From nobody Sat Feb 7 14:28:47 2026 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 264132036E9 for ; Tue, 3 Dec 2024 19:34:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733254485; cv=none; b=ZpGocpn5Sgiarkp7myX+K72AEv+rznCbEC4hJdOlTOZnkLAY0cBIORkkGQ6KcfFaNDAdcfayQgbFbxr9qActgGILvrJoIhJalHF59wiVe33ttQRszmvvtVSs+DcDHjS82Kx7E6WjRxqWK/EIeeQQIPKPALAd2xxQ3N1oGi+wm08= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733254485; c=relaxed/simple; bh=nVyu0O7jaOnlHWvZDvzJtM3dvCxDwoBhKEOqCa6puTs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XqE82GwLwkcofeszgthvriCcNBO9EjmbTcrw31XDlHgdNEOec1enZ2CF0qDLOsyO+Xbkb/nS2/VjxjFU88QcaMIj3kqZ9a3xowsgsvyPioMi3FcT+hOkeq+3r+8RLOC0KhwkaxAOoqxpfPCBo8b0rzyglQoZMjXaV8ikDca/b5I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=t/mLdkmf; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="t/mLdkmf" 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=1733254470; 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=6d9dUcTSe5Y6WYDonPie5MfCzdgvBZJtuRSWHader5s=; b=t/mLdkmfsGz7PT1b7e7HBq51k7vnrSjv3Fv5m2HxK1yxOS4PA+P9EVOjaCLoRlZmqY/kiZ ihzPS5A/paa1VAO2eZlPHIt1TiXBUPD5ejxW6W/MHKzjHYhQNcTkwJMtjQ6gV2prTqNGL5 voS8qB2TUq/jYfglTPdv/gv5Ip1VFuI= 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: [RFC PATCH 14/14] arm64: Enable IMP DEF PMUv3 traps on Apple M2 Date: Tue, 3 Dec 2024 11:34:15 -0800 Message-Id: <20241203193415.1070917-1-oliver.upton@linux.dev> In-Reply-To: <20241203193220.1070811-1-oliver.upton@linux.dev> References: <20241203193220.1070811-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Apple M2 CPUs support IMPDEF traps of the PMUv3 sysregs, allowing a hypervisor to virtualize an architectural PMU for a VM. Flip the appropriate bit in HACR_EL2 on supporting hardware. Signed-off-by: Oliver Upton --- arch/arm64/kernel/cpu_errata.c | 38 ++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index a78f247029ae..441ee4ffc770 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -194,6 +194,37 @@ has_neoverse_n1_erratum_1542419(const struct arm64_cpu= _capabilities *entry, return is_midr_in_range(midr, &range) && has_dic; } =20 +static const struct midr_range impdef_pmuv3_cpus[] =3D { + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_PRO), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_PRO), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_MAX), + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_MAX), + {}, +}; + +static bool has_impdef_pmuv3(const struct arm64_cpu_capabilities *entry, i= nt scope) +{ + u64 dfr0 =3D read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); + unsigned int pmuver; + + if (!is_kernel_in_hyp_mode()) + return false; + + pmuver =3D cpuid_feature_extract_unsigned_field(dfr0, + ID_AA64DFR0_EL1_PMUVer_SHIFT); + if (pmuver !=3D ID_AA64DFR0_EL1_PMUVer_IMP_DEF) + return false; + + return is_midr_in_range_list(read_cpuid_id(), impdef_pmuv3_cpus); +} + +static void cpu_enable_impdef_pmuv3_traps(const struct arm64_cpu_capabilit= ies *__unused) +{ + sysreg_clear_set_s(SYS_HACR_EL2, 0, BIT(56)); +} + #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI static const struct arm64_cpu_capabilities arm64_repeat_tlbi_list[] =3D { #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009 @@ -786,6 +817,13 @@ const struct arm64_cpu_capabilities arm64_errata[] =3D= { ERRATA_MIDR_RANGE_LIST(erratum_ac03_cpu_38_list), }, #endif + { + .desc =3D "Apple IMPDEF PMUv3 Traps", + .capability =3D ARM64_WORKAROUND_PMUV3_IMPDEF_TRAPS, + .type =3D ARM64_CPUCAP_LOCAL_CPU_ERRATUM, + .matches =3D has_impdef_pmuv3, + .cpu_enable =3D cpu_enable_impdef_pmuv3_traps, + }, { } }; --=20 2.39.5