From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot Date: Mon, 11 Feb 2013 11:52:14 +0200 Message-ID: <20130211095214.GW7837@redhat.com> References: <20130207185557.b32ba396.yoshikawa_takuya_b1@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: mtosatti@redhat.com, kvm@vger.kernel.org To: Takuya Yoshikawa Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50542 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754346Ab3BKJwS (ORCPT ); Mon, 11 Feb 2013 04:52:18 -0500 Content-Disposition: inline In-Reply-To: <20130207185557.b32ba396.yoshikawa_takuya_b1@lab.ntt.co.jp> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Feb 07, 2013 at 06:55:57PM +0900, Takuya Yoshikawa wrote: > This field was needed to differentiate memory slots created by the new > API, KVM_SET_USER_MEMORY_REGION, from those by the old equivalent, > KVM_SET_MEMORY_REGION, whose support was dropped long before: > > commit b74a07beed0e64bfba413dcb70dd6749c57f43dc > KVM: Remove kernel-allocated memory regions > > Although we also have private memory slots to which KVM allocates > memory with vm_mmap(), !user_alloc slots in other words, the slot id > should be enough for differentiating them. > > Note: corresponding function parameters will be removed later. > Applied. Thanks. > Signed-off-by: Takuya Yoshikawa > --- > arch/x86/kvm/x86.c | 37 ++++++++++++++++--------------------- > include/linux/kvm_host.h | 1 - > virt/kvm/kvm_main.c | 1 - > 3 files changed, 16 insertions(+), 23 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 373e17a..3c5bb6f 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6897,33 +6897,28 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, > bool user_alloc) > { > int npages = memslot->npages; > - int map_flags = MAP_PRIVATE | MAP_ANONYMOUS; > > - /* Prevent internal slot pages from being moved by fork()/COW. */ > - if (memslot->id >= KVM_USER_MEM_SLOTS) > - map_flags = MAP_SHARED | MAP_ANONYMOUS; > - > - /*To keep backward compatibility with older userspace, > - *x86 needs to handle !user_alloc case. > + /* > + * Only private memory slots need to be mapped here since > + * KVM_SET_MEMORY_REGION ioctl is no longer supported. > */ > - if (!user_alloc) { > - if (npages && !old.npages) { > - unsigned long userspace_addr; > + if ((memslot->id >= KVM_USER_MEM_SLOTS) && npages && !old.npages) { > + unsigned long userspace_addr; > > - userspace_addr = vm_mmap(NULL, 0, > - npages * PAGE_SIZE, > - PROT_READ | PROT_WRITE, > - map_flags, > - 0); > + /* > + * MAP_SHARED to prevent internal slot pages from being moved > + * by fork()/COW. > + */ > + userspace_addr = vm_mmap(NULL, 0, npages * PAGE_SIZE, > + PROT_READ | PROT_WRITE, > + MAP_SHARED | MAP_ANONYMOUS, 0); > > - if (IS_ERR((void *)userspace_addr)) > - return PTR_ERR((void *)userspace_addr); > + if (IS_ERR((void *)userspace_addr)) > + return PTR_ERR((void *)userspace_addr); > > - memslot->userspace_addr = userspace_addr; > - } > + memslot->userspace_addr = userspace_addr; > } > > - > return 0; > } > > @@ -6935,7 +6930,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, > > int nr_mmu_pages = 0, npages = mem->memory_size >> PAGE_SHIFT; > > - if (!user_alloc && !old.user_alloc && old.npages && !npages) { > + if ((mem->slot >= KVM_USER_MEM_SLOTS) && old.npages && !npages) { > int ret; > > ret = vm_munmap(old.userspace_addr, > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 0350e0d..722cae7 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -273,7 +273,6 @@ struct kvm_memory_slot { > unsigned long userspace_addr; > u32 flags; > short id; > - bool user_alloc; > }; > > static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot) > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 2e93630..adc68fe 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -839,7 +839,6 @@ int __kvm_set_memory_region(struct kvm *kvm, > > r = -ENOMEM; > if (change == KVM_MR_CREATE) { > - new.user_alloc = user_alloc; > new.userspace_addr = mem->userspace_addr; > > if (kvm_arch_create_memslot(&new, npages)) > -- > 1.7.5.4 -- Gleb.