From patchwork Wed Sep 14 08:34:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12975801 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 8A4F1ECAAD3 for ; Wed, 14 Sep 2022 08:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230088AbiINIgx (ORCPT ); Wed, 14 Sep 2022 04:36:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbiINIgc (ORCPT ); Wed, 14 Sep 2022 04:36:32 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2796E74CFA for ; Wed, 14 Sep 2022 01:36:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7B1E9B8167C for ; Wed, 14 Sep 2022 08:36:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B5BAC43140; Wed, 14 Sep 2022 08:36:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663144587; bh=C6lb+SGUbChCXAYDSH5eSoT2q/RGEauP1K9rMRYRbXQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R6l7u4rhVRQpBFzCVfPVKCYKhI06IPChZ/Z8/lazLNQ6ALEwwBUhlF3S4O0raeY84 shSTykddmN/7YAvAidsE6dnaU4ObSUXZov8u9h9iu1LVnnBEBLtII1vkjDAgwsi/DB kIUhH6Hd/bPv2pyKCi2mi0D5In5MqGxh4YUDfwxy8Ks8vSfx0vC/ELpIMM61qPFyT1 3Qgk9hJQrFyW9E6ixXHeKLv0MVLyeTog+8IKKGPgZ7kCafDfBMK+IcOIZstytGoz3a FypCgXTRWA3jFoAk8t5/+Dp2EG4terQgY1hbSEZpRUKsiyuCBIRUQj/Ge0vbcvqtWg ptS6TTl+DTICg== From: Will Deacon To: kvmarm@lists.cs.columbia.edu Cc: Will Deacon , Sean Christopherson , Vincent Donnefort , Alexandru Elisei , Catalin Marinas , James Morse , Chao Peng , Quentin Perret , Suzuki K Poulose , Mark Rutland , Fuad Tabba , Oliver Upton , Marc Zyngier , kernel-team@android.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 22/25] KVM: arm64: Maintain a copy of 'kvm_arm_vmid_bits' at EL2 Date: Wed, 14 Sep 2022 09:34:57 +0100 Message-Id: <20220914083500.5118-23-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220914083500.5118-1-will@kernel.org> References: <20220914083500.5118-1-will@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Sharing 'kvm_arm_vmid_bits' between EL1 and EL2 allows the host to modify the variable arbitrarily, potentially leading to all sorts of shenanians as this is used to configure the VTTBR register for the guest stage-2. In preparation for unmapping host sections entirely from EL2, maintain a copy of 'kvm_arm_vmid_bits' in the pKVM hypervisor and initialise it from the host value while it is still trusted. Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_hyp.h | 2 ++ arch/arm64/kernel/image-vars.h | 3 --- arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/hyp/nvhe/pkvm.c | 3 +++ 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index fd99cf09972d..6797eafe7890 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -124,4 +124,6 @@ extern u64 kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val); extern unsigned long kvm_nvhe_sym(__icache_flags); +extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); + #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index 1407533dfb97..d20dc9d555af 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -83,9 +83,6 @@ KVM_NVHE_ALIAS(nvhe_hyp_panic_handler); /* Vectors installed by hyp-init on reset HVC. */ KVM_NVHE_ALIAS(__hyp_stub_vectors); -/* VMID bits set by the KVM VMID allocator */ -KVM_NVHE_ALIAS(kvm_arm_vmid_bits); - /* Kernel symbols needed for cpus_have_final/const_caps checks. */ KVM_NVHE_ALIAS(arm64_const_caps_ready); KVM_NVHE_ALIAS(cpu_hwcap_keys); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 56083ed49708..503046dca288 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1895,6 +1895,7 @@ static void kvm_hyp_init_symbols(void) kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1); kvm_nvhe_sym(__icache_flags) = __icache_flags; + kvm_nvhe_sym(kvm_arm_vmid_bits) = kvm_arm_vmid_bits; } static int kvm_hyp_init_protection(u32 hyp_va_bits) diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 09e221ea6184..3c9ce49dc15c 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -15,6 +15,9 @@ /* Used by icache_is_vpipt(). */ unsigned long __icache_flags; +/* Used by kvm_get_vttbr(). */ +unsigned int kvm_arm_vmid_bits; + /* * Set trap register values based on features in ID_AA64PFR0. */