Date: Mon, 2 Jun 2014 18:55:53 -0700 From: Neel Natu <neelnatu@gmail.com> To: Ryan Stone <rysto32@gmail.com> Cc: "freebsd-virtualization@freebsd.org" <freebsd-virtualization@freebsd.org> Subject: Re: SR-IOV Patch Series 2/7: bhyve integration Message-ID: <CAFgRE9GPqvw-BNbMnUP3oiJOimC5BDnJ2vqVjxNedGMjP_UBMw@mail.gmail.com> In-Reply-To: <CAFMmRNx9hd2RM9AO9hKFs2fLdJChTkx5f-5m41dSM29wwT1euA@mail.gmail.com> References: <CAFMmRNx9hd2RM9AO9hKFs2fLdJChTkx5f-5m41dSM29wwT1euA@mail.gmail.com>
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Hi Ryan, On Mon, May 26, 2014 at 6:51 PM, Ryan Stone <rysto32@gmail.com> wrote: > The bhyve work to interoperate is quite simple. PCI Passthrough > through the ppt driver works just fine with SR-IOV VFs. The three > changes are: > > - allow ppt devices to detach. This would happen if the administrator > destroyed VFs with iovctl -D > - allow the SR-IOV infrastructure to force the ppt driver to attach to > certain devices by using the special BUS_PROBE_NOWILDCARD return value > from device_probe(). This will have no effect on regular devices, but > the SR-IOV infrastructure can create VF devices in a way where > BUS_PROBE_NOWILDCARD will match the device. This allows passthrough > of a given VF to be configured through iovctl (see ioctl.conf(5) for > an example of how to do this). > - Currently if vmm.ko is loaded and no ppt devices are present, the > IOMMU is not enabled. If VFs are subsequently created as passthrough > devices it will not be possible to pass them through to VMs. This > patch adds a new tunable that will force the IOMMU to be enabled. > > Note: Currently ppt suffers from a lack of locking. This is now a > problem because ppt devices can be destroyed, so there would be races > here. I tried to address this by adding a mutex but that failed in > ways that I could not figure out how to resolve (basically, some parts > of ppt are called into from within a critical section, so a spinlock > is needed, but other parts of ppt call into the VM subsystem to do > M_WAITOK allocations, so an sx lock is needed. It wasn't at all > obvious to me how to resolve that conflict, so I'm hoping that a more > experienced bhyve person has an idea). > Your changes look good. Also, yes, locking is now an issue. Let me try a couple of things and see how to fix this properly. best Neel > > http://people.freebsd.org/~rstone/patches/iov/0004-Allow-passthrough-devices-to-be-hinted.patch > [PATCH 04/21] Allow passthrough devices to be hinted. > > Allow the ppt driver to attach to devices that were hinted to be > passthrough devices by the PCI code creating them with a driver > name of "ppt". > > Add a tunable that allows the IOMMU to be forced to be used. With > SR-IOV passthrough devices the VFs may be created after vmm.ko is > loaded. The current code will not initialize the IOMMU in that > case, meaning that the passthrough devices can't actually be used. > --- > sys/amd64/vmm/io/ppt.c | 72 +++++++++++++++++++++++++++----------------------- > sys/amd64/vmm/vmm.c | 7 ++++- > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to "freebsd-virtualization-unsubscribe@freebsd.org"
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