From patchwork Tue Apr 12 06:31:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 560442 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 B80C4C4707F for ; Tue, 12 Apr 2022 07:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353788AbiDLHhh (ORCPT ); Tue, 12 Apr 2022 03:37:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353752AbiDLHZx (ORCPT ); Tue, 12 Apr 2022 03:25:53 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2388B6269; Tue, 12 Apr 2022 00:04:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8CE35B81B4E; Tue, 12 Apr 2022 07:04:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AE93C385AA; Tue, 12 Apr 2022 07:04:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649747058; bh=1fAADtwZr8mUN51KJvbjJw10IrVyo6zwcuvu2c/R9yc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VEC2trbXL96FptfskRl2QQzWnpIAOOKTsZdM85u9pQvzpFKUqnvuwnnnP3/xyiGZy g/9YTmKOXbgm0KHCKu5kp5LmRy1bFxYEK9TlbHjAbKHFRpGs1f3x7G2ogro3eLHP8t gcT1ORp8ot84assD3cTWIp7DoBdqrp795dSW6L0s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Hansen , Pawan Gupta , Borislav Petkov , Linus Torvalds Subject: [PATCH 5.16 228/285] x86/pm: Save the MSR validity status at context setup Date: Tue, 12 Apr 2022 08:31:25 +0200 Message-Id: <20220412062950.241328993@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062943.670770901@linuxfoundation.org> References: <20220412062943.670770901@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pawan Gupta commit 73924ec4d560257004d5b5116b22a3647661e364 upstream. The mechanism to save/restore MSRs during S3 suspend/resume checks for the MSR validity during suspend, and only restores the MSR if its a valid MSR. This is not optimal, as an invalid MSR will unnecessarily throw an exception for every suspend cycle. The more invalid MSRs, higher the impact will be. Check and save the MSR validity at setup. This ensures that only valid MSRs that are guaranteed to not throw an exception will be attempted during suspend. Fixes: 7a9c2dd08ead ("x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume") Suggested-by: Dave Hansen Signed-off-by: Pawan Gupta Reviewed-by: Dave Hansen Acked-by: Borislav Petkov Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/power/cpu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -40,7 +40,8 @@ static void msr_save_context(struct save struct saved_msr *end = msr + ctxt->saved_msrs.num; while (msr < end) { - msr->valid = !rdmsrl_safe(msr->info.msr_no, &msr->info.reg.q); + if (msr->valid) + rdmsrl(msr->info.msr_no, msr->info.reg.q); msr++; } } @@ -424,8 +425,10 @@ static int msr_build_context(const u32 * } for (i = saved_msrs->num, j = 0; i < total_num; i++, j++) { + u64 dummy; + msr_array[i].info.msr_no = msr_id[j]; - msr_array[i].valid = false; + msr_array[i].valid = !rdmsrl_safe(msr_id[j], &dummy); msr_array[i].info.reg.q = 0; } saved_msrs->num = total_num;