From: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> Sent: Tuesday, April 4, 2023 2:01 AM > > Virtual Trust Levels (VTL) helps enable Hyper-V Virtual Secure Mode (VSM) > feature. VSM is a set of hypervisor capabilities and enlightenments > offered to host and guest partitions which enable the creation and > management of new security boundaries within operating system software. > VSM achieves and maintains isolation through VTLs. > > Add early initialization for Virtual Trust Levels (VTL). This includes > initializing the x86 platform for VTL and enabling boot support for > secondary CPUs to start in targeted VTL context. For now, only enable > the code for targeted VTL level as 2. > > When starting an AP at a VTL other than VTL0, the AP must start directly > in 64-bit mode, bypassing the usual 16-bit -> 32-bit -> 64-bit mode > transition sequence that occurs after waking up an AP with SIPI whose > vector points to the 16-bit AP startup trampoline code. > > Signed-off-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> > --- > [V4] > - replace initial_stack with current->thread.sp as per recent upstream changes > > arch/x86/hyperv/Makefile | 1 + > arch/x86/hyperv/hv_vtl.c | 227 ++++++++++++++++++++++++++++++++ > arch/x86/include/asm/mshyperv.h | 10 ++ > arch/x86/kernel/cpu/mshyperv.c | 1 + > 4 files changed, 239 insertions(+) > create mode 100644 arch/x86/hyperv/hv_vtl.c > Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
