In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

hw/qdev-core.h includes sysemu/sysemu.h since recent commit e965ffa7
"qdev: add qdev_add_vm_change_state_handler()".  This is a bad idea:
hw/qdev-core.h is widely included.

Move the declaration of qdev_add_vm_change_state_handler() to
sysemu/sysemu.h, and drop the problematic include from hw/qdev-core.h.

Touching sysemu/sysemu.h now recompiles some 1800 objects.
qemu/uuid.h also drops from 5400 to 1800.  A few more headers show
smaller improvement: qemu/notify.h drops from 5600 to 5200,
qemu/timer.h from 5600 to 4500, and qapi/qapi-types-run-state.h from
5500 to 5000.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NAlistair Francis <alistair.francis@wdc.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190812052359.30071-28-armbru@redhat.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>

GCC 8 introduced the -Wstringop-overflow, which detect buffer overflow
by string-modifying functions declared in <string.h>, such strncpy(),
used in global_state_store_running().

GCC indeed found an incorrect use of strlen(), because this array
is loaded by VMSTATE_BUFFER(runstate, GlobalState) then parsed
using qapi_enum_parse which does not get the buffer length.

Use strnlen() which returns sizeof(s->runstate) if the array is not
NUL-terminated, assert the size is within range, and enforce the array
to be NUL-terminated to avoid an overflow in qapi_enum_parse().

This fixes:

    CC      migration/global_state.o
  qemu/migration/global_state.c: In function 'global_state_pre_save':
  qemu/migration/global_state.c:109:15: error: 'strlen' argument 1 declared attribute 'nonstring' [-Werror=stringop-overflow=]
       s->size = strlen((char *)s->runstate) + 1;
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  qemu/migration/global_state.c:24:13: note: argument 'runstate' declared here
       uint8_t runstate[100] QEMU_NONSTRING;
               ^~~~~~~~
  cc1: all warnings being treated as errors
  make: *** [qemu/rules.mak:69: migration/global_state.o] Error 1
Suggested-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

GCC 8 added a -Wstringop-truncation warning:

  The -Wstringop-truncation warning added in GCC 8.0 via r254630 for
  bug 81117 is specifically intended to highlight likely unintended
  uses of the strncpy function that truncate the terminating NUL
  character from the source string.

This new warning leads to compilation failures:

    CC      migration/global_state.o
  qemu/migration/global_state.c: In function 'global_state_store_running':
  qemu/migration/global_state.c:45:5: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
       strncpy((char *)global_state.runstate, state, sizeof(global_state.runstate));
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  make: *** [qemu/rules.mak:69: migration/global_state.o] Error 1

Adding an assert is enough to silence GCC.

(alternatively, we could hard-code "running")
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
[PMD: More verbose commit message]
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Modify the pre_save method on VMStateDescription to return an int
rather than void so that it potentially can fail.

Changed zillions of devices to make them return 0; the only
case I've made it return non-0 is hw/intc/s390_flic_kvm.c that already
had an error_report/return case.

Note: If you add an error exit in your pre_save you must emit
an error_report to say why.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170925112917.21340-2-dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

A future patch will generate enums with "holes".  NULL-termination
will cease to work then.

To prepare for that, store the length in the FOO_lookup by wrapping it
in a struct and adding a member for the length.

The sentinel will be dropped next.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com>
[Basically redone]
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com>
[Rebased]

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-14-git-send-email-armbru@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

The next commit will put it to use.  May look pointless now, but we're
going to change the FOO_lookup's type, and then it'll help.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-13-git-send-email-armbru@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

The lookup tables have a sentinel, no need to make callers pass their
size.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-3-git-send-email-armbru@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[Rebased, commit message corrected]

Put it into MigrationState then we can use the properties to specify
whether to enable storing global state.

Removing global_state_set_optional() since now we can use HW_COMPAT_2_3
for x86/power, and AccelClass.global_props for Xen.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-6-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>

It don't belong anywhere else, just the global state where everybody
can stick other things.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>