From patchwork Mon Feb 17 11:24:11 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13977629 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 E7897C0219E for ; Mon, 17 Feb 2025 11:28:57 +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=bG5p2pMwHsY3bRuQ4UASbPlGJNVPCVCWWGf7nV9sj6A=; b=z1Q5sHfUltoB6CIjgdORnAgwju 7Jmp/VlZLTXlBzE1plmfSYIM67au9NVJiyJQT4MGVrZe+O25WzNcmUaK0kAo8llF2sJpaonGSuqbe GRkox1/H2vvSJAelYQ+JO1FBPm0R0bCu6KxM1OKsTnmDGnwr6ih1fle+xujUi7+JeaAfR6iq51DgZ p4B4KUHMX271Pkw553Wht5bZg1AiUWxUwHuTD3MslriszpV0Xj4BT+VboYh4S4TiVJ/Uru6N8Q4VG 4tokkrDp/HijC2lr5Z/m/IjDJ4wxmT8OD4kMJPcvtK7hUJNmoshtjg3y+2xI7rcsYrKFekqC7CtEY IfY23bAA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tjzIu-00000004Ixa-1I7m; Mon, 17 Feb 2025 11:28:48 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tjzEZ-00000004INu-3Po2 for linux-arm-kernel@lists.infradead.org; Mon, 17 Feb 2025 11:24:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id EAF055C49B6; Mon, 17 Feb 2025 11:23:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F3C3DC4AF09; Mon, 17 Feb 2025 11:24:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739791459; bh=dYz+hTJxMRqs58+wHRFEMd3G0Mri3nv5zfDY/9xb8X0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GqQHP/CSer1zhF69pvmREx/y72TUZZFJ8cdBebmkEpqYCebvcVuiPcC/CudaH9T6i B2hkkOe96Hzt21HsN8NPIylVz40fqwFDyJcpoqXeAEE2k92qkzVlL53T64DxcLFUkr iYkdGVuuBgd6wJgZLUvY5Bfj5CFyVpp6aj1b/GRaF3rS3DIesYoCDGRTqSGmblzceD tPeS5JWFLq1bgmRbDurWiJJ1BL1d3FHeugOuC4US2LwWI4+yqBRZdflF5epSMISNKj nD1BPlznFwdADf4ybPxEk5iLiWD9UEwv+thXziRtCEUuj8cK1ikYFSiK8mb4JJQcBh jAXaQX98VCwlg== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1tjzEX-0052DP-06; Mon, 17 Feb 2025 11:24:17 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH 1/2] KVM: arm64: Fix MDCR_EL2.HPMN reset value Date: Mon, 17 Feb 2025 11:24:11 +0000 Message-Id: <20250217112412.3963324-2-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250217112412.3963324-1-maz@kernel.org> References: <20250217112412.3963324-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, joey.gouly@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250217_032419_937050_B48DC2C2 X-CRM114-Status: GOOD ( 14.29 ) 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 The MDCR_EL2 documentation indicates that the HPMN field has the following behaviour: "On a Warm reset, this field resets to the expression NUM_PMU_COUNTERS." However, it appears we reset it to zero, which is not very useful. Add a reset helper for MDCR_EL2, and handle the case where userspace changes the target PMU, which may force us to change HPMN again. Reported-by: Joey Gouly Signed-off-by: Marc Zyngier --- arch/arm64/kvm/pmu-emul.c | 13 +++++++++++++ arch/arm64/kvm/sys_regs.c | 7 ++++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 6c5950b9ceac8..5a71c3744c4d7 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -1007,6 +1007,19 @@ static void kvm_arm_set_pmu(struct kvm *kvm, struct arm_pmu *arm_pmu) kvm->arch.arm_pmu = arm_pmu; kvm->arch.pmcr_n = kvm_arm_pmu_get_max_counters(kvm); + + /* Reset MDCR_EL2.HPMN behind the vcpus' back... */ + if (test_bit(KVM_ARM_VCPU_HAS_EL2, kvm->arch.vcpu_features)) { + struct kvm_vcpu *vcpu; + unsigned long i; + + kvm_for_each_vcpu(i, vcpu, kvm) { + u64 val = __vcpu_sys_reg(vcpu, MDCR_EL2); + val &= ~MDCR_EL2_HPMN; + val |= FIELD_PREP(MDCR_EL2_HPMN, kvm->arch.pmcr_n); + __vcpu_sys_reg(vcpu, MDCR_EL2) = val; + } + } } /** diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 82430c1e1dd02..380f22f19cb42 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2493,6 +2493,11 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, return true; } +static u64 reset_mdcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +{ + __vcpu_sys_reg(vcpu, r->reg) = vcpu->kvm->arch.pmcr_n; + return vcpu->kvm->arch.pmcr_n; +} /* * Architected system registers. @@ -3034,7 +3039,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(SCTLR_EL2, access_rw, reset_val, SCTLR_EL2_RES1), EL2_REG(ACTLR_EL2, access_rw, reset_val, 0), EL2_REG_VNCR(HCR_EL2, reset_hcr, 0), - EL2_REG(MDCR_EL2, access_mdcr, reset_val, 0), + EL2_REG(MDCR_EL2, access_mdcr, reset_mdcr, 0), EL2_REG(CPTR_EL2, access_rw, reset_val, CPTR_NVHE_EL2_RES1), EL2_REG_VNCR(HSTR_EL2, reset_val, 0), EL2_REG_VNCR(HFGRTR_EL2, reset_val, 0),