qcow2: Inform block layer about discard boundaries

[mirror_qemu.git] / cpu-exec.c

diff --git a/cpu-exec.c b/cpu-exec.c
index 602d0c4d0cc850ddaab79394d065a405bc8582aa..5d9710a1eaf2b06913eb469d918f722b61764652 100644 (file)
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -225,57 +225,57 @@ 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) {
+        /* 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;
     }
+    return false;
+}
 
-    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;
+static TranslationBlock *tb_find_physical(CPUState *cpu,
+                                          target_ulong pc,
+                                          target_ulong cs_base,
+                                          uint32_t flags)
+{
+    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 TranslationBlock *tb_find_slow(CPUState *cpu,
@@ -345,6 +345,15 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu,
         *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);
@@ -599,17 +608,16 @@ 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);