This enables the multi-threaded system emulation by default for ARMv7 and ARMv8 guests using the x86_64 TCG backend. This is because on the guest side:
- The ARM translate.c/translate-64.c have been converted to - use MTTCG safe atomic primitives - emit the appropriate barrier ops - The ARM machine has been updated to - hold the BQL when modifying shared cross-vCPU state - defer powerctl changes to async safe work All the host backends support the barrier and atomic primitives but need to provide same-or-better support for normal load/store operations. Signed-off-by: Alex Bennée <alex.ben...@linaro.org> Reviewed-by: Richard Henderson <r...@twiddle.net> Acked-by: Peter Maydell <peter.mayd...@linaro.org> Tested-by: Pranith Kumar <bobby.pr...@gmail.com> Reviewed-by: Pranith Kumar <bobby.pr...@gmail.com> --- configure | 6 ++++++ target/arm/cpu.h | 3 +++ tcg/i386/tcg-target.h | 11 +++++++++++ 3 files changed, 20 insertions(+) diff --git a/configure b/configure index 4b68861992..44ecbe6f74 100755 --- a/configure +++ b/configure @@ -5879,6 +5879,7 @@ mkdir -p $target_dir echo "# Automatically generated by configure - do not modify" > $config_target_mak bflt="no" +mttcg="no" interp_prefix1=$(echo "$interp_prefix" | sed "s/%M/$target_name/g") gdb_xml_files="" @@ -5897,11 +5898,13 @@ case "$target_name" in arm|armeb) TARGET_ARCH=arm bflt="yes" + mttcg="yes" gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml" ;; aarch64) TARGET_BASE_ARCH=arm bflt="yes" + mttcg="yes" gdb_xml_files="aarch64-core.xml aarch64-fpu.xml arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml" ;; cris) @@ -6066,6 +6069,9 @@ if test "$target_bigendian" = "yes" ; then fi if test "$target_softmmu" = "yes" ; then echo "CONFIG_SOFTMMU=y" >> $config_target_mak + if test "$mttcg" = "yes" ; then + echo "TARGET_SUPPORTS_MTTCG=y" >> $config_target_mak + fi fi if test "$target_user_only" = "yes" ; then echo "CONFIG_USER_ONLY=y" >> $config_target_mak diff --git a/target/arm/cpu.h b/target/arm/cpu.h index e285ba3b4b..38a8e00908 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -30,6 +30,9 @@ # define TARGET_LONG_BITS 32 #endif +/* ARM processors have a weak memory model */ +#define TCG_GUEST_DEFAULT_MO (0) + #define CPUArchState struct CPUARMState #include "qemu-common.h" diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h index 21d96ec35c..4275787db9 100644 --- a/tcg/i386/tcg-target.h +++ b/tcg/i386/tcg-target.h @@ -165,4 +165,15 @@ static inline void flush_icache_range(uintptr_t start, uintptr_t stop) { } +/* This defines the natural memory order supported by this + * architecture before guarantees made by various barrier + * instructions. + * + * The x86 has a pretty strong memory ordering which only really + * allows for some stores to be re-ordered after loads. + */ +#include "tcg-mo.h" + +#define TCG_TARGET_DEFAULT_MO (TCG_MO_ALL & ~TCG_MO_ST_LD) + #endif -- 2.11.0