From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46169) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eQGUE-0006ZT-1a for qemu-devel@nongnu.org; Sat, 16 Dec 2017 12:42:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eQGUA-0000Wm-4W for qemu-devel@nongnu.org; Sat, 16 Dec 2017 12:42:58 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:55134 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eQGU9-0000Vh-VJ for qemu-devel@nongnu.org; Sat, 16 Dec 2017 12:42:54 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vBGHdVRl122750 for ; Sat, 16 Dec 2017 12:42:49 -0500 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ew0c7bcba-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sat, 16 Dec 2017 12:42:49 -0500 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 16 Dec 2017 10:42:48 -0700 From: Stefan Berger Date: Sat, 16 Dec 2017 12:41:49 -0500 In-Reply-To: <1513446109-9013-1-git-send-email-stefanb@linux.vnet.ibm.com> References: <1513446109-9013-1-git-send-email-stefanb@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Message-Id: <1513446109-9013-33-git-send-email-stefanb@linux.vnet.ibm.com> Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL v1 32/32] tpm: tpm_passthrough: Fail startup if FE buffer size < BE buffer size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, Stefan Berger If the requested buffer size of the frontend is smaller than the fixed buffer size of the host's TPM, fail the startup_tpm() interface function, which will make the device unusable. We fail it because the backend TPM could produce larger packets than what the frontend could pass to the OS. The current combination of TIS frontend and either passthrough or emulato= r backend will not lead to this case since the TIS can support any size of buffer. Signed-off-by: Stefan Berger Reviewed-by: Marc-Andr=C3=A9 Lureau --- hw/tpm/tpm_passthrough.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c index 886af9e..487aae2 100644 --- a/hw/tpm/tpm_passthrough.c +++ b/hw/tpm/tpm_passthrough.c @@ -304,6 +304,20 @@ static TPMBackend *tpm_passthrough_create(QemuOpts *= opts) return TPM_BACKEND(obj); } =20 +static int tpm_passthrough_startup_tpm(TPMBackend *tb, size_t buffersize= ) +{ + TPMPassthruState *tpm_pt =3D TPM_PASSTHROUGH(tb); + + if (buffersize && buffersize < tpm_pt->tpm_buffersize) { + error_report("Requested buffer size of %zu is smaller than host = TPM's " + "fixed buffer size of %zu", + buffersize, tpm_pt->tpm_buffersize); + return -1; + } + + return 0; +} + static TpmTypeOptions *tpm_passthrough_get_tpm_options(TPMBackend *tb) { TpmTypeOptions *options =3D g_new0(TpmTypeOptions, 1); @@ -362,6 +376,7 @@ static void tpm_passthrough_class_init(ObjectClass *k= lass, void *data) tbc->opts =3D tpm_passthrough_cmdline_opts; tbc->desc =3D "Passthrough TPM backend driver"; tbc->create =3D tpm_passthrough_create; + tbc->startup_tpm =3D tpm_passthrough_startup_tpm; tbc->reset =3D tpm_passthrough_reset; tbc->cancel_cmd =3D tpm_passthrough_cancel_cmd; tbc->get_tpm_established_flag =3D tpm_passthrough_get_tpm_establishe= d_flag; --=20 2.5.5