Re: [Qemu-devel] [PATCH v6 0/3] IOMMU: intel_iommu support map and unmap notifications

[Alex Williamson]

On Thu, 10 Nov 2016 17:14:24 +0200
"Michael S. Tsirkin" <address@hidden> wrote:

> On Tue, Nov 08, 2016 at 01:04:21PM +0200, Aviv B.D wrote:
> > From: "Aviv Ben-David" <address@hidden>
> > 
> > * Advertize Cache Mode capability in iommu cap register. 
> >   This capability is controlled by "cache-mode" property of intel-iommu 
> > device.
> >   To enable this option call QEMU with "-device 
> > intel-iommu,cache-mode=true".
> > 
> > * On page cache invalidation in intel vIOMMU, check if the domain belong to
> >   registered notifier, and notify accordingly.  
> 
> This looks sane I think. Alex, care to comment?
> Merging will have to wait until after the release.
> Pls remember to re-test and re-ping then.

I don't think it's suitable for upstream until there's a reasonable
replay mechanism and we straighten out whether it's expected to get
multiple notifies and the notif-ee is responsible for filtering
them or if the notif-er should do filtering.  Without those, this is
effectively just an RFC.  Thanks,

Alex

> > Currently this patch still doesn't enabling VFIO devices support with 
> > vIOMMU 
> > present. Current problems:
> > * vfio_iommu_map_notify is not aware about memory range belong to specific 
> >   VFIOGuestIOMMU.
> > * memory_region_iommu_replay hangs QEMU on start up while it itterate over 
> >   64bit address space. Commenting out the call to this function enables 
> >   workable VFIO device while vIOMMU present.
> > * vfio_iommu_map_notify should check if address space range is suitable for 
> >   current notifier.
> > 
> > Changes from v1 to v2:
> > * remove assumption that the cache do not clears
> > * fix lockup on high load.
> > 
> > Changes from v2 to v3:
> > * remove debug leftovers
> > * split to sepearate commits
> > * change is_write to flags in vtd_do_iommu_translate, add IOMMU_NO_FAIL 
> >   to suppress error propagating to guest.
> > 
> > Changes from v3 to v4:
> > * Add property to intel_iommu device to control the CM capability, 
> >   default to False.
> > * Use s->iommu_ops.notify_flag_changed to register notifiers.
> > 
> > Changes from v4 to v4 RESEND:
> > * Fix codding style pointed by checkpatch.pl script.
> > 
> > Changes from v4 to v5:
> > * Reduce the number of changes in patch 2 and make flags real bitfield.
> > * Revert deleted debug prints.
> > * Fix memory leak in patch 3.
> > 
> > Changes from v5 to v6:
> > * fix prototype of iommu_translate function for more IOMMU types.
> > * VFIO will be notified only on the difference, without unmap 
> >   before change to maps.
> > 
> > Aviv Ben-David (3):
> >   IOMMU: add option to enable VTD_CAP_CM to vIOMMU capility exposoed to
> >     guest
> >   IOMMU: change iommu_op->translate's is_write to flags, add support to
> >     NO_FAIL flag mode
> >   IOMMU: enable intel_iommu map and unmap notifiers
> > 
> >  exec.c                         |   3 +-
> >  hw/alpha/typhoon.c             |   2 +-
> >  hw/i386/amd_iommu.c            |   4 +-
> >  hw/i386/intel_iommu.c          | 160 
> > +++++++++++++++++++++++++++++++++--------
> >  hw/i386/intel_iommu_internal.h |   3 +
> >  hw/pci-host/apb.c              |   2 +-
> >  hw/ppc/spapr_iommu.c           |   2 +-
> >  hw/s390x/s390-pci-bus.c        |   2 +-
> >  include/exec/memory.h          |   6 +-
> >  include/hw/i386/intel_iommu.h  |  11 +++
> >  memory.c                       |   3 +-
> >  11 files changed, 160 insertions(+), 38 deletions(-)
> > 
> > -- 
> > 1.9.1  
>