From: Jan Beulich <jbeulich@suse.com>
Date: Wed, 10 Jun 2015 13:12:16 +0000 (+0100)
Subject: xen/pt: mark all PCIe capability bits read-only
X-Git-Tag: xen-4.4.3-rc1~5
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=65e39c802e62d2427f5c3df2c597e0c3780d50f0;p=qemu-xen-4.4-testing.git

xen/pt: mark all PCIe capability bits read-only

xen_pt_emu_reg_pcie[]'s PCI_EXP_DEVCAP needs to cover all bits as read-
only to avoid unintended write-back (just a precaution, the field ought
to be read-only in hardware).

This is a preparatory patch for XSA-131.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---

diff --git a/hw/pass-through.c b/hw/pass-through.c
index 9ec921140..67c0fd07a 100644
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -577,7 +577,7 @@ static struct pt_reg_info_tbl pt_emu_reg_pcie_tbl[] = {
         .offset     = PCI_EXP_DEVCAP,
         .size       = 4,
         .init_val   = 0x00000000,
-        .ro_mask    = 0x1FFCFFFF,
+        .ro_mask    = 0xFFFFFFFF,
         .emu_mask   = 0x10000000,
         .init       = pt_common_reg_init,
         .u.dw.read  = pt_long_reg_read,