diff options
| author | Eduardo Habkost <ehabkost@redhat.com> | 2015-11-12 15:29:54 -0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2015-11-25 13:42:37 +0200 |
| commit | fac862ffa605f6fa41f52033b27346d26a96bea5 (patch) | |
| tree | 3621d13c24bc340449eb2ab7f071961afbb766b3 | |
| parent | 541abd10a01da56c5f16582cd32d67114ec22a5c (diff) | |
osdep: Change default value of qemu_hw_version() to "2.5+"
There are two issues with qemu_hw_version() today:
1) If a machine has hw_version set, the value returned by it is
not very useful, because it is not the actual QEMU version.
2) If a machine does't set hw_version, the return value of
qemu_hw_version() is broken, because it will change when
upgrading QEMU.
For those reasons, using qemu_hw_version() is strongly
discouraged, and should be used only in code that used
QEMU_VERSION in the past and needs to keep compatibility.
To fix (2), instead of making every machine broken by default
unless they set hw_version, make qemu_hw_version() simply return
"2.5+" if qemu_set_hw_version() is not called.
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | include/hw/boards.h | 5 | ||||
| -rw-r--r-- | include/qemu/osdep.h | 4 | ||||
| -rw-r--r-- | util/osdep.c | 9 |
3 files changed, 17 insertions, 1 deletions
diff --git a/include/hw/boards.h b/include/hw/boards.h index 24eb6f0e77..5da4fb00ee 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -51,6 +51,11 @@ bool machine_mem_merge(MachineState *machine); * used to provide @cpu_index to socket number mapping, allowing * a machine to group CPU threads belonging to the same socket/package * Returns: socket number given cpu_index belongs to. + * @hw_version: + * Value of QEMU_VERSION when the machine was added to QEMU. + * Set only by old machines because they need to keep + * compatibility on code that exposed QEMU_VERSION to guests in + * the past (and now use qemu_hw_version()). */ struct MachineClass { /*< private >*/ diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 861d84b4e4..84e84ac700 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -256,6 +256,10 @@ static inline void qemu_timersub(const struct timeval *val1, void qemu_set_cloexec(int fd); +/* QEMU "hardware version" setting. Used to replace code that exposed + * QEMU_VERSION to guests in the past and need to keep compatibilty. + * Do not use qemu_hw_version() in new code. + */ void qemu_set_hw_version(const char *); const char *qemu_hw_version(void); diff --git a/util/osdep.c b/util/osdep.c index 80c6bfeeb2..534b51147c 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -52,7 +52,14 @@ extern int madvise(caddr_t, size_t, int); static bool fips_enabled = false; -static const char *hw_version = QEMU_VERSION; +/* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default + * instead of QEMU_VERSION, so setting hw_version on MachineClass + * is no longer mandatory. + * + * Do NOT change this string, or it will break compatibility on all + * machine classes that don't set hw_version. + */ +static const char *hw_version = "2.5+"; int socket_set_cork(int fd, int v) { |