From patchwork Tue Dec 17 21:20:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 13912522 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 7165CE7717F for ; Tue, 17 Dec 2024 21:22:29 +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: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:In-Reply-To:References:List-Owner; bh=V7VePf0YbJoItYMxVl7REHFnpHp2lyNorsluFMzYnjk=; b=yZJC1xxmZ8I9Owd9LHOPiuCrvj HfL/aGFAJIyt//jyEwRoF02toakgNlBesI0okCEHE1HL5k0xz2FYr/kJ70XGqlu+1DtpyvVnFGxXD cy8w0i1ftlYj44tRrUB5xS9mirTiNbzqTDdPSUhmVllGSa8lomKuNKtr/Ov/acnH2ofrW0CTP1oSB NMdsI+NTRzmu95sKrNvNo3ypbuNetxFmbOAEr08c/ZUcOCVzv11izGJiirWrrdl6RBjUeKIIGPZZi 8lGxMTbtldITM/TaEOzhGmN5kbqqKMF97/vr94jnoBWUXa3yaUentO63Iwc1laPwbbg9pFxnrql4U doNJdEuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tNf1E-0000000EqcF-11ag; Tue, 17 Dec 2024 21:22:16 +0000 Received: from out-175.mta1.migadu.com ([95.215.58.175]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tNf03-0000000EqRg-1RQ6 for linux-arm-kernel@lists.infradead.org; Tue, 17 Dec 2024 21:21:10 +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=1734470459; 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; bh=V7VePf0YbJoItYMxVl7REHFnpHp2lyNorsluFMzYnjk=; b=DwHjNqs9ZJEVa2BRt7tkMQTKkExlrU1VLlZ3bEESNQVRPZAB0l2+tlmIaui/FGWl1yIleC pqvYKBTuMkWQWjEiZmlaMKAPd3lexI7Igp7lmOorTb7zvD7BKQQQt2bCMUnqHT+jbIkino gNU9YOi2BbTJIqqlGbNPXBDWUibgE60= 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, Oliver Upton Subject: [PATCH 00/18] KVM: arm64: Support FEAT_PMUv3 on Apple hardware Date: Tue, 17 Dec 2024 13:20:30 -0800 Message-Id: <20241217212048.3709204-1-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-20241217_132105_440123_047E3E90 X-CRM114-Status: GOOD ( 13.53 ) 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 One of the interesting features of some Apple M* parts is an IMPDEF trap that routes EL1/EL0 accesses of the PMUv3 registers to EL2. This allows a hypervisor to emulate an architectural PMUv3 on top of the IMPDEF PMU hardware present in the CPU. And if you squint, this _might_ look like a CPU erratum :-) This series takes advantage of these IMPDEF traps to provide PMUv3 to KVM guests. As a starting point, only expose the fixed CPU cycle counter and no event counters. Conveniently, this is enough to get Windows running as a KVM guest on Apple hardware. I've tried to keep the deviation to a minimum by refactoring some of the flows used for PMUv3, e.g. computing PMCEID from the arm_pmu bitmap instead of reading hardware directly. RFC -> v1: - Rebase to 6.13-rc3 - Add support for 1 event counter in addition to CPU cycle counter - Don't sneak past the PMU event filter (Marc) - Have the PMU driver provide a PMUv3 -> HW event ID mapping (Marc) Tested on my M2 with Linux and Windows guests. If possible, I'd appreciate someone testing on an M1 as I haven't added those MIDRs to the erratum yet. Oliver Upton (18): drivers/perf: apple_m1: Refactor event select/filter configuration drivers/perf: apple_m1: Support host/guest event filtering drivers/perf: apple_m1: Map generic branch events drivers/perf: apple_m1: Provide helper for mapping PMUv3 events KVM: arm64: Compute PMCEID from arm_pmu's event bitmaps KVM: arm64: Always support SW_INCR PMU event KVM: arm64: Remap PMUv3 events onto hardware KVM: arm64: Use a cpucap to determine if system supports FEAT_PMUv3 KVM: arm64: Drop kvm_arm_pmu_available static key KVM: arm64: Use guard() to cleanup usage of arm_pmus_lock KVM: arm64: Move PMUVer filtering into KVM code KVM: arm64: Compute synthetic sysreg ESR for Apple PMUv3 traps KVM: arm64: Advertise PMUv3 if IMPDEF traps are present KVM: arm64: Advertise 0 event counters for IMPDEF PMU arm64: Enable IMP DEF PMUv3 traps on Apple M2 drivers/perf: apple_m1: Map a few more PMUv3 events KVM: arm64: Provide 1 event counter on IMPDEF hardware KVM: arm64: selftests: Add test for probing PMUv3 sysregs arch/arm64/include/asm/apple_m1_pmu.h | 1 + arch/arm64/include/asm/cpufeature.h | 28 +--- arch/arm64/kernel/cpu_errata.c | 38 +++++ arch/arm64/kernel/cpufeature.c | 19 +++ arch/arm64/kernel/image-vars.h | 5 - arch/arm64/kvm/arm.c | 4 +- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 +- arch/arm64/kvm/hyp/vhe/switch.c | 22 +++ arch/arm64/kvm/pmu-emul.c | 127 +++++++++++----- arch/arm64/kvm/pmu.c | 10 +- arch/arm64/tools/cpucaps | 2 + drivers/perf/apple_m1_cpu_pmu.c | 103 ++++++++++--- include/kvm/arm_pmu.h | 15 +- include/linux/perf/arm_pmu.h | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../kvm/aarch64/pmuv3_register_probe.c | 135 ++++++++++++++++++ 16 files changed, 407 insertions(+), 108 deletions(-) create mode 100644 tools/testing/selftests/kvm/aarch64/pmuv3_register_probe.c base-commit: 78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8