From: Sean Christopherson <seanjc@google.com>
To: sashiko-reviews@lists.linux.dev
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH] KVM: x86/mmu: WARN and flush TLBs if TDP MMU replaces present SPTE with MMIO SPTE
Date: Thu, 22 Oct 2026 06:34:12 -0700 [thread overview]
Message-ID: <atoQ1Az63PUL8L0l@google.com> (raw)
In-Reply-To: <sashiko-outbox-180886@kernel.org>
On Thu, Oct 22, 2026, sashiko-bot@kernel.org wrote:
> When a shadow-present spte mapping a valid memslot gfn is overwritten with a
> non-shadow-present mmio spte due to gfn truncation in the tdp iterator, does
> flushing iter->gfn via kvm_flush_remote_tlbs_gfn() flush the wrong address
> when range-based tlb invalidation is used?
...
> Should this path call kvm_flush_remote_tlbs(vcpu->kvm) (or mask iter->gfn to
> the root's address space) when !is_shadow_present_pte(new_spte) triggers?
Eh, I don't think we should bother. The right fix is prevent the truncation in
the first place. If kvm_flush_remote_tlbs_gfn() weren't limited to KVM-on-HyperV
I would care, especially since this requires userspace to effectively misconfigure
the VM. I.e. someone would have to go pretty far out of their way to run afoul of
this exact scenario.
prev parent reply other threads:[~2026-10-22 13:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-22 2:22 [PATCH] KVM: x86/mmu: WARN and flush TLBs if TDP MMU replaces present SPTE with MMIO SPTE Sean Christopherson
2026-10-22 2:51 ` sashiko-bot
2026-10-22 13:34 ` Sean Christopherson [this message]
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