From patchwork Tue Jan 21 22:31:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11344611 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 563001398 for ; Tue, 21 Jan 2020 22:32:12 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 317702465A for ; Tue, 21 Jan 2020 22:32:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ByuR0nz1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 317702465A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=je47gVVgAYMfJ2B0ycuPO/yh0GfxZ398kzWf35kSltc=; b=ByuR0nz1hqEEbF RB6FYyqNsyrvtmwNybJ1X5d9LhP0Il7n6MQ1xk+zyf4ic/ic2fCgW6hvsK/jFnGWJJJrLbSYNdkg4 2ntvtm5podmClUikf3eRsFZRO9LcuuKlAQtUEZCq2+oFK2upWRnpRtx5AtqG2ycHR1AKH9cK2U0IT 9wZYz9S+5/Y42EXjGROmiV4e1RFcMi3WRoGftmFb28RX/VIfbUAWw78l36dzuPvGxoqbW4p12Q8QN +xQrS/TF585iJyt30BwZPI300sg8f4x74V8R3gT2Px5draB1GFZRNG3pQC2ynXQ6TgfXJxTzl/0Vv 0c2qP7o5fZorLiorMQPw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iu249-0002Kb-6B; Tue, 21 Jan 2020 22:32:09 +0000 Received: from mga18.intel.com ([134.134.136.126]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iu245-0002IC-FC for linux-arm-kernel@lists.infradead.org; Tue, 21 Jan 2020 22:32:06 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Jan 2020 14:32:02 -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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200121_143205_555987_E33E3E3A X-CRM114-Status: GOOD ( 13.84 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [134.134.136.126 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wanpeng Li , kvm@vger.kernel.org, David Hildenbrand , Peter Xu , linux-mips@vger.kernel.org, Paul Mackerras , kvmarm@lists.cs.columbia.edu, Janosch Frank , Marc Zyngier , Joerg Roedel , Christian Borntraeger , Julien Thierry , Suzuki K Poulose , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jim Mattson , Cornelia Huck , Christoffer Dall , Sean Christopherson , linux-kernel@vger.kernel.org, James Morse , Vitaly Kuznetsov , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 Reviewed-by: Peter Xu --- 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);