aboutsummaryrefslogtreecommitdiff
path: root/hw/vfio/platform.c
diff options
context:
space:
mode:
authorAlex Williamson <alex.williamson@redhat.com>2016-03-10 09:39:07 -0700
committerAlex Williamson <alex.williamson@redhat.com>2016-03-10 09:39:07 -0700
commit7df9381b7aa56c897e344f3bfe43bf5848bbd3e0 (patch)
tree2868a0549dd0b610671cc4c0674ddeb19bf1e578 /hw/vfio/platform.c
parenta648c137383d84bc4f95696e5293978d9541a26e (diff)
vfio: Add sysfsdev property for pci & platform
vfio-pci currently requires a host= parameter, which comes in the form of a PCI address in [domain:]<bus:slot.function> notation. We expect to find a matching entry in sysfs for that under /sys/bus/pci/devices/. vfio-platform takes a similar approach, but defines the host= parameter to be a string, which can be matched directly under /sys/bus/platform/devices/. On the PCI side, we have some interest in using vfio to expose vGPU devices. These are not actual discrete PCI devices, so they don't have a compatible host PCI bus address or a device link where QEMU wants to look for it. There's also really no requirement that vfio can only be used to expose physical devices, a new vfio bus and iommu driver could expose a completely emulated device. To fit within the vfio framework, it would need a kernel struct device and associated IOMMU group, but those are easy constraints to manage. To support such devices, which would include vGPUs, that honor the VFIO PCI programming API, but are not necessarily backed by a unique PCI address, add support for specifying any device in sysfs. The vfio API already has support for probing the device type to ensure compatibility with either vfio-pci or vfio-platform. With this, a vfio-pci device could either be specified as: -device vfio-pci,host=02:00.0 or -device vfio-pci,sysfsdev=/sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0 or even -device vfio-pci,sysfsdev=/sys/bus/pci/devices/0000:02:00.0 When vGPU support comes along, this might look something more like: -device vfio-pci,sysfsdev=/sys/devices/virtual/intel-vgpu/vgpu0@0000:00:02.0 NB - This is only a made up example path The same change is made for vfio-platform, specifying sysfsdev has precedence over the old host option. Tested-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'hw/vfio/platform.c')
-rw-r--r--hw/vfio/platform.c55
1 files changed, 32 insertions, 23 deletions
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index ebc9dcbb99..6c8b54a7c3 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -560,38 +560,45 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
{
VFIOGroup *group;
VFIODevice *vbasedev_iter;
- char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
+ char *tmp, group_path[PATH_MAX], *group_name;
ssize_t len;
struct stat st;
int groupid;
int ret;
- /* name must be set prior to the call */
- if (!vbasedev->name || strchr(vbasedev->name, '/')) {
- return -EINVAL;
- }
+ /* @sysfsdev takes precedence over @host */
+ if (vbasedev->sysfsdev) {
+ g_free(vbasedev->name);
+ vbasedev->name = g_strdup(basename(vbasedev->sysfsdev));
+ } else {
+ if (!vbasedev->name || strchr(vbasedev->name, '/')) {
+ return -EINVAL;
+ }
- /* Check that the host device exists */
- g_snprintf(path, sizeof(path), "/sys/bus/platform/devices/%s/",
- vbasedev->name);
+ vbasedev->sysfsdev = g_strdup_printf("/sys/bus/platform/devices/%s",
+ vbasedev->name);
+ }
- if (stat(path, &st) < 0) {
- error_report("vfio: error: no such host device: %s", path);
+ if (stat(vbasedev->sysfsdev, &st) < 0) {
+ error_report("vfio: error: no such host device: %s",
+ vbasedev->sysfsdev);
return -errno;
}
- g_strlcat(path, "iommu_group", sizeof(path));
- len = readlink(path, iommu_group_path, sizeof(iommu_group_path));
- if (len < 0 || len >= sizeof(iommu_group_path)) {
+ tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
+ len = readlink(tmp, group_path, sizeof(group_path));
+ g_free(tmp);
+
+ if (len < 0 || len >= sizeof(group_path)) {
error_report("vfio: error no iommu_group for device");
return len < 0 ? -errno : -ENAMETOOLONG;
}
- iommu_group_path[len] = 0;
- group_name = basename(iommu_group_path);
+ group_path[len] = 0;
+ group_name = basename(group_path);
if (sscanf(group_name, "%d", &groupid) != 1) {
- error_report("vfio: error reading %s: %m", path);
+ error_report("vfio: error reading %s: %m", group_path);
return -errno;
}
@@ -603,25 +610,24 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
return -ENOENT;
}
- g_snprintf(path, sizeof(path), "%s", vbasedev->name);
-
QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
- error_report("vfio: error: device %s is already attached", path);
+ error_report("vfio: error: device %s is already attached",
+ vbasedev->name);
vfio_put_group(group);
return -EBUSY;
}
}
- ret = vfio_get_device(group, path, vbasedev);
+ ret = vfio_get_device(group, vbasedev->name, vbasedev);
if (ret) {
- error_report("vfio: failed to get device %s", path);
+ error_report("vfio: failed to get device %s", vbasedev->name);
vfio_put_group(group);
return ret;
}
ret = vfio_populate_device(vbasedev);
if (ret) {
- error_report("vfio: failed to populate device %s", path);
+ error_report("vfio: failed to populate device %s", vbasedev->name);
vfio_put_group(group);
}
@@ -681,7 +687,9 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
vbasedev->ops = &vfio_platform_ops;
- trace_vfio_platform_realize(vbasedev->name, vdev->compat);
+ trace_vfio_platform_realize(vbasedev->sysfsdev ?
+ vbasedev->sysfsdev : vbasedev->name,
+ vdev->compat);
ret = vfio_base_device_init(vbasedev);
if (ret) {
@@ -703,6 +711,7 @@ static const VMStateDescription vfio_platform_vmstate = {
static Property vfio_platform_dev_properties[] = {
DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
+ DEFINE_PROP_STRING("sysfsdev", VFIOPlatformDevice, vbasedev.sysfsdev),
DEFINE_PROP_BOOL("x-no-mmap", VFIOPlatformDevice, vbasedev.no_mmap, false),
DEFINE_PROP_UINT32("mmap-timeout-ms", VFIOPlatformDevice,
mmap_timeout, 1100),