From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D303C4332F for ; Thu, 18 Nov 2021 08:14:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78E4961B3A for ; Thu, 18 Nov 2021 08:14:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244524AbhKRIRr (ORCPT ); Thu, 18 Nov 2021 03:17:47 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:47704 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244301AbhKRIQa (ORCPT ); Thu, 18 Nov 2021 03:16:30 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 19FCE217BA; Thu, 18 Nov 2021 08:13:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1637223210; h=from:from:reply-to: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=rydNytA6MHRQbMCt1EMxirsJHx5fRBgzi3NjEbmAKIU=; b=krkkvSvdcqBQaIiurW4vWzuh2XNu5mwmPFIhDMdW+QD1Voa3JFALQSOZEinI8NLU9/wX3w CUcW3yr7gWRZn19TP5MJF6QCBg8jzDlh29yzGr2SpG1KH6FSVYZMj1R52N6r3lj6gJ3L3A wdZnsaURGDT26X7pmu50GV5C4pIEJP4= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C811C13CBE; Thu, 18 Nov 2021 08:13:29 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id pOwLLykLlmHfUAAAMHmgww (envelope-from ); Thu, 18 Nov 2021 08:13:29 +0000 To: Oleksandr Andrushchenko , Geert Uytterhoeven , Boris Ostrovsky Cc: "xen-devel@lists.xenproject.org" , Linux Kernel Mailing List , "julien@xen.org" , Stefano Stabellini , Jan Beulich , Anastasiia Lukianenko References: <20211028061341.1479333-1-andr2000@gmail.com> From: Juergen Gross Subject: Re: [PATCH] xen-pciback: allow compiling on other archs than x86 Message-ID: Date: Thu, 18 Nov 2021 09:13:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="kjDlSqsddPsApzzGQz1djnRLXh7gvIi7q" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --kjDlSqsddPsApzzGQz1djnRLXh7gvIi7q Content-Type: multipart/mixed; boundary="XfZMtVDaabDHq5xYIBiojcvIwNQpfGnBH"; protected-headers="v1" From: Juergen Gross To: Oleksandr Andrushchenko , Geert Uytterhoeven , Boris Ostrovsky Cc: "xen-devel@lists.xenproject.org" , Linux Kernel Mailing List , "julien@xen.org" , Stefano Stabellini , Jan Beulich , Anastasiia Lukianenko Message-ID: Subject: Re: [PATCH] xen-pciback: allow compiling on other archs than x86 References: <20211028061341.1479333-1-andr2000@gmail.com> In-Reply-To: --XfZMtVDaabDHq5xYIBiojcvIwNQpfGnBH Content-Type: multipart/mixed; boundary="------------80A444647212451F77DC65D1" Content-Language: en-US This is a multi-part message in MIME format. --------------80A444647212451F77DC65D1 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable On 16.11.21 11:45, Oleksandr Andrushchenko wrote: > Hi, Geert! >=20 > On 16.11.21 11:36, Geert Uytterhoeven wrote: >> Hi Oleksandr, >> >> On Thu, Oct 28, 2021 at 8:15 AM Oleksandr Andrushchenko >> wrote: >>> From: Oleksandr Andrushchenko >>> >>> Xen-pciback driver was designed to be built for x86 only. But it >>> can also be used by other architectures, e.g. Arm. >>> >>> Currently PCI backend implements multiple functionalities at a time, >>> such as: >>> 1. It is used as a database for assignable PCI devices, e.g. xl >>> pci-assignable-{add|remove|list} manipulates that list. So, when= ever >>> the toolstack needs to know which PCI devices can be passed thro= ugh >>> it reads that from the relevant sysfs entries of the pciback. >>> 2. It is used to hold the unbound PCI devices list, e.g. when passing= >>> through a PCI device it needs to be unbound from the relevant de= vice >>> driver and bound to pciback (strictly speaking it is not require= d >>> that the device is bound to pciback, but pciback is again used a= s a >>> database of the passed through PCI devices, so we can re-bind th= e >>> devices back to their original drivers when guest domain shuts d= own) >>> 3. Device reset for the devices being passed through >>> 4. Para-virtualised use-cases support >>> >>> The para-virtualised part of the driver is not always needed as some >>> architectures, e.g. Arm or x86 PVH Dom0, are not using backend-fronte= nd >>> model for PCI device passthrough. >>> >>> For such use-cases make the very first step in splitting the >>> xen-pciback driver into two parts: Xen PCI stub and PCI PV backend >>> drivers. >>> >>> For that add new configuration options CONFIG_XEN_PCI_STUB and >>> CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its >>> functionality, e.g. no support for para-virtualised scenario. >>> x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the >>> fully featured backend driver. >>> >>> Signed-off-by: Oleksandr Andrushchenko >>> Signed-off-by: Anastasiia Lukianenko = >>> Reviewed-by: Stefano Stabellini >>> Reviewed-by: Juergen Gross >> Thanks for your patch, which is now commit a67efff28832a597 >> ("xen-pciback: allow compiling on other archs than x86") >> in v5.16-rc1. >> >>> --- a/drivers/xen/Kconfig >>> +++ b/drivers/xen/Kconfig >>> @@ -181,10 +181,34 @@ config SWIOTLB_XEN >>> select DMA_OPS >>> select SWIOTLB >>> >>> +config XEN_PCI_STUB >>> + bool >>> + >>> +config XEN_PCIDEV_STUB >>> + tristate "Xen PCI-device stub driver" >>> + depends on PCI && !X86 && XEN >>> + depends on XEN_BACKEND >>> + select XEN_PCI_STUB >>> + default m >> Please note that this means "default y" if CONFIG_MODULES=3Dn. >> Perhaps this should be "default m if MODULES" instead? > I don't really have strong opinion on this and will let Xen maintainers= > speak: @Boris, @Juergen what's your preference here? TBH, I don't have any. All other backends have no "default" line, so maybe the cleanest solution would be to remove the "default" lines for XEN_PCIDEV_STUB and XEN_PCIDEV_BACKEND, too? >> >>> + help >>> + The PCI device stub driver provides limited version of the = PCI >>> + device backend driver without para-virtualized support for = guests. >>> + If you select this to be a module, you will need to make su= re no >>> + other driver has bound to the device(s) you want to make vi= sible to >>> + other guests. >>> + >>> + The "hide" parameter (only applicable if backend driver is = compiled >>> + into the kernel) allows you to bind the PCI devices to this= module >>> + from the default device drivers. The argument is the list o= f PCI BDFs: >>> + xen-pciback.hide=3D(03:00.0)(04:00.0) >>> + >>> + If in doubt, say m. >>> + >>> config XEN_PCIDEV_BACKEND >>> tristate "Xen PCI-device backend driver" >>> depends on PCI && X86 && XEN >>> depends on XEN_BACKEND >>> + select XEN_PCI_STUB >>> default m >>> help >>> The PCI device backend driver allows the kernel to export= arbitrary Juergen --------------80A444647212451F77DC65D1 Content-Type: application/pgp-keys; name="OpenPGP_0xB0DE9DD628BF132F.asc" Content-Transfer-Encoding: quoted-printable Content-Description: OpenPGP public key Content-Disposition: attachment; filename="OpenPGP_0xB0DE9DD628BF132F.asc" -----BEGIN PGP PUBLIC KEY BLOCK----- xsBNBFOMcBYBCACgGjqjoGvbEouQZw/ToiBg9W98AlM2QHV+iNHsEs7kxWhKMjrioyspZKOBy= cWx w3ie3j9uvg9EOB3aN4xiTv4qbnGiTr3oJhkB1gsb6ToJQZ8uxGq2kaV2KL9650I1SJvedYm8O= f8Z d621lSmoKOwlNClALZNew72NjJLEzTalU1OdT7/i1TXkH09XSSI8mEQ/ouNcMvIJNwQpd369y= 9bf IhWUiVXEK7MlRgUG6MvIj6Y3Am/BBLUVbDa4+gmzDC9ezlZkTZG2t14zWPvxXP3FAp2pkW0xq= G7/ 377qptDmrk42GlSKN4z76ELnLxussxc7I2hx18NUcbP8+uty4bMxABEBAAHNHEp1ZXJnZW4gR= 3Jv c3MgPGpnQHBmdXBmLm5ldD7CwHkEEwECACMFAlOMcBYCGwMHCwkIBwMCAQYVCAIJCgsEFgIDA= QIe AQIXgAAKCRCw3p3WKL8TL0KdB/93FcIZ3GCNwFU0u3EjNbNjmXBKDY4FUGNQH2lvWAUy+dnyT= hpw dtF/jQ6j9RwE8VP0+NXcYpGJDWlNb9/JmYqLiX2Q3TyevpB0CA3dbBQp0OW0fgCetToGIQrg0= MbD 1C/sEOv8Mr4NAfbauXjZlvTj30H2jO0u+6WGM6nHwbh2l5O8ZiHkH32iaSTfN7Eu5RnNVUJbv= oPH Z8SlM4KWm8rG+lIkGurqqu5gu8q8ZMKdsdGC4bBxdQKDKHEFExLJK/nRPFmAuGlId1E3fe10v= 5QL +qHI3EIPtyfE7i9Hz6rVwi7lWKgh7pe0ZvatAudZ+JNIlBKptb64FaiIOAWDCx1SzR9KdWVyZ= 2Vu IEdyb3NzIDxqZ3Jvc3NAc3VzZS5jb20+wsB5BBMBAgAjBQJTjHCvAhsDBwsJCAcDAgEGFQgCC= QoL BBYCAwECHgECF4AACgkQsN6d1ii/Ey/HmQf/RtI7kv5A2PS4RF7HoZhPVPogNVbC4YA6lW7Dr= Wf0 teC0RR3MzXfy6pJ+7KLgkqMlrAbN/8Dvjoz78X+5vhH/rDLa9BuZQlhFmvcGtCF8eR0T1v0nC= /nu AFVGy+67q2DH8As3KPu0344TBDpAvr2uYM4tSqxK4DURx5INz4ZZ0WNFHcqsfvlGJALDeE0Lh= ITT d9jLzdDad1pQSToCnLl6SBJZjDOX9QQcyUigZFtCXFst4dlsvddrxyqT1f17+2cFSdu7+ynLm= XBK 7abQ3rwJY8SbRO2iRulogc5vr/RLMMlscDAiDkaFQWLoqHHOdfO9rURssHNN8WkMnQfvUewRz= 80h SnVlcmdlbiBHcm9zcyA8amdyb3NzQG5vdmVsbC5jb20+wsB5BBMBAgAjBQJTjHDXAhsDBwsJC= AcD AgEGFQgCCQoLBBYCAwECHgECF4AACgkQsN6d1ii/Ey8PUQf/ehmgCI9jB9hlgexLvgOtf7PJn= FOX gMLdBQgBlVPO3/D9R8LtF9DBAFPNhlrsfIG/SqICoRCqUcJ96Pn3P7UUinFG/I0ECGF4EvTE1= jnD kfJZr6jrbjgyoZHiw/4BNwSTL9rWASyLgqlA8u1mf+c2yUwcGhgkRAd1gOwungxcwzwqgljf0= N51 N5JfVRHRtyfwq/ge+YEkDGcTU6Y0sPOuj4Dyfm8fJzdfHNQsWq3PnczLVELStJNdapwPOoE+l= otu fe3AM2vAEYJ9rTz3Cki4JFUsgLkHFqGZarrPGi1eyQcXeluldO3m91NK/1xMI3/+8jbO0tsn1= tqS EUGIJi7ox80eSnVlcmdlbiBHcm9zcyA8amdyb3NzQHN1c2UuZGU+wsB5BBMBAgAjBQJTjHDrA= hsD BwsJCAcDAgEGFQgCCQoLBBYCAwECHgECF4AACgkQsN6d1ii/Ey+LhQf9GL45eU5vOowA2u5N3= g3O ZUEBmDHVVbqMtzwlmNC4k9Kx39r5s2vcFl4tXqW7g9/ViXYuiDXb0RfUpZiIUW89siKrkzmQ5= dM7 wRqzgJpJwK8Bn2MIxAKArekWpiCKvBOB/Cc+3EXE78XdlxLyOi/NrmSGRIov0karw2RzMNOu5= D+j LRZQd1Sv27AR+IP3I8U4aqnhLpwhK7MEy9oCILlgZ1QZe49kpcumcZKORmzBTNh30FVKK1Evm= V2x AKDoaEOgQB4iFQLhJCdP1I5aSgM5IVFdn7v5YgEYuJYx37IoN1EblHI//x/e2AaIHpzK5h88N= Eaw QsaNRpNSrcfbFmAg987ATQRTjHAWAQgAyzH6AOODMBjgfWE9VeCgsrwH3exNAU32gLq2xvjpW= nHI s98ndPUDpnoxWQugJ6MpMncr0xSwFmHEgnSEjK/PAjppgmyc57BwKII3sV4on+gDVFJR6Y8ZR= wgn BC5mVM6JjQ5xDk8WRXljExRfUX9pNhdE5eBOZJrDRoLUmmjDtKzWaDhIg/+1Hzz93X4fCQkNV= bVF LELU9bMaLPBG/x5q4iYZ2k2ex6d47YE1ZFdMm6YBYMOljGkZKwYde5ldM9mo45mmwe0icXKLk= pEd IXKTZeKDO+Hdv1aqFuAcccTg9RXDQjmwhC3yEmrmcfl0+rPghO0Iv3OOImwTEe4co3c1mwARA= QAB wsBfBBgBAgAJBQJTjHAWAhsMAAoJELDendYovxMvQ/gH/1ha96vm4P/L+bQpJwrZ/dneZcmEw= Tbe 8YFsw2V/Buv6Z4Mysln3nQK5ZadD534CF7TDVft7fC4tU4PONxF5D+/tvgkPfDAfF77zy2AH1= vJz Q1fOU8lYFpZXTXIHb+559UqvIB8AdgR3SAJGHHt4RKA0F7f5ipYBBrC6cyXJyyoprT10EMvU8= VGi wXvTyJz3fjoYsdFzpWPlJEBRMedCot60g5dmbdrZ5DWClAr0yau47zpWj3enf1tLWaqcsuylW= svi uGjKGw7KHQd3bxALOknAp4dN3QwBYCKuZ7AddY9yjynVaD5X7nF9nO5BjR/i1DG86lem3iBDX= zXs ZDn8R38=3D =3D2wuH -----END PGP PUBLIC KEY BLOCK----- --------------80A444647212451F77DC65D1-- --XfZMtVDaabDHq5xYIBiojcvIwNQpfGnBH-- --kjDlSqsddPsApzzGQz1djnRLXh7gvIi7q Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- wsB5BAABCAAjFiEEhRJncuj2BJSl0Jf3sN6d1ii/Ey8FAmGWCykFAwAAAAAACgkQsN6d1ii/Ey/Q Cwf+Jhc/1Jm9LFxI79T5Jq+bvkmctPEYk9ihYb+/AzNfCCfmi3pv+MLdtfC+o4SwqgMnV4OLJRkz erlNSepcFQ0wywncJ5smsDPCbhRO87t8vSXNOS8yUz27YnEszkn8YrahUzuTxP9mBTTmmu6ggx9k /4luFLQVkBrTI/AcSMYzCxYmVOW+ClqnWut4rtcFtyvOMs0a1Rh+z7LpRazWhR8Uii4qBI0vsobM vck/r7LwAQb+oF/1srQl/v9yx9h4OaRUFA7Z9QQNAq05Eo4AxOvBw0RKWapn+g4e0UehnKTrA9Dv FPJOkRSLbyMhw2OrBRk09r4AFChl+BDGg8aCspIcuQ== =zSZW -----END PGP SIGNATURE----- --kjDlSqsddPsApzzGQz1djnRLXh7gvIi7q--