Re: [PATCH v5 2/9] x86/bugs: Use VM_CLEAR_CPU_BUFFERS in VMX as well

[Brendan Jackman]

On Thu Nov 13, 2025 at 11:37 PM UTC, Sean Christopherson wrote:
> From: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
>
> TSA mitigation:
>
>   d8010d4ba43e ("x86/bugs: Add a Transient Scheduler Attacks mitigation")
>
> introduced VM_CLEAR_CPU_BUFFERS for guests on AMD CPUs. Currently on Intel
> CLEAR_CPU_BUFFERS is being used for guests which has a much broader scope
> (kernel->user also).
>
> Make mitigations on Intel consistent with TSA. This would help handling the
> guest-only mitigations better in future.
>
> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
> [sean: make CLEAR_CPU_BUF_VM mutually exclusive with the MMIO mitigation]
> Acked-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Reviewed-by: Brendan Jackman <jackmanb@xxxxxxxxxx>