On 2/12/26 00:35, Mohamed Mediouni wrote:
On 11. Feb 2026, at 16:54, Magnus Kulke
<[email protected]> wrote:
We implement mshv_get_supported_cpuid() and invoke it in
x86_cpu_get_supported_feature_word() retrieve the cpu features
that the host is supporting. Initially we mask the virtualization
capabilitities potentially we might need to mask more in the
future.
Signed-off-by: Magnus Kulke <[email protected]>
Hi,
Interesting. For WHPX on Arm, what’s done is creating a stub
partition and extract CPUID info from it (with necessary guest stub
code if necessary) but doing it this way like HVF x86 does is
intriguing too…
Is this future-proof or are there catches with this approach?
No, it's absolutely not future proof.
The difference is two-fold: first, HVF on x86 essentially implements the
hypervisor itself. It operates at the VMCS level and is a mix of KVM
and "regular" QEMU code. Second, for feature leaves HVF lists
explicitly all the supported bits and it also limits EAX to 0xD (it does
not try too hard with AMD leaves at 0x800000nn because HVF x86 is
Intel-only anyway).
So, what this patch implements is not like HVF x86. The stub partition
idea is nice and more future proof.
Paolo
