From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 31/33] KVM: MMU: Flush guest tlb when reducing permissions on a pte Date: Thu, 04 Jan 2007 16:20:07 -0000 Message-ID: <20070104162007.AF4E9250048@il.qumranet.com> References: <459D21DD.5090506@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: akpm-3NddpPZAyC0@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org In-Reply-To: <459D21DD.5090506-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org If we reduce permissions on a pte, we must flush the cached copy of the pte from the guest's tlb. This is implemented at the moment by flushing the entire guest tlb, and can be improved by flushing just the relevant virtual address, if it is known. 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 @@ -383,6 +383,7 @@ static void rmap_write_protect(struct kv BUG_ON(!(*spte & PT_WRITABLE_MASK)); rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte); rmap_remove(vcpu, spte); + kvm_arch_ops->tlb_flush(vcpu); *spte &= ~(u64)PT_WRITABLE_MASK; } } @@ -594,6 +595,7 @@ static void kvm_mmu_page_unlink_children rmap_remove(vcpu, &pt[i]); pt[i] = 0; } + kvm_arch_ops->tlb_flush(vcpu); return; } @@ -927,7 +929,10 @@ static inline void set_pte_common(struct pgprintk("%s: found shadow page for %lx, marking ro\n", __FUNCTION__, gfn); access_bits &= ~PT_WRITABLE_MASK; - *shadow_pte &= ~PT_WRITABLE_MASK; + if (is_writeble_pte(*shadow_pte)) { + *shadow_pte &= ~PT_WRITABLE_MASK; + kvm_arch_ops->tlb_flush(vcpu); + } } } ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV