1 files changed, 139 insertions, 0 deletions
diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c
new file mode 100644
index 0000000000..7d64443b7f
--- /dev/null
+++ b/hw/vfio/spapr.c
@@ -0,0 +1,139 @@
+/*
+ * 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,
+};