From patchwork Mon Jul 12 06:04:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 475785 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50D8CC11F67 for ; Mon, 12 Jul 2021 07:10:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A28C61183 for ; Mon, 12 Jul 2021 07:10:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242533AbhGLHNY (ORCPT ); Mon, 12 Jul 2021 03:13:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:38850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240572AbhGLHDr (ORCPT ); Mon, 12 Jul 2021 03:03:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D83C261167; Mon, 12 Jul 2021 07:00:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626073258; bh=n0UOv8XGqRxE8ABKttXEeMPtQWNfPtRpL6ZYJXVh0uQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GHCmhGf0+Qt379oCxNSU6JhPHRGtIaX9ATMgxdTmF8N/rcvJsO/WqJjBL662nbqWG G65GMbJhvtKBbo1to8wcbMws7kN3kSGrPmZtuujgVUDw8goc3IRcHcuMpnRt3eakm0 /bqg+RBwzJuErbvbK1eUyZRbbExGtaXH1koRQOVY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jinank Jain , Marc Zyngier , Sasha Levin Subject: [PATCH 5.12 181/700] KVM: arm64: Restore PMU configuration on first run Date: Mon, 12 Jul 2021 08:04:24 +0200 Message-Id: <20210712060952.200534438@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marc Zyngier [ Upstream commit d0c94c49792cf780cbfefe29f81bb8c3b73bc76b ] Restoring a guest with an active virtual PMU results in no perf counters being instanciated on the host side. Not quite what you'd expect from a restore. In order to fix this, force a writeback of PMCR_EL0 on the first run of a vcpu (using a new request so that it happens once the vcpu has been loaded). This will in turn create all the host-side counters that were missing. Reported-by: Jinank Jain Tested-by: Jinank Jain Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/87wnrbylxv.wl-maz@kernel.org Link: https://lore.kernel.org/r/b53dfcf9bbc4db7f96154b1cd5188d72b9766358.camel@amazon.de Signed-off-by: Sasha Levin --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 4 ++++ arch/arm64/kvm/pmu-emul.c | 3 +++ 3 files changed, 8 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 858c2fcfc043..4e4356add46e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -46,6 +46,7 @@ #define KVM_REQ_VCPU_RESET KVM_ARCH_REQ(2) #define KVM_REQ_RECORD_STEAL KVM_ARCH_REQ(3) #define KVM_REQ_RELOAD_GICv4 KVM_ARCH_REQ(4) +#define KVM_REQ_RELOAD_PMU KVM_ARCH_REQ(5) #define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \ KVM_DIRTY_LOG_INITIALLY_SET) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 7730b81aad6d..8455c5c30116 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -684,6 +684,10 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu) vgic_v4_load(vcpu); preempt_enable(); } + + if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu)) + kvm_pmu_handle_pmcr(vcpu, + __vcpu_sys_reg(vcpu, PMCR_EL0)); } } diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index e32c6e139a09..e9699d10d2bd 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -850,6 +850,9 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) return -EINVAL; } + /* One-off reload of the PMU on first run */ + kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu); + return 0; }