From patchwork Mon Dec 6 19:54:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej S. Szmigiero" X-Patchwork-Id: 12659645 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 804AAC433EF for ; Mon, 6 Dec 2021 19:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349219AbhLFUBE (ORCPT ); Mon, 6 Dec 2021 15:01:04 -0500 Received: from vps-vb.mhejs.net ([37.28.154.113]:50202 "EHLO vps-vb.mhejs.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349115AbhLFT7w (ORCPT ); Mon, 6 Dec 2021 14:59:52 -0500 Received: from MUA by vps-vb.mhejs.net with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1muK5h-0000ts-Dv; Mon, 06 Dec 2021 20:56:01 +0100 From: "Maciej S. Szmigiero" To: Paolo Bonzini , Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Igor Mammedov , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandru Elisei , Ben Gardon , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 15/29] KVM: s390: Skip gfn/size sanity checks on memslot DELETE or FLAGS_ONLY Date: Mon, 6 Dec 2021 20:54:21 +0100 Message-Id: <05430738437ac2c9c7371ac4e11f4a533e1677da.1638817640.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Sean Christopherson Sanity check the hva, gfn, and size of a userspace memory region only if any of those properties can change, i.e. skip the checks for DELETE and FLAGS_ONLY. KVM doesn't allow moving the hva or changing the size, a gfn change shows up as a MOVE even if flags are being modified, and the checks are pointless for the DELETE case as userspace_addr and gfn_base are zeroed by common KVM. No functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Maciej S. Szmigiero --- arch/s390/kvm/kvm-s390.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 481789873c81..a92e36d8a827 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -5011,7 +5011,14 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, struct kvm_memory_slot *new, enum kvm_mr_change change) { - gpa_t size = new->npages * PAGE_SIZE; + gpa_t size; + + /* When we are protected, we should not change the memory slots */ + if (kvm_s390_pv_get_handle(kvm)) + return -EINVAL; + + if (change == KVM_MR_DELETE || change == KVM_MR_FLAGS_ONLY) + return 0; /* A few sanity checks. We can have memory slots which have to be located/ended at a segment boundary (1MB). The memory in userland is @@ -5021,15 +5028,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if (new->userspace_addr & 0xffffful) return -EINVAL; + size = new->npages * PAGE_SIZE; if (size & 0xffffful) return -EINVAL; if ((new->base_gfn * PAGE_SIZE) + size > kvm->arch.mem_limit) return -EINVAL; - /* When we are protected, we should not change the memory slots */ - if (kvm_s390_pv_get_handle(kvm)) - return -EINVAL; return 0; }