On Tue, Mar 08, 2016 at 11:33:45AM -0700, Alex Williamson wrote: > On Tue, 8 Mar 2016 13:10:23 +1100 > David Gibson <da...@gibson.dropbear.id.au> wrote: > > > At present the code handling IBM's Enhanced Error Handling (EEH) interface > > on VFIO devices operates by bypassing the usual VFIO logic with > > vfio_container_ioctl(). That's a poorly designed interface with unclear > > semantics about exactly what can be operated on. > > > > In particular it operates on a single vfio container internally (hence the > > name), but takes an address space and group id, from which it deduces the > > container in a rather roundabout way. groupids are something that code > > outside vfio shouldn't even be aware of. > > > > This patch creates new interfaces for EEH operations. Internally we > > have vfio_eeh_container_op() which takes a VFIOContainer object > > directly. For external use we have vfio_eeh_as_ok() which determines > > if an AddressSpace is usable for EEH (at present this means it has a > > single container with exactly one group attached), and vfio_eeh_as_op() > > which will perform an operation on an AddressSpace in the unambiguous case, > > and otherwise returns an error. > > > > This interface still isn't great, but it's enough of an improvement to > > allow a number of cleanups in other places. > > > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > > Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru> > > --- > > I'll let you push this through your tree: > > Acked-by: Alex Williamson <alex.william...@redhat.com>
Thanks. Any guess at when your vGPU series will be pushed? Mine will
conflict until that is merged upstream.
>
> > hw/vfio/common.c | 95
> > ++++++++++++++++++++++++++++++++++++++++++++++++++
> > include/hw/vfio/vfio.h | 2 ++
> > 2 files changed, 97 insertions(+)
> >
> > diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> > index 96ccb79..0636bb1 100644
> > --- a/hw/vfio/common.c
> > +++ b/hw/vfio/common.c
> > @@ -1137,3 +1137,98 @@ int vfio_container_ioctl(AddressSpace *as, int32_t
> > groupid,
> >
> > return vfio_container_do_ioctl(as, groupid, req, param);
> > }
> > +
> > +/*
> > + * Interfaces for IBM EEH (Enhanced Error Handling)
> > + */
> > +static bool vfio_eeh_container_ok(VFIOContainer *container)
> > +{
> > + /*
> > + * As of 2016-03-04 (linux-4.5) the host kernel EEH/VFIO
> > + * implementation is broken if there are multiple groups in a
> > + * container. The hardware works in units of Partitionable
> > + * Endpoints (== IOMMU groups) and the EEH operations naively
> > + * iterate across all groups in the container, without any logic
> > + * to make sure the groups have their state synchronized. For
> > + * certain operations (ENABLE) that might be ok, until an error
> > + * occurs, but for others (GET_STATE) it's clearly broken.
> > + */
> > +
> > + /*
> > + * XXX Once fixed kernels exist, test for them here
> > + */
> > +
> > + if (QLIST_EMPTY(&container->group_list)) {
> > + return false;
> > + }
> > +
> > + if (QLIST_NEXT(QLIST_FIRST(&container->group_list), container_next)) {
> > + return false;
> > + }
> > +
> > + return true;
> > +}
> > +
> > +static int vfio_eeh_container_op(VFIOContainer *container, uint32_t op)
> > +{
> > + struct vfio_eeh_pe_op pe_op = {
> > + .argsz = sizeof(pe_op),
> > + .op = op,
> > + };
> > + int ret;
> > +
> > + if (!vfio_eeh_container_ok(container)) {
> > + error_report("vfio/eeh: EEH_PE_OP 0x%x: "
> > + "kernel requires a container with exactly one group",
> > op);
> > + return -EPERM;
> > + }
> > +
> > + ret = ioctl(container->fd, VFIO_EEH_PE_OP, &pe_op);
> > + if (ret < 0) {
> > + error_report("vfio/eeh: EEH_PE_OP 0x%x failed: %m", op);
> > + return -errno;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static VFIOContainer *vfio_eeh_as_container(AddressSpace *as)
> > +{
> > + VFIOAddressSpace *space = vfio_get_address_space(as);
> > + VFIOContainer *container = NULL;
> > +
> > + if (QLIST_EMPTY(&space->containers)) {
> > + /* No containers to act on */
> > + goto out;
> > + }
> > +
> > + container = QLIST_FIRST(&space->containers);
> > +
> > + if (QLIST_NEXT(container, next)) {
> > + /* We don't yet have logic to synchronize EEH state across
> > + * multiple containers */
> > + container = NULL;
> > + goto out;
> > + }
> > +
> > +out:
> > + vfio_put_address_space(space);
> > + return container;
> > +}
> > +
> > +bool vfio_eeh_as_ok(AddressSpace *as)
> > +{
> > + VFIOContainer *container = vfio_eeh_as_container(as);
> > +
> > + return (container != NULL) && vfio_eeh_container_ok(container);
> > +}
> > +
> > +int vfio_eeh_as_op(AddressSpace *as, uint32_t op)
> > +{
> > + VFIOContainer *container = vfio_eeh_as_container(as);
> > +
> > + if (!container) {
> > + return -ENODEV;
> > + }
> > + return vfio_eeh_container_op(container, op);
> > +}
> > diff --git a/include/hw/vfio/vfio.h b/include/hw/vfio/vfio.h
> > index 0b26cd8..fd3933b 100644
> > --- a/include/hw/vfio/vfio.h
> > +++ b/include/hw/vfio/vfio.h
> > @@ -5,5 +5,7 @@
> >
> > extern int vfio_container_ioctl(AddressSpace *as, int32_t groupid,
> > int req, void *param);
> > +bool vfio_eeh_as_ok(AddressSpace *as);
> > +int vfio_eeh_as_op(AddressSpace *as, uint32_t op);
> >
> > #endif
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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