/*
* 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_ram_device(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, ®);
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, ®);
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;
IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr);
unsigned pagesize = memory_region_iommu_get_min_page_size(iommu_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);
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;
}
