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 B35AEEB64DC for ; Tue, 11 Jul 2023 09:42:46 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gwkOHVUhERNFCipvGuBqJbrGh0EcwyzIZ55alnOZu2s=; b=mB4lvMKRcM+iIP D1hhCChYPsnoPHBVeuoV7f+ks489xInmho7NinVuqTCH5y2C8r8VH8HhaRKZQokKmzlOiX3qcqBfK krY4Y/PCddH44QeVKZJt7dwzMk7VRUYV/NB+ept0G1Tj/6gdrrqa7t6Y9+3LM5QqfmPxDdXeOWFnz Bb5MbZ37R/NApkx4nx3NKYvrhNV3rlLBArjreNed3ZqcGXhHwKFOH6I2solVg/nqUdPVtLQ2vJ5Tr iquqhakCaUTn8bR+8Lq317SfJpDOHBa52VBfhwV1bZvG3UqhRSLA1Dogz7z6bvBMYFMYyxboEcwkY ghEHpah20ivQqhtR0b7g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qJ9sw-00EKgW-15; Tue, 11 Jul 2023 09:42:18 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qJ9sm-00EKam-08 for linux-arm-kernel@lists.infradead.org; Tue, 11 Jul 2023 09:42:11 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7941F2B; Tue, 11 Jul 2023 02:42:39 -0700 (PDT) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 083593F67D; Tue, 11 Jul 2023 02:41:55 -0700 (PDT) Date: Tue, 11 Jul 2023 10:41:53 +0100 From: Sudeep Holla To: Marc Zyngier 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 , Sudeep Holla , Zenghui Yu Subject: Re: [PATCH] KVM: arm64: Handle kvm_arm_init failure correctly in finalize_pkvm Message-ID: <20230711094153.36b746snfds3cbr7@bogus> References: <20230704193243.3300506-1-sudeep.holla@arm.com> <86fs5ux2sh.wl-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <86fs5ux2sh.wl-maz@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230711_024208_174714_674FBA4E X-CRM114-Status: GOOD ( 19.47 ) 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, Jul 11, 2023 at 09:36:46AM +0100, Marc Zyngier wrote: > 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: > Yes, I too don't like it and was almost tempted to post it as RFC, but then I didn't want it to get ignored ;) as it a bug I hit on my setup with mismatched FF-A version. > Acked-by: Marc Zyngier > Thanks! -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel