]> git.proxmox.com Git - mirror_qemu.git/blobdiff - cpu-exec.c
virtio-9p: handle handle_9p_output() error
[mirror_qemu.git] / cpu-exec.c
index 14df1aacf42a4dd89d6647b2c7ad639f35d9979f..8823d23df7e02c7d0287fd5df953f6626d7b120e 100644 (file)
@@ -20,6 +20,7 @@
 #include "cpu.h"
 #include "trace.h"
 #include "disas/disas.h"
+#include "exec/exec-all.h"
 #include "tcg.h"
 #include "qemu/atomic.h"
 #include "sysemu/qtest.h"
@@ -146,7 +147,8 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)
                            itb->tc_ptr, itb->pc, lookup_symbol(itb->pc));
 
 #if defined(DEBUG_DISAS)
-    if (qemu_loglevel_mask(CPU_LOG_TB_CPU)) {
+    if (qemu_loglevel_mask(CPU_LOG_TB_CPU)
+        && qemu_log_in_addr_range(itb->pc)) {
 #if defined(TARGET_I386)
         log_cpu_state(cpu, CPU_DUMP_CCOP);
 #elif defined(TARGET_M68K)
@@ -202,20 +204,16 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles,
                              TranslationBlock *orig_tb, bool ignore_icount)
 {
     TranslationBlock *tb;
-    bool old_tb_flushed;
 
     /* Should never happen.
        We only end up here when an existing TB is too long.  */
     if (max_cycles > CF_COUNT_MASK)
         max_cycles = CF_COUNT_MASK;
 
-    old_tb_flushed = cpu->tb_flushed;
-    cpu->tb_flushed = false;
     tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,
                      max_cycles | CF_NOCACHE
                          | (ignore_icount ? CF_IGNORE_ICOUNT : 0));
-    tb->orig_tb = cpu->tb_flushed ? NULL : orig_tb;
-    cpu->tb_flushed |= old_tb_flushed;
+    tb->orig_tb = orig_tb;
     /* execute the generated code */
     trace_exec_tb_nocache(tb, tb->pc);
     cpu_tb_exec(cpu, tb);
@@ -224,131 +222,125 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles,
 }
 #endif
 
-static TranslationBlock *tb_find_physical(CPUState *cpu,
-                                          target_ulong pc,
-                                          target_ulong cs_base,
-                                          uint32_t flags)
+struct tb_desc {
+    target_ulong pc;
+    target_ulong cs_base;
+    CPUArchState *env;
+    tb_page_addr_t phys_page1;
+    uint32_t flags;
+};
+
+static bool tb_cmp(const void *p, const void *d)
 {
-    CPUArchState *env = (CPUArchState *)cpu->env_ptr;
-    TranslationBlock *tb, **tb_hash_head, **ptb1;
-    unsigned int h;
-    tb_page_addr_t phys_pc, phys_page1;
-
-    /* find translated block using physical mappings */
-    phys_pc = get_page_addr_code(env, pc);
-    phys_page1 = phys_pc & TARGET_PAGE_MASK;
-    h = tb_phys_hash_func(phys_pc);
-
-    /* Start at head of the hash entry */
-    ptb1 = tb_hash_head = &tcg_ctx.tb_ctx.tb_phys_hash[h];
-    tb = *ptb1;
-
-    while (tb) {
-        if (tb->pc == pc &&
-            tb->page_addr[0] == phys_page1 &&
-            tb->cs_base == cs_base &&
-            tb->flags == flags) {
-
-            if (tb->page_addr[1] == -1) {
-                /* done, we have a match */
-                break;
-            } else {
-                /* check next page if needed */
-                target_ulong virt_page2 = (pc & TARGET_PAGE_MASK) +
-                                          TARGET_PAGE_SIZE;
-                tb_page_addr_t phys_page2 = get_page_addr_code(env, virt_page2);
-
-                if (tb->page_addr[1] == phys_page2) {
-                    break;
-                }
+    const TranslationBlock *tb = p;
+    const struct tb_desc *desc = d;
+
+    if (tb->pc == desc->pc &&
+        tb->page_addr[0] == desc->phys_page1 &&
+        tb->cs_base == desc->cs_base &&
+        tb->flags == desc->flags &&
+        !atomic_read(&tb->invalid)) {
+        /* check next page if needed */
+        if (tb->page_addr[1] == -1) {
+            return true;
+        } else {
+            tb_page_addr_t phys_page2;
+            target_ulong virt_page2;
+
+            virt_page2 = (desc->pc & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
+            phys_page2 = get_page_addr_code(desc->env, virt_page2);
+            if (tb->page_addr[1] == phys_page2) {
+                return true;
             }
         }
-
-        ptb1 = &tb->phys_hash_next;
-        tb = *ptb1;
     }
-
-    if (tb) {
-        /* Move the TB to the head of the list */
-        *ptb1 = tb->phys_hash_next;
-        tb->phys_hash_next = *tb_hash_head;
-        *tb_hash_head = tb;
-    }
-    return tb;
+    return false;
 }
 
-static TranslationBlock *tb_find_slow(CPUState *cpu,
-                                      target_ulong pc,
-                                      target_ulong cs_base,
-                                      uint32_t flags)
+static TranslationBlock *tb_htable_lookup(CPUState *cpu,
+                                          target_ulong pc,
+                                          target_ulong cs_base,
+                                          uint32_t flags)
 {
-    TranslationBlock *tb;
-
-    tb = tb_find_physical(cpu, pc, cs_base, flags);
-    if (tb) {
-        goto found;
-    }
-
-#ifdef CONFIG_USER_ONLY
-    /* mmap_lock is needed by tb_gen_code, and mmap_lock must be
-     * taken outside tb_lock.  Since we're momentarily dropping
-     * tb_lock, there's a chance that our desired tb has been
-     * translated.
-     */
-    tb_unlock();
-    mmap_lock();
-    tb_lock();
-    tb = tb_find_physical(cpu, pc, cs_base, flags);
-    if (tb) {
-        mmap_unlock();
-        goto found;
-    }
-#endif
-
-    /* if no translated code available, then translate it now */
-    tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
-
-#ifdef CONFIG_USER_ONLY
-    mmap_unlock();
-#endif
-
-found:
-    /* we add the TB in the virtual pc hash table */
-    cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;
-    return tb;
+    tb_page_addr_t phys_pc;
+    struct tb_desc desc;
+    uint32_t h;
+
+    desc.env = (CPUArchState *)cpu->env_ptr;
+    desc.cs_base = cs_base;
+    desc.flags = flags;
+    desc.pc = pc;
+    phys_pc = get_page_addr_code(desc.env, pc);
+    desc.phys_page1 = phys_pc & TARGET_PAGE_MASK;
+    h = tb_hash_func(phys_pc, pc, flags);
+    return qht_lookup(&tcg_ctx.tb_ctx.htable, tb_cmp, &desc, h);
 }
 
-static inline TranslationBlock *tb_find_fast(CPUState *cpu,
-                                             TranslationBlock **last_tb,
-                                             int tb_exit)
+static inline TranslationBlock *tb_find(CPUState *cpu,
+                                        TranslationBlock *last_tb,
+                                        int tb_exit)
 {
     CPUArchState *env = (CPUArchState *)cpu->env_ptr;
     TranslationBlock *tb;
     target_ulong cs_base, pc;
     uint32_t flags;
+    bool have_tb_lock = false;
 
     /* we record a subset of the CPU state. It will
        always be the same before a given translated block
        is executed. */
     cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
-    tb_lock();
-    tb = cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];
+    tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]);
     if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
                  tb->flags != flags)) {
-        tb = tb_find_slow(cpu, pc, cs_base, flags);
+        tb = tb_htable_lookup(cpu, pc, cs_base, flags);
+        if (!tb) {
+
+            /* mmap_lock is needed by tb_gen_code, and mmap_lock must be
+             * taken outside tb_lock. As system emulation is currently
+             * single threaded the locks are NOPs.
+             */
+            mmap_lock();
+            tb_lock();
+            have_tb_lock = true;
+
+            /* There's a chance that our desired tb has been translated while
+             * taking the locks so we check again inside the lock.
+             */
+            tb = tb_htable_lookup(cpu, pc, cs_base, flags);
+            if (!tb) {
+                /* if no translated code available, then translate it now */
+                tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
+            }
+
+            mmap_unlock();
+        }
+
+        /* We add the TB in the virtual pc hash table for the fast lookup */
+        atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb);
     }
-    if (cpu->tb_flushed) {
-        /* Ensure that no TB jump will be modified as the
-         * translation buffer has been flushed.
-         */
-        *last_tb = NULL;
-        cpu->tb_flushed = false;
+#ifndef CONFIG_USER_ONLY
+    /* We don't take care of direct jumps when address mapping changes in
+     * system emulation. So it's not safe to make a direct jump to a TB
+     * spanning two pages because the mapping for the second page can change.
+     */
+    if (tb->page_addr[1] != -1) {
+        last_tb = NULL;
     }
+#endif
     /* See if we can patch the calling TB. */
-    if (*last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
-        tb_add_jump(*last_tb, tb_exit, tb);
+    if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
+        if (!have_tb_lock) {
+            tb_lock();
+            have_tb_lock = true;
+        }
+        if (!tb->invalid) {
+            tb_add_jump(last_tb, tb_exit, tb);
+        }
+    }
+    if (have_tb_lock) {
+        tb_unlock();
     }
-    tb_unlock();
     return tb;
 }
 
@@ -427,8 +419,7 @@ static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
     } else if (replay_has_exception()
                && cpu->icount_decr.u16.low + cpu->icount_extra == 0) {
         /* try to cause an exception pending in the log */
-        TranslationBlock *last_tb = NULL; /* Avoid chaining TBs */
-        cpu_exec_nocache(cpu, 1, tb_find_fast(cpu, &last_tb, 0), true);
+        cpu_exec_nocache(cpu, 1, tb_find(cpu, NULL, 0), true);
         *ret = -1;
         return true;
 #endif
@@ -598,21 +589,19 @@ int cpu_exec(CPUState *cpu)
     init_delay_params(&sc, cpu);
 
     for(;;) {
-        TranslationBlock *tb, *last_tb;
-        int tb_exit = 0;
-
         /* prepare setjmp context for exception handling */
         if (sigsetjmp(cpu->jmp_env, 0) == 0) {
+            TranslationBlock *tb, *last_tb = NULL;
+            int tb_exit = 0;
+
             /* if an exception is pending, we execute it here */
             if (cpu_handle_exception(cpu, &ret)) {
                 break;
             }
 
-            last_tb = NULL; /* forget the last executed TB after exception */
-            cpu->tb_flushed = false; /* reset before first TB lookup */
             for(;;) {
                 cpu_handle_interrupt(cpu, &last_tb);
-                tb = tb_find_fast(cpu, &last_tb, tb_exit);
+                tb = tb_find(cpu, last_tb, tb_exit);
                 cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc);
                 /* Try to align the host and virtual clocks
                    if the guest is in advance */