Use the OnOffAuto type as 3-state. Since the TCGState instance is zero-initialized, the mttcg_enabled is initialzed as AUTO (ON_OFF_AUTO_AUTO).
In tcg_init_machine(), if mttcg_enabled is still AUTO, set a default value (effectively inlining the default_mttcg_enabled() method content). Instead of emiting a warning when the 'thread' property is set in tcg_set_thread(), emit it in tcg_init_machine() where it is consumed. This is in preparation of the next commit where we replace the TARGET_SUPPORTS_MTTCG definition by getting the value at runtime via CPUState -> CPUClass -> TCGCPUOps -> mttcg_supported, so we need an initialized CPUState -- which is not possible at instance_init time). In the tcg_get_thread() getter, consider AUTO / OFF states as "single", otherwise ON is "multi". Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org> Reviewed-by: Anton Johansson <a...@rev.ng> --- accel/tcg/tcg-all.c | 69 ++++++++++++++++++++++----------------------- 1 file changed, 34 insertions(+), 35 deletions(-) diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index d75ecf531b6..f83f9b9d79e 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -32,6 +32,7 @@ #include "qemu/error-report.h" #include "qemu/accel.h" #include "qemu/atomic.h" +#include "qapi/qapi-types-common.h" #include "qapi/qapi-builtin-visit.h" #include "qemu/units.h" #if defined(CONFIG_USER_ONLY) @@ -47,7 +48,7 @@ struct TCGState { AccelState parent_obj; - bool mttcg_enabled; + OnOffAuto mttcg_enabled; bool one_insn_per_tb; int splitwx_enabled; unsigned long tb_size; @@ -68,37 +69,10 @@ bool qemu_tcg_mttcg_enabled(void) } #endif -/* - * We default to false if we know other options have been enabled - * which are currently incompatible with MTTCG. Otherwise when each - * guest (target) has been updated to support: - * - atomic instructions - * - memory ordering primitives (barriers) - * they can set the appropriate CONFIG flags in ${target}-softmmu.mak - * - * Once a guest architecture has been converted to the new primitives - * there is one remaining limitation to check: - * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host) - */ - -static bool default_mttcg_enabled(void) -{ - if (icount_enabled()) { - return false; - } -#ifdef TARGET_SUPPORTS_MTTCG - return true; -#else - return false; -#endif -} - static void tcg_accel_instance_init(Object *obj) { TCGState *s = TCG_STATE(obj); - s->mttcg_enabled = default_mttcg_enabled(); - /* If debugging enabled, default "auto on", otherwise off. */ #if defined(CONFIG_DEBUG_TCG) && !defined(CONFIG_USER_ONLY) s->splitwx_enabled = -1; @@ -117,8 +91,37 @@ static int tcg_init_machine(MachineState *ms) #else unsigned max_cpus = ms->smp.max_cpus; #endif +#ifdef TARGET_SUPPORTS_MTTCG + bool mttcg_supported = true; +#else + bool mttcg_supported = false; +#endif tcg_allowed = true; + + if (s->mttcg_enabled == ON_OFF_AUTO_AUTO) { + /* + * We default to false if we know other options have been enabled + * which are currently incompatible with MTTCG. Otherwise when each + * guest (target) has been updated to support: + * - atomic instructions + * - memory ordering primitives (barriers) + * they can set the appropriate CONFIG flags in ${target}-softmmu.mak + * + * Once a guest architecture has been converted to the new primitives + * there is one remaining limitation to check: + * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host) + */ + if (icount_enabled()) { + s->mttcg_enabled = ON_OFF_AUTO_OFF; + } else { + s->mttcg_enabled = mttcg_supported; + } + } + if (s->mttcg_enabled == ON_OFF_AUTO_ON && !mttcg_supported) { + warn_report("Guest not yet converted to MTTCG - " + "you may get unexpected results"); + } mttcg_enabled = s->mttcg_enabled; page_init(); @@ -144,7 +147,7 @@ static char *tcg_get_thread(Object *obj, Error **errp) { TCGState *s = TCG_STATE(obj); - return g_strdup(s->mttcg_enabled ? "multi" : "single"); + return g_strdup(s->mttcg_enabled == ON_OFF_AUTO_ON ? "multi" : "single"); } static void tcg_set_thread(Object *obj, const char *value, Error **errp) @@ -155,14 +158,10 @@ static void tcg_set_thread(Object *obj, const char *value, Error **errp) if (icount_enabled()) { error_setg(errp, "No MTTCG when icount is enabled"); } else { -#ifndef TARGET_SUPPORTS_MTTCG - warn_report("Guest not yet converted to MTTCG - " - "you may get unexpected results"); -#endif - s->mttcg_enabled = true; + s->mttcg_enabled = ON_OFF_AUTO_ON; } } else if (strcmp(value, "single") == 0) { - s->mttcg_enabled = false; + s->mttcg_enabled = ON_OFF_AUTO_OFF; } else { error_setg(errp, "Invalid 'thread' setting %s", value); } -- 2.47.1