From patchwork Fri Mar 10 10:53:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Like Xu X-Patchwork-Id: 13169168 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDEC7C64EC4 for ; Fri, 10 Mar 2023 10:54:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230104AbjCJKyb (ORCPT ); Fri, 10 Mar 2023 05:54:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229981AbjCJKyQ (ORCPT ); Fri, 10 Mar 2023 05:54:16 -0500 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6850E34B1; Fri, 10 Mar 2023 02:54:06 -0800 (PST) Received: by mail-pl1-x62e.google.com with SMTP id i5so5149454pla.2; Fri, 10 Mar 2023 02:54:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678445646; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=r8Hr3QtIgBczYQFBm2I7OLr4pniDkf51aghVy6gKg5k=; b=DEtHjBAdk+4Ao8ILVr17mBoLdOTmMBfX95K/sEkKsjA1mMSQkbhefJH838YtAqHSZF lm2VOPMYBKHibdK5A1y/S/rO39ah85Mt1fK/TMYpV5OlXehyihRnKrgI7ljcWtc32+fQ 4oN135uBZPPgRJhnw76rGxH/9MtHM13G0LPWbmtspEqtjze349O62oVwF70O5tTo+HnF O+ftDtFH+yR1odivSVCcX+yGzuSoq/3AIefgMypbKG1eXOZb8kc6cLV6ypYdFFtuSAJo 3r3VwfSQpLKYQRtuW6L8B8eu6iTFTwFNkgBpicGk0aWaIF2a0f4Wqgtb2ujc/h7ejHRR 00eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678445646; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=r8Hr3QtIgBczYQFBm2I7OLr4pniDkf51aghVy6gKg5k=; b=l18hLU7bmgThKa4cS+Ie+Fq7JkhkiIiBoy1KoC6VTHiHsoWj8DUAKYubwwhedbx14Z 69SXfK2s++wvEmoAa8OCopxxbY6Fu2CCxqamLSJNW6nnj4BQ9dCEx8g4gYcS6JbUmVhC iu50+vFlPojuAtZA7uAhHETynp7DO1Z6NB/Kj1RiNxvV9ee3g1NSVjtqn2rOduq+LMok xANF2e6jpcz7rQmTZSinE7GCWWA2FCT23gFDtdZ7SoD1BS9XIFzC39ZMoEiPXzQ0oBVd QjRFY+T5HUvu+PMjaCNbMaQTJthim9lbcpU+mF0yP3DUVTqWN6oe+9A0Cc3Z6tBmaeTW Y09g== X-Gm-Message-State: AO0yUKV5PD/Q/Z7tl/t8lHi1LXEVM41aqWSjUeL6YXVdJ3zsuU02K5Vq eyA0y4628VyZ7I9Bznbv8as= X-Google-Smtp-Source: AK7set8tpau27kjKDretfW4tbQZtFglfLd0Zw3mMwaYjvCLpxZWX6npZ54l7yPHHme9tuAcnKnCgcQ== X-Received: by 2002:a17:903:283:b0:19e:b9f8:1fca with SMTP id j3-20020a170903028300b0019eb9f81fcamr20596720plr.10.1678445646322; Fri, 10 Mar 2023 02:54:06 -0800 (PST) Received: from localhost.localdomain ([103.7.29.32]) by smtp.gmail.com with ESMTPSA id ks3-20020a170903084300b0019cbabf127dsm1174167plb.182.2023.03.10.02.54.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Mar 2023 02:54:06 -0800 (PST) From: Like Xu X-Google-Original-From: Like Xu To: Sean Christopherson Cc: Paolo Bonzini , Ravi Bangoria , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/5] KVM: x86/pmu: Emulate CTR overflow directly in kvm_pmu_handle_event() Date: Fri, 10 Mar 2023 18:53:42 +0800 Message-Id: <20230310105346.12302-2-likexu@tencent.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310105346.12302-1-likexu@tencent.com> References: <20230310105346.12302-1-likexu@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Like Xu More and more vPMU emulations are deferred to kvm_pmu_handle_event() as it reduces the overhead of repeated execution. The reprogram_counter() is only responsible for creating the required perf_event, and naturally doesn't include the counter overflow part from emulated instruction events. Prior to this change, the assignment of pmc->prev_counter always occurred after pmc was enabled, and to keep the same semantics, pmc->prev_counter always needed to be reset after it has taken effect. No functional change intended. Signed-off-by: Like Xu --- arch/x86/kvm/pmu.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index a1a79b5f49d7..d1c89a6625a0 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -418,9 +418,6 @@ static void reprogram_counter(struct kvm_pmc *pmc) if (!event_is_allowed(pmc)) goto reprogram_complete; - if (pmc->counter < pmc->prev_counter) - __kvm_perf_overflow(pmc, false); - if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL) printk_once("kvm pmu: pin control bit is ignored\n"); @@ -458,6 +455,13 @@ static void reprogram_counter(struct kvm_pmc *pmc) reprogram_complete: clear_bit(pmc->idx, (unsigned long *)&pmc_to_pmu(pmc)->reprogram_pmi); +} + +static inline void kvm_pmu_handle_pmc_overflow(struct kvm_pmc *pmc) +{ + if (pmc->counter < pmc->prev_counter) + __kvm_perf_overflow(pmc, false); + pmc->prev_counter = 0; } @@ -475,6 +479,7 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu) } reprogram_counter(pmc); + kvm_pmu_handle_pmc_overflow(pmc); } /*