From mboxrd@z Thu Jan 1 00:00:00 1970 From: Razvan Cojocaru Subject: Re: [PATCH] libxc: Add xc_domain_hvm_get_mtrr_type() call Date: Tue, 18 Dec 2012 19:24:01 +0200 Message-ID: <50D0A6B1.30702@gmail.com> References: <1355850255.14620.277.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1355850255.14620.277.camel@zakaz.uk.xensource.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" List-Id: xen-devel@lists.xenproject.org Thanks for the reply! > Do you have a user in mind for this new functionality? Yes. An (userspace) application that needs to look at this information to decide if a set of pages are interesting for monitoring. > This version seems to do a lot less than get_mtrr_type() in the > hypervisor. Is that deliberate? Why isn't the fixed mtrr slot and > overlap handling required here? It does do less. It's somewhat deliberate :), ideally it should have done everything that get_mtrr_type() does. It did work with my initial test addresses, but clearly more is required if it is to provide the full functionality of get_mtrr_type(). The code currently only iterates through the var_ranges, not the fixed array, etc. The overlap handling isn't there because there doesn't seem to be a clear correspondence between struct mtrr_state and struct hvm_hw_mtrr. I implemented as much of the get_mtrr_type() logic as was obvious using what mapping was clear bewtween them. Is having the full functionality in libxc feasible? >> /** >> + * This function returns information about the MTRR type of >> + * a given guest physical address/ > > ^ you mean . not / I think. You're right, sorry for the typo. Thanks, Razvan Cojocaru