From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f202.google.com (mail-il1-f202.google.com [209.85.166.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 306F628CF5D for ; Mon, 14 Jul 2025 22:59:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752533989; cv=none; b=cWVT+kOODN3+nOMLBcpwoCvf67hQogLd5d9KV5JIaXOiUDhAhlBMqzq+90Bha6Vf/IqWy+UHhtQfDbkSKXtRl3kph5Q/2ojMZm/LknF5IPr1t4FC/cMKDBh4GMJVC+d6bsyD+z8T5skGYfJJ1p5fadJEPZJVOcCHKHN7RLfUM5Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752533989; c=relaxed/simple; bh=ncTcOod7yCrp61IU4E/ZxVDp0M1AnUaADW8CBXec3HY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=nHInu2BNnKgrlhkOlHd6/Eww3baq9r+smSW/D8zksqagkpVJDro3TvV6LlJ33OVR0qap5ubkqaQZFBUtJnnbaqmy/YrENUo8U7irUuIf1Yx3gr6Cc5YzY8Jtj70du9wi/f+BnEAxHq9ZrRaa6o344ogH/qswwxc6YEZX+HCl2nk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--coltonlewis.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=2zy20dyl; arc=none smtp.client-ip=209.85.166.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--coltonlewis.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="2zy20dyl" Received: by mail-il1-f202.google.com with SMTP id e9e14a558f8ab-3ddd03db21cso79698925ab.1 for ; Mon, 14 Jul 2025 15:59:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1752533984; x=1753138784; 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=FlCY+xVyEz2zjr3F2/cg+ko0FQSJ5xemxrZgto3SvkM=; b=2zy20dyljdshDyqGJEUumogjkTtSE9KU8/lqJ/zNPFpG7mpNTJ0Olju8rlfLoyBsA/ 85CfPV0hjXTekfAGr4v0t4dCPHBS74QBrp/RFOOcaqOr9viVRlxUrc3ywJO6s+kRLPbf upWKw4Ro5HYgA0RUHTVWZ0dfMC5KooqzzN5USxEIv1MV8/pnlYK23iPHTzQnB9hQ4g6s 7PRnww2EkZIIexWOuOHMjOLFvTIvlW33rrYZ7UpRRJ8ALvae4ijFteP35hv3RT71K5EP Sn6Emi7C259SVR6vTHf/OrVGIk8Me4itWcWqKjx5bajaJSywzZw8PHa/O5cmDU/C0I8H voeg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752533984; x=1753138784; 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=FlCY+xVyEz2zjr3F2/cg+ko0FQSJ5xemxrZgto3SvkM=; b=hpm3vdvvrvfYgcTLErEy5e+SLADNUmy7xd4Sarmu5BQTWxwBAXXVwn0D6B/ydcp9C/ 6Ps42uYbRn3M8dmaQA798VxDOg1qksqE3NOJUB7VISlJS5qn9od9riRLcaRjJHfqNQdn eZJa2vsmER8OiN98sDtHx8FTSQNkvnOPPpHtq8vHqrtXN51j23/pnnH86AsntTKjgABV UCutwqIHuU6W/a82zjA8GPtCVHCGrFHWoMqPOVKH2c6/6JXCVWPtnAiqkaDJsc1wB+7A FEA7NFNPw1BNzPcUulHUN8YTJ4MIZqrfOOln536PQ2P8HdHKFoz5m84qg2qSk4ltidsA n+Yg== X-Forwarded-Encrypted: i=1; AJvYcCXqVWHJbfnpmam7TMMQAt23Y6BGXewwG2X0MAMpD0lla2nlZiNMPrGwluCJMnSiL/sAzsFeFGvod4E=@vger.kernel.org X-Gm-Message-State: AOJu0YwCEpwb+P0OdI8P8Vkue86g85mOiP9JxHeP0JUkrELYHjr5pvma BGDpCw2yrqLxKomtSHS7/cKa7ABd8FGOWxqv9uP8A5KpAIuiaeRwrqCxF8lN8IBXQgEJODq3nCw OG4dIyGNeJTmkZ9A1e6yKLvgLHg== X-Google-Smtp-Source: AGHT+IFGXdkNXkw8CoL88YaoE7byRV8SLefT+pkkqRRylYQFB4bn+wurTk8lSssQNgyaC/vm8Th1YX76JUVCTQT87g== X-Received: from ilpp15.prod.google.com ([2002:a92:d28f:0:b0:3e2:47cf:3c9a]) (user=coltonlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6e02:1582:b0:3df:49fa:7af5 with SMTP id e9e14a558f8ab-3e279250199mr5991275ab.21.1752533984589; Mon, 14 Jul 2025 15:59:44 -0700 (PDT) Date: Mon, 14 Jul 2025 22:59:08 +0000 In-Reply-To: <20250714225917.1396543-1-coltonlewis@google.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250714225917.1396543-1-coltonlewis@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250714225917.1396543-15-coltonlewis@google.com> Subject: [PATCH v4 14/23] KVM: arm64: Setup MDCR_EL2 to handle a partitioned PMU From: Colton Lewis To: kvm@vger.kernel.org Cc: Paolo Bonzini , Jonathan Corbet , Russell King , Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Mingwei Zhang , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Mark Rutland , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-kselftest@vger.kernel.org, Colton Lewis Content-Type: text/plain; charset="UTF-8" Setup MDCR_EL2 to handle a partitioned PMU. That means calculate an appropriate value for HPMN instead of the maximum setting the host allows (which implies no partition) so hardware enforces that a guest will only see the counters in the guest partition. With HPMN set, we can now leave the TPM and TPMCR bits unset unless FGT is not available, in which case we need to fall back to that. Also, if available, set the filtering bits HPMD and HCCD to be extra sure nothing counts at EL2. Signed-off-by: Colton Lewis --- arch/arm64/include/asm/kvm_pmu.h | 11 ++++++ arch/arm64/kvm/debug.c | 23 ++++++++++--- arch/arm64/kvm/pmu-direct.c | 57 ++++++++++++++++++++++++++++++++ 3 files changed, 86 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pmu.h b/arch/arm64/include/asm/kvm_pmu.h index 62c8032a548f..35674879aae0 100644 --- a/arch/arm64/include/asm/kvm_pmu.h +++ b/arch/arm64/include/asm/kvm_pmu.h @@ -96,6 +96,9 @@ u64 kvm_pmu_guest_counter_mask(struct arm_pmu *pmu); void kvm_pmu_host_counters_enable(void); void kvm_pmu_host_counters_disable(void); +u8 kvm_pmu_guest_num_counters(struct kvm_vcpu *vcpu); +u8 kvm_pmu_hpmn(struct kvm_vcpu *vcpu); + #if !defined(__KVM_NVHE_HYPERVISOR__) bool kvm_vcpu_pmu_is_partitioned(struct kvm_vcpu *vcpu); bool kvm_vcpu_pmu_use_fgt(struct kvm_vcpu *vcpu); @@ -158,6 +161,14 @@ static inline bool kvm_vcpu_pmu_use_fgt(struct kvm_vcpu *vcpu) { return false; } +static inline u8 kvm_pmu_guest_num_counters(struct kvm_vcpu *vcpu) +{ + return 0; +} +static inline u8 kvm_pmu_hpmn(struct kvm_vcpu *vcpu) +{ + return 0; +} static inline void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) {} static inline void kvm_pmu_set_counter_value_user(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 1a7dab333f55..8ae9d141cad4 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -36,15 +36,28 @@ static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu) * This also clears MDCR_EL2_E2PB_MASK and MDCR_EL2_E2TB_MASK * to disable guest access to the profiling and trace buffers */ - vcpu->arch.mdcr_el2 = FIELD_PREP(MDCR_EL2_HPMN, - *host_data_ptr(nr_event_counters)); - vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | - MDCR_EL2_TPMS | - MDCR_EL2_TTRF | + vcpu->arch.mdcr_el2 = FIELD_PREP(MDCR_EL2_HPMN, kvm_pmu_hpmn(vcpu)); + vcpu->arch.mdcr_el2 |= (MDCR_EL2_TTRF | MDCR_EL2_TPMCR | MDCR_EL2_TDRA | MDCR_EL2_TDOSA); + if (kvm_vcpu_pmu_is_partitioned(vcpu) + && is_pmuv3p1(read_pmuver())) { + /* + * Filtering these should be redundant because we trap + * all the TYPER and FILTR registers anyway and ensure + * they filter EL2, but set the bits if they are here. + */ + vcpu->arch.mdcr_el2 |= MDCR_EL2_HPMD; + + if (is_pmuv3p5(read_pmuver())) + vcpu->arch.mdcr_el2 |= MDCR_EL2_HCCD; + } + + if (!kvm_vcpu_pmu_use_fgt(vcpu)) + vcpu->arch.mdcr_el2 |= MDCR_EL2_TPM | MDCR_EL2_TPMCR; + /* Is the VM being debugged by userspace? */ if (vcpu->guest_debug) /* Route all software debug exceptions to EL2 */ diff --git a/arch/arm64/kvm/pmu-direct.c b/arch/arm64/kvm/pmu-direct.c index 2eef77e8340d..0fac82b152ca 100644 --- a/arch/arm64/kvm/pmu-direct.c +++ b/arch/arm64/kvm/pmu-direct.c @@ -136,3 +136,60 @@ void kvm_pmu_host_counters_disable(void) mdcr &= ~MDCR_EL2_HPME; write_sysreg(mdcr, mdcr_el2); } + +/** + * kvm_pmu_guest_num_counters() - Number of counters to show to guest + * @vcpu: Pointer to struct kvm_vcpu + * + * Calculate the number of counters to show to the guest via + * PMCR_EL0.N, making sure to respect the maximum the host allows, + * which is hpmn_max if partitioned and host_max otherwise. + * + * Return: Valid value for PMCR_EL0.N + */ +u8 kvm_pmu_guest_num_counters(struct kvm_vcpu *vcpu) +{ + u8 nr_cnt = vcpu->kvm->arch.nr_pmu_counters; + int hpmn_max = vcpu->kvm->arch.arm_pmu->hpmn_max; + u8 host_max = *host_data_ptr(nr_event_counters); + + if (kvm_vcpu_pmu_is_partitioned(vcpu)) { + if (nr_cnt <= hpmn_max && nr_cnt <= host_max) + return nr_cnt; + if (hpmn_max <= host_max) + return hpmn_max; + } + + if (nr_cnt <= host_max) + return nr_cnt; + + return host_max; +} + +/** + * kvm_pmu_hpmn() - Calculate HPMN field value + * @vcpu: Pointer to struct kvm_vcpu + * + * Calculate the appropriate value to set for MDCR_EL2.HPMN, ensuring + * it always stays below the number of counters on the current CPU and + * above 0 unless the CPU has FEAT_HPMN0. + * + * This function works whether or not the PMU is partitioned. + * + * Return: A valid HPMN value + */ +u8 kvm_pmu_hpmn(struct kvm_vcpu *vcpu) +{ + u8 hpmn = kvm_pmu_guest_num_counters(vcpu); + int hpmn_max = vcpu->kvm->arch.arm_pmu->hpmn_max; + u8 host_max = *host_data_ptr(nr_event_counters); + + if (hpmn == 0 && !cpus_have_final_cap(ARM64_HAS_HPMN0)) { + if (kvm_vcpu_pmu_is_partitioned(vcpu)) + return hpmn_max; + else + return host_max; + } + + return hpmn; +} -- 2.50.0.727.gbf7dc18ff4-goog