From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andres Lagar-Cavilla Subject: [PATCH] x86/mm/paging: Prevent the guest from faulting on the same gfn when dying Date: Mon, 12 Mar 2012 11:42:43 -0400 Message-ID: <88584a17d2da567cd187.1331566963@xdev.gridcentric.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: 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: andres@gridcentric.ca, tim@xen.org, olaf@aepfle.de, adin@gridcentric.ca List-Id: xen-devel@lists.xenproject.org xen/arch/x86/mm/p2m.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) Please ignore previous post from a minute ago. Use this instead. A crashing guest due to paging may hit an "endless" loop faulting repeatedly on the current paged-out gfn, until the toolstack comes around to killing the domain. Unfortunately domain_crash at this point may not pause the vcpu due to the shutting_down flag, so we pause it explicitly when detecting the condition. Signed-off-by: Andres Lagar-Cavilla diff -r dfbcb092aa66 -r 88584a17d2da xen/arch/x86/mm/p2m.c --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -988,6 +988,9 @@ void p2m_mem_paging_populate(struct doma { gdprintk(XENLOG_ERR, "Domain %hu paging gfn %lx yet no ring " "in place\n", d->domain_id, gfn); + /* Prevent the vcpu from faulting repeatedly on the same gfn */ + if ( v->domain == d ) + vcpu_pause_nosync(v); domain_crash(d); return; }