From 0b4c7c65f882fac328f2c97398f06f16fe6d3f12 Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Wed, 8 Nov 2017 15:30:18 -0500 Subject: [PATCH] tpm_emulator: Add a caching layer for the TPM Established flag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Marc-André Lureau --- 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 38b6f175a1..35c78de5a9 100644 --- a/hw/tpm/tpm_emulator.c +++ b/hw/tpm/tpm_emulator.c @@ -72,6 +72,9 @@ typedef struct TPMEmulator { Error *migration_blocker; QemuMutex mutex; + + unsigned int established_flag:1; + unsigned int established_flag_cached:1; } TPMEmulator; @@ -349,16 +352,22 @@ 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, 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); - return (est.u.resp.bit != 0); + tpm_emu->established_flag_cached = 1; + tpm_emu->established_flag = (est.u.resp.bit != 0); + + return tpm_emu->established_flag; } static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb, @@ -389,6 +398,8 @@ static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb, return -1; } + tpm_emu->established_flag_cached = 0; + return 0; }