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 04869C433F5 for ; Fri, 18 Mar 2022 17:50:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238397AbiCRRwF (ORCPT ); Fri, 18 Mar 2022 13:52:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239862AbiCRRvK (ORCPT ); Fri, 18 Mar 2022 13:51:10 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7E78717B0D0; Fri, 18 Mar 2022 10:49:51 -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 472AF1576; Fri, 18 Mar 2022 10:49:51 -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 9B8083F7B4; Fri, 18 Mar 2022 10:49:50 -0700 (PDT) From: James Morse To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, james.morse@arm.com, catalin.marinas@arm.com Subject: [stable:PATCH v4.19.235 20/22] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated Date: Fri, 18 Mar 2022 17:48:40 +0000 Message-Id: <20220318174842.2321061-21-james.morse@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220318174842.2321061-1-james.morse@arm.com> References: <20220318174842.2321061-1-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 virt/kvm/arm, removed fw regs ABI. Added 32bit stub ] Signed-off-by: James Morse --- arch/arm/include/asm/kvm_host.h | 7 +++++++ arch/arm64/include/asm/kvm_host.h | 5 +++++ virt/kvm/arm/psci.c | 12 ++++++++++++ 3 files changed, 24 insertions(+) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index ae073fceb3f0..db20534912cd 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -26,6 +26,7 @@ #include #include #include +#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -367,4 +368,10 @@ void kvm_arch_free_vm(struct kvm *kvm); #define kvm_arm_vcpu_loaded(vcpu) (false) +static inline int kvm_arm_get_spectre_bhb_state(void) +{ + /* 32bit guests don't need firmware for this */ + return SPECTRE_VULNERABLE; /* aka SMCCC_RET_NOT_SUPPORTED */ +} + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 07472c138ced..7e1b19ea07ea 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -542,4 +542,9 @@ void kvm_arch_free_vm(struct kvm *kvm); #define kvm_arm_vcpu_loaded(vcpu) ((vcpu)->arch.sysregs_loaded_on_cpu) +static inline enum mitigation_state kvm_arm_get_spectre_bhb_state(void) +{ + return arm64_get_spectre_bhb_state(); +} + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 34d08ee63747..a161951e55a5 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -429,6 +429,18 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) break; } break; + case ARM_SMCCC_ARCH_WORKAROUND_3: + switch (kvm_arm_get_spectre_bhb_state()) { + case SPECTRE_VULNERABLE: + break; + case SPECTRE_MITIGATED: + val = SMCCC_RET_SUCCESS; + break; + case SPECTRE_UNAFFECTED: + val = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED; + break; + } + break; } break; default: -- 2.30.2