diff options
author | Stefan Berger <stefanb@linux.vnet.ibm.com> | 2017-11-08 15:30:18 -0500 |
---|---|---|
committer | Stefan Berger <stefanb@linux.vnet.ibm.com> | 2017-12-22 09:01:09 -0500 |
commit | 0b4c7c65f882fac328f2c97398f06f16fe6d3f12 (patch) | |
tree | 179f0a59462463928e77bf9367874777bbaacb92 /hw | |
parent | 281f327487c9c9b1599f93c589a408bbf4a651b8 (diff) |
tpm_emulator: Add a caching layer for the TPM Established flag
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 <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r-- | hw/tpm/tpm_emulator.c | 17 |
1 files 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); + + 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, @@ -389,6 +398,8 @@ static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb, return -1; } + tpm_emu->established_flag_cached = 0; + return 0; } |