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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B1BA2EB64DC for ; Tue, 11 Jul 2023 08:37:26 +0000 (UTC) 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: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7VEBfs58HFH/PnJEA18N/98QG7NfcavSQMEeJrEgLJY=; b=jJVrGWGnCs7BAA cclfQ6L7p5YXwA1OyS1Giy2QfWSxSMn7u0Q/uRmmcQYqW+/B4jQJAxmV7DKbJg0qSYM5Y9tmqLeOQ rL9qVQ7QXGV4cTRrA6TJ4O9hughSUCP+5EC1w58m/soOJUtENzERypu0XfkVhrVzsdgik+QoUAQuC gCg1UgWlCReuH4fvCsB8eL+Kcd55shxffcaPASgum0AbTFhUuiRLYeQ02orL2o4wLMgF2bi9h/7S+ gSOoYr9dR/3RGT9la+Z7lOm1+PyhbwAkym8c5I0AQP9/YLnpCi4g4OP/6ny7m5l1F89Z5ZUeQJwqz Z9yXrkQgFiVgWo3k5wqw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qJ8rc-00E8QY-1W; Tue, 11 Jul 2023 08:36:52 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qJ8ra-00E8Pd-03 for linux-arm-kernel@lists.infradead.org; Tue, 11 Jul 2023 08:36:51 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5701261388; Tue, 11 Jul 2023 08:36:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3309C433C7; Tue, 11 Jul 2023 08:36:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689064608; bh=jJKFtnXMClK0ncXpkYSuCL1aDHFBYXklvEpZYpBHeL8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ou8EBKX4G7AttPYdSNoPmPJnkGeyggQsIOAUOuA1/n/wRqUak+k+naPOKX11ImcwV wb89GBLOqoTeIjVU2bveAb/AJ6qdQQCCynYDVz9xiVK2ZF2rFdVsWXdVoAgnS8zoMA bf71wROIYTqwm6kOWzS/JZ83+T8gMJLJDhGuv68dgEfToNc7idp/Oaq9Lsa1QGJ/H5 jL9BoeBquM4z/TU+OK+u7HdHlfxMksLp95qCwTVn37uiTL1zZ0U42lymmkkmCYFWKf vCWWyPR9O3dpDfrvQB8dTNQefrg2EZ9qyd51wbR64eyQ2hb57666u35qpmIBd1yBua 2if5hXz0teyjA== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qJ8rW-00C3PG-Au; Tue, 11 Jul 2023 09:36:46 +0100 Date: Tue, 11 Jul 2023 09:36:46 +0100 Message-ID: <86fs5ux2sh.wl-maz@kernel.org> From: Marc Zyngier To: Sudeep Holla Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Will Deacon , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH] KVM: arm64: Handle kvm_arm_init failure correctly in finalize_pkvm In-Reply-To: <20230704193243.3300506-1-sudeep.holla@arm.com> References: <20230704193243.3300506-1-sudeep.holla@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: sudeep.holla@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230711_013650_135291_FBEC62BA X-CRM114-Status: GOOD ( 18.18 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 04 Jul 2023 20:32:43 +0100, Sudeep Holla wrote: > > Currently there is no synchronisation between finalize_pkvm() and > kvm_arm_init() initcalls. The finalize_pkvm() proceeds happily even if > kvm_arm_init() fails resulting in the following warning on all the CPUs > and eventually a HYP panic: > > | kvm [1]: IPA Size Limit: 48 bits > | kvm [1]: Failed to init hyp memory protection > | kvm [1]: error initializing Hyp mode: -22 > | > | > | > | WARNING: CPU: 0 PID: 0 at arch/arm64/kvm/pkvm.c:226 _kvm_host_prot_finalize+0x30/0x50 > | Modules linked in: > | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0 #237 > | Hardware name: FVP Base RevC (DT) > | pstate: 634020c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) > | pc : _kvm_host_prot_finalize+0x30/0x50 > | lr : __flush_smp_call_function_queue+0xd8/0x230 > | > | Call trace: > | _kvm_host_prot_finalize+0x3c/0x50 > | on_each_cpu_cond_mask+0x3c/0x6c > | pkvm_drop_host_privileges+0x4c/0x78 > | finalize_pkvm+0x3c/0x5c > | do_one_initcall+0xcc/0x240 > | do_initcall_level+0x8c/0xac > | do_initcalls+0x54/0x94 > | do_basic_setup+0x1c/0x28 > | kernel_init_freeable+0x100/0x16c > | kernel_init+0x20/0x1a0 > | ret_from_fork+0x10/0x20 > | Failed to finalize Hyp protection: -22 > | dtb=fvp-base-revc.dtb > | kvm [95]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/mem_protect.c:540! > | kvm [95]: nVHE call trace: > | kvm [95]: [] __kvm_nvhe_hyp_panic+0xac/0xf8 > | kvm [95]: [] __kvm_nvhe_handle_host_mem_abort+0x1a0/0x2ac > | kvm [95]: [] __kvm_nvhe_handle_trap+0x4c/0x160 > | kvm [95]: [] __kvm_nvhe___skip_pauth_save+0x4/0x4 > | kvm [95]: ---[ end nVHE call trace ]--- > | kvm [95]: Hyp Offset: 0xfffe8db00ffa0000 > | Kernel panic - not syncing: HYP panic: > | PS:a34023c9 PC:0000f250710b973c ESR:00000000f2000800 > | FAR:ffff000800cb00d0 HPFAR:000000000880cb00 PAR:0000000000000000 > | VCPU:0000000000000000 > | CPU: 3 PID: 95 Comm: kworker/u16:2 Tainted: G W 6.4.0 #237 > | Hardware name: FVP Base RevC (DT) > | Workqueue: rpciod rpc_async_schedule > | Call trace: > | dump_backtrace+0xec/0x108 > | show_stack+0x18/0x2c > | dump_stack_lvl+0x50/0x68 > | dump_stack+0x18/0x24 > | panic+0x138/0x33c > | nvhe_hyp_panic_handler+0x100/0x184 > | new_slab+0x23c/0x54c > | ___slab_alloc+0x3e4/0x770 > | kmem_cache_alloc_node+0x1f0/0x278 > | __alloc_skb+0xdc/0x294 > | tcp_stream_alloc_skb+0x2c/0xf0 > | tcp_sendmsg_locked+0x3d0/0xda4 > | tcp_sendmsg+0x38/0x5c > | inet_sendmsg+0x44/0x60 > | sock_sendmsg+0x1c/0x34 > | xprt_sock_sendmsg+0xdc/0x274 > | xs_tcp_send_request+0x1ac/0x28c > | xprt_transmit+0xcc/0x300 > | call_transmit+0x78/0x90 > | __rpc_execute+0x114/0x3d8 > | rpc_async_schedule+0x28/0x48 > | process_one_work+0x1d8/0x314 > | worker_thread+0x248/0x474 > | kthread+0xfc/0x184 > | ret_from_fork+0x10/0x20 > | SMP: stopping secondary CPUs > | Kernel Offset: 0x57c5cb460000 from 0xffff800080000000 > | PHYS_OFFSET: 0x80000000 > | CPU features: 0x00000000,1035b7a3,ccfe773f > | Memory Limit: none > | ---[ end Kernel panic - not syncing: HYP panic: > | PS:a34023c9 PC:0000f250710b973c ESR:00000000f2000800 > | FAR:ffff000800cb00d0 HPFAR:000000000880cb00 PAR:0000000000000000 > | VCPU:0000000000000000 ]--- > > Fix it by checking for the successfull initialisation of kvm_arm_init() > in finalize_pkvm() before proceeding any futher. > > Fixes: 87727ba2bb05 ("KVM: arm64: Ensure CPU PMU probes before pKVM host de-privilege") > Cc: Will Deacon > Cc: Marc Zyngier > Cc: Oliver Upton > Cc: James Morse > Cc: Suzuki K Poulose > Cc: Zenghui Yu > Signed-off-by: Sudeep Holla I really dislike the additional helper, but now that the capabilities are patched, I can't see another way to achieve this so: Acked-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel