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> Reviewed-by: Thomas Huth <th...@redhat.com> --- hw/ppc/spapr_iommu.c | 13 ++++++++++--- hw/ppc/spapr_pci.c | 6 +++--- include/hw/ppc/spapr.h | 2 +- 3 files changed, 14 insertions(+), 7 deletions(-) diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c index 5ea5948..481ce3c 100644 --- a/hw/ppc/spapr_iommu.c +++ b/hw/ppc/spapr_iommu.c @@ -208,11 +208,16 @@ 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; tcet->need_vfio = false; - 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); @@ -290,6 +295,7 @@ static void spapr_tce_table_do_enable(sPAPRTCETable *tcet) 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; } @@ -312,6 +318,7 @@ void spapr_tce_table_enable(sPAPRTCETable *tcet, static void spapr_tce_table_do_disable(sPAPRTCETable *tcet) { + 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); @@ -343,7 +350,7 @@ 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 df5f7b9..f1d49d5 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -826,9 +826,6 @@ static void spapr_phb_dma_window_enable(sPAPRPHBState *sphb, } spapr_tce_table_enable(tcet, page_shift, window_addr, nb_table); - - memory_region_add_subregion(&sphb->iommu_root, tcet->bus_offset, - spapr_tce_get_iommu(tcet)); } /* Macros to operate with address in OF binding to PCI */ @@ -1495,6 +1492,9 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) return; } + memory_region_add_subregion_overlap(&sphb->iommu_root, 0, + spapr_tce_get_iommu(tcet), 0); + /* Register default 32bit DMA window */ spapr_phb_dma_window_enable(sphb, sphb->dma_liobn, SPAPR_TCE_PAGE_SHIFT, sphb->dma_win_addr, sphb->dma_win_size, diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index c1ea49c..e9cdfe3 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -550,7 +550,7 @@ struct sPAPRTCETable { bool bypass; bool need_vfio; int fd; - MemoryRegion iommu; + MemoryRegion root, iommu; struct VIOsPAPRDevice *vdev; /* for @bypass migration compatibility only */ QLIST_ENTRY(sPAPRTCETable) list; }; -- 2.5.0.rc3