From e0f46055a18e3d51ffe4c0a38e09c5263bd4f059 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 20 Jun 2023 18:36:33 +0200 Subject: [PATCH] target/sparc: Set TCG_GUEST_DEFAULT_MO MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Always use TSO, per the Oracle 2015 manual. This is slightly less restrictive than the TCG_MO_ALL default, and happens to match the i386 model, which will eliminate a few extra barriers on that host. Tested-by: Mark Cave-Ayland Acked-by: Mark Cave-Ayland Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- target/sparc/cpu.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/target/sparc/cpu.h b/target/sparc/cpu.h index b3a98f1d74..9fc5c401d2 100644 --- a/target/sparc/cpu.h +++ b/target/sparc/cpu.h @@ -6,6 +6,29 @@ #include "exec/cpu-defs.h" #include "qemu/cpu-float.h" +/* + * From Oracle SPARC Architecture 2015: + * + * Compatibility notes: The PSO memory model described in SPARC V8 and + * SPARC V9 compatibility architecture specifications was never implemented + * in a SPARC V9 implementation and is not included in the Oracle SPARC + * Architecture specification. + * + * The RMO memory model described in the SPARC V9 specification was + * implemented in some non-Sun SPARC V9 implementations, but is not + * directly supported in Oracle SPARC Architecture 2015 implementations. + * + * Therefore always use TSO in QEMU. + * + * D.5 Specification of Partial Store Order (PSO) + * ... [loads] are followed by an implied MEMBAR #LoadLoad | #LoadStore. + * + * D.6 Specification of Total Store Order (TSO) + * ... PSO with the additional requirement that all [stores] are followed + * by an implied MEMBAR #StoreStore. + */ +#define TCG_GUEST_DEFAULT_MO (TCG_MO_LD_LD | TCG_MO_LD_ST | TCG_MO_ST_ST) + #if !defined(TARGET_SPARC64) #define TARGET_DPREGS 16 #else