From patchwork Mon Oct 9 23:08:48 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: 13414636 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 EA25CE94139 for ; Mon, 9 Oct 2023 23:10:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379107AbjJIXKd (ORCPT ); Mon, 9 Oct 2023 19:10:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379093AbjJIXKE (ORCPT ); Mon, 9 Oct 2023 19:10:04 -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 7F1D2C6 for ; Mon, 9 Oct 2023 16:09:06 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-d815354ea7fso6635610276.1 for ; Mon, 09 Oct 2023 16:09:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696892945; x=1697497745; 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=z/EXS3E0QingI/dhMmhRcelks2qlBAd4MtKbKAc3JtE=; b=cN7zoHKishbiJ+nAAZ09lEajoq97OGPCLa73BQid4vOZi1s7DSdW9Mcliq3Cij9/pF IOIv+eb/ot6DKDIpnLu9Rox4lP34Gjv6mnFBBipQEW6p9WG1ZdkHCMWuSNzhN4OjxUV7 XD+ry5HEj1s5Ynvei4dMblvJqQGN3hnzTZ517RKa+88N2UE9T5TLS/mfa75/W/K03j1N 7aj9/QfhdBYKB/hBnFUODdA5/ADwJmQ6lkF9mTpMrEoJJLqZLpxkVQsbI7RfkRmTk91k wb3/3p1TmhzBk2dPoqBkRJG9qN6tuIuLOwrh6ACM8KqcWQgH0W4chmS4oHkcFwGexMED 3Y5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696892945; x=1697497745; 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=z/EXS3E0QingI/dhMmhRcelks2qlBAd4MtKbKAc3JtE=; b=B3cbgUmKFbWvMLdWxrhWzXtCyQ49ZR4Aw/QLwnR9VCeq7TEsArPrSR8om6gtZLdCtG LDIhk1+UqYIhl8osXi3LiQxCMT+hE/dvY5tqpK4iPDCoXBnpV0K+TjUaAYG/xx8prwB+ HBa4kXor2YuESTmYjGioP7G9WpK/wt44I/7DWx1g8kH6Giu6pdJPkrylAZLHwzXcZDMo lJ/47XxbvzXhajOLVsaL//KpBdrSHWHcw05seJpv5OKGiod7mHUKPTET/pmFHF2ORH5q yh5WXy1vIw4d3dIg5ToyePRpKFiBA+I6Uyq1lMMOsF5+9o0zE6VUXqEoiWD/n4MrHvtZ sD6Q== X-Gm-Message-State: AOJu0Yx2AbiUrYYpsJJHeQCrC7fmAlmGfWfYTtwFHZD+encZwocTNWHB 72gF7C1wr2mTGrl+me0bOP/4dcnYV1wj X-Google-Smtp-Source: AGHT+IFKsr7JXVWu1qWTpXDJfo7L0hMPkdhBsdaOWv/PZufLpBw0bG7I4Sg+xG29iJZKC5s8M0y0vdlKLtJf X-Received: from rananta-linux.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:20a1]) (user=rananta job=sendgmr) by 2002:a25:c583:0:b0:d86:56f4:e4a3 with SMTP id v125-20020a25c583000000b00d8656f4e4a3mr248890ybe.13.1696892945384; Mon, 09 Oct 2023 16:09:05 -0700 (PDT) Date: Mon, 9 Oct 2023 23:08:48 +0000 In-Reply-To: <20231009230858.3444834-1-rananta@google.com> Mime-Version: 1.0 References: <20231009230858.3444834-1-rananta@google.com> X-Mailer: git-send-email 2.42.0.609.gbb76f46606-goog Message-ID: <20231009230858.3444834-3-rananta@google.com> Subject: [PATCH v7 02/12] 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 --- arch/arm64/kvm/arm.c | 20 ++++++++++++++++++++ arch/arm64/kvm/pmu-emul.c | 12 ++---------- include/kvm/arm_pmu.h | 6 ++++++ 3 files changed, 28 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 78b0970eb8e6..708a53b70a7b 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1313,6 +1313,23 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu, KVM_VCPU_MAX_FEATURES); } +static int kvm_vcpu_set_pmu(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + + if (!kvm_arm_support_pmu_v3()) + return -EINVAL; + + /* + * When the vCPU has a PMU, but no PMU is set for the guest + * yet, set the default one. + */ + if (unlikely(!kvm->arch.arm_pmu)) + return kvm_arm_set_default_pmu(kvm); + + return 0; +} + static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu, const struct kvm_vcpu_init *init) { @@ -1328,6 +1345,9 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu, bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES); + if (kvm_vcpu_has_pmu(vcpu) && kvm_vcpu_set_pmu(vcpu)) + 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 eb5dcb12dafe..cc30c246c010 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -717,8 +717,7 @@ 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 + * PMU instance for the core during 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. * @@ -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 3546ebc469ad..858ed9ce828a 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