Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932910AbbGGUob (ORCPT ); Tue, 7 Jul 2015 16:44:31 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:29459 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932710AbbGGUoW (ORCPT ); Tue, 7 Jul 2015 16:44:22 -0400 Message-ID: <559C39BD.5030300@oracle.com> Date: Tue, 07 Jul 2015 16:42:37 -0400 From: Boris Ostrovsky User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: david.vrabel@citrix.com, roger.pau@citrix.com, elena.ufimtseva@oracle.com, stefano.stabellini@eu.citrix.com, tim@xen.org, jbeulich@suse.com, andrew.cooper3@citrix.com, ian.campbell@citrix.com, wei.liu2@citrix.com, ian.jackson@eu.citrix.com, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/6] xen/x86/pvh: Set up descriptors for 32-bit PVH guests References: <1436240065-10813-1-git-send-email-boris.ostrovsky@oracle.com> <1436240065-10813-5-git-send-email-boris.ostrovsky@oracle.com> <20150707195424.GD6372@l.oracle.com> In-Reply-To: <20150707195424.GD6372@l.oracle.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2343 Lines: 74 On 07/07/2015 03:54 PM, Konrad Rzeszutek Wilk wrote: > On Mon, Jul 06, 2015 at 11:34:23PM -0400, Boris Ostrovsky wrote: >> Signed-off-by: Boris Ostrovsky >> --- >> arch/x86/xen/enlighten.c | 16 ++++++++++++---- >> 1 file changed, 12 insertions(+), 4 deletions(-) >> >> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c >> index 0b95c9b..7953e68 100644 >> --- a/arch/x86/xen/enlighten.c >> +++ b/arch/x86/xen/enlighten.c >> @@ -1362,12 +1362,12 @@ static void __init xen_boot_params_init_edd(void) >> static void __ref xen_setup_gdt(int cpu) >> { >> if (xen_feature(XENFEAT_auto_translated_physmap)) { >> -#ifdef CONFIG_X86_64 >> unsigned long dummy; >> >> - load_percpu_segment(cpu); /* We need to access per-cpu area */ >> + setup_stack_canary_segment(cpu); >> switch_to_new_gdt(cpu); /* GDT and GS set */ >> >> +#ifdef CONFIG_X86_64 >> /* We are switching of the Xen provided GDT to our HVM mode >> * GDT. The new GDT has __KERNEL_CS with CS.L = 1 >> * and we are jumping to reload it. >> @@ -1392,8 +1392,16 @@ static void __ref xen_setup_gdt(int cpu) >> loadsegment(ds, 0); >> loadsegment(fs, 0); >> #else >> - /* PVH: TODO Implement. */ >> - BUG(); >> + asm volatile ("ljmp %1,$1f\n" >> + "1:\n" >> + "movl %2,%0\n" >> + "movl %0,%%ss\n" >> + "movl %3,%0\n" >> + "movl %0,%%ds\n" >> + "movl %0,%%es\n" >> + : "=&r" (dummy) >> + : "i" (__KERNEL_CS), "i" (__KERNEL_DS), >> + "i" (__USER_DS)); >> #endif > Which comes out to: > ljmp $96,$1f #[KERNEL_CS] > 1: > movl $104,%eax #, dummy #[KERNEL_DS] > movl %eax,%ss # dummy > movl $123,%eax #, dummy #[USER_DS] > movl %eax,%ds # dummy > movl %eax,%es # dummy > > And that looks right Actually, now that look at this again I think I should just use loadsegment(), just like 64-bit code above. -boris > > Reviewed-by: Konrad Rzeszutek Wilk > >> return; /* PVH does not need any PV GDT ops. */ >> } >> -- >> 1.8.1.4 >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/