* [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag
@ 2017-11-08 20:37 Stefan Berger
2017-11-09 12:07 ` Marc-André Lureau
2017-11-13 17:13 ` Stefan Berger
0 siblings, 2 replies; 4+ messages in thread
From: Stefan Berger @ 2017-11-08 20:37 UTC (permalink / raw)
To: qemu-devel, marcandre.lureau; +Cc: amarnath.valluri, 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 <stefanb@linux.vnet.ibm.com>
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag
2017-11-08 20:37 [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag Stefan Berger
@ 2017-11-09 12:07 ` Marc-André Lureau
2017-11-09 14:03 ` Stefan Berger
2017-11-13 17:13 ` Stefan Berger
1 sibling, 1 reply; 4+ messages in thread
From: Marc-André Lureau @ 2017-11-09 12:07 UTC (permalink / raw)
To: Stefan Berger; +Cc: QEMU, Amarnath Valluri
Hi
On Wed, Nov 8, 2017 at 9:37 PM, Stefan Berger
<stefanb@linux.vnet.ibm.com> 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 <stefanb@linux.vnet.ibm.com>
>
> v1->v2:
> - move the caching to the backend layer since detecting the
> TPM 1.2 TSC_ResetEstablishmentBit() command is easier to do
> here.
What about the HASH_START? Is this not supported by qemu TIS? Is the
function gone or done differently with TPM2 or CRB?
> ---
> 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
>
>
--
Marc-André Lureau
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag
2017-11-09 12:07 ` Marc-André Lureau
@ 2017-11-09 14:03 ` Stefan Berger
0 siblings, 0 replies; 4+ messages in thread
From: Stefan Berger @ 2017-11-09 14:03 UTC (permalink / raw)
To: Marc-André Lureau; +Cc: Amarnath Valluri, QEMU
On 11/09/2017 07:07 AM, Marc-André Lureau wrote:
> Hi
>
> On Wed, Nov 8, 2017 at 9:37 PM, Stefan Berger
> <stefanb@linux.vnet.ibm.com> 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 <stefanb@linux.vnet.ibm.com>
>>
>> v1->v2:
>> - move the caching to the backend layer since detecting the
>> TPM 1.2 TSC_ResetEstablishmentBit() command is easier to do
>> here.
> What about the HASH_START? Is this not supported by qemu TIS? Is the
> function gone or done differently with TPM2 or CRB?
Afaik, HASH_START would need emulation of CPU instructions to initiate
it. Reading this flag from the device is there primarily for
completeness reasons.
Stefan
>
>> ---
>> 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
>>
>>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag
2017-11-08 20:37 [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag Stefan Berger
2017-11-09 12:07 ` Marc-André Lureau
@ 2017-11-13 17:13 ` Stefan Berger
1 sibling, 0 replies; 4+ messages in thread
From: Stefan Berger @ 2017-11-13 17:13 UTC (permalink / raw)
To: qemu-devel, marcandre.lureau; +Cc: amarnath.valluri
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 <stefanb@linux.vnet.ibm.com>
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;
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-11-13 17:13 UTC | newest]
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2017-11-08 20:37 [Qemu-devel] [PATCH v2] tpm_emulator: Add a caching layer for the TPM Established flag Stefan Berger
2017-11-09 12:07 ` Marc-André Lureau
2017-11-09 14:03 ` Stefan Berger
2017-11-13 17:13 ` Stefan Berger
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