From patchwork Tue Jul 4 19:32:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 13303073 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 14CC1EB64DA for ; Thu, 6 Jul 2023 02:00:09 +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: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:In-Reply-To:References: List-Owner; bh=7094acb75OKcr8G08NBgSgUccNSGDy4sDjLqXTG/Yao=; b=4MlFK1T8Se2xFk +JXvT7qrjScnEIS5QlBY3qjedi2oJ2AmL77D5GgWSXX0Z5ypo9StoNOfMOrS1PvIcIgEWJAgQKrPu Tg6xX8afFltdBfe8JrNYUDavmCmNIRo4+OODsK7TWXszVWVKIvPCQhoEklJFCPs6LIZuJYdeM+hxn dlBFpgMM9xzENWkFJXUStxFWqwDiNskFot7NcApwgqMQv25l/tz+sGAjvlUaO3krDjq0z3owAqfMy bAIJHhTGaPLM1m8AhJkLfElyec6/DbvM745dt/EiX2QZmVJ/tG0swHOoHzJEuuglA+FcTEgLyNCZ+ 2sGI4XOtT0JwUgEtB3Lw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qHEHU-0003Hz-38; Thu, 06 Jul 2023 01:59:40 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qHEHR-0003HE-2c for linux-arm-kernel@lists.infradead.org; Thu, 06 Jul 2023 01:59:39 +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 E3AFB1650; Tue, 4 Jul 2023 12:33:29 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 385D03F663; Tue, 4 Jul 2023 12:32:46 -0700 (PDT) From: Sudeep Holla To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Sudeep Holla , Will Deacon , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu Subject: [PATCH] KVM: arm64: Handle kvm_arm_init failure correctly in finalize_pkvm Date: Tue, 4 Jul 2023 20:32:43 +0100 Message-ID: <20230704193243.3300506-1-sudeep.holla@arm.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230705_185937_969538_8F658F03 X-CRM114-Status: GOOD ( 13.55 ) 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 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 Acked-by: Marc Zyngier --- arch/arm64/include/asm/virt.h | 1 + arch/arm64/kvm/arm.c | 9 ++++++++- arch/arm64/kvm/pkvm.c | 2 +- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 5227db7640c8..261d6e9df2e1 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -78,6 +78,7 @@ extern u32 __boot_cpu_mode[2]; void __hyp_set_vectors(phys_addr_t phys_vector_base); void __hyp_reset_vectors(void); +bool is_kvm_arm_initialised(void); DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 173abca08b53..4e0176b44af3 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -53,11 +53,16 @@ DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); DECLARE_KVM_NVHE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); -static bool vgic_present; +static bool vgic_present, kvm_arm_initialised; static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled); DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use); +bool is_kvm_arm_initialised(void) +{ + return kvm_arm_initialised; +} + int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; @@ -2484,6 +2489,8 @@ static __init int kvm_arm_init(void) if (err) goto out_subs; + kvm_arm_initialised = true; + return 0; out_subs: diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index 994a494703c3..6ff3ec18c925 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -244,7 +244,7 @@ static int __init finalize_pkvm(void) { int ret; - if (!is_protected_kvm_enabled()) + if (!is_protected_kvm_enabled() || !is_kvm_arm_initialised()) return 0; /*