From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH v7 15/17] vmx: VT-d posted-interrupt core logic handling Date: Wed, 23 Sep 2015 09:11:48 +0200 Message-ID: <1442992308.2691.112.camel@citrix.com> References: <55FFD3CD.3030004@citrix.com> <1442845472.2691.88.camel@citrix.com> <56012CE1.4090308@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4047067229568525840==" Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "Wu, Feng" , George Dunlap , George Dunlap Cc: Andrew Cooper , "Tian, Kevin" , Keir Fraser , Jan Beulich , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org --===============4047067229568525840== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-n6bDMzA7edO1EsEnycqc" --=-n6bDMzA7edO1EsEnycqc Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2015-09-23 at 06:35 +0000, Wu, Feng wrote: > > From: George Dunlap [mailto:george.dunlap@citrix.com] > > On 09/22/2015 08:19 AM, Wu, Feng wrote: > > > In the arch_block() hook, we actually need to > > > - Put vCPU to the blocking list > > > - Set the NV to wakeup vector > > > - Set NDST to the right pCPU > > > - Clear SN > >=20 > > Nit: We shouldn't need to actually clear SN here; SN should already > > be > > clear because the vcpu should be currently running. (I don't think > > there's a way for a vcpu to go from runnable->blocked, is there?)=20 > > And > > if it's just been running, then NDST should also already be the > > correct > > pcpu. >=20 > Yes, we can go to blocked only from running state. let me clarify a > question first: Xen doesn't support kernel preemption, right? > No, it does not. > ( i.e. we > can only perform context switch before returning to guest.)=20 > Yes, we schedule only when SCHEDULE_SOFTIRQ is checked and found to be on. Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-n6bDMzA7edO1EsEnycqc 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 iEYEABECAAYFAlYCULQACgkQk4XaBE3IOsRgPQCdHBSG9OdYJLq614VO2mFaTIov CDQAnj9XU/jwuOnDjIJwAZErtEQcs7cG =8NFU -----END PGP SIGNATURE----- --=-n6bDMzA7edO1EsEnycqc-- --===============4047067229568525840== 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 --===============4047067229568525840==--