Date: Thu, 9 Aug 2018 10:30:05 -0700 From: John Baldwin <jhb@FreeBSD.org> To: Farid Joubbi <djfarid@gmail.com> Cc: freebsd-virtualization@freebsd.org Subject: Re: Passthrough not working with OpenBSD nor NetBSD Message-ID: <ef00fb05-592f-092e-38bf-ca078f60aabd@FreeBSD.org> In-Reply-To: <CAEN4iub7goyKFMhydeNu8yr3u1DQp4ODpUNspxEGWtYY0V4daQ@mail.gmail.com> References: <CAEN4iua-8W8JjU9DNBiP-dcuBiMZRp%2ByCRy0ekeAF9LXc4hQ9Q@mail.gmail.com> <f16bd6d1-6566-6a61-4bca-1333bbdf91e8@FreeBSD.org> <CAEN4iub014PXgjf18VH5xgjTxVeHcmAtRaK2joWgR4=_E-oX5w@mail.gmail.com> <a91706b0-0fc3-22ee-2f56-29a10c923500@FreeBSD.org> <CAEN4iub7goyKFMhydeNu8yr3u1DQp4ODpUNspxEGWtYY0V4daQ@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
They may implement INTx interrupts for pass-through perhaps. INTx are a lot bigger pain to emulate since there isn't a standard way in PCI to determine if an interrupt is pending (and you need that to simulate a level-triggered interrupt like INTx). I think very recent revisions of PCI did add a new bit to test that in the PCI status register, but it is in a new enough version of PCI that any compliant devices would also support MSI anyway. On 8/9/18 10:07 AM, Farid Joubbi wrote: > How does KVM and VMware solve that? > I haven't tried PCI passthrough with them, but I assume that it works..? > > On Thu, Aug 9, 2018, 18:24 John Baldwin <jhb@freebsd.org <mailto:jhb@freebsd.org>> wrote: > > On 8/8/18 11:08 AM, Farid Joubbi wrote: > > That's what I also thought, but it's not anything I can force it to do, is it? Isn't it supposed to detect the MSI interrupt compatibility automatically? > > Apparently Open/Net always try to setup INTx before trying MSI even if they > won't use INTx per the commit log in revision 280725. We could perhaps try > to provide a "fake" INTx interrupt that doesn't work, but I'll have to think > about how to implement that. > > -- > John Baldwin > -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?ef00fb05-592f-092e-38bf-ca078f60aabd>