> -----Original Message----- > From: Jesse Barnes [mailto:jbarnes@xxxxxxxxxxxxxxxx] > Sent: Friday, July 29, 2011 9:52 AM > To: Ian Campbell > Cc: Rose, Gregory V; Konrad Rzeszutek Wilk; netdev@xxxxxxxxxxxxxxx; > davem@xxxxxxxxxxxxx; bhutchings@xxxxxxxxxxxxxx; Kirsher, Jeffrey T; linux- > pci@xxxxxxxxxxxxxxx > Subject: Re: [RFC net-next PATCH 1/4] pci: Add flag indicating device has > been assigned by KVM > > On Thu, 28 Jul 2011 16:11:17 +0100 > Ian Campbell <ijc@xxxxxxxxxxxxxx> wrote: > > > On Wed, 2011-07-27 at 15:17 -0700, Greg Rose wrote: > > > Device drivers that create and destroy SR-IOV virtual functions via > > > calls to pci_enable_sriov() and pci_disable_sriov can cause > catastrophic > > > failures if they attempt to destroy VFs while they are assigned to > > > guest virtual machines. By adding a flag for use by the KVM module > > > to indicate that a device is assigned a device driver can check that > > > flag and avoid destroying VFs while they are assigned and avoid system > > > failures. > > > > > > Signed-off-by: Greg Rose <gregory.v.rose@xxxxxxxxx> > > > --- > > > > > > include/linux/pci.h | 2 ++ > > > > I added Jesse and linux-pci to CC. > > > > > virt/kvm/assigned-dev.c | 2 ++ > > > virt/kvm/iommu.c | 4 ++++ > > > 3 files changed, 8 insertions(+), 0 deletions(-) > > > > I suppose this would also be useful in Xen's pciback or any other system > > which does passthrough? (Konrad CC'd for pciback) > > > > Is there some common lower layer we could hook this in to? (does > > iommu_attach/detach_device make sense?) Or shall we just add the flag > > manipulations to pciback as well? > > > > Ian. > > > > > > > > diff --git a/include/linux/pci.h b/include/linux/pci.h > > > index 2d29218..a297ca2 100644 > > > --- a/include/linux/pci.h > > > +++ b/include/linux/pci.h > > > @@ -174,6 +174,8 @@ enum pci_dev_flags { > > > PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG = (__force pci_dev_flags_t) 1, > > > /* Device configuration is irrevocably lost if disabled into D3 */ > > > PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2, > > > + /* Provide indication device is assigned by KVM */ > > > + PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4, > > > }; > > Looks fine, but I'd make the comment less redundant with the code, e.g. > "set when the device is assigned to a guest instance" or somesuch. Sure, sounds good to me. Rev 2 of the RFC patches will be out in a couple of weeks, I'm away next week. Thanks, - Greg > > -- > Jesse Barnes, Intel Open Source Technology Center -- 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
