On Thu, 2015-09-17 at 23:09 +1000, David Gibson wrote:
> Because of the way non-VFIO guest IOMMU operations are KVM accelerated, not
> all TCE tables (guest IOMMU contexts) can support VFIO devices. Currently,
> this is decided at creation time.
>
> To support hotplug of VFIO devices, we need to allow a TCE table which
> previously didn't allow VFIO devices to be switched so that it can. This
> patch adds an spapr_tce_need_vfio() function to do this, by reallocating
> the table in userspace if necessary.
>
> Currently this doesn't allow the KVM acceleration to be re-enabled if all
> the VFIO devices are removed. That's an optimization for another time.
Same comment as previous patch, spapr_tce_need_userspace_table() (or
something) makes the code much more self documenting.
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr_iommu.c | 19 +++++++++++++++++++
> include/hw/ppc/spapr.h | 2 ++
> 2 files changed, 21 insertions(+)
>
> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
> index 5166cde..109e10d 100644
> --- a/hw/ppc/spapr_iommu.c
> +++ b/hw/ppc/spapr_iommu.c
> @@ -168,6 +168,25 @@ static int spapr_tce_table_realize(DeviceState *dev)
> return 0;
> }
>
> +void spapr_tce_need_vfio(sPAPRTCETable *tcet)
> +{
> + size_t table_size = tcet->nb_table * sizeof(uint64_t);
> + void *newtable;
> +
> + if (tcet->fd < 0) {
> + /* Table is already in userspace, nothing to be done */
> + return;
> + }
> +
> + newtable = g_malloc0(table_size);
> + memcpy(newtable, tcet->table, table_size);
> +
> + kvmppc_remove_spapr_tce(tcet->table, tcet->fd, tcet->nb_table);
> +
> + tcet->fd = -1;
> + tcet->table = newtable;
> +}
> +
> sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
> uint64_t bus_offset,
> uint32_t page_shift,
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 03a9804..38a29fb 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -588,6 +588,8 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner,
> uint32_t liobn,
> uint32_t page_shift,
> uint32_t nb_table,
> bool need_vfio);
> +void spapr_tce_need_vfio(sPAPRTCETable *tcet);
> +
> MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet);
> int spapr_dma_dt(void *fdt, int node_off, const char *propname,
> uint32_t liobn, uint64_t window, uint32_t size);
