Re: [PATCH v3] x86/hyperv: add noop functions to x86_init mpparse functions

From: Wei Liu
Date: Wed Aug 02 2023 - 19:10:30 EST


On Fri, Jun 23, 2023 at 09:28:08AM -0700, Saurabh Sengar wrote:
> Hyper-V can run VMs at different privilege "levels" known as Virtual
> Trust Levels (VTL). Sometimes, it chooses to run two different VMs
> at different levels but they share some of their address space. In
> such setups VTL2 (higher level VM) has visibility of all of the
> VTL0 (level 0) memory space.
>
> When the CONFIG_X86_MPPARSE is enabled for VTL2, the VTL2 kernel
> performs a search within the low memory to locate MP tables. However,
> in systems where VTL0 manages the low memory and may contain valid
> tables, this scanning can result in incorrect MP table information
> being provided to the VTL2 kernel, mistakenly considering VTL0's MP
> table as its own
>
> Add noop functions to avoid MP parse scan by VTL2.
>
> Signed-off-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>

Applied to hyperv-fixes. Thanks.