PCI config space is little-endian, so on a big-endian host we need to
perform byte swaps for values as they are passed to and received from
the generic PCI config space access machinery.

Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>
---
 hw/remote/vfio-user-obj.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index 9f5e385668..46a2036bd1 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -281,7 +281,7 @@ static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf,
     while (bytes > 0) {
         len = (bytes > pci_access_width) ? pci_access_width : bytes;
         if (is_write) {
-            memcpy(&val, ptr, len);
+            val = ldn_le_p(ptr, len);
             pci_host_config_write_common(o->pci_dev, offset,
                                          pci_config_size(o->pci_dev),
                                          val, len);
@@ -289,7 +289,7 @@ static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf,
         } else {
             val = pci_host_config_read_common(o->pci_dev, offset,
                                               pci_config_size(o->pci_dev), len);
-            memcpy(ptr, &val, len);
+            stn_le_p(ptr, len, val);
             trace_vfu_cfg_read(offset, val);
         }
         offset += len;
-- 
2.34.1

> On Nov 1, 2023, at 9:16 AM, Mattias Nissler <mnissler@rivosinc.com> wrote:
> 
> PCI config space is little-endian, so on a big-endian host we need to
> perform byte swaps for values as they are passed to and received from
> the generic PCI config space access machinery.
> 
> Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>

Reviewed-by: Jagannathan Raman <jag.raman@oracle.com>

> ---
> hw/remote/vfio-user-obj.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
> index 9f5e385668..46a2036bd1 100644
> --- a/hw/remote/vfio-user-obj.c
> +++ b/hw/remote/vfio-user-obj.c
> @@ -281,7 +281,7 @@ static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf,
>     while (bytes > 0) {
>         len = (bytes > pci_access_width) ? pci_access_width : bytes;
>         if (is_write) {
> -            memcpy(&val, ptr, len);
> +            val = ldn_le_p(ptr, len);
>             pci_host_config_write_common(o->pci_dev, offset,
>                                          pci_config_size(o->pci_dev),
>                                          val, len);
> @@ -289,7 +289,7 @@ static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf,
>         } else {
>             val = pci_host_config_read_common(o->pci_dev, offset,
>                                               pci_config_size(o->pci_dev), len);
> -            memcpy(ptr, &val, len);
> +            stn_le_p(ptr, len, val);
>             trace_vfu_cfg_read(offset, val);
>         }
>         offset += len;
> -- 
> 2.34.1
>