From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric B Munson Subject: Re: [PATCH 0/4 V13] Avoid soft lockup message when KVM is stopped by host Date: Sat, 10 Mar 2012 14:53:16 -0500 Message-ID: <20120310195316.GB6648@mgebm.net> References: <1328713666-11424-1-git-send-email-emunson@mgebm.net> <20120214152931.GA6881@mgebm.net> <20120214153836.GA21106@amt.cnet> <20120214155013.GB6881@mgebm.net> <20120214161009.GA21515@amt.cnet> <20120214211720.GC6881@mgebm.net> <20120305163943.GA10338@amt.cnet> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="wzJLGUyc3ArbnUjN" Return-path: Received: from oz.csail.mit.edu ([128.30.30.239]:52579 "EHLO mail.mgebm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317Ab2CJTxR (ORCPT ); Sat, 10 Mar 2012 14:53:17 -0500 Content-Disposition: inline In-Reply-To: <20120305163943.GA10338@amt.cnet> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Marcelo Tosatti Cc: avi@redhat.com, mingo@redhat.com, hpa@zytor.com, ryanh@linux.vnet.ibm.com, aliguori@us.ibm.com, kvm@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org --wzJLGUyc3ArbnUjN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, 05 Mar 2012, Marcelo Tosatti wrote: > On Tue, Feb 14, 2012 at 04:17:20PM -0500, Eric B Munson wrote: > > On Tue, 14 Feb 2012, Marcelo Tosatti wrote: > >=20 > > > On Tue, Feb 14, 2012 at 10:50:13AM -0500, Eric B Munson wrote: > > > > On Tue, 14 Feb 2012, Marcelo Tosatti wrote: > > > >=20 > > > > > On Tue, Feb 14, 2012 at 10:29:31AM -0500, Eric B Munson wrote: > > > > > > On Wed, 08 Feb 2012, Eric B Munson wrote: > > > > > >=20 > > > > > > >=20 > > > > > > > When a guest kernel is stopped by the host hypervisor it can = look like a soft > > > > > > > lockup to the guest kernel. This false warning can mask late= r soft lockup > > > > > > > warnings which may be real. This patch series adds a method = for a host > > > > > > > hypervisor to communicate to a guest kernel that it is being = stopped. The > > > > > > > final patch in the series has the watchdog check this flag wh= en it goes to > > > > > > > issue a soft lockup warning and skip the warning if the guest= knows it was > > > > > > > stopped. > > > > > > >=20 > > > > > > > It was attempted to solve this in Qemu, but the side effects = of saving and > > > > > > > restoring the clock and tsc for each vcpu put the wall clock = of the guest behind > > > > > > > by the amount of time of the pause. This forces a guest to h= ave ntp running > > > > > > > in order to keep the wall clock accurate. > > > > > >=20 > > > > > > Avi, > > > > > >=20 > > > > > > Is this set fit for merging or is there something else you want= changed? > > > > >=20 > > > > > Eric, > > > > >=20 > > > > > On Message-ID: <20120210160536.GA23363@amt.cnet>, i asked: > > > > >=20 > > > > > How is the stub getting included for other architectures again? > > > > >=20 > > > >=20 > > > > Marcelo, > > > >=20 > > > > Sorry, I put out V13 to answer that. There is a stub in asm-generi= c that was > > > > lost in the V11-V12 rebase. This stub has be included in the V13 s= et. > > > >=20 > > > > Eric > > >=20 > > > Eric,=20 > > >=20 > > > I know the stub has been included in the series. But i am asking how= =20 > > > it is #include'ed for other architectures? (can't see that). > >=20 > > Marcelo, > >=20 > > kernel/watchdog.c now includes linux/kvm_para.h which includes asm/kvm_= para.h. > > The check_and_clear function is defined in arch include/asm/kvm_para.h = or in > > asm-generic/kvm_para.h for any arch lacking the specific header in thei= r asm > > include dir. If I have misunderstood how these headers work, please le= t me > > know and I will fix it. >=20 > There is no automatic inclusion of asm-generic/ headers. You must create > kvm_para.h in each architecture's include/asm/ directory, #including > asm-generic/kvm_para.h. >=20 Hopefully V16 handles this properly, please let me know if there is anything that needs to be addressed. I'd like to see this set in for the 3.4 window. Eric --wzJLGUyc3ArbnUjN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJPW7EsAAoJEKhG9nGc1bpJh1IQAIYwatNENzqLmgtLERNStiDi +RI5ylPy+7nNsD1Tz+dlIrp4zK/og0YfTD91acEd2mWUSYZjfeSykZHROR/xqbKU es6Qf0ygT5r7miieGGH3u56zRjKqk8DVNbORK4DQVhQdfO6ZwY0cZF2/zY7wVnfz JjTVD+A2AGEC3NU8skcq0ALvfwbxcuxPfrIxULT/Nqkfn+XoGVcXhOSEMlzVfUh3 CZC/Wz6N6jvUmDb/NQgAKgxNsjrshlBq6sfj15bQumOzOFkDngzxPtuH/PKJlTa1 J2mJUXAyPDa1+TlZklwT86m+7/oSqByv0RQlW5spZ8DGSNyUMigQfQIvv+BY+eKS YcreFuTn3JTvNxyoSx7q6SKjFm57Z9HT053RuOH00v9tAlJboqsx2y8q5VcYASDH UxOWgTRzWfG2MpUQT8bd7hAu6taKHDTJyh364Gwv7xz4AGTlo4eP+t3CYJAuRHlb WnEnRm0Pp7ifANdq3djJOCbOT5gJEmSaJCb2trEfrGlzWEGrX7BRQBItXQCyf4c8 sKVurzqunabW+1hsXON0chh4NjEjTYCt8fl/nPMUVOCzgoclUwTz3QyVaNmHDFq/ yMPoSs1FTphVcs2c4GUpbpeFZY8GZcS48QnooSWQXF4eLcShSk6M6KRCe7lvIApc 9AnU21mrOvW6epQhseZZ =c8bz -----END PGP SIGNATURE----- --wzJLGUyc3ArbnUjN--