From patchwork Wed Sep 11 18:50:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 1161217 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46T9wJ04rXz9sQp for ; Thu, 12 Sep 2019 04:51:12 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730160AbfIKSvA (ORCPT ); Wed, 11 Sep 2019 14:51:00 -0400 Received: from mga06.intel.com ([134.134.136.31]:39427 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730266AbfIKSup (ORCPT ); Wed, 11 Sep 2019 14:50:45 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2019 11:50:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,492,1559545200"; d="scan'208";a="196980896" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by orsmga002.jf.intel.com with ESMTP; 11 Sep 2019 11:50:41 -0700 From: Sean Christopherson To: James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Marc Zyngier Cc: David Hildenbrand , Cornelia Huck , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , James Morse , Julien Thierry , Suzuki K Pouloze , linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: [PATCH 11/13] KVM: Ensure validity of memslot with respect to kvm_get_dirty_log() Date: Wed, 11 Sep 2019 11:50:36 -0700 Message-Id: <20190911185038.24341-12-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190911185038.24341-1-sean.j.christopherson@intel.com> References: <20190911185038.24341-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org Rework kvm_get_dirty_log() so that it "returns" the associated memslot on success. A future patch will rework memslot handling such that id_to_memslot() can return NULL, returning the memslot makes it more obvious that the validity of the memslot has been verified, i.e. precludes the need to add validity checks in the arch code that are technically unnecessary. Signed-off-by: Sean Christopherson --- arch/powerpc/kvm/book3s_pr.c | 6 +----- arch/s390/kvm/kvm-s390.c | 12 ++---------- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 27 +++++++++++++++++++-------- 4 files changed, 23 insertions(+), 24 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 5368a5dbac22..f41a136d247f 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1860,7 +1860,6 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) static int kvm_vm_ioctl_get_dirty_log_pr(struct kvm *kvm, struct kvm_dirty_log *log) { - struct kvm_memslots *slots; struct kvm_memory_slot *memslot; struct kvm_vcpu *vcpu; ulong ga, ga_end; @@ -1870,15 +1869,12 @@ static int kvm_vm_ioctl_get_dirty_log_pr(struct kvm *kvm, mutex_lock(&kvm->slots_lock); - r = kvm_get_dirty_log(kvm, log, &is_dirty); + r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot); if (r) goto out; /* If nothing is dirty, don't bother messing with page tables. */ if (is_dirty) { - slots = kvm_memslots(kvm); - memslot = id_to_memslot(slots, log->slot); - ga = memslot->base_gfn << PAGE_SHIFT; ga_end = ga + (memslot->npages << PAGE_SHIFT); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 36d4de1b1409..074f0d7771b6 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -613,9 +613,8 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, { int r; unsigned long n; - struct kvm_memslots *slots; struct kvm_memory_slot *memslot; - int is_dirty = 0; + int is_dirty; if (kvm_is_ucontrol(kvm)) return -EINVAL; @@ -626,14 +625,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, if (log->slot >= KVM_USER_MEM_SLOTS) goto out; - slots = kvm_memslots(kvm); - memslot = id_to_memslot(slots, log->slot); - r = -ENOENT; - if (!memslot->dirty_bitmap) - goto out; - - kvm_arch_sync_dirty_log(kvm, memslot); - r = kvm_get_dirty_log(kvm, log, &is_dirty); + r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot); if (r) goto out; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index feb40a184847..049e20876b8f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -808,7 +808,7 @@ void kvm_arch_dirty_log_tlb_flush(struct kvm *kvm, struct kvm_memory_slot *slot) #else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, - int *is_dirty); + int *is_dirty, struct kvm_memory_slot **memslot); #endif int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 85062477be90..11b130e9f223 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1123,31 +1123,42 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, } #ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT -int kvm_get_dirty_log(struct kvm *kvm, - struct kvm_dirty_log *log, int *is_dirty) +/** + * kvm_get_dirty_log - get a snapshot of dirty pages + * @kvm: pointer to kvm instance + * @log: slot id and address to which we copy the log + * @is_dirty: set to '1' if any dirty pages were found + * @memslot: set to the associated memslot, always valid on success + */ +int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, + int *is_dirty, struct kvm_memory_slot **memslot) { struct kvm_memslots *slots; - struct kvm_memory_slot *memslot; int i, as_id, id; unsigned long n; unsigned long any = 0; + *memslot = NULL; + *is_dirty = 0; + as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) return -EINVAL; slots = __kvm_memslots(kvm, as_id); - memslot = id_to_memslot(slots, id); - if (!memslot->dirty_bitmap) + *memslot = id_to_memslot(slots, id); + if (!(*memslot)->dirty_bitmap) return -ENOENT; - n = kvm_dirty_bitmap_bytes(memslot); + kvm_arch_sync_dirty_log(kvm, *memslot); + + n = kvm_dirty_bitmap_bytes(*memslot); for (i = 0; !any && i < n/sizeof(long); ++i) - any = memslot->dirty_bitmap[i]; + any = (*memslot)->dirty_bitmap[i]; - if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n)) + if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n)) return -EFAULT; if (any)