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-rw-r--r--hw/vfio/spapr.c210
1 files changed, 210 insertions, 0 deletions
diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c
new file mode 100644
index 0000000000..0af342332c
--- /dev/null
+++ b/hw/vfio/spapr.c
@@ -0,0 +1,210 @@
+/*
+ * DMA memory preregistration
+ *
+ * Authors:
+ * Alexey Kardashevskiy <aik@ozlabs.ru>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include <sys/ioctl.h>
+#include <linux/vfio.h>
+
+#include "hw/vfio/vfio-common.h"
+#include "hw/hw.h"
+#include "qemu/error-report.h"
+#include "trace.h"
+
+static bool vfio_prereg_listener_skipped_section(MemoryRegionSection *section)
+{
+ if (memory_region_is_iommu(section->mr)) {
+ hw_error("Cannot possibly preregister IOMMU memory");
+ }
+
+ return !memory_region_is_ram(section->mr) ||
+ memory_region_is_skip_dump(section->mr);
+}
+
+static void *vfio_prereg_gpa_to_vaddr(MemoryRegionSection *section, hwaddr gpa)
+{
+ return memory_region_get_ram_ptr(section->mr) +
+ section->offset_within_region +
+ (gpa - section->offset_within_address_space);
+}
+
+static void vfio_prereg_listener_region_add(MemoryListener *listener,
+ MemoryRegionSection *section)
+{
+ VFIOContainer *container = container_of(listener, VFIOContainer,
+ prereg_listener);
+ const hwaddr gpa = section->offset_within_address_space;
+ hwaddr end;
+ int ret;
+ hwaddr page_mask = qemu_real_host_page_mask;
+ struct vfio_iommu_spapr_register_memory reg = {
+ .argsz = sizeof(reg),
+ .flags = 0,
+ };
+
+ if (vfio_prereg_listener_skipped_section(section)) {
+ trace_vfio_prereg_listener_region_add_skip(
+ section->offset_within_address_space,
+ section->offset_within_address_space +
+ int128_get64(int128_sub(section->size, int128_one())));
+ return;
+ }
+
+ if (unlikely((section->offset_within_address_space & ~page_mask) ||
+ (section->offset_within_region & ~page_mask) ||
+ (int128_get64(section->size) & ~page_mask))) {
+ error_report("%s received unaligned region", __func__);
+ return;
+ }
+
+ end = section->offset_within_address_space + int128_get64(section->size);
+ if (gpa >= end) {
+ return;
+ }
+
+ memory_region_ref(section->mr);
+
+ reg.vaddr = (uintptr_t) vfio_prereg_gpa_to_vaddr(section, gpa);
+ reg.size = end - gpa;
+
+ ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_REGISTER_MEMORY, &reg);
+ trace_vfio_prereg_register(reg.vaddr, reg.size, ret ? -errno : 0);
+ if (ret) {
+ /*
+ * On the initfn path, store the first error in the container so we
+ * can gracefully fail. Runtime, there's not much we can do other
+ * than throw a hardware error.
+ */
+ if (!container->initialized) {
+ if (!container->error) {
+ container->error = ret;
+ }
+ } else {
+ hw_error("vfio: Memory registering failed, unable to continue");
+ }
+ }
+}
+
+static void vfio_prereg_listener_region_del(MemoryListener *listener,
+ MemoryRegionSection *section)
+{
+ VFIOContainer *container = container_of(listener, VFIOContainer,
+ prereg_listener);
+ const hwaddr gpa = section->offset_within_address_space;
+ hwaddr end;
+ int ret;
+ hwaddr page_mask = qemu_real_host_page_mask;
+ struct vfio_iommu_spapr_register_memory reg = {
+ .argsz = sizeof(reg),
+ .flags = 0,
+ };
+
+ if (vfio_prereg_listener_skipped_section(section)) {
+ trace_vfio_prereg_listener_region_del_skip(
+ section->offset_within_address_space,
+ section->offset_within_address_space +
+ int128_get64(int128_sub(section->size, int128_one())));
+ return;
+ }
+
+ if (unlikely((section->offset_within_address_space & ~page_mask) ||
+ (section->offset_within_region & ~page_mask) ||
+ (int128_get64(section->size) & ~page_mask))) {
+ error_report("%s received unaligned region", __func__);
+ return;
+ }
+
+ end = section->offset_within_address_space + int128_get64(section->size);
+ if (gpa >= end) {
+ return;
+ }
+
+ reg.vaddr = (uintptr_t) vfio_prereg_gpa_to_vaddr(section, gpa);
+ reg.size = end - gpa;
+
+ ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY, &reg);
+ trace_vfio_prereg_unregister(reg.vaddr, reg.size, ret ? -errno : 0);
+}
+
+const MemoryListener vfio_prereg_listener = {
+ .region_add = vfio_prereg_listener_region_add,
+ .region_del = vfio_prereg_listener_region_del,
+};
+
+int vfio_spapr_create_window(VFIOContainer *container,
+ MemoryRegionSection *section,
+ hwaddr *pgsize)
+{
+ int ret;
+ unsigned pagesize = memory_region_iommu_get_min_page_size(section->mr);
+ unsigned entries, pages;
+ struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) };
+
+ /*
+ * 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;
+
+ ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
+ if (ret) {
+ error_report("Failed to create a window, ret = %d (%m)", ret);
+ return -errno;
+ }
+
+ if (create.start_addr != section->offset_within_address_space) {
+ vfio_spapr_remove_window(container, create.start_addr);
+
+ error_report("Host doesn't support DMA window at %"HWADDR_PRIx", must be %"PRIx64,
+ section->offset_within_address_space,
+ (uint64_t)create.start_addr);
+ ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
+ return -EINVAL;
+ }
+ trace_vfio_spapr_create_window(create.page_shift,
+ create.window_size,
+ create.start_addr);
+ *pgsize = pagesize;
+
+ return 0;
+}
+
+int vfio_spapr_remove_window(VFIOContainer *container,
+ hwaddr offset_within_address_space)
+{
+ struct vfio_iommu_spapr_tce_remove remove = {
+ .argsz = sizeof(remove),
+ .start_addr = offset_within_address_space,
+ };
+ int ret;
+
+ ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
+ if (ret) {
+ error_report("Failed to remove window at %"PRIx64,
+ (uint64_t)remove.start_addr);
+ return -errno;
+ }
+
+ trace_vfio_spapr_remove_window(offset_within_address_space);
+
+ return 0;
+}
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