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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 A9618C2D0DB for ; Thu, 23 Jan 2020 11:32:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 739E324125 for ; Thu, 23 Jan 2020 11:32:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ieoPRZ0c" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726260AbgAWLcw (ORCPT ); Thu, 23 Jan 2020 06:32:52 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:55771 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726194AbgAWLcv (ORCPT ); Thu, 23 Jan 2020 06:32:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579779170; 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=8xpwabDUT9AeCxzSh2+fjHnI/NjiznPGltneNwagA8c=; b=ieoPRZ0cVZ3EBIJs0Yp2N7yfvuM+I21mfgJ/zGFS9N11+NomZppRQL3r4ou/CK+JcoDf+e WF7td8DhkT3jvKgATEBNuv+6ycGNP+U2wlP7FiX78VNlWW+UMYXywkL1pqYV1rA6mCPFyj TkqIuDpAcTPsGL6qgtB/fN8xTo0+dc8= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-63-mdton_y5N06aLGcuGITrlA-1; Thu, 23 Jan 2020 06:32:48 -0500 X-MC-Unique: mdton_y5N06aLGcuGITrlA-1 Received: by mail-wm1-f69.google.com with SMTP id q26so462050wmq.8 for ; Thu, 23 Jan 2020 03:32:48 -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:in-reply-to:references:date :message-id:mime-version; bh=8xpwabDUT9AeCxzSh2+fjHnI/NjiznPGltneNwagA8c=; b=Mishs3pwC/mHKHHCt2onopXqfbU2t/jrhjsof2ae71vPlaC/m5h6kPDgNvyltmVgBP 3n/gq9tDt9VUqJaVWSkk65ILEKiAE5dAcPaMt2Z/apo7J2iNgJN0v7aO7V3j/vWXj+gh hZcjJ3vzO2mvRRy208C/1Hf9q+xZDPMKqFPk4gZ9EFIBuP/uWwtsedoeNOKQ/IOZ6a49 O2hGo9R/7s4K0zSP+d7vld+ziNV9xB01HMuoSeevRbxoVyRBT/gBwx551LyLa8TzTT9C 3tgsTper/nxNKZzbc005ixbk7zb1mql8n1EoQIjKO9c7d/qcjoZzYogn85KsWrOLiFhC MQHg== X-Gm-Message-State: APjAAAUn6dQLGXZ5wDfidC3lL5QqhYBxz5VhfrIc6wFAUjA1kQSsF1d+ cjvEgX/zo8lL4Y4ffTAuZc6eImQ7rf67+I94uc+pD3Q1eGwYNBs2z720bQt7hecOM4SNwrEZPTW ardOwzMRc9T5kIV5J X-Received: by 2002:adf:fa50:: with SMTP id y16mr16312014wrr.183.1579779167458; Thu, 23 Jan 2020 03:32:47 -0800 (PST) X-Google-Smtp-Source: APXvYqwjx4XjBbNEv6xdmfv7CxRtTLPUvw+HlKG7WH2EnglXtX4rCtufRGwWlTXAZQdTM6mGq1DQjA== X-Received: by 2002:adf:fa50:: with SMTP id y16mr16311990wrr.183.1579779167185; Thu, 23 Jan 2020 03:32:47 -0800 (PST) Received: from vitty.brq.redhat.com (cst-prg-91-164.cust.vodafone.cz. [46.135.91.164]) by smtp.gmail.com with ESMTPSA id o16sm2627249wmc.18.2020.01.23.03.32.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 03:32:46 -0800 (PST) From: Vitaly Kuznetsov To: Paolo Bonzini Cc: mtosatti@redhat.com, stable@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH 1/2] KVM: x86: reorganize pvclock_gtod_data members In-Reply-To: <1579702953-24184-2-git-send-email-pbonzini@redhat.com> References: <1579702953-24184-1-git-send-email-pbonzini@redhat.com> <1579702953-24184-2-git-send-email-pbonzini@redhat.com> Date: Thu, 23 Jan 2020 12:32:44 +0100 Message-ID: <87tv4mqug3.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Paolo Bonzini writes: > We will need a copy of tk->offs_boot in the next patch. Store it and > cleanup the struct: instead of storing tk->tkr_xxx.base with the tk->offs_boot > included, store the raw value in struct pvclock_clock and sum tk->offs_boot > in do_monotonic_raw and do_realtime. tk->tkr_xxx.xtime_nsec also moves > to struct pvclock_clock. > > While at it, fix a (usually harmless) typo in do_monotonic_raw, which > was using gtod->clock.shift instead of gtod->raw_clock.shift. > > Fixes: 53fafdbb8b21f ("KVM: x86: switch KVMCLOCK base to monotonic raw clock") > Cc: stable@vger.kernel.org > Signed-off-by: Paolo Bonzini > --- > arch/x86/kvm/x86.c | 29 ++++++++++++----------------- > 1 file changed, 12 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 89621025577a..1b4273cce63c 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1532,6 +1532,8 @@ struct pvclock_clock { > u64 mask; > u32 mult; > u32 shift; > + u64 base_cycles; > + u64 offset; > }; > > struct pvclock_gtod_data { > @@ -1540,11 +1542,8 @@ struct pvclock_gtod_data { > struct pvclock_clock clock; /* extract of a clocksource struct */ > struct pvclock_clock raw_clock; /* extract of a clocksource struct */ > > - u64 boot_ns_raw; > - u64 boot_ns; > - u64 nsec_base; > + ktime_t offs_boot; > u64 wall_time_sec; > - u64 monotonic_raw_nsec; > }; > > static struct pvclock_gtod_data pvclock_gtod_data; > @@ -1552,10 +1551,6 @@ struct pvclock_gtod_data { > static void update_pvclock_gtod(struct timekeeper *tk) > { > struct pvclock_gtod_data *vdata = &pvclock_gtod_data; > - u64 boot_ns, boot_ns_raw; > - > - boot_ns = ktime_to_ns(ktime_add(tk->tkr_mono.base, tk->offs_boot)); > - boot_ns_raw = ktime_to_ns(ktime_add(tk->tkr_raw.base, tk->offs_boot)); > > write_seqcount_begin(&vdata->seq); > > @@ -1565,20 +1560,20 @@ static void update_pvclock_gtod(struct timekeeper *tk) > vdata->clock.mask = tk->tkr_mono.mask; > vdata->clock.mult = tk->tkr_mono.mult; > vdata->clock.shift = tk->tkr_mono.shift; > + vdata->clock.base_cycles = tk->tkr_mono.xtime_nsec; > + vdata->clock.offset = tk->tkr_mono.base; > > vdata->raw_clock.vclock_mode = tk->tkr_raw.clock->archdata.vclock_mode; > vdata->raw_clock.cycle_last = tk->tkr_raw.cycle_last; > vdata->raw_clock.mask = tk->tkr_raw.mask; > vdata->raw_clock.mult = tk->tkr_raw.mult; > vdata->raw_clock.shift = tk->tkr_raw.shift; > - > - vdata->boot_ns = boot_ns; > - vdata->nsec_base = tk->tkr_mono.xtime_nsec; > + vdata->raw_clock.base_cycles = tk->tkr_raw.xtime_nsec; > + vdata->raw_clock.offset = tk->tkr_raw.base; Likely a personal preference but the suggested naming is a bit confusing: we use 'base_cycles' to keep 'xtime_nsec' and 'offset' to keep ... 'base'. Not that I think that 'struct timekeeper' is perfect but at least it is documented. Should we maybe just stick to it (and name 'struct pvclock_clock' fields accordingly?) > > vdata->wall_time_sec = tk->xtime_sec; > > - vdata->boot_ns_raw = boot_ns_raw; > - vdata->monotonic_raw_nsec = tk->tkr_raw.xtime_nsec; > + vdata->offs_boot = tk->offs_boot; > > write_seqcount_end(&vdata->seq); > } > @@ -2048,10 +2043,10 @@ static int do_monotonic_raw(s64 *t, u64 *tsc_timestamp) > > do { > seq = read_seqcount_begin(>od->seq); > - ns = gtod->monotonic_raw_nsec; > + ns = gtod->raw_clock.base_cycles; > ns += vgettsc(>od->raw_clock, tsc_timestamp, &mode); > - ns >>= gtod->clock.shift; > - ns += gtod->boot_ns_raw; > + ns >>= gtod->raw_clock.shift; > + ns += ktime_to_ns(ktime_add(gtod->raw_clock.offset, gtod->offs_boot)); > } while (unlikely(read_seqcount_retry(>od->seq, seq))); > *t = ns; > > @@ -2068,7 +2063,7 @@ static int do_realtime(struct timespec64 *ts, u64 *tsc_timestamp) > do { > seq = read_seqcount_begin(>od->seq); > ts->tv_sec = gtod->wall_time_sec; > - ns = gtod->nsec_base; > + ns = gtod->clock.base_cycles; > ns += vgettsc(>od->clock, tsc_timestamp, &mode); > ns >>= gtod->clock.shift; > } while (unlikely(read_seqcount_retry(>od->seq, seq))); FWIW, Reviewed-by: Vitaly Kuznetsov -- Vitaly