On Fri, 2011-09-23 at 07:41 -0700, Rose, Gregory V wrote: > > -----Original Message----- > > From: Ian Campbell [mailto:ijc@xxxxxxxxxxxxxx] > > Sent: Friday, September 23, 2011 12:28 AM > > To: Kirsher, Jeffrey T > > Cc: davem@xxxxxxxxxxxxx; konrad.wilk@xxxxxxxxxx; Jesse Barnes; Rose, > > Gregory V; netdev@xxxxxxxxxxxxxxx; gospo@xxxxxxxxxx; linux- > > pci@xxxxxxxxxxxxxxx > > Subject: Re: [net-next 1/8] pci: Add flag indicating device has been > > assigned by KVM > > > > On Thu, 2011-09-22 at 21:16 -0700, Jeff Kirsher wrote: > > > > > > > > > Jesse/Konrad/Ian- > > > > > > I sent this patch out as part of a pull request for David Miller's > > > net-next tree. I know that Greg sent this originally out to the > > > linux-pci mailing list as a RFC. Since Greg also has a patch against > > > ixgbe which implemented this flag, I sent both patches for inclusion > > > into David Miller's net-next. > > > > > > Dave is wanting to ensure that the PCI maintainers have reviewed this > > > and are ok with it before pulls my series of patches. > > > > I'm not a PCI maintainer by any stretch of the imagination but FWIW this > > change is fine by me. > > > > My original reason for commenting on this patch was just to wonder > > whether this would also be useful for Xen and I think the answer is we > > should patch xen-pciback to use this new flag but I've not had time to > > look into that. > > > > I suppose by that measure the comment could be less KVM specific: > > > + /* Provide indication device is assigned by KVM */ > > > + PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4, > > We can resubmit with a more generic comment, maybe this: > > /* Provide indication device is assigned by a Virtual Machine Manager */ Sounds good to me. > > > > > but that's not exactly a big deal. > > > > I suppose really the flag indicates "VF in use" rather than necessarily > > "assigned"? Would it be just as bad to have a VF driver in the host > > active when the PF was unloaded? > > There is no issue with unloading an active VF in the host because the > hot remove event is seen by the host and accesses to the device stop. > However, when you hot remove the device the host and it is assigned to > a VM the VM is unaware of the event and has no way of propagating the > hot remove event. So it really is a VF assigned to VM flag. There's > no need to mark VFs as in use in the host. Ah, ok. Thanks for explaining. Ian. -- Ian Campbell Current Noise: High On Fire - Blessed Black Wings Famous, adj.: Conspicuously miserable. -- Ambrose Bierce, "The Devil's Dictionary" -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
