From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Wed, 26 Mar 2014 14:36:13 +0000 (+0100)
Subject: x86: identify which vcpu's CR4 is being badly modified
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~5342
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=29f7ec2a9231352de05523e88619e9cef9ed695c;p=xen.git

x86: identify which vcpu's CR4 is being badly modified

When the toolstack is setting vcpu state on behalf of a migrating guest, the
domain/vcpu reference from gdprintk() identifies the toolstack, not the
affected domain.

After this change, the error looks more like:

  (XEN) d0 attempted to change d6v0's CR4 flags 00002660 -> 01876000

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index b48f2dce79..796b7752c4 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -651,9 +651,9 @@ unsigned long pv_guest_cr4_fixup(const struct vcpu *v, unsigned long guest_cr4)
         hv_cr4_mask &= ~X86_CR4_OSXSAVE;
 
     if ( (guest_cr4 & hv_cr4_mask) != (hv_cr4 & hv_cr4_mask) )
-        gdprintk(XENLOG_WARNING,
-                 "Attempt to change CR4 flags %08lx -> %08lx\n",
-                 hv_cr4, guest_cr4);
+        printk(XENLOG_G_WARNING
+               "d%d attempted to change %pv's CR4 flags %08lx -> %08lx\n",
+               current->domain->domain_id, v, hv_cr4, guest_cr4);
 
     return (hv_cr4 & hv_cr4_mask) | (guest_cr4 & ~hv_cr4_mask);
 }