visit_struct().  Output is unchanged.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1453902888-20457-4-git-send-email-armbru@redhat.com>
[split out variant handling, rebase to earlier changes]
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-8-git-send-email-eblake@redhat.com>
2016-02-19 11:08:57 +01:00
Markus Armbruster d7445b57f4 qapi-visit: Simplify how we visit common union members
For a simple union SU, gen_visit_union() generates a visit of its
single tag member, like this:

    visit_type_SUKind(v, "type", &(*obj)->type, &err);

For a flat union FU with base B, it generates a visit of its base
fields:

    visit_type_B_fields(v, (B **)obj, &err);

Instead, we can simply visit the common members using the same fields
visit function we use for structs, generated with
gen_visit_struct_fields().  This function visits the base if any, then
the local members.

For a simple union SU, visit_type_SU_fields() contains exactly the old
tag member visit, because there is no base, and the tag member is the
only member.  For instance, the code generated for qapi-schema.json's
KeyValue changes like this:

    +static void visit_type_KeyValue_fields(Visitor *v, KeyValue **obj, Error **errp)
    +{
    +    Error *err = NULL;
    +
    +    visit_type_KeyValueKind(v, "type", &(*obj)->type, &err);
    +    if (err) {
    +        goto out;
    +    }
    +
    +out:
    +    error_propagate(errp, err);
    +}
    +
     void visit_type_KeyValue(Visitor *v, const char *name, KeyValue **obj, Error **errp)
     {
         Error *err = NULL;
    @@ -4863,7 +4911,7 @@ void visit_type_KeyValue(Visitor *v, con
         if (!*obj) {
             goto out_obj;
         }
    -    visit_type_KeyValueKind(v, "type", &(*obj)->type, &err);
    +    visit_type_KeyValue_fields(v, obj, &err);
         if (err) {
             goto out_obj;
         }

For a flat union FU, visit_type_FU_fields() contains exactly the old
base fields visit, because there is a base, but no members.  For
instance, the code generated for qapi-schema.json's CpuInfo changes
like this:

     static void visit_type_CpuInfoBase_fields(Visitor *v, CpuInfoBase **obj, Error **errp);

    +static void visit_type_CpuInfo_fields(Visitor *v, CpuInfo **obj, Error **errp)
    +{
    +    Error *err = NULL;
    +
    +    visit_type_CpuInfoBase_fields(v, (CpuInfoBase **)obj, &err);
    +    if (err) {
    +        goto out;
    +    }
    +
    +out:
    +    error_propagate(errp, err);
    +}
    +
     static void visit_type_CpuInfoX86_fields(Visitor *v, CpuInfoX86 **obj, Error **errp)
...
    @@ -3485,7 +3509,7 @@ void visit_type_CpuInfo(Visitor *v, cons
         if (!*obj) {
             goto out_obj;
         }
    -    visit_type_CpuInfoBase_fields(v, (CpuInfoBase **)obj, &err);
    +    visit_type_CpuInfo_fields(v, obj, &err);
         if (err) {
             goto out_obj;
         }

As you see, the generated code grows a bit, but in practice, it's lost
in the noise: qapi-schema.json's qapi-visit.c gains roughly 1%.

This simplification became possible with commit 441cbac "qapi-visit:
Convert to QAPISchemaVisitor, fixing bugs".  It's a step towards
unifying gen_struct() and gen_union().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1453902888-20457-2-git-send-email-armbru@redhat.com>
[improve commit message examples]
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-6-git-send-email-eblake@redhat.com>
[Commit message tweaked]
2016-02-19 11:08:57 +01:00
Markus Armbruster d76a3bf5c4 HACKING: Add a section on error handling and reporting
Inspired by an RFC PATCH from Lluís Vilanova.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1454522628-28294-3-git-send-email-armbru@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
2016-02-09 13:19:49 +01:00