From patchwork Fri Oct 20 21:40:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Raghavendra Rao Ananta X-Patchwork-Id: 13431205 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 2D1D2C001DF for ; Fri, 20 Oct 2023 21:41:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345216AbjJTVlN (ORCPT ); Fri, 20 Oct 2023 17:41:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345325AbjJTVlJ (ORCPT ); Fri, 20 Oct 2023 17:41:09 -0400 Received: from mail-oa1-x4a.google.com (mail-oa1-x4a.google.com [IPv6:2001:4860:4864:20::4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F13A10C2 for ; Fri, 20 Oct 2023 14:41:00 -0700 (PDT) Received: by mail-oa1-x4a.google.com with SMTP id 586e51a60fabf-1e9adea7952so1768122fac.0 for ; Fri, 20 Oct 2023 14:41:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697838059; x=1698442859; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=OvTbuzt4md5LHr4J4krTZywPcth5GhRuVcM9C2OHqIY=; b=r56AJCBfEWhftQfmQs45Z+jL17ehu1opCAsEhgHie9vaCU/1uB1Z70+++uNJ05Kcc3 Z+AyFRzfdcp7cS/qEMtY17GuH1HUtY3wQp0BNloe0SDuEex/NVJi/KShvTCSsWPgxBms pIPlJqoi6RJZ+XrIdlwHP2gjcd3xoBna9yjtXVPSx15aeHE2QFUZa5iA6+EU3XztXwL2 JAI/K6dHy2tPrQtbCJtGx++E9LWEVs4SlKpcjsqEQr4/MM855QtoaPQUE9rggD6roZJ6 qD3fRqTu41Fses0HFihCbyGT5I47O/CSthsmng6mn/5Og6ZEmTG7QEompZTwnv6W3bXo pAHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697838059; x=1698442859; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=OvTbuzt4md5LHr4J4krTZywPcth5GhRuVcM9C2OHqIY=; b=vBWouOTEozR/J+BTYN0dFQco9S1KjdPjQiTlNCdQsFOcdJNWu56K08PuxZdZ1KGldI SqLrg1qriVUTqp7mtFPK4i4gXyso75D3pntRlhDpnjp+oLfLZKEoX/GakODMMznVclFk +Ck+LY3kO5cmwudo88bLwR/vj6rtXulnWSpc0Z53FgfxTJNKcOZ1kNd+NUJ/BzUzRrNK uB45jmN4Q5hhXqZlc/0efsYL2vAtBa17C4fQef8PJzqveg8688uNPtn7/OSwQKz3/Cwp w8F4BXHLYpSyCEQZ3YB6P+QMl9Lz2kI3wpQN3bT8X6THasZjSMb4hR/U2sJa311vTrZC ZE/Q== X-Gm-Message-State: AOJu0YxhfvCqCK5d8mtKqNmEV/5rTnqj6Z1NEyn6L8cpCEi//3DG4Tyq OPy2oNlPDGkXL/ZQI+nZiMaaayYYs0pV X-Google-Smtp-Source: AGHT+IEdVXep5DKRdz2BRVvgx70nBf8uvoUbKeFebUy6l9z1K84a5p2DuIHe8LQQaBhtnY5EVhvx/QrPErHN X-Received: from rananta-linux.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:20a1]) (user=rananta job=sendgmr) by 2002:a05:6870:d10f:b0:1e9:c975:2ae2 with SMTP id e15-20020a056870d10f00b001e9c9752ae2mr1291816oac.11.1697838059370; Fri, 20 Oct 2023 14:40:59 -0700 (PDT) Date: Fri, 20 Oct 2023 21:40:42 +0000 In-Reply-To: <20231020214053.2144305-1-rananta@google.com> Mime-Version: 1.0 References: <20231020214053.2144305-1-rananta@google.com> X-Mailer: git-send-email 2.42.0.655.g421f12c284-goog Message-ID: <20231020214053.2144305-3-rananta@google.com> Subject: [PATCH v8 02/13] KVM: arm64: PMU: Set the default PMU for the guest before vCPU reset From: Raghavendra Rao Ananta To: Oliver Upton , Marc Zyngier Cc: Alexandru Elisei , James Morse , Suzuki K Poulose , Paolo Bonzini , Zenghui Yu , Shaoqin Huang , Jing Zhang , Reiji Watanabe , Colton Lewis , Raghavendra Rao Anata , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Reiji Watanabe The following patches will use the number of counters information from the arm_pmu and use this to set the PMCR.N for the guest during vCPU reset. However, since the guest is not associated with any arm_pmu until userspace configures the vPMU device attributes, and a reset can happen before this event, assign a default PMU to the guest just before doing the reset. Signed-off-by: Reiji Watanabe Signed-off-by: Raghavendra Rao Ananta Reviewed-by: Sebastian Ott --- arch/arm64/kvm/arm.c | 19 +++++++++++++++++++ arch/arm64/kvm/pmu-emul.c | 16 ++++------------ include/kvm/arm_pmu.h | 6 ++++++ 3 files changed, 29 insertions(+), 12 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index c6cad400490f9..08c2f76983b9d 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1319,6 +1319,21 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu, KVM_VCPU_MAX_FEATURES); } +static int kvm_setup_vcpu(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + + /* + * When the vCPU has a PMU, but no PMU is set for the guest + * yet, set the default one. + */ + if (kvm_vcpu_has_pmu(vcpu) && !kvm->arch.arm_pmu && + kvm_arm_set_default_pmu(kvm)) + return -EINVAL; + + return 0; +} + static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu, const struct kvm_vcpu_init *init) { @@ -1334,6 +1349,10 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu, bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES); + ret = kvm_setup_vcpu(vcpu); + if (ret) + goto out_unlock; + /* Now we know what it is, we can reset it. */ kvm_reset_vcpu(vcpu); diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index eb5dcb12dafe9..66c244021ff08 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -717,10 +717,9 @@ static struct arm_pmu *kvm_pmu_probe_armpmu(void) * It is still necessary to get a valid cpu, though, to probe for the * default PMU instance as userspace is not required to specify a PMU * type. In order to uphold the preexisting behavior KVM selects the - * PMU instance for the core where the first call to the - * KVM_ARM_VCPU_PMU_V3_CTRL attribute group occurs. A dependent use case - * would be a user with disdain of all things big.LITTLE that affines - * the VMM to a particular cluster of cores. + * PMU instance for the core just before the vcpu reset. A dependent use + * case would be a user with disdain of all things big.LITTLE that + * affines the VMM to a particular cluster of cores. * * In any case, userspace should just do the sane thing and use the UAPI * to select a PMU type directly. But, be wary of the baggage being @@ -893,7 +892,7 @@ static void kvm_arm_set_pmu(struct kvm *kvm, struct arm_pmu *arm_pmu) * where vCPUs can be scheduled on any core but the guest * counters could stop working. */ -static int kvm_arm_set_default_pmu(struct kvm *kvm) +int kvm_arm_set_default_pmu(struct kvm *kvm) { struct arm_pmu *arm_pmu = kvm_pmu_probe_armpmu(); @@ -946,13 +945,6 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) if (vcpu->arch.pmu.created) return -EBUSY; - if (!kvm->arch.arm_pmu) { - int ret = kvm_arm_set_default_pmu(kvm); - - if (ret) - return ret; - } - switch (attr->attr) { case KVM_ARM_VCPU_PMU_V3_IRQ: { int __user *uaddr = (int __user *)(long)attr->addr; diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 3546ebc469ad7..858ed9ce828a6 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -101,6 +101,7 @@ void kvm_vcpu_pmu_resync_el0(void); }) u8 kvm_arm_pmu_get_pmuver_limit(void); +int kvm_arm_set_default_pmu(struct kvm *kvm); #else struct kvm_pmu { @@ -174,6 +175,11 @@ static inline u8 kvm_arm_pmu_get_pmuver_limit(void) } static inline void kvm_vcpu_pmu_resync_el0(void) {} +static inline int kvm_arm_set_default_pmu(struct kvm *kvm) +{ + return -ENODEV; +} + #endif #endif