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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB137C33CAA for ; Tue, 21 Jan 2020 22:33:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91D5824655 for ; Tue, 21 Jan 2020 22:33:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727969AbgAUWcE (ORCPT ); Tue, 21 Jan 2020 17:32:04 -0500 Received: from mga14.intel.com ([192.55.52.115]:1735 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726889AbgAUWcE (ORCPT ); Tue, 21 Jan 2020 17:32:04 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Jan 2020 14:32:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,347,1574150400"; d="scan'208";a="244845105" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga002.jf.intel.com with ESMTP; 21 Jan 2020 14:32:02 -0800 From: Sean Christopherson To: Paolo Bonzini Cc: Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, Christoffer Dall , Peter Xu , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Subject: [PATCH v5 02/19] KVM: Reinstall old memslots if arch preparation fails Date: Tue, 21 Jan 2020 14:31:40 -0800 Message-Id: <20200121223157.15263-3-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200121223157.15263-1-sean.j.christopherson@intel.com> References: <20200121223157.15263-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Reinstall the old memslots if preparing the new memory region fails after invalidating a to-be-{re}moved memslot. Remove the superfluous 'old_memslots' variable so that it's somewhat clear that the error handling path needs to free the unused memslots, not simply the 'old' memslots. Fixes: bc6678a33d9b9 ("KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update") Reviewed-by: Christoffer Dall Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index eb3709d55139..1429d8b726ea 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -998,7 +998,7 @@ int __kvm_set_memory_region(struct kvm *kvm, unsigned long npages; struct kvm_memory_slot *slot; struct kvm_memory_slot old, new; - struct kvm_memslots *slots = NULL, *old_memslots; + struct kvm_memslots *slots; int as_id, id; enum kvm_mr_change change; @@ -1106,7 +1106,13 @@ int __kvm_set_memory_region(struct kvm *kvm, slot = id_to_memslot(slots, id); slot->flags |= KVM_MEMSLOT_INVALID; - old_memslots = install_new_memslots(kvm, as_id, slots); + /* + * We can re-use the old memslots, the only difference from the + * newly installed memslots is the invalid flag, which will get + * dropped by update_memslots anyway. We'll also revert to the + * old memslots if preparing the new memory region fails. + */ + slots = install_new_memslots(kvm, as_id, slots); /* From this point no new shadow pages pointing to a deleted, * or moved, memslot will be created. @@ -1116,13 +1122,6 @@ int __kvm_set_memory_region(struct kvm *kvm, * - kvm_is_visible_gfn (mmu_check_root) */ kvm_arch_flush_shadow_memslot(kvm, slot); - - /* - * We can re-use the old_memslots from above, the only difference - * from the currently installed memslots is the invalid flag. This - * will get overwritten by update_memslots anyway. - */ - slots = old_memslots; } r = kvm_arch_prepare_memory_region(kvm, &new, mem, change); @@ -1136,15 +1135,17 @@ int __kvm_set_memory_region(struct kvm *kvm, } update_memslots(slots, &new, change); - old_memslots = install_new_memslots(kvm, as_id, slots); + slots = install_new_memslots(kvm, as_id, slots); kvm_arch_commit_memory_region(kvm, mem, &old, &new, change); kvm_free_memslot(kvm, &old, &new); - kvfree(old_memslots); + kvfree(slots); return 0; out_slots: + if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) + slots = install_new_memslots(kvm, as_id, slots); kvfree(slots); out_free: kvm_free_memslot(kvm, &new, &old); -- 2.24.1