Commit fac862ff authored by Eduardo Habkost's avatar Eduardo Habkost Committed by Michael S. Tsirkin
Browse files

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: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 541abd10

include/hw/boards.h

+5 −0
Original line number Diff line number Diff line
@@ -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 >*/

include/qemu/osdep.h

+4 −0
Original line number Diff line number Diff line
@@ -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);

util/osdep.c

+8 −1
Original line number Diff line number Diff line
@@ -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)

{