On Mon, Mar 21, 2016 at 06:47:05PM +1100, Alexey Kardashevskiy wrote: > New VFIO_SPAPR_TCE_v2_IOMMU type supports dynamic DMA window management. > This adds ability to VFIO common code to dynamically allocate/remove > DMA windows in the host kernel when new VFIO container is added/removed. > > This adds VFIO_IOMMU_SPAPR_TCE_CREATE ioctl to vfio_listener_region_add > and adds just created IOMMU into the host IOMMU list; the opposite > action is taken in vfio_listener_region_del. > > When creating a new window, this uses euristic to decide on the TCE table > levels number. > > This should cause no guest visible change in behavior. > > Signed-off-by: Alexey Kardashevskiy > --- > Changes: > v14: > * new to the series > > --- > TODO: > * export levels to PHB > --- > hw/vfio/common.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++--- > trace-events | 2 ++ > 2 files changed, 105 insertions(+), 5 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 4e873b7..421d6eb 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -279,6 +279,14 @@ static int vfio_host_iommu_add(VFIOContainer *container, > return 0; > } > > +static void vfio_host_iommu_del(VFIOContainer *container, hwaddr min_iova) > +{ > + VFIOHostIOMMU *hiommu = vfio_host_iommu_lookup(container, min_iova, 0x1000); The hard-coded 0x1000 looks dubious.. > + g_assert(hiommu); > + QLIST_REMOVE(hiommu, hiommu_next); > +} > + > static bool vfio_listener_skipped_section(MemoryRegionSection *section) > { > return (!memory_region_is_ram(section->mr) && > @@ -392,6 +400,61 @@ static void vfio_listener_region_add(MemoryListener *listener, > } > end = int128_get64(llend); > > + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { I think this would be clearer split out into a helper function, vfio_create_host_window() or something. > + unsigned entries, pages; > + struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) }; > + > + g_assert(section->mr->iommu_ops); > + g_assert(memory_region_is_iommu(section->mr)); I don't think you need these asserts. AFAICT the same logic should work if a RAM MR was added directly to PCI address space - this would create the new host window, then the existing code for adding a RAM MR would map that block of RAM statically into the new window. > + trace_vfio_listener_region_add_iommu(iova, end - 1); > + /* > + * FIXME: For VFIO iommu types which have KVM acceleration to > + * avoid bouncing all map/unmaps through qemu this way, this > + * would be the right place to wire that up (tell the KVM > + * device emulation the VFIO iommu handles to use). > + */ > + create.window_size = memory_region_size(section->mr); > + create.page_shift = > + ctz64(section->mr->iommu_ops->get_page_sizes(section->mr)); Ah.. except that I guess you'd need to fall back to host page size here to handle a RAM MR. > + /* > + * SPAPR host supports multilevel TCE tables, there is some > + * euristic to decide how many levels we want for our table: > + * 0..64 = 1; 65..4096 = 2; 4097..262144 = 3; 262145.. = 4 > + */ > + entries = create.window_size >> create.page_shift; > + pages = (entries * sizeof(uint64_t)) / getpagesize(); > + create.levels = ctz64(pow2ceil(pages) - 1) / 6 + 1; > + > + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create); > + if (ret) { > + error_report("Failed to create a window, ret = %d (%m)", ret); > + goto fail; > + } > + > + if (create.start_addr != section->offset_within_address_space || > + vfio_host_iommu_lookup(container, create.start_addr, > + create.start_addr + create.window_size - 1)) { Under what circumstances can this trigger? Is the kernel ioctl allowed to return a different window start address than the one requested? The second check looks very strange - if it returns true doesn't that mean you *do* have host window which can accomodate this guest region, which is what you want? > + struct vfio_iommu_spapr_tce_remove remove = { > + .argsz = sizeof(remove), > + .start_addr = create.start_addr > + }; > + error_report("Host doesn't support DMA window at %"HWADDR_PRIx", must be %"PRIx64, > + section->offset_within_address_space, > + create.start_addr); > + ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); > + ret = -EINVAL; > + goto fail; > + } > + trace_vfio_spapr_create_window(create.page_shift, > + create.window_size, > + create.start_addr); > + > + vfio_host_iommu_add(container, create.start_addr, > + create.start_addr + create.window_size - 1, > + 1ULL << create.page_shift); > + } > + > if (!vfio_host_iommu_lookup(container, iova, end - 1)) { > error_report("vfio: IOMMU container %p can't map guest IOVA region" > " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx, > @@ -525,6 +588,22 @@ static void vfio_listener_region_del(MemoryListener *listener, > container, iova, end - iova, ret); > } > > + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { > + struct vfio_iommu_spapr_tce_remove remove = { > + .argsz = sizeof(remove), > + .start_addr = section->offset_within_address_space, > + }; > + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); > + if (ret) { > + error_report("Failed to remove window at %"PRIx64, > + remove.start_addr); > + } > + > + vfio_host_iommu_del(container, section->offset_within_address_space); > + > + trace_vfio_spapr_remove_window(remove.start_addr); > + } > + > if (iommu && iommu->iommu_ops && iommu->iommu_ops->vfio_stop) { > iommu->iommu_ops->vfio_stop(section->mr); > } > @@ -928,11 +1007,30 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) > goto listener_release_exit; > } > > - /* The default table uses 4K pages */ > - vfio_host_iommu_add(container, info.dma32_window_start, > - info.dma32_window_start + > - info.dma32_window_size - 1, > - 0x1000); > + if (v2) { > + /* > + * There is a default window in just created container. > + * To make region_add/del simpler, we better remove this > + * window now and let those iommu_listener callbacks > + * create/remove them when needed. > + */ > + struct vfio_iommu_spapr_tce_remove remove = { > + .argsz = sizeof(remove), > + .start_addr = info.dma32_window_start, > + }; > + ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); > + if (ret) { > + error_report("vfio: VFIO_IOMMU_SPAPR_TCE_REMOVE failed: %m"); > + ret = -errno; > + goto free_container_exit; > + } > + } else { > + /* The default table uses 4K pages */ > + vfio_host_iommu_add(container, info.dma32_window_start, > + info.dma32_window_start + > + info.dma32_window_size - 1, > + 0x1000); > + } > } else { > error_report("vfio: No available IOMMU models"); > ret = -EINVAL; > diff --git a/trace-events b/trace-events > index cc619e1..f2b75a3 100644 > --- a/trace-events > +++ b/trace-events > @@ -1736,6 +1736,8 @@ vfio_region_finalize(const char *name, int index) "Device %s, region %d" > vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps enabled: %d" > vfio_ram_register(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" > vfio_ram_unregister(uint64_t va, uint64_t size, int ret) "va=%"PRIx64" size=%"PRIx64" ret=%d" > +vfio_spapr_create_window(int ps, uint64_t ws, uint64_t off) "pageshift=0x%x winsize=0x%"PRIx64" offset=0x%"PRIx64 > +vfio_spapr_remove_window(uint64_t off) "offset=%"PRIx64 > > # hw/vfio/platform.c > vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d" -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson