From patchwork Fri May 8 18:22:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jon Cargille X-Patchwork-Id: 11537339 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D72C6913 for ; Fri, 8 May 2020 18:22:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE920218AC for ; Fri, 8 May 2020 18:22:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FxsJIw9N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727116AbgEHSWw (ORCPT ); Fri, 8 May 2020 14:22:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726636AbgEHSWw (ORCPT ); Fri, 8 May 2020 14:22:52 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47DC8C061A0C for ; Fri, 8 May 2020 11:22:52 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id w15so3057812ybp.16 for ; Fri, 08 May 2020 11:22:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=36cGNYe6ShNCgmX+2LiEk2mbNEtHey09nCarODUPKds=; b=FxsJIw9Nqt2of5gMxoaFw1W5hQiw5NOsyI94lqgC266bKDNILq19UgSG5w7PXgRrbE tEnk/LbN8OeWhjwpNc3yIX06DHU3sX6I2Z6qayc2vyGJItJmHiv9Aw+67amIEZKFoEtI nLqj/LPIDOfTuflYf8wkrXz+YzA+NP9Lxq+KFL2UwshmYHeqUA97Qdzrgk8lN03yFNNI yRfLGzrUGvnWMf3zG/6CgdxABRGaZERY2CqLmrgb+FVZ8uM8VPR0a49PWW3gzC0rrfBD 70/ixtsW+4oHQDTfIW8regY68iFqpFaraMprEo+4jwC7Cc5Mkf4zD3ahYoo734Bbcq4v AgzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=36cGNYe6ShNCgmX+2LiEk2mbNEtHey09nCarODUPKds=; b=OT5HydHilwubTwNC/g70RDWy8v7V78fQlctEZMSsMNY2QwXWh+dX6+gBKpMFsseupo 0Pz1b9BuJq9x6aZdi7wJe4Z7HrxnF4nKrGCMlO5m/yfYB/RnH2UqbGzTnlr7w5Azrtau VSE5Tf5bX/9iu2L+22KaH0ynq+J2H9w1LBlz3vJ5qLcoYFBlZrOvI/S0RKVGlzTUZRE9 CxY4vWR4cMm3khAmHbUAYQCr08/quGSmtCNoXubc/vOAz11couBGllnuySbHgKjiqcml G6sTKsTNvNsRX4XKN+I0KJGCuvENpv15nxZkQcaXZ0C10hLJvMOiDe+B2dvdMxgZEH89 lhyw== X-Gm-Message-State: AGi0Pubcab+CwrcMtnaw7+DK97fIGFCEWIwtjriQ8EsBQ/zJiYaXvPQl +yNlL++5mJJhwRoqsmlst41q8qH/i8umXg== X-Google-Smtp-Source: APiQypKHnac9ibG0+zijqvOKATCu+FaUpuVnT1jlsq4K4eTgwmg4aYoNgIvp73R9IMCdQXmZuESLz5iLNgpzhw== X-Received: by 2002:a25:b9c5:: with SMTP id y5mr6305255ybj.421.1588962171430; Fri, 08 May 2020 11:22:51 -0700 (PDT) Date: Fri, 8 May 2020 11:22:40 -0700 Message-Id: <20200508182240.68440-1-jcargill@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.26.2.645.ge9eca65c58-goog Subject: [PATCH] kvm: add halt-polling cpu usage stats From: Jon Cargille To: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: David Matlack , Jon Cargille Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: David Matlack Two new stats for exposing halt-polling cpu usage: halt_poll_success_ns halt_poll_fail_ns Thus sum of these 2 stats is the total cpu time spent polling. "success" means the VCPU polled until a virtual interrupt was delivered. "fail" means the VCPU had to schedule out (either because the maximum poll time was reached or it needed to yield the CPU). To avoid touching every arch's kvm_vcpu_stat struct, only update and export halt-polling cpu usage stats if we're on x86. Exporting cpu usage as a u64 and in nanoseconds means we will overflow at ~500 years, which seems reasonably large. Signed-off-by: David Matlack Signed-off-by: Jon Cargille Reviewed-by: Jim Mattson --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/x86.c | 2 ++ virt/kvm/kvm_main.c | 20 +++++++++++++++++--- 3 files changed, 21 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a239a297be33..3287159ab15b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1032,6 +1032,8 @@ struct kvm_vcpu_stat { u64 irq_injections; u64 nmi_injections; u64 req_event; + u64 halt_poll_success_ns; + u64 halt_poll_fail_ns; }; struct x86_instruction_info; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8c0b77ac8dc6..9736d91ce877 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -217,6 +217,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { VCPU_STAT("nmi_injections", nmi_injections), VCPU_STAT("req_event", req_event), VCPU_STAT("l1d_flush", l1d_flush), + VCPU_STAT( "halt_poll_success_ns", halt_poll_success_ns), + VCPU_STAT( "halt_poll_fail_ns", halt_poll_fail_ns), VM_STAT("mmu_shadow_zapped", mmu_shadow_zapped), VM_STAT("mmu_pte_write", mmu_pte_write), VM_STAT("mmu_pte_updated", mmu_pte_updated), diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 33e1eee96f75..348b4a6bde53 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2664,19 +2664,30 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) return ret; } +static inline void +update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited) +{ +#ifdef CONFIG_X86 + if (waited) + vcpu->stat.halt_poll_fail_ns += poll_ns; + else + vcpu->stat.halt_poll_success_ns += poll_ns; +#endif +} + /* * The vCPU has executed a HLT instruction with in-kernel mode enabled. */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { - ktime_t start, cur; + ktime_t start, cur, poll_end; DECLARE_SWAITQUEUE(wait); bool waited = false; u64 block_ns; kvm_arch_vcpu_blocking(vcpu); - start = cur = ktime_get(); + start = cur = poll_end = ktime_get(); if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) { ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); @@ -2692,7 +2703,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) ++vcpu->stat.halt_poll_invalid; goto out; } - cur = ktime_get(); + poll_end = cur = ktime_get(); } while (single_task_running() && ktime_before(cur, stop)); } @@ -2712,6 +2723,9 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) kvm_arch_vcpu_unblocking(vcpu); block_ns = ktime_to_ns(cur) - ktime_to_ns(start); + update_halt_poll_stats( + vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited); + if (!kvm_arch_no_poll(vcpu)) { if (!vcpu_valid_wakeup(vcpu)) { shrink_halt_poll_ns(vcpu);