From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: List of unaccessible x86 states Date: Sun, 25 Oct 2009 16:08:13 +0200 Message-ID: <4AE45BCD.5040305@redhat.com> References: <4ADDB49B.3010101@siemens.com> <5D3F39A4-0532-4027-8D71-87FE9BCA1C27@suse.de> <4ADDBD19.6040107@siemens.com> <20091020134811.GO29477@redhat.com> <20091020185501.GD8278@redhat.com> <32ACB0C3-1607-4D4F-A085-25D1AA1FB255@suse.de> <20091020190958.GE8278@redhat.com> <4AE41E5B.7080406@redhat.com> <761AD9DC-7CCA-4AEC-BD5E-687E718BF899@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Jan Kiszka , "oritw@il.ibm.com" , kvm-devel , Marcelo Tosatti To: Alexander Graf Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32394 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753586AbZJYOIQ (ORCPT ); Sun, 25 Oct 2009 10:08:16 -0400 In-Reply-To: <761AD9DC-7CCA-4AEC-BD5E-687E718BF899@suse.de> Sender: kvm-owner@vger.kernel.org List-ID: On 10/25/2009 03:53 PM, Alexander Graf wrote: > > Am 25.10.2009 um 10:46 schrieb Avi Kivity : > >> On 10/20/2009 09:23 PM, Alexander Graf wrote: >>> >>> If the nested hypervisor doesn't intercept INTR we don't support it >>> anyways. >> >> That's a bug. > > It's a question of how accurate we want to be. Even if we don't implement it immediately, it's still a bug. It won't matter much until we hit a guest that needs it. >>> Really, pushing the whole nesting state over is not a good idea. >> >> Isn't the entire state just one bit? Everything else should be saved >> to guest memory. > > It's not. We can't use the guest memory for hsave because then the > guest could break the l1 state, so a malicious hypervisor could break us. Guest hsave should be used for storing guest state when switching into the nested guest, not host state. Host state is not part of the save/restore state in any case. -- error compiling committee.c: too many arguments to function