From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59744) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bI96m-0005Ek-Bk for qemu-devel@nongnu.org; Wed, 29 Jun 2016 02:36:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bI96h-0003Qu-Av for qemu-devel@nongnu.org; Wed, 29 Jun 2016 02:36:23 -0400 Received: from mout.web.de ([217.72.192.78]:57344) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bI96h-0003Qp-0J for qemu-devel@nongnu.org; Wed, 29 Jun 2016 02:36:19 -0400 References: <20160629063221.GF16629@pxdev.xzpeter.org> From: Jan Kiszka Message-ID: <57736C59.8010503@web.de> Date: Wed, 29 Jun 2016 08:36:09 +0200 MIME-Version: 1.0 In-Reply-To: <20160629063221.GF16629@pxdev.xzpeter.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="fHhrnnU2lSvPdxR97npfb19GA1Tdx729x" Subject: Re: [Qemu-devel] Question about qtest and IOMMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu , QEMU Devel Mailing List Cc: Paolo Bonzini , "Michael S. Tsirkin" , Peter Maydell , John Snow , David kiarie , Valentine Sinitsyn This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --fHhrnnU2lSvPdxR97npfb19GA1Tdx729x From: Jan Kiszka To: Peter Xu , QEMU Devel Mailing List Cc: Paolo Bonzini , "Michael S. Tsirkin" , Peter Maydell , John Snow , David kiarie , Valentine Sinitsyn Message-ID: <57736C59.8010503@web.de> Subject: Re: Question about qtest and IOMMU References: <20160629063221.GF16629@pxdev.xzpeter.org> In-Reply-To: <20160629063221.GF16629@pxdev.xzpeter.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2016-06-29 08:32, Peter Xu wrote: > Hi, all, >=20 > I am thinking about whether it's possible to write up a unit test > program for emulated IOMMUs (of course, Intel IOMMU would be the first > one). This can provide us the chance to do quick functional regression > tests for IOMMU just like other devices, as well as customized test > sequences which is hard to do in real guests (e.g., specific cache > invalidations, error injections), etc.. >=20 > I see that current qtest framework cannot support well on testing > IOMMUs. For DMA remapping, things would be quite smooth. The problem > is that, we still do not have a complete test framework on the > interrupts. E.g., currently qtest is still an acceleration type, in > which we have no vCPUs, as well as interrupt chips like APICs (please > correct me if I am wrong). It's even further if we want to test > something like kernel irqchips with QEMU. Not sure whether it's > possible to do test based on a much realistic VM (e.g., with KVM > enabled, but just keep the CPUs stall?). >=20 > I'd say that IOMMU is still experimental, and there are only limited > number of patches for it (so maybe we do not need a unit test at all). > Just want to post this idea out, to see: >=20 > - Whether we need a IOMMU unit test after all? >=20 > - Whether there is other potential consumer who has similar needs to > IOMMU, so that we can see whether try to move qtest a step further > if there are common requirements. >=20 Adding David and Valentine as we were discussing this need in the context of the AMD IOMMU as well: You cannot test errors with workload (like Linux) that do not trigger them in normal conditions. Jan --fHhrnnU2lSvPdxR97npfb19GA1Tdx729x Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAldzbFkACgkQitSsb3rl5xRQXACeOFdLl2GHKOiUL54SfsJt+nFv v2sAoJaYSmZvni1Y/UfZui2zBfGYQ9EF =eQp/ -----END PGP SIGNATURE----- --fHhrnnU2lSvPdxR97npfb19GA1Tdx729x--