From patchwork Wed Mar 5 20:26:33 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 14003394 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 01758C19F32 for ; Wed, 5 Mar 2025 21:17:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=fMolSMro59Ca+eo5+KC/3QVyQOdAKcjNGqGIeoq5FRk=; b=u0VOKjTH7rIYBPj23F6ard58++ DOUvaPlctd9yroctA5aRvtNP/SoMvQHYJG0yBd734yNv1BjicI/PVIndsEbBxJUUE+hvca1SgapHl epV/lUpETBOvEJFElm/mdKx2USTYb+aOsn5fZ/HXvwMeu8Bjz1DTxLa637GBOWwrgJS76GTaKUbOr rwcYyP5FugxOpU18CMnyIn4+QjUgBAiFIi15WALaPptY16DO+B/YEHr0YAnnKvjHRlVs+D9skCQtO 6dLf8ydHwYzZ5M+k1TOkhJXyUNOyI7hOe44nvBZweE3aat/hY/wstYfTuPty4Q1AQoc4mKe4Yo/bd vE+xgvcw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tpw76-00000009K8T-2oGJ; Wed, 05 Mar 2025 21:17:12 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tpvKn-00000009D8j-20st for linux-arm-kernel@bombadil.infradead.org; Wed, 05 Mar 2025 20:27:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=fMolSMro59Ca+eo5+KC/3QVyQOdAKcjNGqGIeoq5FRk=; b=J6BYjb9Y89fqVuthY0fZwCPM6N LK6mxe8KOFH8j0Uts+bhh5aISr3yqkZk+EhQMRHvDALRmoA6zcokn75BByyd61WToVO7C/0qgmNNO IaMTIpaCo09osiYSTIAhy84WHqZ6xMboZ82FcdqBRbtYkP3/6ODe/PDfGOsdGRXiNR3t43n3yNWcg +p/meDpL6oPb53kf8noPqt1YL+mLh90ysjh+yEShXJ3WAuUQxc25xWwZKrlyRJ1llHOqXoD3PpJK2 S9CiV1QTFvQc4fGjijNaNt9LPQC02Pp4SpJKFdzUFtHZx66X6/gGoNOai0/QXyUppYfMRhgbQDFVV wKHZGH0A==; Received: from out-178.mta1.migadu.com ([95.215.58.178]) by casper.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tpvKk-00000006AV3-1sEe for linux-arm-kernel@lists.infradead.org; Wed, 05 Mar 2025 20:27:16 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1741206432; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fMolSMro59Ca+eo5+KC/3QVyQOdAKcjNGqGIeoq5FRk=; b=pX37egNMcod03driNkZK6YqDwy+cYLeVQqpNfNixJN1DJv+w+nCiIm7ve/64y0F60dykck qoePi1MZKFIkf01E7ubdhm9yK1Sr4JA4xg6QINPEe0Qw0KRGhidYYwzFHY7SqRDfWAa4Tq VGG0WvFdTksKhNeSV+XBkxsFHDj5lh4= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Mingwei Zhang , Colton Lewis , Raghavendra Rao Ananta , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Janne Grunau , Oliver Upton Subject: [PATCH v3 06/14] KVM: arm64: Drop kvm_arm_pmu_available static key Date: Wed, 5 Mar 2025 12:26:33 -0800 Message-Id: <20250305202641.428114-7-oliver.upton@linux.dev> In-Reply-To: <20250305202641.428114-1-oliver.upton@linux.dev> References: <20250305202641.428114-1-oliver.upton@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250305_202714_530022_92F8FC99 X-CRM114-Status: GOOD ( 12.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org With the PMUv3 cpucap, kvm_arm_pmu_available is no longer used in the hot path of guest entry/exit. On top of that, guest support for PMUv3 may not correlate with host support for the feature, e.g. on IMPDEF hardware. Throw out the static key and just inspect the list of PMUs to determine if PMUv3 is supported for KVM guests. Tested-by: Janne Grunau Signed-off-by: Oliver Upton --- arch/arm64/kernel/image-vars.h | 5 ----- arch/arm64/kvm/arm.c | 4 ++-- arch/arm64/kvm/pmu-emul.c | 11 ++++++----- include/kvm/arm_pmu.h | 10 ++-------- 4 files changed, 10 insertions(+), 20 deletions(-) diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index ef3a69cc398e..e705c64138ce 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -112,11 +112,6 @@ KVM_NVHE_ALIAS(broken_cntvoff_key); KVM_NVHE_ALIAS(__start___kvm_ex_table); KVM_NVHE_ALIAS(__stop___kvm_ex_table); -/* PMU available static key */ -#ifdef CONFIG_HW_PERF_EVENTS -KVM_NVHE_ALIAS(kvm_arm_pmu_available); -#endif - /* Position-independent library routines */ KVM_NVHE_ALIAS_HYP(clear_page, __pi_clear_page); KVM_NVHE_ALIAS_HYP(copy_page, __pi_copy_page); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index b8e55a441282..dc27d4eb503a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -366,7 +366,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = get_num_wrps(); break; case KVM_CAP_ARM_PMU_V3: - r = kvm_arm_support_pmu_v3(); + r = kvm_supports_guest_pmuv3(); break; case KVM_CAP_ARM_INJECT_SERROR_ESR: r = cpus_have_final_cap(ARM64_HAS_RAS_EXTN); @@ -1388,7 +1388,7 @@ static unsigned long system_supported_vcpu_features(void) if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1)) clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features); - if (!kvm_arm_support_pmu_v3()) + if (!kvm_supports_guest_pmuv3()) clear_bit(KVM_ARM_VCPU_PMU_V3, &features); if (!system_supports_sve()) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 62349b670cf9..120f48136a0f 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -17,8 +17,6 @@ #define PERF_ATTR_CFG1_COUNTER_64BIT BIT(0) -DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available); - static LIST_HEAD(arm_pmus); static DEFINE_MUTEX(arm_pmus_lock); @@ -26,6 +24,12 @@ static void kvm_pmu_create_perf_event(struct kvm_pmc *pmc); static void kvm_pmu_release_perf_event(struct kvm_pmc *pmc); static bool kvm_pmu_counter_is_enabled(struct kvm_pmc *pmc); +bool kvm_supports_guest_pmuv3(void) +{ + guard(mutex)(&arm_pmus_lock); + return !list_empty(&arm_pmus); +} + static struct kvm_vcpu *kvm_pmc_to_vcpu(const struct kvm_pmc *pmc) { return container_of(pmc, struct kvm_vcpu, arch.pmu.pmc[pmc->idx]); @@ -795,9 +799,6 @@ void kvm_host_pmu_init(struct arm_pmu *pmu) entry->arm_pmu = pmu; list_add_tail(&entry->entry, &arm_pmus); - if (list_is_singular(&arm_pmus)) - static_branch_enable(&kvm_arm_pmu_available); - out_unlock: mutex_unlock(&arm_pmus_lock); } diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 3a8edd78240f..58fc7f932b3f 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -37,13 +37,7 @@ struct arm_pmu_entry { struct arm_pmu *arm_pmu; }; -DECLARE_STATIC_KEY_FALSE(kvm_arm_pmu_available); - -static __always_inline bool kvm_arm_support_pmu_v3(void) -{ - return static_branch_likely(&kvm_arm_pmu_available); -} - +bool kvm_supports_guest_pmuv3(void); #define kvm_arm_pmu_irq_initialized(v) ((v)->arch.pmu.irq_num >= VGIC_NR_SGIS) u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx); void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val); @@ -102,7 +96,7 @@ void kvm_pmu_nested_transition(struct kvm_vcpu *vcpu); struct kvm_pmu { }; -static inline bool kvm_arm_support_pmu_v3(void) +static inline bool kvm_supports_guest_pmuv3(void) { return false; }