From nobody Tue May 02 07:57:21 2023 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Q9XVX63k9z48fmX; Tue, 2 May 2023 07:57:24 +0000 (UTC) (envelope-from corvink@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Q9XVX5WlQz4d0Z; Tue, 2 May 2023 07:57:24 +0000 (UTC) (envelope-from corvink@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1683014244; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K5i1ZpYw/NE7Tzd2JNdf7HyERA7mNMxRRE0rHYb1CKk=; b=jm/va3Ebu81jahPKXRJelJemSO9EMQtUWvWs8KSN3hyV92BUpa1C9yhwnPo9VDbbBoRsL9 yVaJbGc4odf5B/BuhsIpUrlt5glMGStrkYGYbnqlB5EpoXcKnl7Pa8aNKzUJEiIqkp/JhT VTMOlIfX0swd0uA8QL9ygt/ROW7GUbgynzDM/vA51j+arEe0lNHmr4+yVPGma687UJKmPA 6NICc3lZEJYPQ38G1Q01zvKmonGqBS2hFVxwxqcQyyvPp8ycSQj13MyBjmur8F1MdemOqA ++HyImJWV7/WzpnWbJFcGIC8qm9T6SPcXcfxQHvw4MAwyr1WowNw43Wo/U5Oug== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1683014244; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K5i1ZpYw/NE7Tzd2JNdf7HyERA7mNMxRRE0rHYb1CKk=; b=fthOHJka70ZF3P4VIB23Bp+nMm7ybcrBoQ031r6JfAKqoYeBPIMVWDAOgwJtjFe6vX+uVN tocaO6zE4s9gTrhL0K2JZZf/abEPu1S0PJGhg6oPrwSSq442VD4yZ1OYmF9jF9CDkIbDM3 Ddlh6fOFOVEhg1lOACl73pEyPvqWySVBVMmlqmr6HuLWnYDkXXIOB4i8iUoDpZXxBh0zDi 99MLJBDnlnyznOH1KiHOrzqK2QSpbz5aqCphJkUH1lCuFEpTU6ibgC113LghnzRgDHn1PX wYLNtCJyp5ngJsBmY33LQmutbCSI31rMgSj+2mpXwCeYYFku+ODfZMI1fU0bNQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1683014244; a=rsa-sha256; cv=none; b=LbXd15SyeyhO0Dexxk8PyLJDQ4EqD1PWRjytpNAGWi0Ay3MQhfdfsjQ+RQcNZa5nuWBo8Z 60IRsY08k6xsi35tS3s6KgRw+JjyKTs56g8WqsGDsBEnk1vxVKK0v/PRtEfEr+WkZbR4s3 moRQXQ8KKafhVSByJEbkoeVd8LDBCcLO9kuxqSzET2c5zrCAWpDrSyTyP0n0t6t9YCMH9e cRHnTFdurZdIb/bx/hyxzBuZGj/jHlbag8MSw1ZRh22y2+vJkXL7x254dyU5LvUHwsftMM Ip6G7WBaZbiNlXlf3K08IoBVvDeTViKmt7Mo6c0T0SxJV9jkx1Wx8UtxWtVf/g== Received: from [IPv6:2001:9e8:da52:5e00:4d86:a2e1:ac9d:59c8] (unknown [IPv6:2001:9e8:da52:5e00:4d86:a2e1:ac9d:59c8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: corvink) by smtp.freebsd.org (Postfix) with ESMTPSA id 4Q9XVW5l7Cz16bc; Tue, 2 May 2023 07:57:23 +0000 (UTC) (envelope-from corvink@FreeBSD.org) Message-ID: <3ab4e6d94fb0153fb6ff4a53ac6f53b2eaae0cf7.camel@FreeBSD.org> Subject: Re: BHYVE_SNAPSHOT From: Corvin =?ISO-8859-1?Q?K=F6hne?= To: Matthew Grooms , Rob Wing Cc: freebsd-hackers@freebsd.org, freebsd-virtualization@freebsd.org, elenamihailescu22@gmail.com, Mihai Carabas , gusev.vitaliy@gmail.com Date: Tue, 02 May 2023 09:57:21 +0200 In-Reply-To: <89c84bd7-a925-02f4-acbe-12c3000e7007@shrew.net> References: <89c84bd7-a925-02f4-acbe-12c3000e7007@shrew.net> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-1ejwBLksvRG43eWs0Fu8" User-Agent: Evolution 3.46.4 List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org MIME-Version: 1.0 X-ThisMailContainsUnwantedMimeParts: N --=-1ejwBLksvRG43eWs0Fu8 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2023-05-02 at 01:16 -0500, Matthew Grooms wrote: > On 4/30/23 21:31, Rob Wing wrote: > > =C2=A0Hey Matthew, > >=20 > > On Sun, Apr 30, 2023 at 1:41=E2=80=AFPM Matthew Grooms > > wrote: > > >=20 > > > =C2=A0Would you like to see support for VM snapshots in the generic > > > kernel? > >=20 > > Is there a review open that addresses the limitations described in > > the commit message that brought the snapshot feature in? > > https://github.com/freebsd/freebsd-src/commit/483d953a86a2507355f8287c5= 107dc827a0ff516 >=20 > Yes. The next set of project goals where not pulled out of thin air. > They were selected specifically to address the limitations that > prevented snapshots from being in the mainline kernel after the > initial commit. That's why patches for AMD CPU, Multiple Devices ( >1 > of the same type ), Capsicum and JSON file format for snapshots were > developed. They were identified as the major per-requisite for > lifting conditional compilation. > > >=20 > > > =C2=A0How about support for warm or live migration? > >=20 > > This builds off the snapshot work, right? Seems like it'd make more > > sense to address the current limitations of the snapshot code > > before extending the functionality off the top of it. >=20 > Yup. See above. I appreciate your input, but the goal of live > migration was set in 2016 with a prototype first demonstrated in > 2018. How long do you suggest a developer wait without review > feedback before moving forward out of tree? The snapshot feature isn't compiled in by default. So, it's likely that changes break it and only a few people are testing it. We have to focus on getting this into the tree. > > > There are experimental patches for all these features that were > > > developed by students at UPB. In a lot of cases, there are open > > > reviews that have been waiting on feedback for ages. > >=20 > > In general, most people don't want to review large experimental > > patches. >=20 > Yup. That approach was attempted with the Warm Migration patches. > From slide 17 in Elena's presentation: >=20 > =C2=A0First review opened in 2021: https://reviews.freebsd.org/D28270 > =C2=A05 reviews from 2022 starting with https://reviews.freebsd.org/D3471= 7 > (same feature split in multiple parts) > =C2=A0 > =C2=A0A similar request was made recently to Gusev Vitaliy WRT the > multiple device support patch which he took ownership of. Thanks for > adding feedback to that review BTW. We'll see how that pans out ... >=20 > =C2=A0https://reviews.freebsd.org/D35590 >=20 I've already reviewed Vitaliy's multi device support patch=C2=A0and people had more than enough time to complain about it. I'm going to commit it as soon as he splits his commit. =C2=A0=C2=A0 > > > =C2=A0The case is quite plain. I'm not sure what the solution is to > > > this=20 > > > =C2=A0problem. I'd love to hear feedback from the community about how > > > I've got=20 > > > =C2=A0this completely wrong and how the course could be corrected. > > > That would=20 > > > =C2=A0be something. > > >=20 > >=20 > > My perspective is that it would have been better to focus student > > efforts on completing the snapshot feature. By completing the > > snapshot feature, I mean getting the code into a state where it's > > compiled in by default and no longer considered an experimental > > feature. > >=20 > I'm not sure what more to say hear regarding the snapshot feature or > what might have been done in the past. We need a solution for the > present. If you have any comments related to the follow up reviews > submitted by UPB, I'm sure they'd love to hear them. > And lastly: I get that FreeBSD is a non paid volunteer project for > most. Without the efforts of folks like Peter, Neel, John and others, > there would be no bhyve. I'm not saying that they, as project > maintainers, should somehow be doing more. We all have limited time > to invest, paid work to do and families to feed. I'm asking if there > are other developers that might be willing and able to help with > reviews? Is there something the FreeBSD foundation can do help out in > situations like these? > Thanks, > -Matthew > =C2=A0 UPB has developed some interesting features and I'd like to see those in tree. I can take some time to review the patches. Nevertheless, we really need the snapshot feature compiled in by default. Otherwise, it's wasted time for all of us. --=20 Kind regards, Corvin --=-1ejwBLksvRG43eWs0Fu8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEgvRSla3m2t/H2U9G2FTaVjFeAmoFAmRQwmEACgkQ2FTaVjFe Amq4vxAAumSDeuzxwoIng8rnHPIuaUYlTyQveawd+FEGs32aulOJvBs3hgs0KLNm t8C7uj04JjENwj4USNOVYFh87pfk9L5Qve0pmDbkJHRqI/3nNWj8WGhs3Bk4yWtH /b5yXSsrM8PBXBowKX+nYGOj7LJxayLUof/glSNJgNbCTy0/7v9qtCDLc2BMTfXU BZNVo405iJdaTvktDFTrugApWvpUb8hSETaDknZa8pV6UXmerAcR3VVb9Xfe75fS UWuamynh0s5IEJGA5d6Da30aI16Bv9cTvqNJuC05MlWJ/7Oy/G3YMMjuNW4zK+9U 9ePpgu49ZEl2AZlmGpI8O8zoZMw58Cr3YRVgj1cyEBi0Zv97nbvhCZW9ujvmQ3lQ Ub7GcIxQ6EHYKYik9DXruedH0HPwZB5OPHPRCPYM4YPL/47ayyjUcHkleSCMnc2n nA3Zga+0yr3H0qNHcGs3TzWMhUj4x7wrYf4bOi0y6SlHsFkCvWd1jJybRqbGpPR4 9rY9Dpjp8CrVfVloAe8tLp+Npwxs7ddU/EAplgv1NdaE6yzEXDBYoZ6xAjMynNkr G63mZ/+iq0bxwWtdR2gznJYy6PPCkb5o13tGnIoW6236sMA2iHHQkMrskzq8k75M yGq+0lsSWNt13+9pXsX75dhpMZGs5D4SA/lnTNAAdsFliFdVHMw= =dU7I -----END PGP SIGNATURE----- --=-1ejwBLksvRG43eWs0Fu8--