[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 18/19] memory: Introduce DEVICE_HOST_ENDIAN for ram d
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 18/19] memory: Introduce DEVICE_HOST_ENDIAN for ram device |
Date: |
Tue, 28 Feb 2017 17:14:01 +0100 |
From: Yongji Xie <address@hidden>
At the moment ram device's memory regions are DEVICE_NATIVE_ENDIAN. It's
incorrect. This memory region is backed by a MMIO area in host, so the
uint64_t data that MemoryRegionOps read from/write to this area should be
host-endian rather than target-endian. Hence, current code does not work
when target and host endianness are different which is the most common case
on PPC64. To fix it, this introduces DEVICE_HOST_ENDIAN for the ram device.
This has been tested on PPC64 BE/LE host/guest in all possible combinations
including TCG.
Suggested-by: Paolo Bonzini <address@hidden>
Signed-off-by: Yongji Xie <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
include/exec/cpu-common.h | 6 ++++++
memory.c | 2 +-
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index bd15853..eef74df 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -36,6 +36,12 @@ enum device_endian {
DEVICE_LITTLE_ENDIAN,
};
+#if defined(HOST_WORDS_BIGENDIAN)
+#define DEVICE_HOST_ENDIAN DEVICE_BIG_ENDIAN
+#else
+#define DEVICE_HOST_ENDIAN DEVICE_LITTLE_ENDIAN
+#endif
+
/* address in the RAM (different from a physical address) */
#if defined(CONFIG_XEN_BACKEND)
typedef uint64_t ram_addr_t;
diff --git a/memory.c b/memory.c
index d61caee..573fa6e 100644
--- a/memory.c
+++ b/memory.c
@@ -1182,7 +1182,7 @@ static void memory_region_ram_device_write(void *opaque,
hwaddr addr,
static const MemoryRegionOps ram_device_mem_ops = {
.read = memory_region_ram_device_read,
.write = memory_region_ram_device_write,
- .endianness = DEVICE_NATIVE_ENDIAN,
+ .endianness = DEVICE_HOST_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 8,
--
2.9.3