From patchwork Fri Oct 8 13:58:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12545477 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F07D3C433F5 for ; Fri, 8 Oct 2021 14:01:16 +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 B4AC46101E for ; Fri, 8 Oct 2021 14:01:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B4AC46101E 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=6T+ZdC7jjIIt5bsrKSekVbMURBQQ7CPtYsZmDbjNDa4=; b=boIEyTCHiTskWb YDWorqPFlDl5NwDVGFPubCUHlMa9/6mC5Uvjzjd53p3AA4vsb75t107lNoQXxdS/XOsflJmcEbTXt u2YOl2b3zM+9CTokN6oqhtIugo0XJkzTSM3q4jpHOQJAfyZeNuiJjzyHwBXNuyfhDuumRAetFxZZz 2kQVXh6C1vWqOUT1R3SeafyZiRrq1q7zbDd+lIWiaW3MWMcNYGs4OA7JKeiFENUH4mB5tbSF6zxPI CMSi6Arw9LHNb9LNbhrpZrQYYsxfS89gfo0r00BUk5RdXoFKfntG3AVpxA7A+U85IxN60MD+cxlrW ZDfGhoECd4CeCXejjtPw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mYqPD-002ymp-RW; Fri, 08 Oct 2021 13:59:23 +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 1mYqOl-002yhE-T7 for linux-arm-kernel@lists.infradead.org; Fri, 08 Oct 2021 13:58:58 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 18E0861056; Fri, 8 Oct 2021 13:58:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633701535; bh=THAlxcDV712qvLejzcM9lEPGBVTOj85hI6UndSHWDKg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nOWO2PXB0Gu+Ow9FoCztac2S16PKjIm0eujzQk36OfMS96Lcbn033D4OiMXTs8G9c vaSwXz1k51S1DF9Argmhs183BwNAEAw5jlStx8fOHa+MbA194MO6k3M/teNh5Ts3GM syCr5UfKQ5rPEwPkRxAhwWm9ZTNdROYxIuYbe1xaN0FRcVG13RzeAPUnUDmXvpPRjS lHHzd3W1wzExcpRld5I4xs8B2+6zlgwARwg/S6KHTZPQlQOqvdZTVdkflnctMaV90q ZPLKZ4bJmMPid52WWHq/bmg9sCeWpCRpxUtFrn+neSB09nsWcBezt5g5n6yGnnUGFk vqY14/+xltMFA== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon , Marc Zyngier , Quentin Perret , Catalin Marinas , Alexandru Elisei , Suzuki K Poulose , Mark Rutland , kvmarm@lists.cs.columbia.edu Subject: [PATCH v3 3/6] KVM: arm64: Reject stub hypercalls after pKVM has been initialised Date: Fri, 8 Oct 2021 14:58:36 +0100 Message-Id: <20211008135839.1193-4-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20211008135839.1193-1-will@kernel.org> References: <20211008135839.1193-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211008_065855_994692_51118885 X-CRM114-Status: GOOD ( 13.30 ) 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 The stub hypercalls provide mechanisms to reset and replace the EL2 code, so uninstall them once pKVM has been initialised in order to ensure the integrity of the hypervisor code. To ensure pKVM initialisation remains functional, split cpu_hyp_reinit() into two helper functions to separate usage of the stub from usage of pkvm hypercalls either side of __pkvm_init on the boot CPU. Cc: Marc Zyngier Cc: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/kvm/arm.c | 31 +++++++++++++++++++++++-------- arch/arm64/kvm/hyp/nvhe/host.S | 26 +++++++++++++++++--------- 2 files changed, 40 insertions(+), 17 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index fe102cd2e518..9506cf88fa0e 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1579,25 +1579,33 @@ static void cpu_set_hyp_vector(void) kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot); } -static void cpu_hyp_reinit(void) +static void cpu_hyp_init_context(void) { kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt); - cpu_hyp_reset(); - - if (is_kernel_in_hyp_mode()) - kvm_timer_init_vhe(); - else + if (!is_kernel_in_hyp_mode()) cpu_init_hyp_mode(); +} +static void cpu_hyp_init_features(void) +{ cpu_set_hyp_vector(); - kvm_arm_init_debug(); + if (is_kernel_in_hyp_mode()) + kvm_timer_init_vhe(); + if (vgic_present) kvm_vgic_init_cpu_hardware(); } +static void cpu_hyp_reinit(void) +{ + cpu_hyp_reset(); + cpu_hyp_init_context(); + cpu_hyp_init_features(); +} + static void _kvm_arch_hardware_enable(void *discard) { if (!__this_cpu_read(kvm_arm_hardware_enabled)) { @@ -1788,10 +1796,17 @@ static int do_pkvm_init(u32 hyp_va_bits) int ret; preempt_disable(); - hyp_install_host_vector(); + cpu_hyp_init_context(); ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size, num_possible_cpus(), kern_hyp_va(per_cpu_base), hyp_va_bits); + cpu_hyp_init_features(); + + /* + * The stub hypercalls are now disabled, so set our local flag to + * prevent a later re-init attempt in kvm_arch_hardware_enable(). + */ + __this_cpu_write(kvm_arm_hardware_enabled, 1); preempt_enable(); return ret; diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 4b652ffb591d..0c6116d34e18 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -110,17 +110,14 @@ SYM_FUNC_START(__hyp_do_panic) b __host_enter_for_panic SYM_FUNC_END(__hyp_do_panic) -.macro host_el1_sync_vect - .align 7 -.L__vect_start\@: - stp x0, x1, [sp, #-16]! - mrs x0, esr_el2 - lsr x0, x0, #ESR_ELx_EC_SHIFT - cmp x0, #ESR_ELx_EC_HVC64 - b.ne __host_exit - +SYM_FUNC_START(__host_hvc) ldp x0, x1, [sp] // Don't fixup the stack yet + /* No stub for you, sonny Jim */ +alternative_if ARM64_KVM_PROTECTED_MODE + b __host_exit +alternative_else_nop_endif + /* Check for a stub HVC call */ cmp x0, #HVC_STUB_HCALL_NR b.hs __host_exit @@ -137,6 +134,17 @@ SYM_FUNC_END(__hyp_do_panic) ldr x5, =__kvm_handle_stub_hvc hyp_pa x5, x6 br x5 +SYM_FUNC_END(__host_hvc) + +.macro host_el1_sync_vect + .align 7 +.L__vect_start\@: + stp x0, x1, [sp, #-16]! + mrs x0, esr_el2 + lsr x0, x0, #ESR_ELx_EC_SHIFT + cmp x0, #ESR_ELx_EC_HVC64 + b.eq __host_hvc + b __host_exit .L__vect_end\@: .if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) .error "host_el1_sync_vect larger than vector entry"