3cdd801b0b
The "systempagesize" name suggests that it is the host system page size while it is the smallest page size of memory backing the guest RAM so let's rename it to stop confusion. This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Message-Id: <20190227085149.38596-4-aik@ozlabs.ru> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
253 lines
8.7 KiB
C
253 lines
8.7 KiB
C
/*
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* DMA memory preregistration
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*
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* Authors:
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* Alexey Kardashevskiy <aik@ozlabs.ru>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "cpu.h"
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#include <sys/ioctl.h>
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#include <linux/vfio.h>
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#include "hw/vfio/vfio-common.h"
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#include "hw/hw.h"
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#include "exec/ram_addr.h"
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#include "qemu/error-report.h"
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#include "trace.h"
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static bool vfio_prereg_listener_skipped_section(MemoryRegionSection *section)
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{
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if (memory_region_is_iommu(section->mr)) {
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hw_error("Cannot possibly preregister IOMMU memory");
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}
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return !memory_region_is_ram(section->mr) ||
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memory_region_is_ram_device(section->mr);
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}
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static void *vfio_prereg_gpa_to_vaddr(MemoryRegionSection *section, hwaddr gpa)
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{
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return memory_region_get_ram_ptr(section->mr) +
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section->offset_within_region +
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(gpa - section->offset_within_address_space);
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}
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static void vfio_prereg_listener_region_add(MemoryListener *listener,
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MemoryRegionSection *section)
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{
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VFIOContainer *container = container_of(listener, VFIOContainer,
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prereg_listener);
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const hwaddr gpa = section->offset_within_address_space;
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hwaddr end;
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int ret;
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hwaddr page_mask = qemu_real_host_page_mask;
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struct vfio_iommu_spapr_register_memory reg = {
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.argsz = sizeof(reg),
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.flags = 0,
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};
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if (vfio_prereg_listener_skipped_section(section)) {
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trace_vfio_prereg_listener_region_add_skip(
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section->offset_within_address_space,
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section->offset_within_address_space +
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int128_get64(int128_sub(section->size, int128_one())));
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return;
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}
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if (unlikely((section->offset_within_address_space & ~page_mask) ||
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(section->offset_within_region & ~page_mask) ||
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(int128_get64(section->size) & ~page_mask))) {
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error_report("%s received unaligned region", __func__);
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return;
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}
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end = section->offset_within_address_space + int128_get64(section->size);
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if (gpa >= end) {
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return;
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}
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memory_region_ref(section->mr);
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reg.vaddr = (uintptr_t) vfio_prereg_gpa_to_vaddr(section, gpa);
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reg.size = end - gpa;
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ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_REGISTER_MEMORY, ®);
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trace_vfio_prereg_register(reg.vaddr, reg.size, ret ? -errno : 0);
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if (ret) {
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/*
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* On the initfn path, store the first error in the container so we
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* can gracefully fail. Runtime, there's not much we can do other
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* than throw a hardware error.
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*/
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if (!container->initialized) {
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if (!container->error) {
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container->error = ret;
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}
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} else {
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hw_error("vfio: Memory registering failed, unable to continue");
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}
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}
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}
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static void vfio_prereg_listener_region_del(MemoryListener *listener,
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MemoryRegionSection *section)
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{
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VFIOContainer *container = container_of(listener, VFIOContainer,
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prereg_listener);
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const hwaddr gpa = section->offset_within_address_space;
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hwaddr end;
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int ret;
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hwaddr page_mask = qemu_real_host_page_mask;
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struct vfio_iommu_spapr_register_memory reg = {
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.argsz = sizeof(reg),
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.flags = 0,
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};
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if (vfio_prereg_listener_skipped_section(section)) {
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trace_vfio_prereg_listener_region_del_skip(
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section->offset_within_address_space,
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section->offset_within_address_space +
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int128_get64(int128_sub(section->size, int128_one())));
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return;
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}
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if (unlikely((section->offset_within_address_space & ~page_mask) ||
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(section->offset_within_region & ~page_mask) ||
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(int128_get64(section->size) & ~page_mask))) {
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error_report("%s received unaligned region", __func__);
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return;
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}
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end = section->offset_within_address_space + int128_get64(section->size);
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if (gpa >= end) {
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return;
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}
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reg.vaddr = (uintptr_t) vfio_prereg_gpa_to_vaddr(section, gpa);
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reg.size = end - gpa;
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ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY, ®);
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trace_vfio_prereg_unregister(reg.vaddr, reg.size, ret ? -errno : 0);
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}
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const MemoryListener vfio_prereg_listener = {
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.region_add = vfio_prereg_listener_region_add,
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.region_del = vfio_prereg_listener_region_del,
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};
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int vfio_spapr_create_window(VFIOContainer *container,
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MemoryRegionSection *section,
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hwaddr *pgsize)
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{
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int ret = 0;
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IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr);
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uint64_t pagesize = memory_region_iommu_get_min_page_size(iommu_mr);
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unsigned entries, bits_total, bits_per_level, max_levels;
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struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) };
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long rampagesize = qemu_getrampagesize();
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/*
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* The host might not support the guest supported IOMMU page size,
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* so we will use smaller physical IOMMU pages to back them.
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*/
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if (pagesize > rampagesize) {
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pagesize = rampagesize;
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}
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pagesize = 1ULL << (63 - clz64(container->pgsizes &
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(pagesize | (pagesize - 1))));
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if (!pagesize) {
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error_report("Host doesn't support page size 0x%"PRIx64
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", the supported mask is 0x%lx",
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memory_region_iommu_get_min_page_size(iommu_mr),
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container->pgsizes);
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return -EINVAL;
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}
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/*
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* FIXME: For VFIO iommu types which have KVM acceleration to
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* avoid bouncing all map/unmaps through qemu this way, this
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* would be the right place to wire that up (tell the KVM
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* device emulation the VFIO iommu handles to use).
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*/
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create.window_size = int128_get64(section->size);
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create.page_shift = ctz64(pagesize);
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/*
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* SPAPR host supports multilevel TCE tables. We try to guess optimal
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* levels number and if this fails (for example due to the host memory
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* fragmentation), we increase levels. The DMA address structure is:
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* rrrrrrrr rxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx iiiiiiii
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* where:
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* r = reserved (bits >= 55 are reserved in the existing hardware)
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* i = IOMMU page offset (64K in this example)
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* x = bits to index a TCE which can be split to equal chunks to index
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* within the level.
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* The aim is to split "x" to smaller possible number of levels.
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*/
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entries = create.window_size >> create.page_shift;
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/* bits_total is number of "x" needed */
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bits_total = ctz64(entries * sizeof(uint64_t));
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/*
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* bits_per_level is a safe guess of how much we can allocate per level:
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* 8 is the current minimum for CONFIG_FORCE_MAX_ZONEORDER and MAX_ORDER
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* is usually bigger than that.
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* Below we look at getpagesize() as TCEs are allocated from system pages.
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*/
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bits_per_level = ctz64(getpagesize()) + 8;
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create.levels = bits_total / bits_per_level;
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if (bits_total % bits_per_level) {
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++create.levels;
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}
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max_levels = (64 - create.page_shift) / ctz64(getpagesize());
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for ( ; create.levels <= max_levels; ++create.levels) {
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ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
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if (!ret) {
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break;
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}
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}
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if (ret) {
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error_report("Failed to create a window, ret = %d (%m)", ret);
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return -errno;
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}
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if (create.start_addr != section->offset_within_address_space) {
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vfio_spapr_remove_window(container, create.start_addr);
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error_report("Host doesn't support DMA window at %"HWADDR_PRIx", must be %"PRIx64,
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section->offset_within_address_space,
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(uint64_t)create.start_addr);
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return -EINVAL;
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}
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trace_vfio_spapr_create_window(create.page_shift,
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create.levels,
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create.window_size,
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create.start_addr);
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*pgsize = pagesize;
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return 0;
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}
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int vfio_spapr_remove_window(VFIOContainer *container,
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hwaddr offset_within_address_space)
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{
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struct vfio_iommu_spapr_tce_remove remove = {
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.argsz = sizeof(remove),
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.start_addr = offset_within_address_space,
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};
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int ret;
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ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
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if (ret) {
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error_report("Failed to remove window at %"PRIx64,
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(uint64_t)remove.start_addr);
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return -errno;
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}
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trace_vfio_spapr_remove_window(offset_within_address_space);
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return 0;
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}
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