[tip:x86/urgent] x86, amd, xen: Avoid NULL pointer paravirt references

[tip:x86/urgent] x86, amd, xen: Avoid NULL pointer paravirt references

[tip-bot for Konrad Rzeszutek Wilk]

Commit-ID:  1ab46fd319bcf1fcd9fb6311727d532b580e4eba
Gitweb:     http://git.kernel.org/tip/1ab46fd319bcf1fcd9fb6311727d532b580e4eba
Author:     Konrad Rzeszutek Wilk <konrad@darnok.org>
AuthorDate: Wed, 30 May 2012 18:23:56 -0400
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Wed, 30 May 2012 16:15:02 -0700

x86, amd, xen: Avoid NULL pointer paravirt references

Stub out MSR methods that aren't actually needed.  This fixes a crash
as Xen Dom0 on AMD Trinity systems.  A bigger patch should be added to
remove the paravirt machinery completely for the methods which
apparently have no users!

Reported-by: Andre Przywara <andre.przywara@amd.com>
Link: http://lkml.kernel.org/r/20120530222356.GA28417@andromeda.dapyr.net
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
---
 arch/x86/xen/enlighten.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 75f33b2..e74df95 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1116,7 +1116,10 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
 	.wbinvd = native_wbinvd,
 
 	.read_msr = native_read_msr_safe,
+	.rdmsr_regs = native_rdmsr_safe_regs,
 	.write_msr = xen_write_msr_safe,
+	.wrmsr_regs = native_wrmsr_safe_regs,
+
 	.read_tsc = native_read_tsc,
 	.read_pmc = native_read_pmc,