From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43743) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b1LXe-0001WB-MM for qemu-devel@nongnu.org; Fri, 13 May 2016 18:26:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b1LXZ-0004i4-Bm for qemu-devel@nongnu.org; Fri, 13 May 2016 18:26:42 -0400 Date: Fri, 13 May 2016 16:26:34 -0600 From: Alex Williamson Message-ID: <20160513162634.278ad267@t450s.home> In-Reply-To: <1462344751-28281-19-git-send-email-aik@ozlabs.ru> References: <1462344751-28281-1-git-send-email-aik@ozlabs.ru> <1462344751-28281-19-git-send-email-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org, Alexander Graf , David Gibson , Paolo Bonzini On Wed, 4 May 2016 16:52:30 +1000 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 heuristic to decide on the TCE table > levels number. > > This should cause no guest visible change in behavior. > > Signed-off-by: Alexey Kardashevskiy > --- > Changes: > v16: > * used memory_region_iommu_get_page_sizes() in vfio_listener_region_add() > * enforced no intersections between windows > > v14: > * new to the series > --- > hw/vfio/common.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++----- > trace-events | 2 + > 2 files changed, 125 insertions(+), 10 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 03daf88..bd2dee8 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -240,6 +240,18 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr iova, > return -errno; > } > > +static bool range_contains(hwaddr start, hwaddr end, hwaddr addr) > +{ > + return start <= addr && addr <= end; > +} a) If you want a "range_foo" function then put it in range.h b) I suspect there are already range.h functions that can do this. > + > +static bool vfio_host_win_intersects(VFIOHostDMAWindow *hostwin, > + hwaddr min_iova, hwaddr max_iova) > +{ > + return range_contains(hostwin->min_iova, hostwin->min_iova, min_iova) || > + range_contains(min_iova, max_iova, hostwin->min_iova); > +} How is this different than ranges_overlap()? > + > static VFIOHostDMAWindow *vfio_host_win_lookup(VFIOContainer *container, > hwaddr min_iova, hwaddr max_iova) > { > @@ -279,6 +291,14 @@ static int vfio_host_win_add(VFIOContainer *container, > return 0; > } > > +static void vfio_host_win_del(VFIOContainer *container, hwaddr min_iova) > +{ > + VFIOHostDMAWindow *hostwin = vfio_host_win_lookup(container, min_iova, 1); > + > + g_assert(hostwin); Handle the error please. > + QLIST_REMOVE(hostwin, hostwin_next); > +} > + > static bool vfio_listener_skipped_section(MemoryRegionSection *section) > { > return (!memory_region_is_ram(section->mr) && > @@ -392,6 +412,69 @@ static void vfio_listener_region_add(MemoryListener *listener, > } > end = int128_get64(int128_sub(llend, int128_one())); > > + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) { > + VFIOHostDMAWindow *hostwin; > + unsigned pagesizes = memory_region_iommu_get_page_sizes(section->mr); > + unsigned pagesize = (hwaddr)1 << ctz64(pagesizes); > + unsigned entries, pages; > + struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) }; > + > + trace_vfio_listener_region_add_iommu(iova, end); > + /* > + * 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 = int128_get64(section->size); > + create.page_shift = ctz64(pagesize); > + /* > + * SPAPR host supports multilevel TCE tables, there is some > + * heuristic 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 = MAX((entries * sizeof(uint64_t)) / getpagesize(), 1); > + pages = MAX(pow2ceil(pages) - 1, 1); /* Round up */ > + create.levels = ctz64(pages) / 6 + 1; > + > + /* For now intersections are not allowed, we may relax this later */ > + QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) { > + if (vfio_host_win_intersects(hostwin, > + section->offset_within_address_space, > + section->offset_within_address_space + > + create.window_size - 1)) { > + goto fail; > + } > + } > + > + 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) { > + 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_win_add(container, create.start_addr, > + create.start_addr + create.window_size - 1, > + 1ULL << create.page_shift); > + } This is a function on its own, split it out and why not stop pretending prereg is some sort of generic interface and let's just make a spapr support file. > + > if (!vfio_host_win_lookup(container, iova, end)) { > error_report("vfio: IOMMU container %p can't map guest IOVA region" > " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx, > @@ -566,6 +649,22 @@ static void vfio_listener_region_del(MemoryListener *listener, > container, iova, int128_get64(llsize), 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_win_del(container, section->offset_within_address_space); > + > + trace_vfio_spapr_remove_window(remove.start_addr); > + } This would be in that spapr file too. > + > if (iommu && iommu->iommu_ops && iommu->iommu_ops->vfio_stop) { > iommu->iommu_ops->vfio_stop(section->mr); > } > @@ -957,11 +1056,6 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) > } > } > > - /* > - * This only considers the host IOMMU's 32-bit window. At > - * some point we need to add support for the optional 64-bit > - * window and dynamic windows > - */ > info.argsz = sizeof(info); > ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info); > if (ret) { > @@ -970,11 +1064,30 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as) > goto listener_release_exit; > } > > - /* The default table uses 4K pages */ > - vfio_host_win_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_win_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 d0d8615..b5419de 100644 > --- a/trace-events > +++ b/trace-events > @@ -1739,6 +1739,8 @@ 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"