On Thu, Mar 26, 2015 at 11:53:48AM +1100, Gavin Shan wrote:
> On Tue, Mar 24, 2015 at 06:53:29AM -0600, Alex Williamson wrote:
> >On Tue, 2015-03-24 at 17:54 +1100, David Gibson wrote:
> >> On Tue, Mar 24, 2015 at 05:24:55PM +1100, Gavin Shan wrote:
> >> > On Tue, Mar 24, 2015 at 04:41:21PM +1100, David Gibson wrote:
> >> > >On Mon, Mar 23, 2015 at 04:25:10PM +1100, Gavin Shan wrote:
> >> > >> On Mon, Mar 23, 2015 at 04:06:56PM +1100, David Gibson wrote:
> >> > >> >On Fri, Mar 20, 2015 at 05:27:29PM +1100, Gavin Shan wrote:
> >> > >> >> On Fri, Mar 20, 2015 at 05:04:01PM +1100, David Gibson wrote:
> >> > >> >> >On Tue, Mar 17, 2015 at 03:31:24AM +1100, Gavin Shan wrote:
> >> > >> >> >> The PCI device MSIx table is cleaned out in hardware after EEH
> >> > >> >> >> PE
> >> > >> >> >> reset. However, we still hold the stale MSIx entries in QEMU,
> >> > >> >> >> which
> >> > >> >> >> should be cleared accordingly. Otherwise, we will run into
> >> > >> >> >> another
> >> > >> >> >> (recursive) EEH error and the PCI devices contained in the PE
> >> > >> >> >> have
> >> > >> >> >> to be offlined exceptionally.
> >> > >> >> >>
> >> > >> >> >> The patch clears stale MSIx table before EEH PE reset so that
> >> > >> >> >> MSIx
> >> > >> >> >> table could be restored properly after EEH PE reset.
> >> > >> >> >>
> >> > >> >> >> Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
> >> > >> >> >> ---
> >> > >> >> >> v2: vfio_container_eeh_event() stub for !CONFIG_PCI and separate
> >> > >> >> >> error message for this function. Dropped vfio_put_group()
> >> > >> >> >> on NULL group
> >> > >> >> >> ---
> >> > >> >> >> hw/vfio/Makefile.objs | 6 +++++-
> >> > >> >> >> hw/vfio/common.c | 7 +++++++
> >> > >> >> >> hw/vfio/pci-stub.c | 17 +++++++++++++++++
> >> > >> >> >> hw/vfio/pci.c | 38
> >> > >> >> >> ++++++++++++++++++++++++++++++++++++++
> >> > >> >> >> include/hw/vfio/vfio.h | 2 ++
> >> > >> >> >> 5 files changed, 69 insertions(+), 1 deletion(-)
> >> > >> >> >> create mode 100644 hw/vfio/pci-stub.c
> >> > >> >> >>
> >> > >> >> >> diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
> >> > >> >> >> index e31f30e..1b8a065 100644
> >> > >> >> >> --- a/hw/vfio/Makefile.objs
> >> > >> >> >> +++ b/hw/vfio/Makefile.objs
> >> > >> >> >> @@ -1,4 +1,8 @@
> >> > >> >> >> ifeq ($(CONFIG_LINUX), y)
> >> > >> >> >> obj-$(CONFIG_SOFTMMU) += common.o
> >> > >> >> >> -obj-$(CONFIG_PCI) += pci.o
> >> > >> >> >> +ifeq ($(CONFIG_PCI), y)
> >> > >> >> >> +obj-y += pci.o
> >> > >> >> >> +else
> >> > >> >> >> +obj-y += pci-stub.o
> >> > >> >> >> +endif
> >> > >> >> >> endif
> >> > >> >> >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> >> > >> >> >> index 148eb53..ed07814 100644
> >> > >> >> >> --- a/hw/vfio/common.c
> >> > >> >> >> +++ b/hw/vfio/common.c
> >> > >> >> >> @@ -949,7 +949,14 @@ int vfio_container_ioctl(AddressSpace *as,
> >> > >> >> >> int32_t groupid,
> >> > >> >> >> switch (req) {
> >> > >> >> >> case VFIO_CHECK_EXTENSION:
> >> > >> >> >> case VFIO_IOMMU_SPAPR_TCE_GET_INFO:
> >> > >> >> >> + break;
> >> > >> >> >> case VFIO_EEH_PE_OP:
> >> > >> >> >> + if (vfio_container_eeh_event(as, groupid, param) != 0)
> >> > >> >> >> {
> >> > >> >> >
> >> > >> >> >I really dislike the idea of having an arbitrarily complex side
> >> > >> >> >effect
> >> > >> >> >from a function whose name suggest's it's just a trivial wrapper
> >> > >> >> >around the ioctl().
> >> > >> >> >
> >> > >> >>
> >> > >> >> Ok. I guess you would like putting the complex in the callers of
> >> > >> >> vfio_container_ioctl().
> >> > >> >
> >> > >> >Well.. maybe. I'd also be happy if helper functions were
> >> > >> >implemeneted
> >> > >> >which both called the ioctl() and did the other necessary pieces.
> >> > >> >They should just be called something that indicates their full
> >> > >> >function, not a name which suggests they're just an ioctl wrapper.
> >> > >> >
> >> > >>
> >> > >> Indeed, vfio_container_ioctl() isn't indicating what the function is
> >> > >> doing.
> >> > >> How about renaming it to vfio_container_event_and_ioctl()? I'm always
> >> > >> bad
> >> > >> at giving a good function name :)
> >> > >
> >> > >Well, I don't think your wrapper should be multiplexed. The multiplex
> >> > >works for the simple ioctl() wrapper, because there really is nothing
> >> > >that varies apart from the exact ioctl number called.
> >> > >
> >> > >But now that you have different operations here, I think you want
> >> > >wrappers for each one - each one will call the ioctl(), then do the
> >> > >specific extra steps necessary for that operation. So
> >> > >vfio_container_event() will go away as well, split into various other
> >> > >functions.
> >> > >
> >> >
> >> > It wouldn't a good idea if I understand your proposal correctly.
> >> > Currnetly,
> >> > the global function vfio_container_ioctl() can be called from sPAPR
> >> > platform
> >> > for any ioctl commands handled in kernel source file
> >> > vfio_iommu_spapr_tce.c,
> >> > which means the function isn't called for EEH only. Other sPAPR TCE
> >> > container
> >> > ioctl commands are also routed by this function. There will be lots if
> >> > having
> >> > one global function for each ioctl commands, which just improve the cost
> >> > to
> >> > maintain the code.
> >>
> >> I don't really follow your objection. I'm only suggesting separate
> >> wrappers for things which require extra actions currently implemented
> >> in vfio_container_event(). Things which only ned the plain ioctl()
> >> can still use the simple vfio_container_ioctl() wrapper.
> >
> >vfio_container_ioctl() also filters to a limited set of ioctls, it
> >clearly does not allow any ioctl.
> >
>
> Ok. I think your guys expect something like follows. Note that the following
> vfio_container_eeh_ioctl() will accept a limited set of EEH operations,
> similar
> to what's doing in vfio_contain_ioctl() to the ioctl commands:
>
> If you agree to have the changes, I'll put another patch on top of this one
> to replace vfio_container_ioctl() in spapr_pci_vfio.c with
> vfio_container_eeh_ioctl()
> for EEH cases.
>
> int vfio_container_eeh_ioctl(AddressSpace *as, int32_t groupid,
> struct vfio_eeh_pe_op *op)
> {
> switch (op->op) {
> case VFIO_EEH_PE_RESET_HOT:
> case VFIO_EEH_PE_RESET_FUNDAMENTAL: {
> VFIOGroup *group;
> VFIODevice *vbasedev;
> VFIOPCIDevice *vdev;
>
> /*
> * The MSIx table will be cleaned out by reset. We need
> * disable it so that it can be reenabled properly. Also,
> * the cached MSIx table should be cleared as it's not
> * reflecting the contents in hardware.
> */
> group = vfio_get_group(groupid, as);
> if (!group) {
> error_report("vfio: group %d not found\n", groupid);
> return -1;
> }
>
> QLIST_FOREACH(vbasedev, &group->device_list, next) {
> vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
> if (msix_enabled(&vdev->pdev)) {
> vfio_disable_msix(vdev);
> }
>
> msix_reset(&vdev->pdev);
> }
>
> vfio_put_group(group);
>
> break;
> }
> case VFIO_EEH_PE_DISABLE:
> case VFIO_EEH_PE_ENABLE:
> case VFIO_EEH_PE_UNFREEZE_IO:
> case VFIO_EEH_PE_UNFREEZE_DMA:
> case VFIO_EEH_PE_GET_STATE:
> case VFIO_EEH_PE_RESET_DEACTIVATE:
> case VFIO_EEH_PE_CONFIGURE:
> break;
> default:
> error_report("vfio: unsupported EEH operation %X\n", op->op);
> return -1;
> }
>
> return vfio_container_ioctl(as, groupid, VFIO_EEH_PE_OP, op);
> }
No, extra operation specific logic inside the ioctl wrapper is exactly
what I want to avoid. Instead I want to see
vfio_container_eeh_ioctl() remain as it is now - doing nothing but
verifying the ioctl() number, then passing the arguments on to
ioctl().
What I'm expecting is then to add a new functions, along the lines of:
int vfio_eeh_pe_reset(...)
{
VFIOGroup *group;
VFIODevice *vbasedev;
VFIOPCIDevice *vdev;
/*
* The MSIx table will be cleaned out by reset. We need
* disable it so that it can be reenabled properly. Also,
* the cached MSIx table should be cleared as it's not
* reflecting the contents in hardware.
*/
group = vfio_get_group(groupid, as);
if (!group) {
error_report("vfio: group %d not found\n", groupid);
return -1;
}
QLIST_FOREACH(vbasedev, &group->device_list, next) {
vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
if (msix_enabled(&vdev->pdev)) {
vfio_disable_msix(vdev);
}
msix_reset(&vdev->pdev);
}
vfio_put_group(group);
return vfio_eeh_container_ioctl(as, groupid,
VFIO_EEH_PE_RESET_FUNDAMENTAL, op);
}
I this function can build the op structure itself from sensible
arguments, then that's even better.
--
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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