[Qemu-devel] [PATCH v2 09/11] target/mips/op_helper: hold BQL before calling cpu_mips_get_count

["Alex Bennée" <alex.bennee@linaro.org>]

We should hold the BQL before we transition to HW emulation. This is
because all HW emulation needs to be serialised under MTTCG
conditions. This is picked up by asserts that fire when
cpu_mips_get_count triggers and IRQ.

Reported-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 target/mips/op_helper.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
index b683fcb025..38bca03f52 100644
--- a/target/mips/op_helper.c
+++ b/target/mips/op_helper.c
@@ -17,6 +17,7 @@
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "qemu/osdep.h"
+#include "qemu/main-loop.h"
 #include "cpu.h"
 #include "qemu/host-utils.h"
 #include "exec/helper-proto.h"
@@ -827,7 +828,13 @@ target_ulong helper_mftc0_tcschefback(CPUMIPSState *env)
 
 target_ulong helper_mfc0_count(CPUMIPSState *env)
 {
-    return (int32_t)cpu_mips_get_count(env);
+    int32_t count;
+
+    qemu_mutex_lock_iothread();
+    count = (int32_t)cpu_mips_get_count(env);
+    qemu_mutex_unlock_iothread();
+
+    return count;
 }
 
 target_ulong helper_mftc0_entryhi(CPUMIPSState *env)
@@ -2296,12 +2303,16 @@ target_ulong helper_rdhwr_synci_step(CPUMIPSState *env)
 
 target_ulong helper_rdhwr_cc(CPUMIPSState *env)
 {
+    int32_t count;
     check_hwrena(env, 2, GETPC());
 #ifdef CONFIG_USER_ONLY
-    return env->CP0_Count;
+    count = env->CP0_Count;
 #else
-    return (int32_t)cpu_mips_get_count(env);
+    qemu_mutex_lock_iothread();
+    count = (int32_t)cpu_mips_get_count(env);
+    qemu_mutex_unlock_iothread();
 #endif
+    return count;
 }
 
 target_ulong helper_rdhwr_ccres(CPUMIPSState *env)
-- 
2.11.0