From patchwork Thu Sep 23 11:22:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12512431 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=-18.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, 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 47719C433F5 for ; Thu, 23 Sep 2021 11:26:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0AE1660EC0 for ; Thu, 23 Sep 2021 11:26:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0AE1660EC0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZecFl0pGNmO2fk6c7k1Ag+yotzEEgqg2EvRvLzjg38M=; b=VjeFzf0qMO9lY5 6BOoSohblV7gj5CRZ70DYKHGNuiq0eMExiHd+4SdU8zOaJByoGlCSnJX38nBQ2Vd5ViZYDnGGU7HU OrLkNUB8vp9ewanhev1OVAocIWbnnCsqTTVvBvz8QspknCb/YdP8WX45vMAEE7ucQjFMqvFtOw0bp h1DxXeUG47gYNuXy53eYYm+Sxl7oWUi3VIBuoHCUYV226oPwYjwMBI1FofwbqXEtil59ZrH/2nW4e mc2N1/ovUbUWeUSshfRe5tohJhKI5P4LzmwsnSbGYcIJHtZWsDQp6j/4G/b7eOV9xXT+kuotntQRW B8nuqJJNR8mc/RUCpUlA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTMpf-00B53q-SE; Thu, 23 Sep 2021 11:24:04 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTMop-00B4ok-Ui for linux-arm-kernel@lists.infradead.org; Thu, 23 Sep 2021 11:23:13 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 48B1B611C6; Thu, 23 Sep 2021 11:23:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632396191; bh=DMbPTWIl8l89NmtqiofRXVDto4/SgvGfTeCv5+IxVA4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T/OpiqDkB5iYJpHJqk/+B4abVTRPILrHLDdWJlryB/ClPzMU8CK+I3YHhaCoZzZn0 8qXgkRZ2gI27nc/uMjEU8Bzk5CTBt+jCt3FErFGARvy+26PJC6lkc+JdandGbF7FI1 55DSPiiTxlgiJEwhxcSDbvwCgvfHEDZPcWJzdzueB7FJzFwNmmBUV6oe1vX9xLefdT 0WII+ELVsQ4ViateeWNJznqiPcG11hwsB9LD07NHqDpQTYLBM74hhE9b6OJ0Zfm339 nyQdoeJhQjJHyLT42dNT+oZUGXZ7s2jo8T7VR+w7YaIJ/AZOHsuxZAG8qNjX4EW6rg o21VPAp7L6n3w== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon , Marc Zyngier , Quentin Perret , Catalin Marinas , Alexandru Elisei , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu Subject: [PATCH 5/5] KVM: arm64: Disable privileged hypercalls after pKVM finalisation Date: Thu, 23 Sep 2021 12:22:56 +0100 Message-Id: <20210923112256.15767-6-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210923112256.15767-1-will@kernel.org> References: <20210923112256.15767-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210923_042312_066066_77F391F3 X-CRM114-Status: GOOD ( 13.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org After pKVM has been 'finalised' using the __pkvm_prot_finalize hypercall, the calling CPU will have a Stage-2 translation enabled to prevent access to memory pages owned by EL2. Although this forms a significant part of the process to deprivilege the host kernel, we also need to ensure that the hypercall interface is reduced so that the EL2 code cannot, for example, be re-initialised using a new set of vectors. Re-order the hypercalls so that only a suffix remains available after finalisation of pKVM. Cc: Marc Zyngier Cc: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_asm.h | 43 ++++++++++++++++-------------- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 26 +++++++++++------- 2 files changed, 39 insertions(+), 30 deletions(-) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index e86045ac43ba..68630fd382c5 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -43,27 +43,30 @@ #define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name) +/* Hypercalls available only prior to pKVM finalisation */ #define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init 0 -#define __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run 1 -#define __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context 2 -#define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa 3 -#define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid 4 -#define __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context 5 -#define __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff 6 -#define __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs 7 -#define __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config 8 -#define __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr 9 -#define __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr 10 -#define __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs 11 -#define __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2 12 -#define __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs 13 -#define __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs 14 -#define __KVM_HOST_SMCCC_FUNC___pkvm_init 15 -#define __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp 16 -#define __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping 17 -#define __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector 18 -#define __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize 19 -#define __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc 20 +#define __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2 1 +#define __KVM_HOST_SMCCC_FUNC___pkvm_init 2 +#define __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping 3 +#define __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector 4 +#define __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs 5 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs 6 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config 7 +#define __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize 8 + +/* Hypercalls available after pKVM finalisation */ +#define __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp 9 +#define __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc 10 +#define __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run 11 +#define __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context 12 +#define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa 13 +#define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid 14 +#define __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context 15 +#define __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff 16 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr 17 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr 18 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs 19 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs 20 #ifndef __ASSEMBLY__ diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 2da6aa8da868..4120e34288e1 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -165,36 +165,42 @@ typedef void (*hcall_t)(struct kvm_cpu_context *); #define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x static const hcall_t host_hcall[] = { - HANDLE_FUNC(__kvm_vcpu_run), + /* ___kvm_hyp_init */ + HANDLE_FUNC(__kvm_get_mdcr_el2), + HANDLE_FUNC(__pkvm_init), + HANDLE_FUNC(__pkvm_create_private_mapping), + HANDLE_FUNC(__pkvm_cpu_set_vector), + HANDLE_FUNC(__kvm_enable_ssbs), + HANDLE_FUNC(__vgic_v3_init_lrs), + HANDLE_FUNC(__pkvm_prot_finalize), + + HANDLE_FUNC(__pkvm_host_share_hyp), HANDLE_FUNC(__kvm_adjust_pc), + HANDLE_FUNC(__kvm_vcpu_run), HANDLE_FUNC(__kvm_flush_vm_context), HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa), HANDLE_FUNC(__kvm_tlb_flush_vmid), HANDLE_FUNC(__kvm_flush_cpu_context), HANDLE_FUNC(__kvm_timer_set_cntvoff), - HANDLE_FUNC(__kvm_enable_ssbs), HANDLE_FUNC(__vgic_v3_get_gic_config), HANDLE_FUNC(__vgic_v3_read_vmcr), HANDLE_FUNC(__vgic_v3_write_vmcr), - HANDLE_FUNC(__vgic_v3_init_lrs), - HANDLE_FUNC(__kvm_get_mdcr_el2), HANDLE_FUNC(__vgic_v3_save_aprs), HANDLE_FUNC(__vgic_v3_restore_aprs), - HANDLE_FUNC(__pkvm_init), - HANDLE_FUNC(__pkvm_cpu_set_vector), - HANDLE_FUNC(__pkvm_host_share_hyp), - HANDLE_FUNC(__pkvm_create_private_mapping), - HANDLE_FUNC(__pkvm_prot_finalize), }; static void handle_host_hcall(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(unsigned long, id, host_ctxt, 0); + unsigned long hcall_min = 0; hcall_t hfn; + if (static_branch_unlikely(&kvm_protected_mode_initialized)) + hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize; + id -= KVM_HOST_SMCCC_ID(0); - if (unlikely(id >= ARRAY_SIZE(host_hcall))) + if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall))) goto inval; hfn = host_hcall[id];