From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53331) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eEIIc-0008B8-37 for qemu-devel@nongnu.org; Mon, 13 Nov 2017 12:13:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eEIIX-00059E-Rr for qemu-devel@nongnu.org; Mon, 13 Nov 2017 12:13:30 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47650) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eEIIX-00057W-Hp for qemu-devel@nongnu.org; Mon, 13 Nov 2017 12:13:25 -0500 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vADHCBcD105863 for ; Mon, 13 Nov 2017 12:13:17 -0500 Received: from e16.ny.us.ibm.com (e16.ny.us.ibm.com [129.33.205.206]) by mx0a-001b2d01.pphosted.com with ESMTP id 2e7dtty2mc-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 13 Nov 2017 12:13:17 -0500 Received: from localhost by e16.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 13 Nov 2017 12:13:16 -0500 References: <1510173421-19895-1-git-send-email-stefanb@linux.vnet.ibm.com> From: Stefan Berger Date: Mon, 13 Nov 2017 12:13:13 -0500 MIME-Version: 1.0 In-Reply-To: <1510173421-19895-1-git-send-email-stefanb@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Message-Id: Subject: Re: [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, marcandre.lureau@redhat.com Cc: amarnath.valluri@intel.com On 11/08/2017 03:37 PM, Stefan Berger wrote: > Add a caching layer for the TPM established flag so that we don't > need to go to the emulator every time the flag is read by accessing > the REG_ACCESS register. > > Signed-off-by: Stefan Berger Can anyone have a look, please? Stefan > > v1->v2: > - move the caching to the backend layer since detecting the > TPM 1.2 TSC_ResetEstablishmentBit() command is easier to do > here. > --- > hw/tpm/tpm_emulator.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/hw/tpm/tpm_emulator.c b/hw/tpm/tpm_emulator.c > index 9aaec8e..507e2cb 100644 > --- a/hw/tpm/tpm_emulator.c > +++ b/hw/tpm/tpm_emulator.c > @@ -71,6 +71,9 @@ typedef struct TPMEmulator { > ptm_cap caps; /* capabilities of the TPM */ > uint8_t cur_locty_number; /* last set locality */ > Error *migration_blocker; > + > + unsigned int established_flag:1; > + unsigned int established_flag_cached:1; > } TPMEmulator; > > > @@ -277,16 +280,22 @@ static bool tpm_emulator_get_tpm_established_flag(TPMBackend *tb) > TPMEmulator *tpm_emu = TPM_EMULATOR(tb); > ptm_est est; > > - DPRINTF("%s", __func__); > + if (tpm_emu->established_flag_cached) { > + return tpm_emu->established_flag; > + } > + > if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_GET_TPMESTABLISHED, &est, > 0, sizeof(est)) < 0) { > error_report("tpm-emulator: Could not get the TPM established flag: %s", > strerror(errno)); > return false; > } > - DPRINTF("established flag: %0x", est.u.resp.bit); > + DPRINTF("got established flag: %0x", est.u.resp.bit); > + > + tpm_emu->established_flag_cached = 1; > + tpm_emu->established_flag = (est.u.resp.bit != 0); > > - return (est.u.resp.bit != 0); > + return tpm_emu->established_flag; > } > > static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb, > @@ -317,6 +326,8 @@ static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb, > return -1; > } > > + tpm_emu->established_flag_cached = 0; > + > return 0; > } >