Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964935AbXADQCJ (ORCPT ); Thu, 4 Jan 2007 11:02:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964965AbXADQCJ (ORCPT ); Thu, 4 Jan 2007 11:02:09 -0500 Received: from il.qumranet.com ([62.219.232.206]:46925 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964935AbXADQCI (ORCPT ); Thu, 4 Jan 2007 11:02:08 -0500 Subject: [PATCH 13/33] KVM: MMU: Zap shadow page table entries on writes to guest page tables From: Avi Kivity Date: Thu, 04 Jan 2007 16:02:06 -0000 To: kvm-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, akpm@osdl.org, mingo@elte.hu References: <459D21DD.5090506@qumranet.com> In-Reply-To: <459D21DD.5090506@qumranet.com> Message-Id: <20070104160206.A1BDB250048@il.qumranet.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1910 Lines: 60 Iterate over all shadow pages which correspond to a the given guest page table and remove the mappings. A subsequent page fault will reestablish the new mapping. Signed-off-by: Avi Kivity Index: linux-2.6/drivers/kvm/mmu.c =================================================================== --- linux-2.6.orig/drivers/kvm/mmu.c +++ linux-2.6/drivers/kvm/mmu.c @@ -958,7 +958,43 @@ int kvm_mmu_reset_context(struct kvm_vcp void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) { + gfn_t gfn = gpa >> PAGE_SHIFT; + struct kvm_mmu_page *page; + struct kvm_mmu_page *child; + struct hlist_node *node; + struct hlist_head *bucket; + unsigned index; + u64 *spte; + u64 pte; + unsigned offset = offset_in_page(gpa); + unsigned page_offset; + int level; + pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); + index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; + bucket = &vcpu->kvm->mmu_page_hash[index]; + hlist_for_each_entry(page, node, bucket, hash_link) { + if (page->gfn != gfn || page->role.metaphysical) + continue; + page_offset = offset; + level = page->role.level; + if (page->role.glevels == PT32_ROOT_LEVEL) { + page_offset <<= 1; /* 32->64 */ + page_offset &= ~PAGE_MASK; + } + spte = __va(page->page_hpa); + spte += page_offset / sizeof(*spte); + pte = *spte; + if (is_present_pte(pte)) { + if (level == PT_PAGE_TABLE_LEVEL) + rmap_remove(vcpu->kvm, spte); + else { + child = page_header(pte & PT64_BASE_ADDR_MASK); + mmu_page_remove_parent_pte(child, spte); + } + } + *spte = 0; + } } void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/