On Wed, Jan 12, 2022 at 11:55:17AM -0500, Yang Zhong wrote:
> When Libvirt start, it get the vcpu's unavailable-features from
> /machine/unattached/device[0] path by qom-get command, but in SGX
> guest, since the sgx-epc virtual device is initialized before VCPU
> creation(virtual sgx need set the virtual EPC info in the cpuid). This
> /machine/unattached/device[0] is occupied by sgx-epc device, which
> fail to get the unvailable-features from /machine/unattached/device[0].
If libvirt decides to enable SGX in a VM, then surely it knows
that it should just query /machine/unattached/device[1] to get
the CPU features instead. Why do we need to do anything in QEMU ?
>
> This patch make one new /machine/sgx object to avoid this issue.
> (qemu) qom-list /machine/unattached/
> device[0] (child<host-x86_64-cpu>)
>
> (qemu) qom-list /machine/sgx
> device[0] (child<sgx-epc>)
>
> Signed-off-by: Yang Zhong <yang.zh...@intel.com>
> ---
> hw/core/qdev.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 84f3019440..4154eef0d8 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -497,7 +497,7 @@ static void device_set_realized(Object *obj, bool value,
> Error **errp)
> NamedClockList *ncl;
> Error *local_err = NULL;
> bool unattached_parent = false;
> - static int unattached_count;
> + static int unattached_count, sgx_count;
>
> if (dev->hotplugged && !dc->hotpluggable) {
> error_setg(errp, QERR_DEVICE_NO_HOTPLUG, object_get_typename(obj));
> @@ -509,7 +509,15 @@ static void device_set_realized(Object *obj, bool value,
> Error **errp)
> goto fail;
> }
>
> - if (!obj->parent) {
> + if (!obj->parent && !strcmp(object_get_typename(obj), "sgx-epc")) {
> + gchar *name = g_strdup_printf("device[%d]", sgx_count++);
> +
> + object_property_add_child(container_get(qdev_get_machine(),
> + "/sgx"),
> + name, obj);
> + unattached_parent = true;
> + g_free(name);
The qdev.c file is part of our generic object code. It should not
contain any code that is tied to very specific object types like
this.
> + } else if (!obj->parent) {
> gchar *name = g_strdup_printf("device[%d]", unattached_count++);
>
> object_property_add_child(container_get(qdev_get_machine(),
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
