From: Sean Christopherson <seanjc@google.com>
To: Jack Wang <jinpu.wang@ionos.com>
Cc: gregkh@linuxfoundation.org, sashal@kernel.org,
stable@vger.kernel.org, Tom Lendacky <thomas.lendacky@amd.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [stable-6.12 v2 2/3] KVM: SEV: Reject MMIO requests larger than 8 bytes with GHCB v2+
Date: Tue, 30 Jun 2026 07:45:27 -0700 [thread overview]
Message-ID: <akPWh6PelrFlotF1@google.com> (raw)
In-Reply-To: <20260626193343.256956-3-jinpu.wang@ionos.com>
On Fri, Jun 26, 2026, Jack Wang wrote:
> From: Sean Christopherson <seanjc@google.com>
>
> commit dcf1b2d4b0564a27e4ca7c654871aab4f9620046 upstream.
>
> When using GHCB v2+, reject MMIO requests that are larger than 8 bytes.
> Per the GHCB spec:
>
> SW_EXITINFO2 must be less than or equal to 0x7fffffff for version 1 and
> less than or equal to 0x8 for all other versions.
>
> Fixes: 4af663c2f64a ("KVM: SEV: Allow per-guest configuration of GHCB protocol version")
> Cc: stable@vger.kernel.org
> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Message-ID: <20260501202250.2115252-4-seanjc@google.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Same comment about documentation the changes.
[Jack: Open code response as svm_vmgexit_bad_input() doesn't exist in 6.12,
nor does GHCB_HV_RESP_MALFORMED_INPUT (the literal '2'). Duplicate
fix to split READ/WRITE paths. ]
> Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Acked-by: Sean Christopherson <seanjc@google.com>
next prev parent reply other threads:[~2026-06-30 14:45 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-26 19:28 [stable-6.12 v2 0/3] 3 SEV fixes backport Jack Wang
2026-06-26 19:28 ` [stable-6.12 v2 1/3] KVM: SEV: Ignore MMIO requests of length '0' Jack Wang
2026-06-30 14:42 ` Sean Christopherson
2026-07-01 4:10 ` Jinpu Wang
2026-06-26 19:28 ` [stable-6.12 v2 2/3] KVM: SEV: Reject MMIO requests larger than 8 bytes with GHCB v2+ Jack Wang
2026-06-30 14:45 ` Sean Christopherson [this message]
2026-06-26 19:28 ` [stable-6.12 v2 3/3] KVM: SEV: Ignore Port I/O requests of length '0' Jack Wang
2026-06-30 14:53 ` Sean Christopherson
2026-06-27 16:35 ` [stable-6.12 v2 0/3] 3 SEV fixes backport Sasha Levin
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