[ 3.5.yuz extended stable ] Patch "xen/bootup: allow read_tscp call for Xen PV guests." has been added to staging queue

Herton Ronaldo Krzesinski herton.krzesinski at canonical.com
Thu Nov 15 05:50:21 UTC 2012

This is a note to let you know that I have just added a patch titled

    xen/bootup: allow read_tscp call for Xen PV guests.

to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.yuz tree, see



>From 2e986cac30ba1afe4e03ba4f2e79556cc7846481 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
Date: Wed, 10 Oct 2012 13:30:47 -0400
Subject: [PATCH] xen/bootup: allow read_tscp call for Xen PV guests.

commit cd0608e71e9757f4dae35bcfb4e88f4d1a03a8ab upstream.

The hypervisor will trap it. However without this patch,
we would crash as the .read_tscp is set to NULL. This patch
fixes it and sets it to the native_read_tscp call.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
 arch/x86/xen/enlighten.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 405307f..93dcfdc 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1131,6 +1131,8 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
 	.read_tsc = native_read_tsc,
 	.read_pmc = native_read_pmc,

+	.read_tscp = native_read_tscp,
 	.iret = xen_iret,
 	.irq_enable_sysexit = xen_sysexit,
 #ifdef CONFIG_X86_64

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