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H A Dx86_cpuid.c9c267239 Wed Jun 05 06:25:50 CDT 2024 Phil Dennis-Jordan <phil@philjordan.eu> i386/hvf: Adds support for INVTSC cpuid bit

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.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>
Message-ID: <20240605112556.43193-2-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
H A Dhvf.c9c267239 Wed Jun 05 06:25:50 CDT 2024 Phil Dennis-Jordan <phil@philjordan.eu> i386/hvf: Adds support for INVTSC cpuid bit

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.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Roman Bolshakov <roman@roolebo.dev>
Tested-by: Roman Bolshakov <roman@roolebo.dev>
Message-ID: <20240605112556.43193-2-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>