From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964940Ab2JSD0J (ORCPT ); Thu, 18 Oct 2012 23:26:09 -0400 Received: from mail.kernel.org ([198.145.19.201]:54388 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758014Ab2JSDRS (ORCPT ); Thu, 18 Oct 2012 23:17:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Konrad Rzeszutek Wilk Subject: [ 10/37] xen/bootup: allow {read|write}_cr8 pvops call. Date: Thu, 18 Oct 2012 20:16:33 -0700 Message-Id: <20121019031304.506514778@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.rc0.18.gf84667d In-Reply-To: <20121019031302.789593147@linuxfoundation.org> References: <20121019031302.789593147@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konrad Rzeszutek Wilk commit 1a7bbda5b1ab0e02622761305a32dc38735b90b2 upstream. We actually do not do anything about it. Just return a default value of zero and if the kernel tries to write anything but 0 we BUG_ON. This fixes the case when an user tries to suspend the machine and it blows up in save_processor_state b/c 'read_cr8' is set to NULL and we get: kernel BUG at /home/konrad/ssd/linux/arch/x86/include/asm/paravirt.h:100! invalid opcode: 0000 [#1] SMP Pid: 2687, comm: init.late Tainted: G O 3.6.0upstream-00002-gac264ac-dirty #4 Bochs Bochs RIP: e030:[] [] save_processor_state+0x212/0x270 .. snip.. Call Trace: [] do_suspend_lowlevel+0xf/0xac [] ? x86_acpi_suspend_lowlevel+0x10c/0x150 [] acpi_suspend_enter+0x57/0xd5 Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- arch/x86/xen/enlighten.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -803,7 +803,16 @@ static void xen_write_cr4(unsigned long native_write_cr4(cr4); } - +#ifdef CONFIG_X86_64 +static inline unsigned long xen_read_cr8(void) +{ + return 0; +} +static inline void xen_write_cr8(unsigned long val) +{ + BUG_ON(val); +} +#endif static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) { int ret; @@ -968,6 +977,11 @@ static const struct pv_cpu_ops xen_cpu_o .read_cr4_safe = native_read_cr4_safe, .write_cr4 = xen_write_cr4, +#ifdef CONFIG_X86_64 + .read_cr8 = xen_read_cr8, + .write_cr8 = xen_write_cr8, +#endif + .wbinvd = native_wbinvd, .read_msr = native_read_msr_safe,