From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH v2] KVM: MMU: Don't flush shadow when enabling dirty tracking Date: Mon, 27 Dec 2010 12:08:45 +0200 Message-ID: <1293444525-3920-1-git-send-email-avi@redhat.com> To: Marcelo Tosatti , kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51667 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753003Ab0L0KI6 (ORCPT ); Mon, 27 Dec 2010 05:08:58 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oBRA8wgd031946 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 27 Dec 2010 05:08:58 -0500 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id oBRA8v7i015648 for ; Mon, 27 Dec 2010 05:08:58 -0500 Sender: kvm-owner@vger.kernel.org List-ID: Instead, drop large mappings, which were the reason we dropped shadow. Signed-off-by: Avi Kivity --- v2: maintain largepage stats arch/x86/kvm/mmu.c | 12 ++++++++---- virt/kvm/kvm_main.c | 7 +------ 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 43bd5e3..dc36088 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3444,14 +3444,18 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) if (!test_bit(slot, sp->slot_bitmap)) continue; - if (sp->role.level != PT_PAGE_TABLE_LEVEL) - continue; - pt = sp->spt; - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) + for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { + if (sp->role.level != PT_PAGE_TABLE_LEVEL + && is_large_pte(pt[i])) { + drop_spte(kvm, &pt[i], + shadow_trap_nonpresent_pte); + --kvm->stat.lpages; + } /* avoid RMW */ if (is_writable_pte(pt[i])) update_spte(&pt[i], pt[i] & ~PT_WRITABLE_MASK); + } } kvm_flush_remote_tlbs(kvm); } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b1b6cbb..b3bfeb8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -586,7 +586,7 @@ int __kvm_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem, int user_alloc) { - int r, flush_shadow = 0; + int r; gfn_t base_gfn; unsigned long npages; unsigned long i; @@ -706,8 +706,6 @@ skip_lpage: if (kvm_create_dirty_bitmap(&new) < 0) goto out_free; /* destroy any largepage mappings for dirty tracking */ - if (old.npages) - flush_shadow = 1; } #else /* not defined CONFIG_S390 */ new.user_alloc = user_alloc; @@ -778,9 +776,6 @@ skip_lpage: kvm_free_physmem_slot(&old, &new); kfree(old_memslots); - if (flush_shadow) - kvm_arch_flush_shadow(kvm); - return 0; out_free: -- 1.7.1