Patchwork [for,1.6,1/2] memory: Provide separate handling of unassigned io ports accesses

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Submitter Jan Kiszka
Date Aug. 9, 2013, 12:01 p.m.
Message ID <5c0f4c470f93a477cf12751a8106d728a3c319d8.1376049708.git.jan.kiszka@siemens.com>
Download mbox | patch
Permalink /patch/266014/
State New
Headers show

Comments

Jan Kiszka - Aug. 9, 2013, 12:01 p.m.
Accesses to unassigned io ports shall return -1 on read and be ignored
on write. Ensure these properties via dedicated ops, decoupling us from
the memory core's handling of unassigned accesses.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 exec.c                |    3 ++-
 include/exec/ioport.h |    2 ++
 ioport.c              |   16 ++++++++++++++++
 3 files changed, 20 insertions(+), 1 deletions(-)
Anthony Liguori - Aug. 12, 2013, 2:34 p.m.
Jan Kiszka <jan.kiszka@siemens.com> writes:

> Accesses to unassigned io ports shall return -1 on read and be ignored
> on write. Ensure these properties via dedicated ops, decoupling us from
> the memory core's handling of unassigned accesses.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Breaks the build (linux-user):

  LINK  xtensa-softmmu/qemu-system-xtensa
  CC    alpha-linux-user/exec.o
In file included from /home/aliguori/git/qemu/include/hw/hw.h:11:0,
                 from /home/aliguori/git/qemu/exec.c:30:
/home/aliguori/git/qemu/include/exec/ioport.h:48:1: error: unknown type name ‘MemoryRegionOps’
make[1]: *** [exec.o] Error 1
make: *** [subdir-alpha-linux-user] Error 2

Regards,

Anthony Liguori

> ---
>  exec.c                |    3 ++-
>  include/exec/ioport.h |    2 ++
>  ioport.c              |   16 ++++++++++++++++
>  3 files changed, 20 insertions(+), 1 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 3ca9381..9ed598f 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1820,7 +1820,8 @@ static void memory_map_init(void)
>      address_space_init(&address_space_memory, system_memory, "memory");
>  
>      system_io = g_malloc(sizeof(*system_io));
> -    memory_region_init(system_io, NULL, "io", 65536);
> +    memory_region_init_io(system_io, NULL, &unassigned_io_ops, NULL, "io",
> +                          65536);
>      address_space_init(&address_space_io, system_io, "I/O");
>  
>      memory_listener_register(&core_memory_listener, &address_space_memory);
> diff --git a/include/exec/ioport.h b/include/exec/ioport.h
> index bdd4e96..84f7f85 100644
> --- a/include/exec/ioport.h
> +++ b/include/exec/ioport.h
> @@ -45,6 +45,8 @@ typedef struct MemoryRegionPortio {
>  
>  #define PORTIO_END_OF_LIST() { }
>  
> +extern const MemoryRegionOps unassigned_io_ops;
> +
>  void cpu_outb(pio_addr_t addr, uint8_t val);
>  void cpu_outw(pio_addr_t addr, uint16_t val);
>  void cpu_outl(pio_addr_t addr, uint32_t val);
> diff --git a/ioport.c b/ioport.c
> index 79b7f1a..707cce8 100644
> --- a/ioport.c
> +++ b/ioport.c
> @@ -44,6 +44,22 @@ typedef struct MemoryRegionPortioList {
>      MemoryRegionPortio ports[];
>  } MemoryRegionPortioList;
>  
> +static uint64_t unassigned_io_read(void *opaque, hwaddr addr, unsigned size)
> +{
> +    return -1ULL;
> +}
> +
> +static void unassigned_io_write(void *opaque, hwaddr addr, uint64_t val,
> +                                unsigned size)
> +{
> +}
> +
> +const MemoryRegionOps unassigned_io_ops = {
> +    .read = unassigned_io_read,
> +    .write = unassigned_io_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
>  void cpu_outb(pio_addr_t addr, uint8_t val)
>  {
>      LOG_IOPORT("outb: %04"FMT_pioaddr" %02"PRIx8"\n", addr, val);
> -- 
> 1.7.3.4

Patch

diff --git a/exec.c b/exec.c
index 3ca9381..9ed598f 100644
--- a/exec.c
+++ b/exec.c
@@ -1820,7 +1820,8 @@  static void memory_map_init(void)
     address_space_init(&address_space_memory, system_memory, "memory");
 
     system_io = g_malloc(sizeof(*system_io));
-    memory_region_init(system_io, NULL, "io", 65536);
+    memory_region_init_io(system_io, NULL, &unassigned_io_ops, NULL, "io",
+                          65536);
     address_space_init(&address_space_io, system_io, "I/O");
 
     memory_listener_register(&core_memory_listener, &address_space_memory);
diff --git a/include/exec/ioport.h b/include/exec/ioport.h
index bdd4e96..84f7f85 100644
--- a/include/exec/ioport.h
+++ b/include/exec/ioport.h
@@ -45,6 +45,8 @@  typedef struct MemoryRegionPortio {
 
 #define PORTIO_END_OF_LIST() { }
 
+extern const MemoryRegionOps unassigned_io_ops;
+
 void cpu_outb(pio_addr_t addr, uint8_t val);
 void cpu_outw(pio_addr_t addr, uint16_t val);
 void cpu_outl(pio_addr_t addr, uint32_t val);
diff --git a/ioport.c b/ioport.c
index 79b7f1a..707cce8 100644
--- a/ioport.c
+++ b/ioport.c
@@ -44,6 +44,22 @@  typedef struct MemoryRegionPortioList {
     MemoryRegionPortio ports[];
 } MemoryRegionPortioList;
 
+static uint64_t unassigned_io_read(void *opaque, hwaddr addr, unsigned size)
+{
+    return -1ULL;
+}
+
+static void unassigned_io_write(void *opaque, hwaddr addr, uint64_t val,
+                                unsigned size)
+{
+}
+
+const MemoryRegionOps unassigned_io_ops = {
+    .read = unassigned_io_read,
+    .write = unassigned_io_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
 void cpu_outb(pio_addr_t addr, uint8_t val)
 {
     LOG_IOPORT("outb: %04"FMT_pioaddr" %02"PRIx8"\n", addr, val);