[Qemu-devel] [PATCH v3 0/2] Fix unassigned memory and I/O access handling

[Qemu-devel] [PATCH v3 0/2] Fix unassigned memory and I/O access handling

[Jan Kiszka]

Repost of what missed the 1.6 release.

Jan Kiszka (2):
  memory: Provide separate handling of unassigned io ports accesses
  Revert "memory: Return -1 again on reads from unsigned regions"

 exec.c                |  3 ++-
 include/exec/ioport.h |  4 ++++
 ioport.c              | 16 ++++++++++++++++
 memory.c              |  2 +-
 4 files changed, 23 insertions(+), 2 deletions(-)

-- 
1.8.1.1.298.ge7eed54

[Qemu-devel] [PATCH v3 1/2] memory: Provide separate handling of unassigned io ports accesses

[Jan Kiszka]

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 |  4 ++++
 ioport.c              | 16 ++++++++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

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..b3848be 100644
--- a/include/exec/ioport.h
+++ b/include/exec/ioport.h
@@ -45,6 +45,10 @@ typedef struct MemoryRegionPortio {
 
 #define PORTIO_END_OF_LIST() { }
 
+#ifndef CONFIG_USER_ONLY
+extern const MemoryRegionOps unassigned_io_ops;
+#endif
+
 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);
-- 
1.8.1.1.298.ge7eed54

[Qemu-devel] [PATCH v3 2/2] Revert "memory: Return -1 again on reads from unsigned regions"

[Jan Kiszka]

This reverts commit 9b8c69243585a32d14b9bb9fcd52c37b0b5a1b71.

The commit was wrong: We only return -1 on invalid accesses, not on
valid but unbacked ones. This broke various corner cases.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/memory.c b/memory.c
index 886f838..5a10fd0 100644
--- a/memory.c
+++ b/memory.c
@@ -872,7 +872,7 @@ static uint64_t unassigned_mem_read(void *opaque, hwaddr addr,
     if (current_cpu != NULL) {
         cpu_unassigned_access(current_cpu, addr, false, false, 0, size);
     }
-    return -1ULL;
+    return 0;
 }
 
 static void unassigned_mem_write(void *opaque, hwaddr addr,
-- 
1.8.1.1.298.ge7eed54

Re: [Qemu-devel] [PATCH v3 0/2] Fix unassigned memory and I/O access handling

[Peter Maydell]

On 2 September 2013 17:43, Jan Kiszka <jan.kiszka@siemens.com> wrote:
> Repost of what missed the 1.6 release.
>
> Jan Kiszka (2):
>   memory: Provide separate handling of unassigned io ports accesses
>   Revert "memory: Return -1 again on reads from unsigned regions"

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

This fixes booting of integratorcp.

thanks
-- PMM

Re: [Qemu-devel] [PATCH v3 0/2] Fix unassigned memory and I/O access handling

[Andreas Färber]

Am 02.09.2013 18:43, schrieb Jan Kiszka:
> Repost of what missed the 1.6 release.
> 
> Jan Kiszka (2):
>   memory: Provide separate handling of unassigned io ports accesses
>   Revert "memory: Return -1 again on reads from unsigned regions"

These were:

Tested-by: Andreas Färber <andreas.faerber@web.de>

and they're also missing

Cc: qemu-stable@nongnu.org

in the commit messages to get them into 1.6.1 now.

Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg