[RFC PATCH 5/5] hw/usb/hcd-xhci: allow unaligned access to Capability Registers

[Tomoyuki HIROSE]

According to xHCI spec rev 1.2, unaligned access to xHCI Host
Controller Capability Registers is not prohibited. In addition, the
limit of access size is also unspecified. Actually, some real devices
allow unaligned access and 8-byte access to these registers.

This commit makes it possible to unaligned access and 8-byte access to
Host Controller Capability Registers.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/143
Signed-off-by: Tomoyuki HIROSE <tomoyuki.hirose@igel.co.jp>
---
 hw/usb/hcd-xhci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index d85adaca0d..f35cbe526f 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -3165,9 +3165,11 @@ static const MemoryRegionOps xhci_cap_ops = {
     .read = xhci_cap_read,
     .write = xhci_cap_write,
     .valid.min_access_size = 1,
-    .valid.max_access_size = 4,
+    .valid.max_access_size = 8,
+    .valid.unaligned = true,
     .impl.min_access_size = 4,
     .impl.max_access_size = 4,
+    .impl.unaligned = false,
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
-- 
2.43.0