Re: [PATCH MANUALSEL 5.15 1/8] KVM: X86: Fix tlb flush for tdp in kvm_invalidate_pcid()

[Paolo Bonzini]

On 11/23/21 17:36, Sasha Levin wrote:
> From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
>
> [ Upstream commit e45e9e3998f0001079b09555db5bb3b4257f6746 ]
>
> The KVM doesn't know whether any TLB for a specific pcid is cached in
> the CPU when tdp is enabled.  So it is better to flush all the guest
> TLB when invalidating any single PCID context.
>
> The case is very rare or even impossible since KVM generally doesn't
> intercept CR3 write or INVPCID instructions when tdp is enabled, so the
> fix is mostly for the sake of overall robustness.
>
> Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
> Message-Id: <20211019110154.4091-2-jiangshanlai@xxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

for this patch, but not to all the others.

Paolo