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 31D4DC43219 for ; Mon, 18 Apr 2022 14:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245436AbiDROC6 (ORCPT ); Mon, 18 Apr 2022 10:02:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244449AbiDRNo1 (ORCPT ); Mon, 18 Apr 2022 09:44:27 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BAED3F33B; Mon, 18 Apr 2022 05:59:59 -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 1C3C2B80E44; Mon, 18 Apr 2022 12:59:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D2B8C385A1; Mon, 18 Apr 2022 12:59:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650286796; bh=1m3xIrLcO5FIijhI2wj1F439x8Le5NCM2hWe+oEGa6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fm20q065B9sfyYAMC2+g25FnrZ8yj0du2/kDTVdMh1cUMejUrLb57jdI2+GNgNOrk hbtIpkF1Od2j8QRONCHSMgMdlmdIUvlSes7Irq6RBmUAVQto9K2300UN8YtSTTsxaI KczD8ugvAOzpuqTK3yadkSfmlWUP15Q9mc3d+wZQ= 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 4.14 247/284] x86/pm: Save the MSR validity status at context setup Date: Mon, 18 Apr 2022 14:13:48 +0200 Message-Id: <20220418121219.177917828@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121210.689577360@linuxfoundation.org> References: <20220418121210.689577360@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -41,7 +41,8 @@ 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++; } } @@ -426,8 +427,10 @@ 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;