Date: Thu, 08 Jun 2023 16:20:37 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 271785] PCI: HotPlug: no BAR mapping after attaching a virtual function to the VM Message-ID: <bug-271785-227-RxWJE30mHL@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-271785-227@https.bugs.freebsd.org/bugzilla/> References: <bug-271785-227@https.bugs.freebsd.org/bugzilla/>
next in thread | previous in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D271785 John Baldwin <jhb@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jhb@FreeBSD.org --- Comment #2 from John Baldwin <jhb@FreeBSD.org> --- I'm not quite sure I follow exactly. Are you creating the VFs in a FreeBSD bare metal machine, or have you created a VF on a host and are then passing that VF through to the guest as a PCI-e hot-plug event? Generally speaking, FreeBSD's PCI bus driver does not try to assign resourc= es to a device when it discovers it. When a device is enumerated, if the BARs already have a resource that has been assigned by firmware (e.g. during boo= t), then this existing resource allocations are preserved and the address space= is reserved when enumerating the device. However, if a BAR doesn't have a firmware-assigned address range when a qdevice is enumerated, the BAR is st= ill sized but left unallocated. If a device driver attaches and calls bus_alloc_resource to reserve a BAR, at that point resources are allocated = for the BAR. For HotPlug, BARs are always unassigned when the device appears, so they are only assigned resources when you attach a driver. Thus, if you create a VF= on the host and pass through to the FreeBSD guest and the guest doesn't have a driver for the VF device loaded, I would expect to see all the BARs unassig= ned. However, once you load a driver the BARs should be assigned resources duri= ng the attach of the device driver. --=20 You are receiving this mail because: You are the assignee for the bug.=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-271785-227-RxWJE30mHL>