On Mon, 6 Jul 2015 12:11:03 +1000
Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> We are going to have multiple DMA windows at different offsets on
> a PCI bus. For the sake of migration, we will have as many TCE table
> objects pre-created as many windows supported.
> So we need a way to map windows dynamically onto a PCI bus
> when migration of a table is completed but at this stage a TCE table
> object does not have access to a PHB to ask it to map a DMA window
> backed by just migrated TCE table.
>
> This adds a "root" memory region (UINT64_MAX long) to the TCE object.
> This new region is mapped on a PCI bus with enabled overlapping as
> there will be one root MR per TCE table, each of them mapped at 0.
> The actual IOMMU memory region is a subregion of the root region and
> a TCE table enables/disables this subregion and maps it at
> the specific offset inside the root MR which is 1:1 mapping of
> a PCI address space.
>
> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr_iommu.c | 13 ++++++++++---
> hw/ppc/spapr_pci.c | 2 +-
> include/hw/ppc/spapr.h | 2 +-
> 3 files changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
> index 1378a7a..45c00d8 100644
> --- a/hw/ppc/spapr_iommu.c
> +++ b/hw/ppc/spapr_iommu.c
> @@ -171,11 +171,16 @@ static MemoryRegionIOMMUOps spapr_iommu_ops = {
> static int spapr_tce_table_realize(DeviceState *dev)
> {
> sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev);
> + Object *tcetobj = OBJECT(tcet);
> + char tmp[32];
>
> tcet->fd = -1;
>
> - memory_region_init_iommu(&tcet->iommu, OBJECT(dev), &spapr_iommu_ops,
> - "iommu-spapr", 0);
> + snprintf(tmp, sizeof(tmp), "tce-root-%x", tcet->liobn);
> + memory_region_init(&tcet->root, tcetobj, tmp, UINT64_MAX);
> +
> + snprintf(tmp, sizeof(tmp), "tce-iommu-%x", tcet->liobn);
> + memory_region_init_iommu(&tcet->iommu, tcetobj, &spapr_iommu_ops, tmp,
> 0);
>
> QLIST_INSERT_HEAD(&spapr_tce_tables, tcet, list);
>
> @@ -221,6 +226,7 @@ static void spapr_tce_table_do_enable(sPAPRTCETable
> *tcet, bool vfio_accel)
>
> memory_region_set_size(&tcet->iommu,
> (uint64_t)tcet->nb_table << tcet->page_shift);
> + memory_region_add_subregion(&tcet->root, tcet->bus_offset, &tcet->iommu);
>
> tcet->enabled = true;
> }
> @@ -246,6 +252,7 @@ void spapr_tce_table_disable(sPAPRTCETable *tcet)
> return;
> }
>
> + memory_region_del_subregion(&tcet->root, &tcet->iommu);
> memory_region_set_size(&tcet->iommu, 0);
>
> spapr_tce_free_table(tcet->table, tcet->fd, tcet->nb_table);
> @@ -268,7 +275,7 @@ static void spapr_tce_table_unrealize(DeviceState *dev,
> Error **errp)
>
> MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet)
> {
> - return &tcet->iommu;
> + return &tcet->root;
> }
>
> static void spapr_tce_reset(DeviceState *dev)
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 3ddd72f..e27ca15 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1405,7 +1405,7 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
> error_setg(errp, "failed to create TCE table");
> return;
> }
> - memory_region_add_subregion(&sphb->iommu_root, tcet->bus_offset,
> + memory_region_add_subregion(&sphb->iommu_root, 0,
> spapr_tce_get_iommu(tcet));
>
> sphb->msi = g_hash_table_new_full(g_int_hash, g_int_equal, g_free,
> g_free);
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 1da0ade..e32e787 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -560,7 +560,7 @@ struct sPAPRTCETable {
> uint64_t *table;
> bool bypass;
> int fd;
> - MemoryRegion iommu;
> + MemoryRegion root, iommu;
> struct VIOsPAPRDevice *vdev; /* for @bypass migration compatibility only
> */
> QLIST_ENTRY(sPAPRTCETable) list;
> };
Reviewed-by: Thomas Huth <th...@redhat.com>
