From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 9C047C433E0 for ; Tue, 16 Jun 2020 16:15:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8259C2071A for ; Tue, 16 Jun 2020 16:15:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592324129; bh=QE52FG2xOUXV33Cg5XUI/t3yU+pakCPIncMqd6LhEz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qCdFGqoLIeM3l112zd7UL9PLEImPcABI00aoPXst38XP6Wcu3pjq4fDoy5EFHGe5D MjdcMFa/oGROkwAsYbGvsMOIF7obpbBi2+ppAPlzDQ4IkpEBKib+Ykepp/Gk2kJelz xCS7nsoGW/60HSq7XKEyHoPrJKMtSdkVtqQ0Jz4s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730695AbgFPPln (ORCPT ); Tue, 16 Jun 2020 11:41:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:57438 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731476AbgFPPlg (ORCPT ); Tue, 16 Jun 2020 11:41:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F1FD9207C4; Tue, 16 Jun 2020 15:41:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592322095; bh=QE52FG2xOUXV33Cg5XUI/t3yU+pakCPIncMqd6LhEz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BUM98tTfisAxlRSuj9kTprkRM3XML6EpJB+HYyuuCibRzw8NZFACQddfJ3W/b2n8g gE+zIBTC1VeSNxu84jloEopo7yG8tMFfMlq+Ahlu2KF9N/KiBJTtTcTS25JT7WN2HU i0rVVujDyucAZmZ4RIMpU5gQsvWZH+sbOeSre+94= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Morse , Marc Zyngier Subject: [PATCH 5.4 133/134] KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception Date: Tue, 16 Jun 2020 17:35:17 +0200 Message-Id: <20200616153107.157813635@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200616153100.633279950@linuxfoundation.org> References: <20200616153100.633279950@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marc Zyngier commit 0370964dd3ff7d3d406f292cb443a927952cbd05 upstream. On a VHE system, the EL1 state is left in the CPU most of the time, and only syncronized back to memory when vcpu_put() is called (most of the time on preemption). Which means that when injecting an exception, we'd better have a way to either: (1) write directly to the EL1 sysregs (2) synchronize the state back to memory, and do the changes there For an AArch64, we already do (1), so we are safe. Unfortunately, doing the same thing for AArch32 would be pretty invasive. Instead, we can easily implement (2) by calling the put/load architectural backends, and keep preemption disabled. We can then reload the state back into EL1. Cc: stable@vger.kernel.org Reported-by: James Morse Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/kvm_host.h | 2 ++ arch/arm64/include/asm/kvm_host.h | 2 ++ virt/kvm/arm/aarch32.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 32 insertions(+) --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -421,4 +421,6 @@ static inline bool kvm_arm_vcpu_is_final return true; } +#define kvm_arm_vcpu_loaded(vcpu) (false) + #endif /* __ARM_KVM_HOST_H__ */ --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -679,4 +679,6 @@ bool kvm_arm_vcpu_is_finalized(struct kv #define kvm_arm_vcpu_sve_finalized(vcpu) \ ((vcpu)->arch.flags & KVM_ARM64_VCPU_SVE_FINALIZED) +#define kvm_arm_vcpu_loaded(vcpu) ((vcpu)->arch.sysregs_loaded_on_cpu) + #endif /* __ARM64_KVM_HOST_H__ */ --- a/virt/kvm/arm/aarch32.c +++ b/virt/kvm/arm/aarch32.c @@ -33,6 +33,26 @@ static const u8 return_offsets[8][2] = { [7] = { 4, 4 }, /* FIQ, unused */ }; +static bool pre_fault_synchronize(struct kvm_vcpu *vcpu) +{ + preempt_disable(); + if (kvm_arm_vcpu_loaded(vcpu)) { + kvm_arch_vcpu_put(vcpu); + return true; + } + + preempt_enable(); + return false; +} + +static void post_fault_synchronize(struct kvm_vcpu *vcpu, bool loaded) +{ + if (loaded) { + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + } +} + /* * When an exception is taken, most CPSR fields are left unchanged in the * handler. However, some are explicitly overridden (e.g. M[4:0]). @@ -155,7 +175,10 @@ static void prepare_fault32(struct kvm_v void kvm_inject_undef32(struct kvm_vcpu *vcpu) { + bool loaded = pre_fault_synchronize(vcpu); + prepare_fault32(vcpu, PSR_AA32_MODE_UND, 4); + post_fault_synchronize(vcpu, loaded); } /* @@ -168,6 +191,9 @@ static void inject_abt32(struct kvm_vcpu u32 vect_offset; u32 *far, *fsr; bool is_lpae; + bool loaded; + + loaded = pre_fault_synchronize(vcpu); if (is_pabt) { vect_offset = 12; @@ -191,6 +217,8 @@ static void inject_abt32(struct kvm_vcpu /* no need to shuffle FS[4] into DFSR[10] as its 0 */ *fsr = DFSR_FSC_EXTABT_nLPAE; } + + post_fault_synchronize(vcpu, loaded); } void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr)