Add GETPC_EXT which is used by MMU helpers to selectively calculate the code
address of accessing guest memory when called from a qemu_ld/st optimized code
or a C function. Currently, it supports only i386 and x86-64 hosts.
Signed-off-by: Yeongkyoon Lee <yeongkyoon....@samsung.com>
---
exec-all.h | 36 ++++++++++++++++++++++++++++++++++++
exec.c | 11 +++++++++++
softmmu_template.h | 16 ++++++++--------
3 files changed, 55 insertions(+), 8 deletions(-)
diff --git a/exec-all.h b/exec-all.h
index 2ea0e4f..ad6d22b 100644
--- a/exec-all.h
+++ b/exec-all.h
@@ -310,6 +310,42 @@ extern uintptr_t tci_tb_ptr;
# define GETPC() ((uintptr_t)__builtin_return_address(0) - 1)
#endif
+#if defined(CONFIG_QEMU_LDST_OPTIMIZATION) && defined(CONFIG_SOFTMMU)
+/* qemu_ld/st optimization split code generation to fast and slow path, thus,
+ it needs special handling for an MMU helper which is called from the slow
+ path, to get the fast path's pc without any additional argument.
+ It uses a tricky solution which embeds the fast path pc into the slow path.
+
+ Code flow in slow path:
+ (1) pre-process
+ (2) call MMU helper
+ (3) jump to (5)
+ (4) fast path information (implementation specific)
+ (5) post-process (e.g. stack adjust)
+ (6) jump to corresponding code of the next of fast path
+ */
+# if defined(__i386__) || defined(__x86_64__)
+/* To avoid broken disassembling, long jmp is used for embedding fast path pc,
+ so that the destination is the next code of fast path, though this jmp is
+ never executed.
+
+ call MMU helper
+ jmp POST_PROC (2byte) <- GETRA()
+ jmp NEXT_CODE (5byte)
+ POST_PROCESS ... <- GETRA() + 7
+ */
+# define GETRA() ((uintptr_t)__builtin_return_address(0))
+# define GETPC_LDST() ((uintptr_t)(GETRA() + 7 + \
+ *(int32_t *)((void *)GETRA() + 3) - 1))
+# else
+# error "CONFIG_QEMU_LDST_OPTIMIZATION needs GETPC_LDST() implementation!"
+# endif
+bool is_tcg_gen_code(uintptr_t pc_ptr);
+# define GETPC_EXT() (is_tcg_gen_code(GETRA()) ? GETPC_LDST() : GETPC())
+#else
+# define GETPC_EXT() GETPC()
+#endif
+
#if !defined(CONFIG_USER_ONLY)
struct MemoryRegion *iotlb_to_region(hwaddr index);
diff --git a/exec.c b/exec.c
index b0ed593..1089250 100644
--- a/exec.c
+++ b/exec.c
@@ -1387,6 +1387,17 @@ void tb_link_page(TranslationBlock *tb,
mmap_unlock();
}
+#if defined(CONFIG_QEMU_LDST_OPTIMIZATION) && defined(CONFIG_SOFTMMU)
+/* check whether the given addr is in TCG generated code buffer or not */
+bool is_tcg_gen_code(uintptr_t tc_ptr)
+{
+ /* This can be called during code generation, code_gen_buffer_max_size
+ is used instead of code_gen_ptr for upper boundary checking */
+ return (tc_ptr >= (uintptr_t)code_gen_buffer &&
+ tc_ptr < (uintptr_t)(code_gen_buffer + code_gen_buffer_max_size));
+}
+#endif
+
/* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
tb[1].tc_ptr. Return NULL if not found */
TranslationBlock *tb_find_pc(uintptr_t tc_ptr)
diff --git a/softmmu_template.h b/softmmu_template.h
index 20d6bab..ce30d8b 100644
--- a/softmmu_template.h
+++ b/softmmu_template.h
@@ -111,13 +111,13 @@ glue(glue(helper_ld, SUFFIX), MMUSUFFIX)(CPUArchState
*env, target_ulong addr,
/* IO access */
if ((addr & (DATA_SIZE - 1)) != 0)
goto do_unaligned_access;
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
ioaddr = env->iotlb[mmu_idx][index];
res = glue(io_read, SUFFIX)(env, ioaddr, addr, retaddr);
} else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >=
TARGET_PAGE_SIZE) {
/* slow unaligned access (it spans two pages or IO) */
do_unaligned_access:
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
#ifdef ALIGNED_ONLY
do_unaligned_access(env, addr, READ_ACCESS_TYPE, mmu_idx, retaddr);
#endif
@@ -128,7 +128,7 @@ glue(glue(helper_ld, SUFFIX), MMUSUFFIX)(CPUArchState *env,
target_ulong addr,
uintptr_t addend;
#ifdef ALIGNED_ONLY
if ((addr & (DATA_SIZE - 1)) != 0) {
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
do_unaligned_access(env, addr, READ_ACCESS_TYPE, mmu_idx,
retaddr);
}
#endif
@@ -138,7 +138,7 @@ glue(glue(helper_ld, SUFFIX), MMUSUFFIX)(CPUArchState *env,
target_ulong addr,
}
} else {
/* the page is not in the TLB : fill it */
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
#ifdef ALIGNED_ONLY
if ((addr & (DATA_SIZE - 1)) != 0)
do_unaligned_access(env, addr, READ_ACCESS_TYPE, mmu_idx, retaddr);
@@ -257,12 +257,12 @@ void glue(glue(helper_st, SUFFIX),
MMUSUFFIX)(CPUArchState *env,
/* IO access */
if ((addr & (DATA_SIZE - 1)) != 0)
goto do_unaligned_access;
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
ioaddr = env->iotlb[mmu_idx][index];
glue(io_write, SUFFIX)(env, ioaddr, val, addr, retaddr);
} else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >=
TARGET_PAGE_SIZE) {
do_unaligned_access:
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
#ifdef ALIGNED_ONLY
do_unaligned_access(env, addr, 1, mmu_idx, retaddr);
#endif
@@ -273,7 +273,7 @@ void glue(glue(helper_st, SUFFIX), MMUSUFFIX)(CPUArchState
*env,
uintptr_t addend;
#ifdef ALIGNED_ONLY
if ((addr & (DATA_SIZE - 1)) != 0) {
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
do_unaligned_access(env, addr, 1, mmu_idx, retaddr);
}
#endif
@@ -283,7 +283,7 @@ void glue(glue(helper_st, SUFFIX), MMUSUFFIX)(CPUArchState
*env,
}
} else {
/* the page is not in the TLB : fill it */
- retaddr = GETPC();
+ retaddr = GETPC_EXT();
#ifdef ALIGNED_ONLY
if ((addr & (DATA_SIZE - 1)) != 0)
do_unaligned_access(env, addr, 1, mmu_idx, retaddr);
--
1.7.9.5
