mshv: Extend create partition ioctl to support cpu features

mshv: Extend create partition ioctl to support cpu features

The existing mshv create partition ioctl does not provide a way to
specify which cpu features are enabled in the guest. Instead, it
attempts to enable all features and those that are not supported are
silently disabled by the hypervisor.

This was done to reduce unnecessary complexity and is sufficient for
many cases. However, new scenarios require fine-grained control over
these features.

Define a new mshv_create_partition_v2 structure which supports
passing the disabled processor and xsave feature bits through to the
create partition hypercall directly.

Introduce a new flag MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES which enables
the new structure. If unset, the original mshv_create_partition struct
is used, with the old behavior of enabling all features.

Co-developed-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>