From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55008) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eCX69-0000R4-7M for qemu-devel@nongnu.org; Wed, 08 Nov 2017 15:37:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eCX64-0004uI-Ay for qemu-devel@nongnu.org; Wed, 08 Nov 2017 15:37:21 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40544) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eCX64-0004tc-2P for qemu-devel@nongnu.org; Wed, 08 Nov 2017 15:37:16 -0500 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vA8Ka2wJ107046 for ; Wed, 8 Nov 2017 15:37:09 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 2e48abtf33-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 08 Nov 2017 15:37:09 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 8 Nov 2017 13:37:08 -0700 From: Stefan Berger Date: Wed, 8 Nov 2017 15:37:01 -0500 Message-Id: <1510173421-19895-1-git-send-email-stefanb@linux.vnet.ibm.com> Subject: [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, Stefan Berger 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 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; } -- 2.5.5