Re: [PATCH v2 1/4] i386: hvf: Adds support for INVTSC cpuid bit

[Roman Bolshakov]

On Sat, Oct 21, 2023 at 10:05:15PM +0200, Phil Dennis-Jordan wrote:
> This patch adds the INVTSC bit to the Hypervisor.framework accelerator's
> CPUID bit passthrough allow-list. Previously, specifying +invtsc in the CPU
> configuration would fail with the following warning despite the host CPU
> advertising the feature:
> 
> qemu-system-x86_64: warning: host doesn't support requested feature:
> CPUID.80000007H:EDX.invtsc [bit 8]
> 
> x86 macOS itself relies on a fixed rate TSC for its own Mach absolute time
> timestamp mechanism, so there's no reason we can't enable this bit for guests.
> When the feature is enabled, a migration blocker is installed.
> 

Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>

Thanks,
Roman