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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 073DFC4332B for ; Wed, 6 Jan 2021 20:34:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBC5423132 for ; Wed, 6 Jan 2021 20:34:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727417AbhAFUel (ORCPT ); Wed, 6 Jan 2021 15:34:41 -0500 Received: from mail-wm1-f48.google.com ([209.85.128.48]:52222 "EHLO mail-wm1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727323AbhAFUek (ORCPT ); Wed, 6 Jan 2021 15:34:40 -0500 Received: by mail-wm1-f48.google.com with SMTP id v14so3451016wml.1; Wed, 06 Jan 2021 12:34:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5A3GMg0kaUdhNbdjiZ51gEYmRqMxSWUTkm0nm29z41k=; b=bPx+Dy5+JxdJok+SaaNykOQfsG1BaOxDD3Bl1K/Nwp9fQSixGMV4c846MH+/MV4CDY bosOFtvB/Ehq+h71OBL2qm2Boi/vXx1pNhJJ58mrNEqew/caYC/5XT9PZ43yCRc8S9co Al7rzYgRCXE1HqYOeOFGFvBJtMbwN+2Djy52tov7CRErc/+V924FQ1Sts7cbrHobWZ5F qgE2n/+d5qZk8I8TMR4k0l3uxpJUQRni4E+w6R/qysDlKCbGVQKvuImjILBGUucyy+eY DZR6AzZZmXA464N6Ks917z5vwSAbn1b2pnLXfPnd3wDt2lR4O7+wwpG5PMBUV731WZKi y3nw== X-Gm-Message-State: AOAM533CaMVa9xza+bVoTV31QR5pU4s7pW/fwjSZL7IKswtKW0ljfeFZ 1XWELXo/uXd20fXjeS3W0cHbV+OxcrI= X-Google-Smtp-Source: ABdhPJwvCl2JxTR3uAY3juzC/plKXrLUA6gXmSQcGD7Ug/XAUohd/w+1qW3+VYuqND3FQHgpIY08Cg== X-Received: by 2002:a1c:a9c8:: with SMTP id s191mr5224786wme.89.1609965238215; Wed, 06 Jan 2021 12:33:58 -0800 (PST) Received: from liuwe-devbox-debian-v2.j3c5onc20sse1dnehy4noqpfcg.zx.internal.cloudapp.net ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id u9sm4499456wmb.32.2021.01.06.12.33.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Jan 2021 12:33:57 -0800 (PST) From: Wei Liu To: Linux on Hyper-V List Cc: virtualization@lists.linux-foundation.org, Linux Kernel List , Michael Kelley , Vineeth Pillai , Sunil Muthuswamy , Nuno Das Neves , Wei Liu , Daniel Lezcano , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Thomas Gleixner Subject: [PATCH v4 05/17] clocksource/hyperv: use MSR-based access if running as root Date: Wed, 6 Jan 2021 20:33:38 +0000 Message-Id: <20210106203350.14568-6-wei.liu@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210106203350.14568-1-wei.liu@kernel.org> References: <20210106203350.14568-1-wei.liu@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When Linux runs as the root partition, the setup required for TSC page is different. Luckily Linux also has access to the MSR based clocksource. We can just disable the TSC page clocksource if Linux is the root partition. Signed-off-by: Wei Liu Acked-by: Daniel Lezcano --- drivers/clocksource/hyperv_timer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index ba04cb381cd3..269a691bd2c4 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -426,6 +426,9 @@ static bool __init hv_init_tsc_clocksource(void) if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; + if (hv_root_partition) + return false; + hv_read_reference_counter = read_hv_clock_tsc; phys_addr = virt_to_phys(hv_get_tsc_page()); -- 2.20.1