The earlier commit (6d1b11726) read /sys/class/dmi/id/sys_vendor
and /sys/class/dmi/id/product_name. Those are the Linux paths.
Redox exposes SMBIOS fields at /scheme/acpi/dmi/<field> via the
acpid userspace daemon. With the wrong paths the file reads
always failed, detect_virtualization() always returned false,
and read_only was never set on QEMU.
Now we read /scheme/acpi/dmi/sys_vendor and product_name (the
Redox-correct paths), and as a fallback when SMBIOS is absent
or uninformative we check the CPUID hypervisor-present bit
(leaf 1 ECX bit 31) via inline assembly. The CPUID pattern
mirrors local/recipes/system/redbear-power/source/src/cpuid.rs:168
which already uses this bit for the same purpose.
When either signal indicates virtualization, every CpuInfo is
constructed with read_only = true and apply_pstate() short-
circuits at the top. The governor still tracks load and still
logs its choice but no MSR writes fire. On bare metal the
existing path is preserved exactly.
The companion kernel fix in local/sources/kernel (commit
c2312627 on master) corrects a path-strip bug in the sys
scheme dispatcher that was preventing every MSR open from
succeeding with ENOENT. With both fixes together, cpufreqd
on QEMU enters read-only mode and the Ondemand governor stops
the P0->P1->P0 oscillation.
vasilito
68b1f74dbf