From patchwork Tue May 28 05:01:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 10963703 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A4A68112C for ; Tue, 28 May 2019 05:02:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9390C20134 for ; Tue, 28 May 2019 05:02:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 878E12855A; Tue, 28 May 2019 05:02:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E88562852A for ; Tue, 28 May 2019 05:02:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726866AbfE1FCN (ORCPT ); Tue, 28 May 2019 01:02:13 -0400 Received: from ozlabs.org ([203.11.71.1]:57953 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725927AbfE1FCM (ORCPT ); Tue, 28 May 2019 01:02:12 -0400 Received: by ozlabs.org (Postfix, from userid 1003) id 45ChXd06fkz9s9T; Tue, 28 May 2019 15:02:08 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1559019729; bh=kij+9vyJMujl4+gPuMxa08y0nmt3IQcEzS/Nd/CZz7M=; h=Date:From:To:Cc:Subject:From; b=FxgN3m9dot/lxgjmUMmwwl8Ip6QAGt1lTriErte/lbxVQSGgJiASbK7i/xiMH0Xld jg1TLm9gNwTKkdRlan8XKsqTl+28cyMYeLSbidH+VbcaCqIVj9SktxEhmImxeQZ6TQ Is+o74GXPj3ZfgEMmlybVohVFZ7nmZwVNQiJPukxYbd8N7MYFqB0V7tqXrDwJuWVMu EcPv+pqAuZx7PHIVRvrV3oJecWz2ORD7bxZtb3klfeBt/bc/rRvdlBlxKoS74oeOLI qM6Fy2rI0+kQ3434qVxyX6U7n4mFkTzoGUpqvLCT388nWE/lxJ3oqEMwDdlYiVTwOc e6LqDYRTDCVRA== Date: Tue, 28 May 2019 15:01:59 +1000 From: Paul Mackerras To: kvm@vger.kernel.org Cc: kvm-ppc@vger.kernel.org, =?iso-8859-1?q?C=E9dric?= Le Goater Subject: [PATCH] KVM: PPC: Book3S HV: Fix lockdep warning when entering guest on POWER9 Message-ID: <20190528050159.rd5lrvdp6kaydcxx@oak.ozlabs.ibm.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 3309bec85e60 ("KVM: PPC: Book3S HV: Fix lockdep warning when entering the guest") moved calls to trace_hardirqs_{on,off} in the entry path used for HPT guests. Similar code exists in the new streamlined entry path used for radix guests on POWER9. This makes the same change there, so as to avoid lockdep warnings such as this: [ 228.686461] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) [ 228.686480] WARNING: CPU: 116 PID: 3803 at ../kernel/locking/lockdep.c:4219 check_flags.part.23+0x21c/0x270 [ 228.686544] Modules linked in: vhost_net vhost xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat +xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter +ebtables ip6table_filter ip6_tables iptable_filter fuse kvm_hv kvm at24 ipmi_powernv regmap_i2c ipmi_devintf +uio_pdrv_genirq ofpart ipmi_msghandler uio powernv_flash mtd ibmpowernv opal_prd ip_tables ext4 mbcache jbd2 btrfs +zstd_decompress zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx libcrc32c xor +raid6_pq raid1 raid0 ses sd_mod enclosure scsi_transport_sas ast i2c_opal i2c_algo_bit drm_kms_helper syscopyarea +sysfillrect sysimgblt fb_sys_fops ttm drm i40e e1000e cxl aacraid tg3 drm_panel_orientation_quirks i2c_core [ 228.686859] CPU: 116 PID: 3803 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc1-xive+ #42 [ 228.686911] NIP: c0000000001b394c LR: c0000000001b3948 CTR: c000000000bfad20 [ 228.686963] REGS: c000200cdb50f570 TRAP: 0700 Not tainted (5.2.0-rc1-xive+) [ 228.687001] MSR: 9000000002823033 CR: 48222222 XER: 20040000 [ 228.687060] CFAR: c000000000116db0 IRQMASK: 1 [ 228.687060] GPR00: c0000000001b3948 c000200cdb50f800 c0000000015e7600 000000000000002e [ 228.687060] GPR04: 0000000000000001 c0000000001c71a0 000000006e655f73 72727563284e4f5f [ 228.687060] GPR08: 0000200e60680000 0000000000000000 c000200cdb486180 0000000000000000 [ 228.687060] GPR12: 0000000000002000 c000200fff61a680 0000000000000000 00007fffb75c0000 [ 228.687060] GPR16: 0000000000000000 0000000000000000 c0000000017d6900 c000000001124900 [ 228.687060] GPR20: 0000000000000074 c008000006916f68 0000000000000074 0000000000000074 [ 228.687060] GPR24: ffffffffffffffff ffffffffffffffff 0000000000000003 c000200d4b600000 [ 228.687060] GPR28: c000000001627e58 c000000001489908 c000000001627e58 c000000002304de0 [ 228.687377] NIP [c0000000001b394c] check_flags.part.23+0x21c/0x270 [ 228.687415] LR [c0000000001b3948] check_flags.part.23+0x218/0x270 [ 228.687466] Call Trace: [ 228.687488] [c000200cdb50f800] [c0000000001b3948] check_flags.part.23+0x218/0x270 (unreliable) [ 228.687542] [c000200cdb50f870] [c0000000001b6548] lock_is_held_type+0x188/0x1c0 [ 228.687595] [c000200cdb50f8d0] [c0000000001d939c] rcu_read_lock_sched_held+0xdc/0x100 [ 228.687646] [c000200cdb50f900] [c0000000001dd704] rcu_note_context_switch+0x304/0x340 [ 228.687701] [c000200cdb50f940] [c0080000068fcc58] kvmhv_run_single_vcpu+0xdb0/0x1120 [kvm_hv] [ 228.687756] [c000200cdb50fa20] [c0080000068fd5b0] kvmppc_vcpu_run_hv+0x5e8/0xe40 [kvm_hv] [ 228.687816] [c000200cdb50faf0] [c0080000071797dc] kvmppc_vcpu_run+0x34/0x48 [kvm] [ 228.687863] [c000200cdb50fb10] [c0080000071755dc] kvm_arch_vcpu_ioctl_run+0x244/0x420 [kvm] [ 228.687916] [c000200cdb50fba0] [c008000007165ccc] kvm_vcpu_ioctl+0x424/0x838 [kvm] [ 228.687957] [c000200cdb50fd10] [c000000000433a24] do_vfs_ioctl+0xd4/0xcd0 [ 228.687995] [c000200cdb50fdb0] [c000000000434724] ksys_ioctl+0x104/0x120 [ 228.688033] [c000200cdb50fe00] [c000000000434768] sys_ioctl+0x28/0x80 [ 228.688072] [c000200cdb50fe20] [c00000000000b888] system_call+0x5c/0x70 [ 228.688109] Instruction dump: [ 228.688142] 4bf6342d 60000000 0fe00000 e8010080 7c0803a6 4bfffe60 3c82ff87 3c62ff87 [ 228.688196] 388472d0 3863d738 4bf63405 60000000 <0fe00000> 4bffff4c 3c82ff87 3c62ff87 [ 228.688251] irq event stamp: 205 [ 228.688287] hardirqs last enabled at (205): [] kvmhv_run_single_vcpu+0x30c/0x1120 [kvm_hv] [ 228.688344] hardirqs last disabled at (204): [] kvmhv_run_single_vcpu+0x148/0x1120 [kvm_hv] [ 228.688412] softirqs last enabled at (180): [] __do_softirq+0x4ac/0x5d4 [ 228.688464] softirqs last disabled at (169): [] irq_exit+0x1f8/0x210 [ 228.688513] ---[ end trace eb16f6260022a812 ]--- [ 228.688548] possible reason: unannotated irqs-off. [ 228.688571] irq event stamp: 205 [ 228.688607] hardirqs last enabled at (205): [] kvmhv_run_single_vcpu+0x30c/0x1120 [kvm_hv] [ 228.688664] hardirqs last disabled at (204): [] kvmhv_run_single_vcpu+0x148/0x1120 [kvm_hv] [ 228.688719] softirqs last enabled at (180): [] __do_softirq+0x4ac/0x5d4 [ 228.688758] softirqs last disabled at (169): [] irq_exit+0x1f8/0x210 Signed-off-by: Paul Mackerras Reviewed-by: Cédric Le Goater Tested-by: Cédric Le Goater --- arch/powerpc/kvm/book3s_hv.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 27054d301852..9f49339c6d50 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4090,16 +4090,20 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run, kvmppc_check_need_tlb_flush(kvm, pcpu, nested); } - trace_hardirqs_on(); guest_enter_irqoff(); srcu_idx = srcu_read_lock(&kvm->srcu); this_cpu_disable_ftrace(); + /* Tell lockdep that we're about to enable interrupts */ + trace_hardirqs_on(); + trap = kvmhv_p9_guest_entry(vcpu, time_limit, lpcr); vcpu->arch.trap = trap; + trace_hardirqs_off(); + this_cpu_enable_ftrace(); srcu_read_unlock(&kvm->srcu, srcu_idx); @@ -4109,7 +4113,6 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run, isync(); } - trace_hardirqs_off(); set_irq_happened(trap); kvmppc_set_host_core(pcpu);