From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF5593FF882 for ; Mon, 10 Aug 2026 23:57:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786406259; cv=none; b=UBmJ3qO3SUgwZBk+orM2HQ5Z4Yk2wAgJ2+Xa2qhcPWhv/1cSEkRLAFZVGrUpDxs0iwWTvtCc3c3MA5P4vihGmmDoFDHMyEu8l+G4Oq26h24EJGfEXgwBCDeyQ+Yi0m2aqekCqNbhvCNMzZ2pkxEw7tTFP+RGvvokCVltcwZc7YQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786406259; c=relaxed/simple; bh=4BupJwdVyL6umlPiGYOwer+ZhuGrupEyMF3dhJCrF+k=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=otzJg7AdrmPRnJtnW1Dji+da9529q556Hg/JxisLgCt7E0/nyPqilUdPQBSMUjYcHtigon2yIgaFoFGqSxeWZlG/b9FcwVDY6aC29ZsGej5SPrRZ5xUBR49B8963rXKPBpRE/ujYGEt6XvLqQMdoAjd1Hzafge1n3hqD2X2JlH0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GS3Snx1d; arc=none smtp.client-ip=209.85.215.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GS3Snx1d" Received: by mail-pg1-f200.google.com with SMTP id 41be03b00d2f7-c9fe4c5eb39so1690603a12.1 for ; Mon, 10 Aug 2026 16:57:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786406258; x=1787011058; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=PeZGsgiDsMXG6LZQ2iDpLtip3LMl/NmxKydR78skp+E=; b=GS3Snx1dsJqL2R28OlzooZaplJnTENZJaw02R8RzvToEHMYc3WOsXOxINxT/tDgeE7 Wdqm/wyMr0l6aIkC8moFbTyh3iJWsWDXVzbWfyf2H2X/lzHVfOQ02W0czmIVD/BZdE+e dmifoc5KiUqz2H4mNdCcK0kHy4hBd9jwWL4mbCkh230PM+kvwGkrKw1OLpfAHxdaROCJ a7G39etvQhtaGSBsKcc0xUpEQm00j4sy6Jz+dbEpHi5I0LZ5555HylYPOz7AkzJ4iUAQ IR/U+6oxDkqAogt0UY4BXKysn1ucn2B2wHYcONP37CZhuIs7oN3w7hjY9R30UsP/8d/F FTYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786406258; x=1787011058; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=PeZGsgiDsMXG6LZQ2iDpLtip3LMl/NmxKydR78skp+E=; b=StRPbQClPBI9Pdlvo8nItLT1eGQ6ipLSxhbNVYcVqv5ucHlxWcdyn054eCR4F+Mkau NuK/rbXX9ToHN+7tvREa/+TfyvSh9KGf+c+NrCCtHBZtugaWm5D7XF0edPXHQMwQpdQv 7Jr3n6yV0LTxRnbC0CLlxon9hp6h/HTvuz3h1yeikiZD+zIEU72xBC5umcGXJHhnvmP4 FTbAq10XvzVvJwGOajg8hxtfalo5420c0OU7K4XzTXXP7Srsw7hnmrMrtCmJEM/nCR1Q PTBajV8QmozdiKf8BXuL8brfkLlCYqMdqtJraspUx4n1aBMhJIS77Q0DrvbwI4zs7VDM uSYw== X-Forwarded-Encrypted: i=1; AHgh+RrN2ZOpdFA+94H+TIq5iFzEjRT/3g2l14+qF8pvbQxonLX0Y7RkqOp9YfrgPrigenPKV5c=@vger.kernel.org X-Gm-Message-State: AOJu0YzsSIsy12fsB5FwgbqYiJwh2ed4tiRSNO59t0nirg/lWixOlISZ La5zYF0FurnYhKkPsEWFE3QBcuPAipznpQh1kLP4uTwi4DmnGNIFGWFZSGCsF6TUb3t0Nmd9Xk+ REKXhmA== X-Received: from pgdi6.prod.google.com ([2002:a05:6a02:51e6:b0:c99:aff5:707d]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:e598:b0:3c3:93ce:663 with SMTP id adf61e73a8af0-3cc1a35367cmr6912795637.26.1786406257898; Mon, 10 Aug 2026 16:57:37 -0700 (PDT) Date: Mon, 10 Aug 2026 16:57:37 -0700 In-Reply-To: <13ea6279-a342-493b-a0f8-15ac5b4c59ad@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260810112200.2326727-1-xiaoyao.li@intel.com> <20260810112200.2326727-3-xiaoyao.li@intel.com> <20260810113924.4ACBE1F000E9@smtp.kernel.org> <13ea6279-a342-493b-a0f8-15ac5b4c59ad@intel.com> Message-ID: Subject: Re: [PATCH v2 2/3] KVM: TDX: Fix the exit reason handling From: Sean Christopherson To: Xiaoyao Li Cc: sashiko-reviews@lists.linux.dev, kvm@vger.kernel.org, Paolo Bonzini Content-Type: text/plain; charset="us-ascii" On Mon, Aug 10, 2026, Xiaoyao Li wrote: > On 8/10/2026 7:39 PM, sashiko-bot@kernel.org wrote: > > > @@ -2147,7 +2156,7 @@ void tdx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason, > > > struct vcpu_tdx *tdx = to_tdx(vcpu); > > > *reason = tdx->vt.exit_reason.full; > > > - if (*reason != -1u) { > > > + if (tdx->vt.exit_reason.basic != -1) { > > [Severity: Medium] > > Will this check always evaluate to true due to C integer promotion rules? > > > > The basic field in union vmx_exit_reason is a 16-bit unsigned bitfield. When > > comparing it to -1, the unsigned 16-bit value is promoted to a signed 32-bit > > integer. If the value was set to -1 (65535), the comparison evaluates as > > 65535 != -1, which is always true. > > > > Well, how about something below on top of this patch? No, we need to not rely on magic exit_reason.basic values. Can't this be? if ((tdx->vp_enter_ret & TDX_SW_ERROR) != TDX_SW_ERROR) { } else { } We'd need to use the unsafe version if we go with my suggestion[*], but other than that wrinkle, the above seems like the obviously correct fix (maybe too obvious)? [*] https://lore.kernel.org/all/anXxBzO41_5eaaOI@google.com