From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756751Ab3L2DA5 (ORCPT ); Sat, 28 Dec 2013 22:00:57 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54998 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751963Ab3L2CJy (ORCPT ); Sat, 28 Dec 2013 21:09:54 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Marcelo Tosatti" , "Gleb Natapov" , "Alex Williamson" Date: Sun, 29 Dec 2013 03:08:44 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 175/185] KVM: Fix iommu map/unmap to handle memory slot moves In-Reply-To: X-SA-Exim-Connect-IP: 31.18.200.85 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alex Williamson commit e40f193f5bb022e927a57a4f5d5194e4f12ddb74 upstream. The iommu integration into memory slots expects memory slots to be added or removed and doesn't handle the move case. We can unmap slots from the iommu after we mark them invalid and map them before installing the final memslot array. Also re-order the kmemdup vs map so we don't leave iommu mappings if we get ENOMEM. Reviewed-by: Gleb Natapov Signed-off-by: Alex Williamson Signed-off-by: Marcelo Tosatti [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- virt/kvm/kvm_main.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -788,6 +788,8 @@ skip_lpage: old_memslots = kvm->memslots; rcu_assign_pointer(kvm->memslots, slots); synchronize_srcu_expedited(&kvm->srcu); + /* slot was deleted or moved, clear iommu mapping */ + kvm_iommu_unmap_pages(kvm, &old); /* From this point no new shadow pages pointing to a deleted, * or moved, memslot will be created. * @@ -803,14 +805,6 @@ skip_lpage: if (r) goto out_free; - /* map/unmap the pages in iommu page table */ - if (npages) { - r = kvm_iommu_map_pages(kvm, &new); - if (r) - goto out_free; - } else - kvm_iommu_unmap_pages(kvm, &old); - r = -ENOMEM; slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!slots) @@ -820,6 +814,13 @@ skip_lpage: slots->nmemslots = mem->slot + 1; slots->generation++; + /* map new memory slot into the iommu */ + if (npages) { + r = kvm_iommu_map_pages(kvm, &new); + if (r) + goto out_slots; + } + /* actual memory is freed via old in kvm_free_physmem_slot below */ if (!npages) { new.rmap = NULL; @@ -847,6 +848,8 @@ skip_lpage: return 0; +out_slots: + kfree(slots); out_free: kvm_free_physmem_slot(&new, &old); out: