On Sun, 26 May 2019 23:44:37 -0400
Yan Zhao <yan.y.zhao@xxxxxxxxx> wrote:
> This feature implements the migration_version attribute for Intel's vGPU
> mdev devices.
>
> migration_version attribute is rw.
> It's used to check migration compatibility for two mdev devices of the
> same mdev type.
> migration_version string is defined by vendor driver and opaque to
> userspace.
>
> For Intel vGPU of gen8 and gen9, the format of migration_version string
> is:
> <vendor id>-<device id>-<vgpu type>-<software version>.
>
> For future platforms, the format of migration_version string is to be
> expanded to include more meta data to identify Intel vGPUs for live
> migration compatibility check
>
> For old platforms, and for GVT not supporting vGPU live migration
> feature, -ENODEV is returned on read(2)/write(2) of migration_version
> attribute.
> For vGPUs running old GVT who do not expose migration_version
> attribute, live migration is regarded as not supported for those vGPUs.
>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Cc: Erik Skultety <eskultet@xxxxxxxxxx>
> Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
> Cc: Cornelia Huck <cohuck@xxxxxxxxxx>
> Cc: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
> Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
> Cc: "Wang, Zhi A" <zhi.a.wang@xxxxxxxxx>
> c: Neo Jia <cjia@xxxxxxxxxx>
> Cc: Kirti Wankhede <kwankhede@xxxxxxxxxx>
>
> Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
>
> ---
> v3:
> 1. renamed version to migration_version
> (Christophe de Dinechin, Cornelia Huck, Alex Williamson)
> 2. instead of generating migration version strings each time, storing
> them in vgpu types generated during initialization.
> (Zhenyu Wang, Cornelia Huck)
> 3. replaced multiple snprintf to one big snprintf in
> intel_gvt_get_vfio_migration_version()
> (Dr. David Alan Gilbert)
> 4. printed detailed error log
> (Alex Williamson, Erik Skultety, Cornelia Huck, Dr. David Alan Gilbert)
> 5. incorporated <software version> into migration_version string
> (Alex Williamson)
> 6. do not use ifndef macro to switch off migration_version attribute
> (Zhenyu Wang)
>
> v2:
> 1. removed 32 common part of version string
> (Alex Williamson)
> 2. do not register version attribute for GVT not supporting live
> migration.(Cornelia Huck)
> 3. for platforms out of gen8, gen9, return -EINVAL --> -ENODEV for
> incompatible. (Cornelia Huck)
> ---
> drivers/gpu/drm/i915/gvt/Makefile | 2 +-
> drivers/gpu/drm/i915/gvt/gvt.c | 39 +++++
> drivers/gpu/drm/i915/gvt/gvt.h | 5 +
> drivers/gpu/drm/i915/gvt/migration_version.c | 167 +++++++++++++++++++
> drivers/gpu/drm/i915/gvt/vgpu.c | 13 +-
> 5 files changed, 223 insertions(+), 3 deletions(-)
> create mode 100644 drivers/gpu/drm/i915/gvt/migration_version.c
>
(...)
> diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
> index 43f4242062dd..be2980e8ac75 100644
> --- a/drivers/gpu/drm/i915/gvt/gvt.c
> +++ b/drivers/gpu/drm/i915/gvt/gvt.c
> @@ -105,14 +105,53 @@ static ssize_t description_show(struct kobject *kobj, struct device *dev,
> type->weight);
> }
>
> +static ssize_t migration_version_show(struct kobject *kobj, struct device *dev,
> + char *buf)
Indentation looks a bit odd? (Also below.)
> +{
> + struct intel_vgpu_type *type;
> + void *gvt = kdev_to_i915(dev)->gvt;
> +
> + type = intel_gvt_find_vgpu_type(gvt, kobject_name(kobj));
> + if (!type || !type->migration_version) {
> + gvt_err("Does not support migraion on type %s. Please search previous detailed log\n",
s/migraion/migration/ (also below)
Or reword to "Migration not supported on type %s."?
> + kobject_name(kobj));
> + return -ENODEV;
> + }
> +
> + return snprintf(buf, strlen(type->migration_version) + 2,
> + "%s\n", type->migration_version);
> +}
> +
> +static ssize_t migration_version_store(struct kobject *kobj, struct device *dev,
> + const char *buf, size_t count)
> +{
> + int ret = 0;
> + struct intel_vgpu_type *type;
> + void *gvt = kdev_to_i915(dev)->gvt;
> +
> + type = intel_gvt_find_vgpu_type(gvt, kobject_name(kobj));
> + if (!type || !type->migration_version) {
> + gvt_err("Does not support migraion on type %s. Please search previous detailed log\n",
> + kobject_name(kobj));
> + return -ENODEV;
> + }
> +
> + ret = intel_gvt_check_vfio_migration_version(gvt,
> + type->migration_version, buf);
> +
> + return (ret < 0 ? ret : count);
> +}
> +
> static MDEV_TYPE_ATTR_RO(available_instances);
> static MDEV_TYPE_ATTR_RO(device_api);
> static MDEV_TYPE_ATTR_RO(description);
> +static MDEV_TYPE_ATTR_RW(migration_version);
>
> static struct attribute *gvt_type_attrs[] = {
> &mdev_type_attr_available_instances.attr,
> &mdev_type_attr_device_api.attr,
> &mdev_type_attr_description.attr,
> + &mdev_type_attr_migration_version.attr,
> NULL,
> };
(...)
> +char *
> +intel_gvt_get_vfio_migration_version(struct intel_gvt *gvt,
> + const char *vgpu_type)
> +{
> + int cnt = 0;
> + struct drm_i915_private *dev_priv = gvt->dev_priv;
> + char *version = NULL;
> +
> + /* currently only gen8 & gen9 are supported */
> + if (!IS_GEN(dev_priv, 8) && !IS_GEN(dev_priv, 9)) {
> + gvt_err("Local hardware does not support migration on %d\n",
> + INTEL_INFO(dev_priv)->gen);
> + return NULL;
> + }
> +
> + if (GVT_VFIO_MIGRATION_SOFTWARE_VERSION == INV_SOFTWARE_VERSION) {
> + gvt_err("Local GVT does not support migration\n");
> + return NULL;
> + }
> +
> + version = kzalloc(MIGRATION_VERSION_TOTAL_LEN, GFP_KERNEL);
> +
> + if (unlikely(!version)) {
> + gvt_err("memory allocation failed when get local migraiton version\n");
s/migraiton/migration/
Or "cannot allocate memory for local migration version"?
> + return NULL;
> + }
> +
> + /* vendor id + device id + vgpu type + software version */
> + cnt = snprintf(version, MIGRATION_VERSION_TOTAL_LEN, PRINTF_FORMAT,
> + PCI_VENDOR_ID_INTEL,
> + INTEL_DEVID(dev_priv),
> + vgpu_type,
> + GVT_VFIO_MIGRATION_SOFTWARE_VERSION);
> +
> + if (cnt)
> + return version;
> +
> + gvt_err("string generation failed when get local migration version\n");
> + return NULL;
> +}
(...)
Only some nitpicks from me, but I'm not really familiar with this
driver. Overall, this looks sane to me, so have an
Acked-by: Cornelia Huck <cohuck@xxxxxxxxxx>
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