ide: fail I/O to empty disk

[qemu.git] / exec.c

diff --git a/exec.c b/exec.c
index 8916825688ab48634ee5c4d71bbcf9056c250521..b81677ade9c7c67add6c4adbf4ceeb3d0d5ffe26 100644 (file)
--- a/exec.c
+++ b/exec.c
@@ -511,7 +511,7 @@ static void code_gen_alloc(unsigned long tb_size)
         if (code_gen_buffer_size > (512 * 1024 * 1024))
             code_gen_buffer_size = (512 * 1024 * 1024);
 #elif defined(__arm__)
-        /* Keep the buffer no bigger than 16GB to branch between blocks */
+        /* Keep the buffer no bigger than 16MB to branch between blocks */
         if (code_gen_buffer_size > 16 * 1024 * 1024)
             code_gen_buffer_size = 16 * 1024 * 1024;
 #elif defined(__s390x__)
@@ -1876,8 +1876,18 @@ static CPUTLBEntry s_cputlb_empty_entry = {
     .addend     = -1,
 };
 
-/* NOTE: if flush_global is true, also flush global entries (not
-   implemented yet) */
+/* NOTE:
+ * If flush_global is true (the usual case), flush all tlb entries.
+ * If flush_global is false, flush (at least) all tlb entries not
+ * marked global.
+ *
+ * Since QEMU doesn't currently implement a global/not-global flag
+ * for tlb entries, at the moment tlb_flush() will also flush all
+ * tlb entries in the flush_global == false case. This is OK because
+ * CPU architectures generally permit an implementation to drop
+ * entries from the TLB at any time, so flushing more entries than
+ * required is only an efficiency issue, not a correctness issue.
+ */
 void tlb_flush(CPUState *env, int flush_global)
 {
     int i;
@@ -2096,7 +2106,7 @@ static bool is_romd(ram_addr_t pd)
     MemoryRegion *mr;
 
     pd &= ~TARGET_PAGE_MASK;
-    mr = io_mem_region[pd >> IO_MEM_SHIFT];
+    mr = io_mem_region[pd];
     return mr->rom_device && mr->readable;
 }
 
@@ -2556,8 +2566,7 @@ void cpu_register_physical_memory_log(MemoryRegionSection *section,
             ram_addr_t orig_memory = p->phys_offset;
             target_phys_addr_t start_addr2, end_addr2;
             int need_subpage = 0;
-            MemoryRegion *mr = io_mem_region[(orig_memory & ~TARGET_PAGE_MASK)
-                                             >> IO_MEM_SHIFT];
+            MemoryRegion *mr = io_mem_region[orig_memory & ~TARGET_PAGE_MASK];
 
             CHECK_SUBPAGE(addr, start_addr, start_addr2, end_addr, end_addr2,
                           need_subpage);
@@ -3378,7 +3387,7 @@ static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end,
     if ((memory & ~TARGET_PAGE_MASK) == io_mem_ram.ram_addr) {
         memory = io_mem_subpage_ram.ram_addr;
     }
-    memory = (memory >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+    memory &= IO_MEM_NB_ENTRIES - 1;
     for (; idx <= eidx; idx++) {
         mmio->sub_io_index[idx] = memory;
         mmio->region_offset[idx] = region_offset;
@@ -3438,14 +3447,13 @@ static int cpu_register_io_memory_fixed(int io_index, MemoryRegion *mr)
         if (io_index == -1)
             return io_index;
     } else {
-        io_index >>= IO_MEM_SHIFT;
         if (io_index >= IO_MEM_NB_ENTRIES)
             return -1;
     }
 
     io_mem_region[io_index] = mr;
 
-    return (io_index << IO_MEM_SHIFT);
+    return io_index;
 }
 
 int cpu_register_io_memory(MemoryRegion *mr)
@@ -3453,10 +3461,8 @@ int cpu_register_io_memory(MemoryRegion *mr)
     return cpu_register_io_memory_fixed(0, mr);
 }
 
-void cpu_unregister_io_memory(int io_table_address)
+void cpu_unregister_io_memory(int io_index)
 {
-    int io_index = io_table_address >> IO_MEM_SHIFT;
-
     io_mem_region[io_index] = NULL;
     io_mem_used[io_index] = 0;
 }
@@ -3568,7 +3574,7 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
         if (is_write) {
             if ((pd & ~TARGET_PAGE_MASK) != io_mem_ram.ram_addr) {
                 target_phys_addr_t addr1;
-                io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+                io_index = pd & (IO_MEM_NB_ENTRIES - 1);
                 addr1 = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
                 /* XXX: could force cpu_single_env to NULL to avoid
                    potential bugs */
@@ -3607,7 +3613,7 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
             if (!is_ram_rom_romd(pd)) {
                 target_phys_addr_t addr1;
                 /* I/O case */
-                io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+                io_index = pd & (IO_MEM_NB_ENTRIES - 1);
                 addr1 = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
                 if (l >= 4 && ((addr1 & 3) == 0)) {
                     /* 32 bit read access */
@@ -3829,7 +3835,7 @@ static inline uint32_t ldl_phys_internal(target_phys_addr_t addr,
 
     if (!is_ram_rom_romd(pd)) {
         /* I/O case */
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
         val = io_mem_read(io_index, addr, 4);
 #if defined(TARGET_WORDS_BIGENDIAN)
@@ -3890,7 +3896,7 @@ static inline uint64_t ldq_phys_internal(target_phys_addr_t addr,
 
     if (!is_ram_rom_romd(pd)) {
         /* I/O case */
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
 
         /* XXX This is broken when device endian != cpu endian.
@@ -3959,7 +3965,7 @@ static inline uint32_t lduw_phys_internal(target_phys_addr_t addr,
 
     if (!is_ram_rom_romd(pd)) {
         /* I/O case */
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
         val = io_mem_read(io_index, addr, 2);
 #if defined(TARGET_WORDS_BIGENDIAN)
@@ -4019,7 +4025,7 @@ void stl_phys_notdirty(target_phys_addr_t addr, uint32_t val)
     pd = p.phys_offset;
 
     if ((pd & ~TARGET_PAGE_MASK) != io_mem_ram.ram_addr) {
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
         io_mem_write(io_index, addr, val, 4);
     } else {
@@ -4050,7 +4056,7 @@ void stq_phys_notdirty(target_phys_addr_t addr, uint64_t val)
     pd = p.phys_offset;
 
     if ((pd & ~TARGET_PAGE_MASK) != io_mem_ram.ram_addr) {
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
 #ifdef TARGET_WORDS_BIGENDIAN
         io_mem_write(io_index, addr, val >> 32, 4);
@@ -4079,7 +4085,7 @@ static inline void stl_phys_internal(target_phys_addr_t addr, uint32_t val,
     pd = p.phys_offset;
 
     if ((pd & ~TARGET_PAGE_MASK) != io_mem_ram.ram_addr) {
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
 #if defined(TARGET_WORDS_BIGENDIAN)
         if (endian == DEVICE_LITTLE_ENDIAN) {
@@ -4152,7 +4158,7 @@ static inline void stw_phys_internal(target_phys_addr_t addr, uint32_t val,
     pd = p.phys_offset;
 
     if ((pd & ~TARGET_PAGE_MASK) != io_mem_ram.ram_addr) {
-        io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+        io_index = pd & (IO_MEM_NB_ENTRIES - 1);
         addr = (addr & ~TARGET_PAGE_MASK) + p.region_offset;
 #if defined(TARGET_WORDS_BIGENDIAN)
         if (endian == DEVICE_LITTLE_ENDIAN) {
@@ -4394,6 +4400,20 @@ tb_page_addr_t get_page_addr_code(CPUState *env1, target_ulong addr)
     return qemu_ram_addr_from_host_nofail(p);
 }
 
+/*
+ * A helper function for the _utterly broken_ virtio device model to find out if
+ * it's running on a big endian machine. Don't do this at home kids!
+ */
+bool virtio_is_big_endian(void);
+bool virtio_is_big_endian(void)
+{
+#if defined(TARGET_WORDS_BIGENDIAN)
+    return true;
+#else
+    return false;
+#endif
+}
+
 #define MMUSUFFIX _cmmu
 #undef GETPC
 #define GETPC() NULL