Re: [Qemu-arm] [PATCH v7 13/20] hw/arm/smmuv3: Implement IOMMU memory region replay callback

[Tomasz Nowicki]

On 14.09.2017 16:31, Tomasz Nowicki wrote:
> Hi Eric,
>
> On 14.09.2017 11:27, Linu Cherian wrote:
> > Hi Eric,
> >
> > On Fri Sep 01, 2017 at 07:21:16PM +0200, Eric Auger wrote:
> > > memory_region_iommu_replay() is used for VFIO integration.
> > >
> > > However its default implementation is not adapted to SMMUv3
> > > IOMMU memory region. Indeed the input address range is too
> > > huge and its execution is too slow as it calls the translate()
> > > callback on each granule.
> > >
> > > Let's implement the replay callback which hierarchically walk
> > > over the page table structure and notify only the segments
> > > that are populated with valid entries.
> > >
> > > Signed-off-by: Eric Auger <address@hidden>
> > > ---
> > >   hw/arm/smmuv3.c     | 36 ++++++++++++++++++++++++++++++++++++
> > >   hw/arm/trace-events |  1 +
> > >   2 files changed, 37 insertions(+)
> > >
> > > diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> > > index 8e7d10d..c43bd93 100644
> > > --- a/hw/arm/smmuv3.c
> > > +++ b/hw/arm/smmuv3.c
> > > @@ -657,6 +657,41 @@ static int smmuv3_notify_entry(IOMMUTLBEntry 
> > > *entry, void *private)
> > >       return 0;
> > >   }
> > > +/* Unmap the whole notifier's range */
> > > +static void smmuv3_unmap_notifier_range(IOMMUNotifier *n)
> > > +{
> > > +    IOMMUTLBEntry entry;
> > > +    hwaddr size = n->end - n->start + 1;
> > > +
> > > +    entry.target_as = &address_space_memory;
> > > +    entry.iova = n->start & ~(size - 1);
> > > +    entry.perm = IOMMU_NONE;
> > > +    entry.addr_mask = size - 1;
> > > +
> > > +    memory_region_notify_one(n, &entry);
> > > +}
> > > +
> > > +static void smmuv3_replay(IOMMUMemoryRegion *mr, IOMMUNotifier *n)
> > > +{
> > > +    SMMUTransCfg cfg = {};
> > > +    int ret;
> > > +
> > > +    trace_smmuv3_replay(mr->parent_obj.name, n, n->start, n->end);
> > > +    smmuv3_unmap_notifier_range(n);
> > > +
> > > +    ret = smmuv3_decode_config(mr, &cfg);
> > > +    if (ret) {
> > > +        error_report("%s error decoding the configuration for iommu 
> > > mr=%s",
> > > +                     __func__, mr->parent_obj.name);
> > > +    }
> >
> > On an invalid config being found, shouldnt we return rather than 
> > proceeding with
> > page table walk. For example on an invalid Stream table entry.
>
> Indeed, without return here vhost case is not working for me.

I was just lucky one time. return here has no influence. Vhost still not 
working. Sorry for noise.

Tomasz

> Thanks,
> Tomasz
>
> > +
> > > +    if (cfg.disabled || cfg.bypassed) {
> > > +        return;
> > > +    }
> > > +    /* walk the page tables and replay valid entries */
> > > +    smmu_page_walk(&cfg, 0, (1ULL << (64 - cfg.tsz)) - 1, false,
> > > +                   smmuv3_notify_entry, n);
> > > +}
> > >   static void smmuv3_notify_iova_range(IOMMUMemoryRegion *mr, 
> > > IOMMUNotifier *n,
> > >                                        uint64_t iova, size_t size)
> > >   {
> > > @@ -1095,6 +1130,7 @@ static void 
> > > smmuv3_iommu_memory_region_class_init(ObjectClass *klass,
> > >       imrc->translate = smmuv3_translate;
> > >       imrc->notify_flag_changed = smmuv3_notify_flag_changed;
> > > +    imrc->replay = smmuv3_replay;
> > >   }
> > >   static const TypeInfo smmuv3_type_info = {
> > > diff --git a/hw/arm/trace-events b/hw/arm/trace-events
> > > index 4ac264d..15f84d6 100644
> > > --- a/hw/arm/trace-events
> > > +++ b/hw/arm/trace-events
> > > @@ -46,5 +46,6 @@ smmuv3_cfg_stage(int s, uint32_t oas, uint32_t tsz, 
> > > uint64_t ttbr, bool aa64, ui
> > >   smmuv3_notify_flag_add(const char *iommu) "ADD SMMUNotifier node 
> > > for iommu mr=%s"
> > >   smmuv3_notify_flag_del(const char *iommu) "DEL SMMUNotifier node 
> > > for iommu mr=%s"
> > >   smmuv3_replay_mr(const char *name) "iommu mr=%s"
> > > +smmuv3_replay(const char *name, void *n, hwaddr start, hwaddr end) 
> > > "iommu mr=%s notifier=%p [0x%"PRIx64",0x%"PRIx64"]"
> > >   smmuv3_notify_entry(hwaddr iova, hwaddr pa, hwaddr mask, int perm) 
> > > "iova=0x%"PRIx64" pa=0x%" PRIx64" mask=0x%"PRIx64" perm=%d"
> > >   smmuv3_notify_iova_range(const char *name, uint64_t iova, size_t 
> > > size, void *n) "iommu mr=%s iova=0x%"PRIx64" size=0x%lx n=%p"
> > > --
> > > 2.5.5