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 B055CC4332F for ; Tue, 12 Apr 2022 06:54:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236623AbiDLG4V (ORCPT ); Tue, 12 Apr 2022 02:56:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245566AbiDLGsd (ORCPT ); Tue, 12 Apr 2022 02:48:33 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D200A25E82; Mon, 11 Apr 2022 23:39:35 -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 58EEFB81B46; Tue, 12 Apr 2022 06:39:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3512C385A1; Tue, 12 Apr 2022 06:39:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649745572; bh=hgWqPv0qp5XKtQyjo6xnVe2Wx2vOCKHxAO/Zm1Lvht4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EIEz6OnudXcZbom9EFTGIrSS8dcBk8Jjpw/Gq5HSWMtTCVX5RFrmqX6yz+tECY7PU ZYJnIIQMBzrw1rn5ljCve68dvIXNl5C9EMYJkkjg+J8jT45gqD3ZwOlVFWszlxtxIE BsDbYRdkkXdELo3GilHZbt3pW36N6KIVn49V9tCM= 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 5.10 142/171] x86/pm: Save the MSR validity status at context setup Date: Tue, 12 Apr 2022 08:30:33 +0200 Message-Id: <20220412062932.000715095@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062927.870347203@linuxfoundation.org> References: <20220412062927.870347203@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 @@ -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++; } } @@ -427,8 +428,10 @@ 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;