From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH v8 15/17] vmx: VT-d posted-interrupt core logic handling Date: Wed, 28 Oct 2015 02:50:43 +0100 Message-ID: <1445997043.2937.258.camel@citrix.com> References: <1444640103-4685-1-git-send-email-feng.wu@intel.com> <1444640103-4685-16-git-send-email-feng.wu@intel.com> <1445870370.2717.103.camel@citrix.com> <562F574A02000078000AEFC7@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============5357857266738153418==" Return-path: In-Reply-To: <562F574A02000078000AEFC7@prv-mh.provo.novell.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: Jan Beulich , Feng Wu Cc: GeorgeDunlap , Andrew Cooper , Kevin Tian , Keir Fraser , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org --===============5357857266738153418== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-gEnKYxGS6EjW2e7ueRdQ" --=-gEnKYxGS6EjW2e7ueRdQ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2015-10-27 at 03:51 -0600, Jan Beulich wrote: > > > > On 27.10.15 at 06:19, wrote: > > > From: Dario Faggioli [mailto:dario.faggioli@citrix.com] > > > Sent: Monday, October 26, 2015 10:40 PM > > > In any case, it would have been nice, given the situation, if > > > you'd have put a few > > > words about, e.g., which solution you ended up implementing and > > > why, either in > > > the cover or here (e.g., in the '---' area). > >=20 > > Thanks for the suggestion. As I mentioned before, updating the PI > > descriptor=20 > > needs > > to be atomic, I think it should be a little expensive. So doing it > > every=20 > > VM-exit seems > > not a good idea to me. >=20 > You could check whether any update is needed before doing the > (atomic) cmpxchg16b. >=20 Indeed! Do we have enough state, when in the VMX entry/exit handlers, to check that? If yes, I really think this solution is worth at least a try. Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-gEnKYxGS6EjW2e7ueRdQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEABECAAYFAlYwKfQACgkQk4XaBE3IOsQGvgCcCOVDSH9bIyRRJtYTcoQ8oD8d 4TAAoIYYTcw4fk/RiXBt20jJHq6M4MuX =5pEQ -----END PGP SIGNATURE----- --=-gEnKYxGS6EjW2e7ueRdQ-- --===============5357857266738153418== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============5357857266738153418==--