tcg: add options for enabling MTTCG

We know there will be cases where MTTCG won't work until additional work
is done in the front/back ends to support. It will however be useful to
be able to turn it on.

As a result MTTCG will default to off unless the combination is
supported. However the user can turn it on for the sake of testing.

Backports commit 8d4e9146b3568022ea5730d92841345d41275d66 from qemu

include/uc_priv.h

@@ -175,6 +175,9 @@ struct uc_struct {
 
     uc_insn_hook_validate insn_hook_validate;
 
+    // qemu/cpus.c
+    bool mttcg_enabled;
+
     // qemu/exec.c
     MemoryRegion *system_memory;
     MemoryRegion io_mem_rom;

qemu/aarch64.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_aarch64
 #define qemu_strnlen qemu_strnlen_aarch64
 #define qemu_strsep qemu_strsep_aarch64
+#define qemu_tcg_configure qemu_tcg_configure_aarch64
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_aarch64
 #define qemu_try_memalign qemu_try_memalign_aarch64
 #define qentry_destroy qentry_destroy_aarch64

qemu/aarch64eb.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_aarch64eb
 #define qemu_strnlen qemu_strnlen_aarch64eb
 #define qemu_strsep qemu_strsep_aarch64eb
+#define qemu_tcg_configure qemu_tcg_configure_aarch64eb
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_aarch64eb
 #define qemu_try_memalign qemu_try_memalign_aarch64eb
 #define qentry_destroy qentry_destroy_aarch64eb

qemu/arm.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_arm
 #define qemu_strnlen qemu_strnlen_arm
 #define qemu_strsep qemu_strsep_arm
+#define qemu_tcg_configure qemu_tcg_configure_arm
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_arm
 #define qemu_try_memalign qemu_try_memalign_arm
 #define qentry_destroy qentry_destroy_arm

qemu/armeb.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_armeb
 #define qemu_strnlen qemu_strnlen_armeb
 #define qemu_strsep qemu_strsep_armeb
+#define qemu_tcg_configure qemu_tcg_configure_armeb
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_armeb
 #define qemu_try_memalign qemu_try_memalign_armeb
 #define qentry_destroy qentry_destroy_armeb

qemu/cpus.c

@@ -31,6 +31,7 @@
 #include "sysemu/sysemu.h"
 #include "exec/exec-all.h"
 
+#include "tcg.h"
 #include "qemu/thread.h"
 #include "sysemu/cpus.h"
 
@@ -45,6 +46,17 @@ static bool tcg_exec_all(struct uc_struct* uc);
 static int qemu_tcg_init_vcpu(CPUState *cpu);
 static void *qemu_tcg_cpu_loop(struct uc_struct *uc);
 
+
+static bool default_mttcg_enabled(void)
+{
+    return false;
+}
+
+void qemu_tcg_configure(struct uc_struct *uc)
+{
+    uc->mttcg_enabled = default_mttcg_enabled();
+}
+
 int vm_start(struct uc_struct* uc)
 {
     if (resume_all_vcpus(uc)) {

qemu/header_gen.py

@@ -2671,6 +2671,7 @@ symbols = (
     'qemu_st_helpers',
     'qemu_strnlen',
     'qemu_strsep',
+    'qemu_tcg_configure',
     'qemu_tcg_init_vcpu',
     'qemu_try_memalign',
     'qentry_destroy',

qemu/include/qom/cpu.h

@@ -328,6 +328,14 @@ struct CPUState {
     struct uc_struct* uc;
 };
 
+/**
+ * qemu_tcg_mttcg_enabled:
+ * Check whether we are running MultiThread TCG or not.
+ *
+ * Returns: %true if we are in MTTCG mode %false otherwise.
+ */
+extern bool mttcg_enabled;
+#define qemu_tcg_mttcg_enabled() (mttcg_enabled)
 
 /**
  * cpu_paging_enabled:

qemu/include/sysemu/cpus.h

@@ -17,4 +17,6 @@ extern int smp_threads;
 #define smp_threads 1
 #endif
 
+void qemu_tcg_configure(struct uc_struct *uc);
+
 #endif

qemu/m68k.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_m68k
 #define qemu_strnlen qemu_strnlen_m68k
 #define qemu_strsep qemu_strsep_m68k
+#define qemu_tcg_configure qemu_tcg_configure_m68k
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_m68k
 #define qemu_try_memalign qemu_try_memalign_m68k
 #define qentry_destroy qentry_destroy_m68k

qemu/mips.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_mips
 #define qemu_strnlen qemu_strnlen_mips
 #define qemu_strsep qemu_strsep_mips
+#define qemu_tcg_configure qemu_tcg_configure_mips
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_mips
 #define qemu_try_memalign qemu_try_memalign_mips
 #define qentry_destroy qentry_destroy_mips

qemu/mips64.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_mips64
 #define qemu_strnlen qemu_strnlen_mips64
 #define qemu_strsep qemu_strsep_mips64
+#define qemu_tcg_configure qemu_tcg_configure_mips64
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_mips64
 #define qemu_try_memalign qemu_try_memalign_mips64
 #define qentry_destroy qentry_destroy_mips64

qemu/mips64el.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_mips64el
 #define qemu_strnlen qemu_strnlen_mips64el
 #define qemu_strsep qemu_strsep_mips64el
+#define qemu_tcg_configure qemu_tcg_configure_mips64el
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_mips64el
 #define qemu_try_memalign qemu_try_memalign_mips64el
 #define qentry_destroy qentry_destroy_mips64el

qemu/mipsel.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_mipsel
 #define qemu_strnlen qemu_strnlen_mipsel
 #define qemu_strsep qemu_strsep_mipsel
+#define qemu_tcg_configure qemu_tcg_configure_mipsel
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_mipsel
 #define qemu_try_memalign qemu_try_memalign_mipsel
 #define qentry_destroy qentry_destroy_mipsel

qemu/powerpc.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_powerpc
 #define qemu_strnlen qemu_strnlen_powerpc
 #define qemu_strsep qemu_strsep_powerpc
+#define qemu_tcg_configure qemu_tcg_configure_powerpc
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_powerpc
 #define qemu_try_memalign qemu_try_memalign_powerpc
 #define qentry_destroy qentry_destroy_powerpc

qemu/sparc.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_sparc
 #define qemu_strnlen qemu_strnlen_sparc
 #define qemu_strsep qemu_strsep_sparc
+#define qemu_tcg_configure qemu_tcg_configure_sparc
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_sparc
 #define qemu_try_memalign qemu_try_memalign_sparc
 #define qentry_destroy qentry_destroy_sparc

qemu/sparc64.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_sparc64
 #define qemu_strnlen qemu_strnlen_sparc64
 #define qemu_strsep qemu_strsep_sparc64
+#define qemu_tcg_configure qemu_tcg_configure_sparc64
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_sparc64
 #define qemu_try_memalign qemu_try_memalign_sparc64
 #define qentry_destroy qentry_destroy_sparc64

qemu/tcg/tcg.h

@@ -83,6 +83,15 @@ typedef uint64_t tcg_target_ulong;
 #error unsupported
 #endif
 
+/* Oversized TCG guests make things like MTTCG hard
+ * as we can't use atomics for cputlb updates.
+ */
+#if TARGET_LONG_BITS > TCG_TARGET_REG_BITS
+#define TCG_OVERSIZED_GUEST 1
+#else
+#define TCG_OVERSIZED_GUEST 0
+#endif
+
 #if TCG_TARGET_NB_REGS <= 32
 typedef uint32_t TCGRegSet;
 #elif TCG_TARGET_NB_REGS <= 64

qemu/vl.c

@@ -137,6 +137,9 @@ int machine_initialize(struct uc_struct *uc)
     uc->machine_state = current_machine;
     current_machine->uc = uc;
 
+    // Unicorn: FIXME: ditto with regards to below
+    //qemu_tcg_configure(uc);
+
     // Unicorn: FIXME: this should be uncommented
     //          However due to the "stellar" way unicorn
     //          handles multiple targets (e.g. the YOLO

qemu/x86_64.h

@@ -2665,6 +2665,7 @@
 #define qemu_st_helpers qemu_st_helpers_x86_64
 #define qemu_strnlen qemu_strnlen_x86_64
 #define qemu_strsep qemu_strsep_x86_64
+#define qemu_tcg_configure qemu_tcg_configure_x86_64
 #define qemu_tcg_init_vcpu qemu_tcg_init_vcpu_x86_64
 #define qemu_try_memalign qemu_try_memalign_x86_64
 #define qentry_destroy qentry_destroy_x86_64