From patchwork Sat Sep 25 00:55:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12517129 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C49A2C433EF for ; Sat, 25 Sep 2021 00:56:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F8266125F for ; Sat, 25 Sep 2021 00:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346741AbhIYA6X (ORCPT ); Fri, 24 Sep 2021 20:58:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346834AbhIYA5i (ORCPT ); Fri, 24 Sep 2021 20:57:38 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1D3BC06173F for ; Fri, 24 Sep 2021 17:55:55 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id p12-20020ad4496c000000b0037a535cb8b2so43084429qvy.15 for ; Fri, 24 Sep 2021 17:55:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=6T7U4FXDkZ4wSGR8PtdmKZv58jArlrzHMsBoVgMor+w=; b=KgOQHaJyXdK+GWQ+2KMuSUf8InFqvhIUK/RxDy04xLvESXB6G2X9Jrj1x+kNBAkBne PhOPZCYyVTUtZk6I8w8hOOLbiyX3n5M/2piepUvMuIeJBbfMZODdPBqWRJwDQLPaSQaV ewfzmZaiB/oD/jH9DEY0fO4j1eb1EJD3/BuOYOmy3Z3p8tliNWZ3jgZE0pCoLAqL2Vps m5RIhb9I1VErm10gqjjLk+L9EXIdeOdjyBhSzqXoCpxEKT+r+HDGPmZylA5xz8VPnVSN xkjZ3BURokP4QeF2PBXLrqVKvIiL/oQGDt7iU9yMu62sr1RqEYFvj68QISSAxPBFN6sX XnfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=6T7U4FXDkZ4wSGR8PtdmKZv58jArlrzHMsBoVgMor+w=; b=2BHHH06H8xlU0HARqUiTKMNuR1jsaXKzS6QQ4KsZG5jQSfXlbfaF01TXsMzkF/icV5 bcodIxF5sjA5v1y4Ca3/Vz52UChbBnysQIAfuwASY6fHsxn88GeV/TwFVcqoopUXyquH x4jHDOQV5cq77BZkYMX/TPWdMgvcfZ/8qYC/yXFkPp6GvN9A9zw1i+8lzUHXUlCmBhBm bGhmyNC5v8Lpd01TkuIUDwZo8k9jxIOZK7zKmvg9WCbRR39P2J29NEBLOAp3iedk5qqt iFokhbNhTz5/GvcH/74pUrg821nYlP7HGn0ocK4u4QQHfkfygjYIsPpof8E9W9fD5Ous SafA== X-Gm-Message-State: AOAM533HKug+3yh9/0C/+uNwzk73tAwJSZ1hIdEt8+kV6CFYQdlTLEzG BdVquiuJ0/Elq4+H8uWxZQf+PCmFfUo= X-Google-Smtp-Source: ABdhPJxLb+obVS+gVpjC5G0ly7yv0fDwQXsQOvFcbn5XQYMMnEu8TwQl4KzgaC2kLIcfTeYpbPGVyglE2HA= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:4c72:89be:dba3:2bcb]) (user=seanjc job=sendgmr) by 2002:ad4:446f:: with SMTP id s15mr13334020qvt.3.1632531354888; Fri, 24 Sep 2021 17:55:54 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 24 Sep 2021 17:55:25 -0700 In-Reply-To: <20210925005528.1145584-1-seanjc@google.com> Message-Id: <20210925005528.1145584-12-seanjc@google.com> Mime-Version: 1.0 References: <20210925005528.1145584-1-seanjc@google.com> X-Mailer: git-send-email 2.33.0.685.g46640cef36-goog Subject: [PATCH 11/14] KVM: stats: Add stat to detect if vcpu is currently blocking From: Sean Christopherson To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org, David Matlack , Jing Zhang Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Jing Zhang Add a "blocking" stat that userspace can use to detect the case where a vCPU is not being run because of a vCPU/guest action, e.g. HLT or WFS on x86, WFI on arm64, etc... Current guest/host/halt stats don't show this well, e.g. if a guest halts for a long period of time then the vCPU could appear pathologically blocked due to a host condition, when in reality the vCPU has been put into a not-runnable state by the guest. Originally-by: Cannon Matthews Suggested-by: Sean Christopherson Signed-off-by: Jing Zhang [sean: renamed stat to "blocking", massaged changelog] Signed-off-by: Sean Christopherson Reviewed-by: David Matlack --- include/linux/kvm_host.h | 3 ++- include/linux/kvm_types.h | 1 + virt/kvm/kvm_main.c | 2 ++ 3 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 655c2b24db2d..9bb1972e396a 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1453,7 +1453,8 @@ struct _kvm_stats_desc { STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_hist, \ HALT_POLL_HIST_COUNT), \ STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_wait_hist, \ - HALT_POLL_HIST_COUNT) + HALT_POLL_HIST_COUNT), \ + STATS_DESC_ICOUNTER(VCPU_GENERIC, blocking) extern struct dentry *kvm_debugfs_dir; diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h index 2237abb93ccd..c4f9257bf32d 100644 --- a/include/linux/kvm_types.h +++ b/include/linux/kvm_types.h @@ -94,6 +94,7 @@ struct kvm_vcpu_stat_generic { u64 halt_poll_success_hist[HALT_POLL_HIST_COUNT]; u64 halt_poll_fail_hist[HALT_POLL_HIST_COUNT]; u64 halt_wait_hist[HALT_POLL_HIST_COUNT]; + u64 blocking; }; #define KVM_STATS_NAME_SIZE 48 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fe34457530c2..2980d2b88559 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3208,6 +3208,7 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) { bool waited = false; + vcpu->stat.generic.blocking = 1; kvm_arch_vcpu_blocking(vcpu); prepare_to_rcuwait(&vcpu->wait); @@ -3223,6 +3224,7 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) finish_rcuwait(&vcpu->wait); kvm_arch_vcpu_unblocking(vcpu); + vcpu->stat.generic.blocking = 0; return waited; }