From 33e907b7be4636a726d40a3d68cab24574bc597a Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Wed, 21 Apr 2021 22:30:05 -0400
Subject: [PATCH 6/8] xhci: fix valid.max_access_size to access address
 registers
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RH-Author: Jon Maloy <jmaloy@redhat.com>
Message-id: <20210421223006.19650-6-jmaloy@redhat.com>
Patchwork-id: 101483
O-Subject: [RHEL-8.5.0 qemu-kvm PATCH v2 5/6] xhci: fix valid.max_access_size to access address registers
Bugzilla: 1944621
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

From: Laurent Vivier <lvivier@redhat.com>

QEMU XHCI advertises AC64 (64-bit addressing) but doesn't allow
64-bit mode access in "runtime" and "operational" MemoryRegionOps.

Set the max_access_size based on sizeof(dma_addr_t) as AC64 is set.

XHCI specs:
"If the xHC supports 64-bit addressing (AC64 = ‘1’), then software
should write 64-bit registers using only Qword accesses.  If a
system is incapable of issuing Qword accesses, then writes to the
64-bit address fields shall be performed using 2 Dword accesses;
low Dword-first, high-Dword second.  If the xHC supports 32-bit
addressing (AC64 = ‘0’), then the high Dword of registers containing
64-bit address fields are unused and software should write addresses
using only Dword accesses"

The problem has been detected with SLOF, as linux kernel always accesses
registers using 32-bit access even if AC64 is set and revealed by
5d971f9e6725 ("memory: Revert "memory: accept mismatching sizes in memory_region_access_valid"")

Suggested-by: Alexey Kardashevskiy <aik@au1.ibm.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-id: 20200721083322.90651-1-lvivier@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

(cherry picked from commit 8e67fda2dd6202ccec093fda561107ba14830a17)
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 hw/usb/hcd-xhci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 646c78cde9..ab449bb003 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -3183,7 +3183,7 @@ static const MemoryRegionOps xhci_oper_ops = {
     .read = xhci_oper_read,
     .write = xhci_oper_write,
     .valid.min_access_size = 4,
-    .valid.max_access_size = 4,
+    .valid.max_access_size = sizeof(dma_addr_t),
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
@@ -3199,7 +3199,7 @@ static const MemoryRegionOps xhci_runtime_ops = {
     .read = xhci_runtime_read,
     .write = xhci_runtime_write,
     .valid.min_access_size = 4,
-    .valid.max_access_size = 4,
+    .valid.max_access_size = sizeof(dma_addr_t),
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
-- 
2.27.0