From a35b3e14157b9d912898d4800f329dc5f3c200a6 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 28 Oct 2020 20:50:29 -0700 Subject: [PATCH] tcg: Add --accel tcg,split-wx property Plumb the value through to alloc_code_gen_buffer. This is not supported by any os or tcg backend, so for now enabling it will result in an error. Reviewed-by: Joelle van Dyne Signed-off-by: Richard Henderson --- accel/tcg/tcg-all.c | 26 +++++++++++++++++++++++++- accel/tcg/translate-all.c | 35 +++++++++++++++++++++++++++-------- bsd-user/main.c | 2 +- include/sysemu/tcg.h | 3 ++- linux-user/main.c | 2 +- qemu-options.hx | 7 +++++++ tcg/aarch64/tcg-target.h | 1 + tcg/arm/tcg-target.h | 1 + tcg/i386/tcg-target.h | 1 + tcg/mips/tcg-target.h | 1 + tcg/ppc/tcg-target.h | 1 + tcg/riscv/tcg-target.h | 1 + tcg/s390/tcg-target.h | 1 + tcg/sparc/tcg-target.h | 1 + tcg/tci/tcg-target.h | 1 + 15 files changed, 72 insertions(+), 12 deletions(-) diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index 1ac0b76515f5..2eea8c32ee1e 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -38,6 +38,7 @@ struct TCGState { AccelState parent_obj; bool mttcg_enabled; + int splitwx_enabled; unsigned long tb_size; }; typedef struct TCGState TCGState; @@ -94,6 +95,13 @@ 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. */ +#ifdef CONFIG_DEBUG_TCG + s->splitwx_enabled = -1; +#else + s->splitwx_enabled = 0; +#endif } bool mttcg_enabled; @@ -102,7 +110,7 @@ static int tcg_init(MachineState *ms) { TCGState *s = TCG_STATE(current_accel()); - tcg_exec_init(s->tb_size * 1024 * 1024); + tcg_exec_init(s->tb_size * 1024 * 1024, s->splitwx_enabled); mttcg_enabled = s->mttcg_enabled; /* @@ -179,6 +187,18 @@ static void tcg_set_tb_size(Object *obj, Visitor *v, s->tb_size = value; } +static bool tcg_get_splitwx(Object *obj, Error **errp) +{ + TCGState *s = TCG_STATE(obj); + return s->splitwx_enabled; +} + +static void tcg_set_splitwx(Object *obj, bool value, Error **errp) +{ + TCGState *s = TCG_STATE(obj); + s->splitwx_enabled = value; +} + static void tcg_accel_class_init(ObjectClass *oc, void *data) { AccelClass *ac = ACCEL_CLASS(oc); @@ -196,6 +216,10 @@ static void tcg_accel_class_init(ObjectClass *oc, void *data) object_class_property_set_description(oc, "tb-size", "TCG translation block cache size"); + object_class_property_add_bool(oc, "split-wx", + tcg_get_splitwx, tcg_set_splitwx); + object_class_property_set_description(oc, "split-wx", + "Map jit pages into separate RW and RX regions"); } static const TypeInfo tcg_accel_type = { diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index ae87b2342a1b..022f9c743d38 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1015,13 +1015,19 @@ static inline void *split_cross_256mb(void *buf1, size_t size1) static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE] __attribute__((aligned(CODE_GEN_ALIGN))); -static bool alloc_code_gen_buffer(size_t tb_size, Error **errp) +static bool alloc_code_gen_buffer(size_t tb_size, int splitwx, Error **errp) { - void *buf = static_code_gen_buffer; - void *end = static_code_gen_buffer + sizeof(static_code_gen_buffer); + void *buf, *end; size_t size; + if (splitwx > 0) { + error_setg(errp, "jit split-wx not supported"); + return false; + } + /* page-align the beginning and end of the buffer */ + buf = static_code_gen_buffer; + end = static_code_gen_buffer + sizeof(static_code_gen_buffer); buf = QEMU_ALIGN_PTR_UP(buf, qemu_real_host_page_size); end = QEMU_ALIGN_PTR_DOWN(end, qemu_real_host_page_size); @@ -1050,9 +1056,16 @@ static bool alloc_code_gen_buffer(size_t tb_size, Error **errp) return true; } #elif defined(_WIN32) -static bool alloc_code_gen_buffer(size_t size, Error **errp) +static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) { - void *buf = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, + void *buf; + + if (splitwx > 0) { + error_setg(errp, "jit split-wx not supported"); + return false; + } + + buf = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE); if (buf == NULL) { error_setg_win32(errp, GetLastError(), @@ -1065,12 +1078,17 @@ static bool alloc_code_gen_buffer(size_t size, Error **errp) return true; } #else -static bool alloc_code_gen_buffer(size_t size, Error **errp) +static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) { int prot = PROT_WRITE | PROT_READ | PROT_EXEC; int flags = MAP_PRIVATE | MAP_ANONYMOUS; void *buf; + if (splitwx > 0) { + error_setg(errp, "jit split-wx not supported"); + return false; + } + buf = mmap(NULL, size, prot, flags, -1, 0); if (buf == MAP_FAILED) { error_setg_errno(errp, errno, @@ -1145,7 +1163,7 @@ static void tb_htable_init(void) /* Must be called before using the QEMU cpus. 'tb_size' is the size (in bytes) allocated to the translation buffer. Zero means default size. */ -void tcg_exec_init(unsigned long tb_size) +void tcg_exec_init(unsigned long tb_size, int splitwx) { bool ok; @@ -1154,7 +1172,8 @@ void tcg_exec_init(unsigned long tb_size) page_init(); tb_htable_init(); - ok = alloc_code_gen_buffer(size_code_gen_buffer(tb_size), &error_fatal); + ok = alloc_code_gen_buffer(size_code_gen_buffer(tb_size), + splitwx, &error_fatal); assert(ok); #if defined(CONFIG_SOFTMMU) diff --git a/bsd-user/main.c b/bsd-user/main.c index 9c700c623450..65163e1396c6 100644 --- a/bsd-user/main.c +++ b/bsd-user/main.c @@ -909,7 +909,7 @@ int main(int argc, char **argv) } /* init tcg before creating CPUs and to get qemu_host_page_size */ - tcg_exec_init(0); + tcg_exec_init(0, false); cpu_type = parse_cpu_option(cpu_model); cpu = cpu_create(cpu_type); diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h index d9d3ca85596f..00349fb18a79 100644 --- a/include/sysemu/tcg.h +++ b/include/sysemu/tcg.h @@ -8,7 +8,8 @@ #ifndef SYSEMU_TCG_H #define SYSEMU_TCG_H -void tcg_exec_init(unsigned long tb_size); +void tcg_exec_init(unsigned long tb_size, int splitwx); + #ifdef CONFIG_TCG extern bool tcg_allowed; #define tcg_enabled() (tcg_allowed) diff --git a/linux-user/main.c b/linux-user/main.c index 750a01118fa5..bb4e55e8fcee 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -701,7 +701,7 @@ int main(int argc, char **argv, char **envp) cpu_type = parse_cpu_option(cpu_model); /* init tcg before creating CPUs and to get qemu_host_page_size */ - tcg_exec_init(0); + tcg_exec_init(0, false); cpu = cpu_create(cpu_type); env = cpu->env_ptr; diff --git a/qemu-options.hx b/qemu-options.hx index 459c916d3d6a..1698a0c751ff 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -115,6 +115,7 @@ DEF("accel", HAS_ARG, QEMU_OPTION_accel, " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n" " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n" " kvm-shadow-mem=size of KVM shadow MMU in bytes\n" + " split-wx=on|off (enable TCG split w^x mapping)\n" " tb-size=n (TCG translation block cache size)\n" " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) SRST @@ -140,6 +141,12 @@ SRST ``kvm-shadow-mem=size`` Defines the size of the KVM shadow MMU. + ``split-wx=on|off`` + Controls the use of split w^x mapping for the TCG code generation + buffer. Some operating systems require this to be enabled, and in + such a case this will default on. On other operating systems, this + will default off, but one may enable this for testing or debugging. + ``tb-size=n`` Controls the size (in MiB) of the TCG translation block cache. diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h index 5ec30dba2536..23bf87db3d94 100644 --- a/tcg/aarch64/tcg-target.h +++ b/tcg/aarch64/tcg-target.h @@ -155,5 +155,6 @@ void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t); #define TCG_TARGET_NEED_LDST_LABELS #endif #define TCG_TARGET_NEED_POOL_LABELS +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif /* AARCH64_TCG_TARGET_H */ diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h index 8d1fee6327f5..494837d12820 100644 --- a/tcg/arm/tcg-target.h +++ b/tcg/arm/tcg-target.h @@ -142,5 +142,6 @@ void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t); #define TCG_TARGET_NEED_LDST_LABELS #endif #define TCG_TARGET_NEED_POOL_LABELS +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h index b693d3692d3b..73aa45a6659e 100644 --- a/tcg/i386/tcg-target.h +++ b/tcg/i386/tcg-target.h @@ -235,5 +235,6 @@ static inline void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_rx, #define TCG_TARGET_NEED_LDST_LABELS #endif #define TCG_TARGET_NEED_POOL_LABELS +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif diff --git a/tcg/mips/tcg-target.h b/tcg/mips/tcg-target.h index c2c32fb38f53..fbfe775fb454 100644 --- a/tcg/mips/tcg-target.h +++ b/tcg/mips/tcg-target.h @@ -201,6 +201,7 @@ extern bool use_mips32r2_instructions; #define TCG_TARGET_DEFAULT_MO (0) #define TCG_TARGET_HAS_MEMORY_BSWAP 1 +#define TCG_TARGET_SUPPORT_MIRROR 0 void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t); diff --git a/tcg/ppc/tcg-target.h b/tcg/ppc/tcg-target.h index d1339afc6668..ba61a31b3e46 100644 --- a/tcg/ppc/tcg-target.h +++ b/tcg/ppc/tcg-target.h @@ -185,5 +185,6 @@ void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t); #define TCG_TARGET_NEED_LDST_LABELS #endif #define TCG_TARGET_NEED_POOL_LABELS +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h index 727c8df418dc..6263af4dd1f6 100644 --- a/tcg/riscv/tcg-target.h +++ b/tcg/riscv/tcg-target.h @@ -171,5 +171,6 @@ void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t); #define TCG_TARGET_NEED_POOL_LABELS #define TCG_TARGET_HAS_MEMORY_BSWAP 0 +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif diff --git a/tcg/s390/tcg-target.h b/tcg/s390/tcg-target.h index 641464eea489..b8f4296e4bec 100644 --- a/tcg/s390/tcg-target.h +++ b/tcg/s390/tcg-target.h @@ -159,5 +159,6 @@ static inline void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_rx, #define TCG_TARGET_NEED_LDST_LABELS #endif #define TCG_TARGET_NEED_POOL_LABELS +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h index 95ab9af955d8..6f6cefaa1556 100644 --- a/tcg/sparc/tcg-target.h +++ b/tcg/sparc/tcg-target.h @@ -172,5 +172,6 @@ extern bool use_vis3_instructions; void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t); #define TCG_TARGET_NEED_POOL_LABELS +#define TCG_TARGET_SUPPORT_MIRROR 0 #endif diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h index bb784e018e2e..d8c78d1dc718 100644 --- a/tcg/tci/tcg-target.h +++ b/tcg/tci/tcg-target.h @@ -198,6 +198,7 @@ void tci_disas(uint8_t opc); #define TCG_TARGET_DEFAULT_MO (0) #define TCG_TARGET_HAS_MEMORY_BSWAP 1 +#define TCG_TARGET_SUPPORT_MIRROR 0 static inline void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_rx, uintptr_t jmp_rw, uintptr_t addr)