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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CE77C433F5 for ; Wed, 6 Apr 2022 18:09:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239775AbiDFSLa (ORCPT ); Wed, 6 Apr 2022 14:11:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240114AbiDFSIz (ORCPT ); Wed, 6 Apr 2022 14:08:55 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CFC3C1A8446; Wed, 6 Apr 2022 09:46:38 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B0AAE12FC; Wed, 6 Apr 2022 09:46:38 -0700 (PDT) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0F5B03F73B; Wed, 6 Apr 2022 09:46:37 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: James Morse , Catalin Marinas Subject: [stable:PATCH v4.9.309 41/43] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated Date: Wed, 6 Apr 2022 17:45:44 +0100 Message-Id: <20220406164546.1888528-41-james.morse@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220406164546.1888528-1-james.morse@arm.com> References: <0220406164217.1888053-1-james.morse@arm.com> <20220406164546.1888528-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit a5905d6af492ee6a4a2205f0d550b3f931b03d03 upstream. KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are implemented, and to preserve that state during migration through its firmware register interface. Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3. Reviewed-by: Russell King (Oracle) Reviewed-by: Catalin Marinas [ kvm code moved to arch/arm/kvm, removed fw regs ABI. Added 32bit stub ] Signed-off-by: James Morse --- arch/arm/include/asm/kvm_host.h | 5 +++++ arch/arm/kvm/psci.c | 4 ++++ arch/arm64/include/asm/kvm_host.h | 4 ++++ 3 files changed, 13 insertions(+) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 2fda7e905754..82c71a147f21 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -349,4 +349,9 @@ static inline int kvm_arm_have_ssbd(void) return KVM_SSBD_UNKNOWN; } +static inline bool kvm_arm_spectre_bhb_mitigated(void) +{ + /* 32bit guests don't need firmware for this */ + return false; +} #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 83365bec04b6..a262c175456d 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -431,6 +431,10 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) break; } break; + case ARM_SMCCC_ARCH_WORKAROUND_3: + if (kvm_arm_spectre_bhb_mitigated()) + val = SMCCC_RET_SUCCESS; + break; } break; default: diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a152a7bbc85a..a75f02e5f0fd 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -452,4 +452,8 @@ static inline int kvm_arm_have_ssbd(void) } } +static inline bool kvm_arm_spectre_bhb_mitigated(void) +{ + return arm64_get_spectre_bhb_state() == SPECTRE_MITIGATED; +} #endif /* __ARM64_KVM_HOST_H__ */ -- 2.30.2