From patchwork Tue Oct 5 11:37:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12536433 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 3E072C433F5 for ; Tue, 5 Oct 2021 11:40:31 +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 0FBFF610A2 for ; Tue, 5 Oct 2021 11:40:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0FBFF610A2 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=EiWCUKNdtMcMDO1xjI5EnS8aD7AZ3y4tfWFRzLETEEg=; b=ylfISALPfR61Uh w1p/Q7KRfSZ1kWJ8+KFNc0Wr/RZCd9MLuzucwxOJzTaKKRFNGHDe/EiS1r4J1ZLaiO07L/D8Gq38X uPR/dNzxITN7ffzEbM6k4Sh6DbeIQM9aTz0xHieDhI1XjshmwndYX2Wl/7J0dCi7vFu0thcXz9FzS l+tXLvwR/cWjDQVqNqoNkOicGvdx7OHrUyQVDb9/vm6iFYzR4svUD+kvJZzHsLD8r/JeQjpHHcZQO 581lSkl3q21KQp1XQhinylDd/jq46zfppWaNB3jrjWNbWfPuzrJEXk/WFbejNLWT5dyUFQ/XFBoCk 7l4PDAZ+c9dFjPBtiDYQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mXim6-00AA9f-JI; Tue, 05 Oct 2021 11:38:22 +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 1mXilS-00A9rS-6B for linux-arm-kernel@lists.infradead.org; Tue, 05 Oct 2021 11:37:43 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4F94761409; Tue, 5 Oct 2021 11:37:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633433861; bh=81APP0HkVWjClm/QUvOApf7a16x3+vt8o38wAAcEsSA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aqN/yZemkRGEOIk1Q+e0CZSKR6MiT5gy1N7A8veSVtRiUvcsTOgc9OEw8P5rJORb2 IZHf6WjR+yH9swrwCXgGwAz1rSzZe0RKcI/4KeLwwxM7f2Kz9BN6fT1XzBIBfU3ocD 7Y/Ug1txZ8NJyaRipPC/KGGc5r4T3XNM9C/NFwXhd/JTWjp3SeReKDJndmCEXYf5KP +RbLBx9MfdsEZ1d9WOWe+pe4lZ3EzhKIJE9NMPaKspehops+zaQyL4F/iyLJu925YC 7XlifG3TM1mcKN/kYghnR4flO6OJii7pE7NbY1qcvQTeOmQDXNSBMBtyHkdPvhfX0L 7cb1UiIhCIYOw== 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 v2 3/5] KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall Date: Tue, 5 Oct 2021 12:37:19 +0100 Message-Id: <20211005113721.29441-4-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20211005113721.29441-1-will@kernel.org> References: <20211005113721.29441-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211005_043742_297585_5E2A8E23 X-CRM114-Status: GOOD ( 14.11 ) 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 If the __pkvm_prot_finalize hypercall returns an error, we WARN but fail to propagate the failure code back to kvm_arch_init(). Pass a pointer to a zero-initialised return variable so that failure to finalise the pKVM protections on a host CPU can be reported back to KVM. Cc: Marc Zyngier Cc: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/kvm/arm.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9506cf88fa0e..13bbf35896cd 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1986,9 +1986,25 @@ static int init_hyp_mode(void) return err; } -static void _kvm_host_prot_finalize(void *discard) +static void _kvm_host_prot_finalize(void *arg) { - WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)); + int *err = arg; + + if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize))) + WRITE_ONCE(*err, -EINVAL); +} + +static int pkvm_drop_host_privileges(void) +{ + int ret = 0; + + /* + * Flip the static key upfront as that may no longer be possible + * once the host stage 2 is installed. + */ + static_branch_enable(&kvm_protected_mode_initialized); + on_each_cpu(_kvm_host_prot_finalize, &ret, 1); + return ret; } static int finalize_hyp_mode(void) @@ -2002,15 +2018,7 @@ static int finalize_hyp_mode(void) * None of other sections should ever be introspected. */ kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); - - /* - * Flip the static key upfront as that may no longer be possible - * once the host stage 2 is installed. - */ - static_branch_enable(&kvm_protected_mode_initialized); - on_each_cpu(_kvm_host_prot_finalize, NULL, 1); - - return 0; + return pkvm_drop_host_privileges(); } struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)