Commit c99a29e7 authored by Yongji Xie's avatar Yongji Xie Committed by Paolo Bonzini
Browse files

memory: Introduce DEVICE_HOST_ENDIAN for ram device 



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: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarYongji Xie <xyjxie@linux.vnet.ibm.com>
Message-Id: <1488171164-28319-1-git-send-email-xyjxie@linux.vnet.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 11953be7

include/exec/cpu-common.h

+6 −0
Original line number Diff line number Diff line
@@ -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;

memory.c

+1 −1
Original line number Diff line number Diff line
@@ -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,