RE: [PATCH] hv: fix msi affinity when device requests all possible CPU's

[Jork Loeser <Jork.Loeser@microsoft.com>]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Wednesday, June 28, 2017 4:22 PM
> To: KY Srinivasan <kys@microsoft.com>; bhelgaas@google.com
> Cc: linux-pci@vger.kernel.org; devel@linuxdriverproject.org; Stephen
> Hemminger <sthemmin@microsoft.com>
> Subject: [PATCH] hv: fix msi affinity when device requests all possible C=
PU's
>=20
> When Intel 10G (ixgbevf) is passed to a Hyper-V guest with SR-IOV, the dr=
iver
> requests affinity with all possible CPU's (0-239) even those CPU's are no=
t online
> (and will never be). Because of this the device is unable to correctly ge=
t MSI
> interrupt's setup.
>=20
> This was caused by the change in 4.12 that converted this affinity into a=
ll
> possible CPU's (0-31) but then host reports an error since this is larger=
 than the
> number of online cpu's.
>=20
> Previously, this worked (up to 4.12-rc1) because only online cpu's would =
be put
> in mask passed to the host.
>=20
> This patch applies only to 4.12.
> The driver in linux-next needs a a different fix because of the changes t=
o PCI
> host protocol version.

The vPCI patch in linux-next has the issue fixed already.

Regards,
Jork