KVM: X86: Fix tlb flush for tdp in kvm_invalidate_pcid()

KVM: X86: Fix tlb flush for tdp in kvm_invalidate_pcid()

[ 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@linux.alibaba.com>
Message-Id: <20211019110154.4091-2-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>