The CMB is marked as DEVICE_LITTLE_ENDIAN, so the data must be
read/written as if it was little-endian output (in the case of
big endian, we get two swaps, one in the memory core and one
in nvme.c).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/block/nvme.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 5d92794ef7..8a12fba24f 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1175,16 +1175,13 @@ static void nvme_cmb_write(void *opaque, hwaddr addr, uint64_t data,
     unsigned size)
 {
     NvmeCtrl *n = (NvmeCtrl *)opaque;
-    memcpy(&n->cmbuf[addr], &data, size);
+    stn_le_p(&n->cmbuf[addr], size, data);
 }
 
 static uint64_t nvme_cmb_read(void *opaque, hwaddr addr, unsigned size)
 {
-    uint64_t val;
     NvmeCtrl *n = (NvmeCtrl *)opaque;
-
-    memcpy(&val, &n->cmbuf[addr], size);
-    return val;
+    return ldn_le_p(&n->cmbuf[addr], size);
 }
 
 static const MemoryRegionOps nvme_cmb_ops = {
-- 
2.19.1

On 22 November 2018 at 18:23, Paolo Bonzini <pbonzini@redhat.com> wrote:
> The CMB is marked as DEVICE_LITTLE_ENDIAN, so the data must be
> read/written as if it was little-endian output (in the case of
> big endian, we get two swaps, one in the memory core and one
> in nvme.c).
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/block/nvme.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)

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

This is sufficient to get the nvme-test to pass on sparc
(big-endian host).

thanks
-- PMM

Am 22.11.2018 um 19:23 hat Paolo Bonzini geschrieben:
> The CMB is marked as DEVICE_LITTLE_ENDIAN, so the data must be
> read/written as if it was little-endian output (in the case of
> big endian, we get two swaps, one in the memory core and one
> in nvme.c).
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Thanks, applied to the block branch.

Kevin