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=-14.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 DC60FC433E0 for ; Tue, 23 Mar 2021 17:04:48 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 762DE60C41 for ; Tue, 23 Mar 2021 17:04:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 762DE60C41 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Subject:Cc:To: From:Message-ID:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=e+0WSLNc+2baG547rDwr97uFyFYpujblsuvvmhIt7rk=; b=ZiyMs5+NhYI9OBbAZnIyMqm9W jxnsnkRyf/AAhkEiFO0tz2KYzjQ9i01pFYYUOw2WufkcSQYxuCym6zc8ujo6KEzRVf/Z/Y7+js6YY 2QJ1JxYb0lWq3kw4LaeiXU7ejJtax0h5ZorKuekvhtRwxzjwbHb788qw450eyC2+hwedRa7d8TpPL RMTD/rO0kN0SRhTpdIOAABYOGEb/fUlyOwN3rDBc3DjrhsnENNv+QT/P3cm82Ku0Tyja/J2QoH9wQ LgR0I9QJzwiirmttsrWn/70DGSdfQpVXRq+mp8+dysTnMtU9so5xTUEY5Y8zsUktvJIS+XafL7G1R +kiIKwmYg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lOkR1-00FM8P-K9; Tue, 23 Mar 2021 17:03:16 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lOkQx-00FM7x-PZ for linux-arm-kernel@lists.infradead.org; Tue, 23 Mar 2021 17:03:13 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 32DFD619BA; Tue, 23 Mar 2021 17:03:10 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lOkQu-003LrN-7H; Tue, 23 Mar 2021 17:03:08 +0000 Date: Tue, 23 Mar 2021 17:03:02 +0000 Message-ID: <87tup1kdkp.wl-maz@kernel.org> From: Marc Zyngier To: Keqian Zhu , Yoan Picchi Cc: , , , , , , Subject: Re: [PATCH 1/7] KVM: arm64: Add two page mapping counters for kvm_stat In-Reply-To: References: <20210319161711.24972-1-yoan.picchi@arm.com> <20210319161711.24972-2-yoan.picchi@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: zhukeqian1@huawei.com, yoan.picchi@arm.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, catalin.marinas@arm.com, will@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210323_170312_213242_9B225896 X-CRM114-Status: GOOD ( 25.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 23 Mar 2021 11:52:38 +0000, Keqian Zhu wrote: > > Hi Yoan, > > On 2021/3/20 0:17, Yoan Picchi wrote: > > Add a counter for when a regular page is mapped, and another > > for when a huge page is mapped. > > > > Signed-off-by: Yoan Picchi > > --- > > arch/arm64/include/asm/kvm_host.h | 2 ++ > > arch/arm64/kvm/guest.c | 2 ++ > > arch/arm64/kvm/mmu.c | 7 +++++++ > > 3 files changed, 11 insertions(+) > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > index 3d10e6527..863603285 100644 > > --- a/arch/arm64/include/asm/kvm_host.h > > +++ b/arch/arm64/include/asm/kvm_host.h > > @@ -561,6 +561,8 @@ struct kvm_vcpu_stat { > > u64 wfi_exit_stat; > > u64 mmio_exit_user; > > u64 mmio_exit_kernel; > > + u64 regular_page_mapped; > > + u64 huge_page_mapped; > > u64 exits; > > }; > > > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > > index 9bbd30e62..14b15fb8f 100644 > > --- a/arch/arm64/kvm/guest.c > > +++ b/arch/arm64/kvm/guest.c > > @@ -38,6 +38,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > > VCPU_STAT("wfi_exit_stat", wfi_exit_stat), > > VCPU_STAT("mmio_exit_user", mmio_exit_user), > > VCPU_STAT("mmio_exit_kernel", mmio_exit_kernel), > > + VCPU_STAT("regular_page_mapped", regular_page_mapped), > > + VCPU_STAT("huge_page_mapped", huge_page_mapped), > > VCPU_STAT("exits", exits), > > VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns), > > VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns), > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > index 77cb2d28f..3996b28da 100644 > > --- a/arch/arm64/kvm/mmu.c > > +++ b/arch/arm64/kvm/mmu.c > > @@ -914,6 +914,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > > mark_page_dirty(kvm, gfn); > > } > > > > + if (ret >= 0) { > > + if (vma_pagesize == PAGE_SIZE) { > > + vcpu->stat.regular_page_mapped++; > > + } else { > > + vcpu->stat.huge_page_mapped++; > > + } > > + } > This looks too simple, as we don't always map a new regular_page or > huge_page here. We may just relax permission or change mapping > size, etc. If we mix these operations, the stat result seems not > very valuable... I can only agree. There is no such thing as a *huge page*. We have a whole gamut of block mappings depending on the base granule size, and we even have concatenation of pages/blocks (not yet implemented at S2, but there is hope...). What is this trying to express? Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel