From patchwork Wed Dec 23 11:38:41 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 69507 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.2) with ESMTP id nBNBkQJY013034 for ; Wed, 23 Dec 2009 11:46:27 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752949AbZLWLqO (ORCPT ); Wed, 23 Dec 2009 06:46:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753099AbZLWLqM (ORCPT ); Wed, 23 Dec 2009 06:46:12 -0500 Received: from mx1.redhat.com ([209.132.183.28]:65435 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752809AbZLWLqJ (ORCPT ); Wed, 23 Dec 2009 06:46:09 -0500 Received: from int-mx05.intmail.prod.int.phx2.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nBNBk81h024052 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 23 Dec 2009 06:46:08 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx05.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id nBNBk7M1015920; Wed, 23 Dec 2009 06:46:08 -0500 Received: from amt.cnet (vpn-11-120.rdu.redhat.com [10.11.11.120]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id nBNBk6BT027787; Wed, 23 Dec 2009 06:46:06 -0500 Received: from amt.cnet (amt.cnet [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 21065680298; Wed, 23 Dec 2009 09:45:58 -0200 (BRST) Received: (from marcelo@localhost) by amt.cnet (8.14.3/8.14.3/Submit) id nBNBjv6M013301; Wed, 23 Dec 2009 09:45:57 -0200 Message-Id: <20091223114438.870086520@redhat.com> User-Agent: quilt/0.47-1 Date: Wed, 23 Dec 2009 09:38:41 -0200 From: Marcelo Tosatti To: kvm@vger.kernel.org Cc: avi@redhat.com, Marcelo Tosatti Subject: [patch 08/11] KVM: x86: switch kvm_set_memory_alias to SRCU update References: <20091223113833.742662117@redhat.com> Content-Disposition: inline; filename=srcu-alias-update X-Scanned-By: MIMEDefang 2.67 on 10.5.11.18 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Index: kvm/arch/x86/include/asm/kvm_host.h =================================================================== --- kvm.orig/arch/x86/include/asm/kvm_host.h +++ kvm/arch/x86/include/asm/kvm_host.h @@ -368,8 +368,12 @@ struct kvm_mem_alias { gfn_t base_gfn; unsigned long npages; gfn_t target_gfn; +#define KVM_ALIAS_INVALID 1UL + unsigned long flags; }; +#define KVM_ARCH_HAS_UNALIAS_INSTANTIATION + struct kvm_mem_aliases { struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS]; int naliases; Index: kvm/arch/x86/kvm/x86.c =================================================================== --- kvm.orig/arch/x86/kvm/x86.c +++ kvm/arch/x86/kvm/x86.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #undef TRACE_INCLUDE_FILE #define CREATE_TRACE_POINTS @@ -2224,11 +2225,32 @@ static int kvm_vm_ioctl_get_nr_mmu_pages return kvm->arch.n_alloc_mmu_pages; } +gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn) +{ + int i; + struct kvm_mem_alias *alias; + struct kvm_mem_aliases *aliases; + + aliases = rcu_dereference(kvm->arch.aliases); + + for (i = 0; i < aliases->naliases; ++i) { + alias = &aliases->aliases[i]; + if (alias->flags & KVM_ALIAS_INVALID) + continue; + if (gfn >= alias->base_gfn + && gfn < alias->base_gfn + alias->npages) + return alias->target_gfn + gfn - alias->base_gfn; + } + return gfn; +} + gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) { int i; struct kvm_mem_alias *alias; - struct kvm_mem_aliases *aliases = kvm->arch.aliases; + struct kvm_mem_aliases *aliases; + + aliases = rcu_dereference(kvm->arch.aliases); for (i = 0; i < aliases->naliases; ++i) { alias = &aliases->aliases[i]; @@ -2249,7 +2271,7 @@ static int kvm_vm_ioctl_set_memory_alias { int r, n; struct kvm_mem_alias *p; - struct kvm_mem_aliases *aliases; + struct kvm_mem_aliases *aliases, *old_aliases; r = -EINVAL; /* General sanity checks */ @@ -2266,28 +2288,48 @@ static int kvm_vm_ioctl_set_memory_alias < alias->target_phys_addr) goto out; + r = -ENOMEM; + aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); + if (!aliases) + goto out; + down_write(&kvm->slots_lock); - spin_lock(&kvm->mmu_lock); - aliases = kvm->arch.aliases; + /* invalidate any gfn reference in case of deletion/shrinking */ + memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases)); + aliases->aliases[alias->slot].flags |= KVM_ALIAS_INVALID; + old_aliases = kvm->arch.aliases; + rcu_assign_pointer(kvm->arch.aliases, aliases); + synchronize_srcu_expedited(&kvm->srcu); + kvm_mmu_zap_all(kvm); + kfree(old_aliases); + + r = -ENOMEM; + aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); + if (!aliases) + goto out_unlock; + + memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases)); p = &aliases->aliases[alias->slot]; p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT; p->npages = alias->memory_size >> PAGE_SHIFT; p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT; + p->flags &= ~(KVM_ALIAS_INVALID); for (n = KVM_ALIAS_SLOTS; n > 0; --n) if (aliases->aliases[n - 1].npages) break; aliases->naliases = n; - spin_unlock(&kvm->mmu_lock); - kvm_mmu_zap_all(kvm); + old_aliases = kvm->arch.aliases; + rcu_assign_pointer(kvm->arch.aliases, aliases); + synchronize_srcu_expedited(&kvm->srcu); + kfree(old_aliases); + r = 0; +out_unlock: up_write(&kvm->slots_lock); - - return 0; - out: return r; } Index: kvm/include/linux/kvm_host.h =================================================================== --- kvm.orig/include/linux/kvm_host.h +++ kvm/include/linux/kvm_host.h @@ -265,6 +265,8 @@ void kvm_arch_commit_memory_region(struc void kvm_disable_largepages(void); void kvm_arch_flush_shadow(struct kvm *kvm); gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn); +gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn); + struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn); void kvm_release_page_clean(struct page *page); @@ -538,6 +540,10 @@ static inline int mmu_notifier_retry(str } #endif +#ifndef KVM_ARCH_HAS_UNALIAS_INSTANTIATION +#define unalias_gfn_instantiation unalias_gfn +#endif + #ifdef CONFIG_HAVE_KVM_IRQCHIP #define KVM_MAX_IRQ_ROUTES 1024 Index: kvm/virt/kvm/kvm_main.c =================================================================== --- kvm.orig/virt/kvm/kvm_main.c +++ kvm/virt/kvm/kvm_main.c @@ -847,7 +847,7 @@ int kvm_is_visible_gfn(struct kvm *kvm, int i; struct kvm_memslots *slots = rcu_dereference(kvm->memslots); - gfn = unalias_gfn(kvm, gfn); + gfn = unalias_gfn_instantiation(kvm, gfn); for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { struct kvm_memory_slot *memslot = &slots->memslots[i]; @@ -884,7 +884,7 @@ unsigned long gfn_to_hva(struct kvm *kvm { struct kvm_memory_slot *slot; - gfn = unalias_gfn(kvm, gfn); + gfn = unalias_gfn_instantiation(kvm, gfn); slot = gfn_to_memslot_unaliased(kvm, gfn); if (!slot || slot->flags & KVM_MEMSLOT_INVALID) return bad_hva();