From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mukesh Rathor Subject: Re: [V1 PATCH 1/3] pvh: early return from hvm_hap_nested_page_fault Date: Thu, 27 Feb 2014 18:25:05 -0800 Message-ID: <20140227182505.160841e8@mantra.us.oracle.com> References: <1393290237-28427-1-git-send-email-mukesh.rathor@oracle.com> <1393290237-28427-2-git-send-email-mukesh.rathor@oracle.com> <20140227105605.GB53925@deinos.phlegethon.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WJD8U-0000ye-F7 for xen-devel@lists.xenproject.org; Fri, 28 Feb 2014 02:25:14 +0000 In-Reply-To: <20140227105605.GB53925@deinos.phlegethon.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Tim Deegan Cc: xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On Thu, 27 Feb 2014 11:56:05 +0100 Tim Deegan wrote: > At 17:03 -0800 on 24 Feb (1393257835), Mukesh Rathor wrote: > > pvh does not support nested hvm at present. As such, return if pvh. > > Nack, sorry. > > 1: this is the nested pagefault (i.e. EPT/NPT) handler, not part of > the nested HVM code. yeah, jan already pointed that out. i just quickly whipped it out last minute after seeing a crash in hvm_hap_nested_page_fault from running xentrace on pvh. anyways, i'll take a look at it. > 2: If there _is_ a problem with the interaction between nested HVM and > PVH, the right way to fix it is to enforce that they can't both be > enabled at the same time, and then make sure all the nested-HVM code > properly checks for being enabled. It's not a good idea to scatter > PVH checks all over code for unrelated features. Yup. thanks. Mueksh > > > Signed-off-by: Mukesh Rathor > > --- > > xen/arch/x86/hvm/hvm.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c > > index 69f7e74..a4a3dcf 100644 > > --- a/xen/arch/x86/hvm/hvm.c > > +++ b/xen/arch/x86/hvm/hvm.c > > @@ -1416,6 +1416,9 @@ int hvm_hap_nested_page_fault(paddr_t gpa, > > int sharing_enomem = 0; > > mem_event_request_t *req_ptr = NULL; > > > > + if ( is_pvh_vcpu(v) ) > > + return 0; > > + > > /* On Nested Virtualization, walk the guest page table. > > * If this succeeds, all is fine. > > * If this fails, inject a nested page fault into the guest. > > -- > > 1.8.3.1 > > > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xen.org > > http://lists.xen.org/xen-devel