From patchwork Wed Aug 28 08:49:57 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 270409 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E7BC02C00D7 for ; Wed, 28 Aug 2013 18:50:13 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754794Ab3H1IuM (ORCPT ); Wed, 28 Aug 2013 04:50:12 -0400 Received: from mail-pd0-f169.google.com ([209.85.192.169]:61585 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754779Ab3H1IuL (ORCPT ); Wed, 28 Aug 2013 04:50:11 -0400 Received: by mail-pd0-f169.google.com with SMTP id r10so6059002pdi.0 for ; Wed, 28 Aug 2013 01:50:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+XOAdJanzgiywDNUOVELCfoOBSs9Fu0a85QDyEK4Drs=; b=JjNbZmiH/FvqX7xaILkynbxf4TUYZ6vfp/LUDeDXx90YwYx2fKCE5kB2Aqderff+cj K6yjl4C22iKxrNRz25HweWbYcrO0mWziXR1bZvfla7hC/AmqNRpUyqCjNx/OjWBrQq1r qj+289D9RGC4y6acOg86AyxxkDFzW4/5zkmCPdHkkIMQ/BZwtowfbyYP6nqCcANRNc76 L8Ybmm5B0H77BIOjhqYgfDMKl5QP8v1optFpo5x8WS6xrbFz6syRTCSMjNHxTFzpSAWs XX7LbEcPlJ3lnPDqwjk/5zk/jOwZM+0Q2k6WR2CVQPWq3+UJ3X3LIQyqskupQ9ltUDID vDIA== X-Gm-Message-State: ALoCoQmuukgphcnYEZWmpM3qIc14tE2/bwS/tJB3SEwrneYM4lFOqeNJpaFTZ2Kk6K3Ny6FymbAU X-Received: by 10.68.110.98 with SMTP id hz2mr26287649pbb.94.1377679810805; Wed, 28 Aug 2013 01:50:10 -0700 (PDT) Received: from ka1.ozlabs.ibm.com (ibmaus65.lnk.telstra.net. [165.228.126.9]) by mx.google.com with ESMTPSA id ht5sm29868159pbb.29.1969.12.31.16.00.00 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 28 Aug 2013 01:50:09 -0700 (PDT) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , David Gibson , Benjamin Herrenschmidt , Paul Mackerras , Gleb Natapov , Paolo Bonzini , Alexander Graf , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v9 10/13] KVM: PPC: remove warning from kvmppc_core_destroy_vm Date: Wed, 28 Aug 2013 18:49:57 +1000 Message-Id: <1377679797-3744-1-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 1.8.4.rc4 In-Reply-To: <1377679070-3515-1-git-send-email-aik@ozlabs.ru> References: <1377679070-3515-1-git-send-email-aik@ozlabs.ru> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org Book3S KVM implements in-kernel TCE tables via kvmppc_spapr_tce_table structs list (created per KVM). Entries in the list are per LIOBN (logical bus number) and have a TCE table so DMA hypercalls (such as H_PUT_TCE) can convert LIOBN to a TCE table. The entry in the list is created via KVM_CREATE_SPAPR_TCE ioctl which returns an anonymous fd. This fd is used to map the TCE table to the user space and it also defines the lifetime of the TCE table in the kernel. Every list item also hold the link to KVM so when KVM is about to be destroyed, all kvmppc_spapr_tce_table objects are expected to be released and removed from the global list. And this is what the warning verifies. The upcoming support of VFIO IOMMU will extend kvmppc_spapr_tce_table use. Unlike emulated devices, it will create kvmppc_spapr_tce_table structs via new KVM device API which opens an anonymous fd (as KVM_CREATE_SPAPR_TCE) but the release callback does not call KVM Device's destroy callback immediately. Instead, KVM devices destruction is postponed this till KVM destruction but this happens after arch-specific KVM destroy function so the warning does a false alarm. This removes the warning as it never happens in real life and there is no any obvious place to put it. Signed-off-by: Alexey Kardashevskiy --- arch/powerpc/kvm/book3s_hv.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 9e823ad..5f15ff7 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1974,7 +1974,6 @@ void kvmppc_core_destroy_vm(struct kvm *kvm) kvmppc_rtas_tokens_free(kvm); kvmppc_free_hpt(kvm); - WARN_ON(!list_empty(&kvm->arch.spapr_tce_tables)); } /* These are stubs for now */