From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: [PATCH v15 09/19] pvh: Do not allow PVH guests to change paging modes Date: Mon, 11 Nov 2013 14:57:11 +0000 Message-ID: <1384181841-22739-10-git-send-email-george.dunlap@eu.citrix.com> References: <1384181841-22739-1-git-send-email-george.dunlap@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1384181841-22739-1-git-send-email-george.dunlap@eu.citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: George Dunlap , Keir Fraser , Tim Deegan , Jan Beulich List-Id: xen-devel@lists.xenproject.org Signed-off-by: George Dunlap Signed-off-by: Mukesh Rathor Reviewed-by: Jan Beulich Acked-by: Tim Deegan --- v15: Fix up whitespace issue v13: Removed unnecessary else. CC: Jan Beulich CC: Tim Deegan CC: Keir Fraser --- xen/arch/x86/hvm/hvm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 10ddc34..6992106 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -1818,6 +1818,16 @@ int hvm_set_cr0(unsigned long value) (value & (X86_CR0_PE | X86_CR0_PG)) == X86_CR0_PG ) goto gpf; + /* A pvh is not expected to change to real mode. */ + if ( is_pvh_vcpu(v) + && (value & (X86_CR0_PE | X86_CR0_PG)) != (X86_CR0_PG | X86_CR0_PE) ) + { + printk(XENLOG_G_WARNING + "PVH attempting to turn off PE/PG. CR0:%lx\n", value); + goto gpf; + } + + if ( (value & X86_CR0_PG) && !(old_value & X86_CR0_PG) ) { if ( v->arch.hvm_vcpu.guest_efer & EFER_LME ) -- 1.7.9.5