| Message ID | 9fe40ce91ada6dfdade83f32940f420e8b373db2.1504696921.git.mprivozn@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | watchdog: Allow setting action on the fly | expand |
On 09/06/2017 06:24 AM, Michal Privoznik wrote: > We already have enum that enumerates all the action that a s/action/actions/ > watchdog can take when hitting its timeout: WatchdogAction. > Use that instead of inventing our own. > > Signed-off-by: Michal Privoznik <mprivozn@redhat.com> > --- > @@ -77,27 +77,16 @@ int select_watchdog(const char *p) > > int select_watchdog_action(const char *p) > { > - if (strcasecmp(p, "reset") == 0) > - watchdog_action = WDT_RESET; The old code was case-insensitive, > + action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL); the new code is not. Do we care? (I don't, but we could be breaking someone's control flow). Should qapi_enum_parse be taught to be case-insensitive? Or perhaps we answer related questions first: Do we have any QAPI enums that have values differing only in case? Do we prevent such QAPI definitions, to give us the potential of making the parsing insensitive?
Eric Blake <eblake@redhat.com> writes: > On 09/06/2017 06:24 AM, Michal Privoznik wrote: >> We already have enum that enumerates all the action that a > > s/action/actions/ > >> watchdog can take when hitting its timeout: WatchdogAction. >> Use that instead of inventing our own. >> >> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> >> --- > >> @@ -77,27 +77,16 @@ int select_watchdog(const char *p) >> >> int select_watchdog_action(const char *p) >> { >> - if (strcasecmp(p, "reset") == 0) >> - watchdog_action = WDT_RESET; > > The old code was case-insensitive, > >> + action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL); > > the new code is not. Do we care? (I don't, but we could be breaking > someone's control flow). Should qapi_enum_parse be taught to be > case-insensitive? Or perhaps we answer related questions first: Do we > have any QAPI enums that have values differing only in case? Do we > prevent such QAPI definitions, to give us the potential of making the > parsing insensitive? Case-sensitive everywhere is fine. Case-insensitive everywhere also fine, just not my personal preference. What's not fine is "guess whether this part of the interface is case-sensitive or not". QMP is case-sensitive. Let's keep it that way. The -watchdog-action option has a case-insensitive argument. The obvious way to remain misfeature-^Wbackwards compatible is converting the argument to lower case before handing it off to qapi_enum_parse. I doubt it matters, but just doing it is less work than debating how far exactly we want to bend over backwards. g_ascii_strdown() should do. It only converts ASCII characters, but anything else is going to fail in qapi_enum_parse() anyway.
On 09/06/2017 07:25 PM, Markus Armbruster wrote: > Eric Blake <eblake@redhat.com> writes: > >> On 09/06/2017 06:24 AM, Michal Privoznik wrote: >>> We already have enum that enumerates all the action that a >> >> s/action/actions/ >> >>> watchdog can take when hitting its timeout: WatchdogAction. >>> Use that instead of inventing our own. >>> >>> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> >>> --- >> >>> @@ -77,27 +77,16 @@ int select_watchdog(const char *p) >>> >>> int select_watchdog_action(const char *p) >>> { >>> - if (strcasecmp(p, "reset") == 0) >>> - watchdog_action = WDT_RESET; >> >> The old code was case-insensitive, >> >>> + action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL); >> >> the new code is not. Do we care? (I don't, but we could be breaking >> someone's control flow). Should qapi_enum_parse be taught to be >> case-insensitive? Or perhaps we answer related questions first: Do we >> have any QAPI enums that have values differing only in case? Do we >> prevent such QAPI definitions, to give us the potential of making the >> parsing insensitive? > > Case-sensitive everywhere is fine. Case-insensitive everywhere also > fine, just not my personal preference. What's not fine is "guess > whether this part of the interface is case-sensitive or not". > > QMP is case-sensitive. Let's keep it that way. > > The -watchdog-action option has a case-insensitive argument. The > obvious way to remain misfeature-^Wbackwards compatible is converting > the argument to lower case before handing it off to qapi_enum_parse. I > doubt it matters, but just doing it is less work than debating how far > exactly we want to bend over backwards. > > g_ascii_strdown() should do. It only converts ASCII characters, but > anything else is going to fail in qapi_enum_parse() anyway. > On the other hand, the documentation enumerates the accepted values in lowercase. So one can argue that upper- or mixed-case is just a misuse of a bug in the code. But getting the code in is more important to me so I'll do the strdown() conversion and sent yet another version. Michal
Michal Privoznik <mprivozn@redhat.com> writes: > On 09/06/2017 07:25 PM, Markus Armbruster wrote: >> Eric Blake <eblake@redhat.com> writes: >> >>> On 09/06/2017 06:24 AM, Michal Privoznik wrote: >>>> We already have enum that enumerates all the action that a >>> >>> s/action/actions/ >>> >>>> watchdog can take when hitting its timeout: WatchdogAction. >>>> Use that instead of inventing our own. >>>> >>>> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> >>>> --- >>> >>>> @@ -77,27 +77,16 @@ int select_watchdog(const char *p) >>>> >>>> int select_watchdog_action(const char *p) >>>> { >>>> - if (strcasecmp(p, "reset") == 0) >>>> - watchdog_action = WDT_RESET; >>> >>> The old code was case-insensitive, >>> >>>> + action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL); >>> >>> the new code is not. Do we care? (I don't, but we could be breaking >>> someone's control flow). Should qapi_enum_parse be taught to be >>> case-insensitive? Or perhaps we answer related questions first: Do we >>> have any QAPI enums that have values differing only in case? Do we >>> prevent such QAPI definitions, to give us the potential of making the >>> parsing insensitive? >> >> Case-sensitive everywhere is fine. Case-insensitive everywhere also >> fine, just not my personal preference. What's not fine is "guess >> whether this part of the interface is case-sensitive or not". >> >> QMP is case-sensitive. Let's keep it that way. >> >> The -watchdog-action option has a case-insensitive argument. The >> obvious way to remain misfeature-^Wbackwards compatible is converting >> the argument to lower case before handing it off to qapi_enum_parse. I >> doubt it matters, but just doing it is less work than debating how far >> exactly we want to bend over backwards. >> >> g_ascii_strdown() should do. It only converts ASCII characters, but >> anything else is going to fail in qapi_enum_parse() anyway. >> > > On the other hand, the documentation enumerates the accepted values in > lowercase. So one can argue that upper- or mixed-case is just a misuse > of a bug in the code. I quite agree, but... > But getting the code in is more important to me so > I'll do the strdown() conversion and sent yet another version. ... like you, I have to pick my battles. A respin adding the stupid case conversion seems safer for both of us than risking a debate on how far we need to go for backward compatibility.
diff --git a/hw/watchdog/watchdog.c b/hw/watchdog/watchdog.c index 358d79804d..547a49a1e4 100644 --- a/hw/watchdog/watchdog.c +++ b/hw/watchdog/watchdog.c @@ -30,7 +30,7 @@ #include "hw/nmi.h" #include "qemu/help_option.h" -static int watchdog_action = WDT_RESET; +static WatchdogAction watchdog_action = WATCHDOG_ACTION_RESET; static QLIST_HEAD(watchdog_list, WatchdogTimerModel) watchdog_list; void watchdog_add_model(WatchdogTimerModel *model) @@ -77,27 +77,16 @@ int select_watchdog(const char *p) int select_watchdog_action(const char *p) { - if (strcasecmp(p, "reset") == 0) - watchdog_action = WDT_RESET; - else if (strcasecmp(p, "shutdown") == 0) - watchdog_action = WDT_SHUTDOWN; - else if (strcasecmp(p, "poweroff") == 0) - watchdog_action = WDT_POWEROFF; - else if (strcasecmp(p, "pause") == 0) - watchdog_action = WDT_PAUSE; - else if (strcasecmp(p, "debug") == 0) - watchdog_action = WDT_DEBUG; - else if (strcasecmp(p, "none") == 0) - watchdog_action = WDT_NONE; - else if (strcasecmp(p, "inject-nmi") == 0) - watchdog_action = WDT_NMI; - else - return -1; + int action; + action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL); + if (action < 0) + return -1; + watchdog_action = action; return 0; } -int get_watchdog_action(void) +WatchdogAction get_watchdog_action(void) { return watchdog_action; } @@ -108,21 +97,21 @@ int get_watchdog_action(void) void watchdog_perform_action(void) { switch (watchdog_action) { - case WDT_RESET: /* same as 'system_reset' in monitor */ + case WATCHDOG_ACTION_RESET: /* same as 'system_reset' in monitor */ qapi_event_send_watchdog(WATCHDOG_ACTION_RESET, &error_abort); qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); break; - case WDT_SHUTDOWN: /* same as 'system_powerdown' in monitor */ + case WATCHDOG_ACTION_SHUTDOWN: /* same as 'system_powerdown' in monitor */ qapi_event_send_watchdog(WATCHDOG_ACTION_SHUTDOWN, &error_abort); qemu_system_powerdown_request(); break; - case WDT_POWEROFF: /* same as 'quit' command in monitor */ + case WATCHDOG_ACTION_POWEROFF: /* same as 'quit' command in monitor */ qapi_event_send_watchdog(WATCHDOG_ACTION_POWEROFF, &error_abort); exit(0); - case WDT_PAUSE: /* same as 'stop' command in monitor */ + case WATCHDOG_ACTION_PAUSE: /* same as 'stop' command in monitor */ /* In a timer callback, when vm_stop calls qemu_clock_enable * you would get a deadlock. Bypass the problem. */ @@ -131,19 +120,22 @@ void watchdog_perform_action(void) qemu_system_vmstop_request(RUN_STATE_WATCHDOG); break; - case WDT_DEBUG: + case WATCHDOG_ACTION_DEBUG: qapi_event_send_watchdog(WATCHDOG_ACTION_DEBUG, &error_abort); fprintf(stderr, "watchdog: timer fired\n"); break; - case WDT_NONE: + case WATCHDOG_ACTION_NONE: qapi_event_send_watchdog(WATCHDOG_ACTION_NONE, &error_abort); break; - case WDT_NMI: + case WATCHDOG_ACTION_INJECT_NMI: qapi_event_send_watchdog(WATCHDOG_ACTION_INJECT_NMI, &error_abort); nmi_monitor_handle(0, NULL); break; + + default: + assert(0); } } diff --git a/hw/watchdog/wdt_diag288.c b/hw/watchdog/wdt_diag288.c index 47f289216a..1475743527 100644 --- a/hw/watchdog/wdt_diag288.c +++ b/hw/watchdog/wdt_diag288.c @@ -57,9 +57,9 @@ static void diag288_timer_expired(void *dev) * the BQL; reset before triggering the action to avoid races with * diag288 instructions. */ switch (get_watchdog_action()) { - case WDT_DEBUG: - case WDT_NONE: - case WDT_PAUSE: + case WATCHDOG_ACTION_DEBUG: + case WATCHDOG_ACTION_NONE: + case WATCHDOG_ACTION_PAUSE: break; default: wdt_diag288_reset(dev); diff --git a/include/sysemu/watchdog.h b/include/sysemu/watchdog.h index 72a4da07a6..677ace3945 100644 --- a/include/sysemu/watchdog.h +++ b/include/sysemu/watchdog.h @@ -23,15 +23,7 @@ #define QEMU_WATCHDOG_H #include "qemu/queue.h" - -/* Possible values for action parameter. */ -#define WDT_RESET 1 /* Hard reset. */ -#define WDT_SHUTDOWN 2 /* Shutdown. */ -#define WDT_POWEROFF 3 /* Quit. */ -#define WDT_PAUSE 4 /* Pause. */ -#define WDT_DEBUG 5 /* Prints a message and continues running. */ -#define WDT_NONE 6 /* Do nothing. */ -#define WDT_NMI 7 /* Inject nmi into the guest. */ +#include "qapi-types.h" struct WatchdogTimerModel { QLIST_ENTRY(WatchdogTimerModel) entry; @@ -46,7 +38,7 @@ typedef struct WatchdogTimerModel WatchdogTimerModel; /* in hw/watchdog.c */ int select_watchdog(const char *p); int select_watchdog_action(const char *action); -int get_watchdog_action(void); +WatchdogAction get_watchdog_action(void); void watchdog_add_model(WatchdogTimerModel *model); void watchdog_perform_action(void);
We already have enum that enumerates all the action that a watchdog can take when hitting its timeout: WatchdogAction. Use that instead of inventing our own. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- hw/watchdog/watchdog.c | 42 +++++++++++++++++------------------------- hw/watchdog/wdt_diag288.c | 6 +++--- include/sysemu/watchdog.h | 12 ++---------- 3 files changed, 22 insertions(+), 38 deletions(-)