From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57CE9C433EF for ; Mon, 18 Jul 2022 06:54:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233463AbiGRGyr (ORCPT ); Mon, 18 Jul 2022 02:54:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232753AbiGRGyp (ORCPT ); Mon, 18 Jul 2022 02:54:45 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 523A965AE for ; Sun, 17 Jul 2022 23:54:44 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1658127281; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=F3oMg+xgvxHikv+tJ6oZey82TaGFT5DoD5cvGkQB4iU=; b=ryHT9HdE6knXP+ik6pAtNLdqHISeKr0/wua7GfbXQ6XFzUOQ5XufTU1THvP1T5m6kpAx7/ fIjSXgZCp62b1vaj8d+IK5PN9UKb54EMzZmmbenI1UvdlXg+3OkUsfALtg7OkgEFXIrtei TVqYXGwgWPB5h1nlqm68ZnCgAh8tRMge3bXxjvWaNK1UBD2AAuB0sRs/A5jSt4QoeOxDZ+ pmSJ9RBmHop5RpE5hvR9rrskc6xfUTQojF2ZerVtU2v1kee+JBXVevcViOfdYXnvgMknFw U240yuCKlqI9yPVgkT2wfDHvpl3nen5oekXJ56/1+jtBU3excoe7hK7eKd79ow== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1658127281; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=F3oMg+xgvxHikv+tJ6oZey82TaGFT5DoD5cvGkQB4iU=; b=kDoDPFYp7z/wNjK3iD62+BH0V1nUNF/QdqIfNDmk8rvM5etzesX/WQC5n0vz7Pk5fll368 nKwXIeQS5i0E0HBA== To: Juergen Gross , Andrew Cooper , LKML Cc: "x86@kernel.org" , Linus Torvalds , Tim Chen , Josh Poimboeuf , Pawan Gupta , Johannes Wikner , Alyssa Milburn , Jann Horn , "H.J. Lu" , Joao Moreira , Joseph Nuzman , Steven Rostedt Subject: Re: [patch 02/38] x86/cpu: Use native_wrmsrl() in load_percpu_segment() In-Reply-To: <70b03d06-6ab9-1693-f811-f784a7dced76@suse.com> References: <20220716230344.239749011@linutronix.de> <20220716230952.787452088@linutronix.de> <0bec8fe2-d1e3-f01c-6e52-06ab542efdd8@citrix.com> <87zgh7wo91.ffs@tglx> <87tu7fwlhr.ffs@tglx> <87r12jwl9l.ffs@tglx> <87o7xnwgl3.ffs@tglx> <70b03d06-6ab9-1693-f811-f784a7dced76@suse.com> Date: Mon, 18 Jul 2022 08:54:41 +0200 Message-ID: <87lesqx64u.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 18 2022 at 07:11, Juergen Gross wrote: > On 17.07.22 23:54, Thomas Gleixner wrote: >> void __init native_smp_prepare_boot_cpu(void) >> { >> int me = smp_processor_id(); >> - switch_to_new_gdt(me); >> + >> + /* SMP invokes this from setup_per_cpu_areas() */ >> + if (!IS_ENABLED(CONFIG_SMP)) >> + switch_to_real_gdt(me); >> + >> /* already set me in cpu_online_mask in boot_cpu_init() */ >> cpumask_set_cpu(me, cpu_callout_mask); >> cpu_set_state_online(me); >> --- a/arch/x86/xen/enlighten_pv.c >> +++ b/arch/x86/xen/enlighten_pv.c >> @@ -1164,7 +1164,7 @@ static void __init xen_setup_gdt(int cpu >> pv_ops.cpu.write_gdt_entry = xen_write_gdt_entry_boot; >> pv_ops.cpu.load_gdt = xen_load_gdt_boot; >> >> - switch_to_new_gdt(cpu); >> + switch_to_real_gdt(cpu); > > ... can't you use the paravirt variant of load_gdt in switch_to_real_gdt() ? That does not solve the problem of having a disagreement between GDT and GS_BASE. Let me dig into this some more. Thanks, tglx