On 3/7/25 15:39, Kalra, Ashish wrote:
> On 3/7/2025 3:29 PM, Tom Lendacky wrote:
>> On 3/7/25 15:06, Kalra, Ashish wrote:
>>> On 3/7/2025 2:57 PM, Tom Lendacky wrote:
>>>> On 3/7/25 14:54, Tom Lendacky wrote:
>>>>> On 3/6/25 17:09, Ashish Kalra wrote:
>>>>>> From: Ashish Kalra <ashish.kalra@xxxxxxx>
>>>>>>
>>>>>> If SNP host support (SYSCFG.SNPEn) is set, then RMP table must be
>>>>>
>>>>> s/RMP/the RMP/
>>>>>
>>>>>> initialized up before calling SEV INIT.
>>>>>
>>>>> s/up//
>>>>>
>>>>>>
>>>>>> In other words, if SNP_INIT(_EX) is not issued or fails then
>>>>>> SEV INIT will fail once SNP host support (SYSCFG.SNPEn) is enabled.
>>>>>
>>>>> s/once/if/
>>>>>
>>>>>>
>>>>>> Fixes: 1ca5614b84eed ("crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP")
>>>>>> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
>>>>>> ---
>>>>>> drivers/crypto/ccp/sev-dev.c | 7 ++-----
>>>>>> 1 file changed, 2 insertions(+), 5 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
>>>>>> index 2e87ca0e292a..a0e3de94704e 100644
>>>>>> --- a/drivers/crypto/ccp/sev-dev.c
>>>>>> +++ b/drivers/crypto/ccp/sev-dev.c
>>>>>> @@ -1112,7 +1112,7 @@ static int __sev_snp_init_locked(int *error)
>>>>>> if (!sev_version_greater_or_equal(SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR)) {
>>>>>> dev_dbg(sev->dev, "SEV-SNP support requires firmware version >= %d:%d\n",
>>>>>> SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR);
>>>>>> - return 0;
>>>>>> + return -EOPNOTSUPP;
>>>>>> }
>>>>>>
>>>>>> /* SNP_INIT requires MSR_VM_HSAVE_PA to be cleared on all CPUs. */
>>>>>> @@ -1325,12 +1325,9 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
>>>>>> */
>>>>>> rc = __sev_snp_init_locked(&args->error);
>>>>>> if (rc && rc != -ENODEV) {
>>>>>
>>>>> Can we get ride of this extra -ENODEV check? It can only be returned
>>>>> because of the same check that is made earlier in this function so it
>>>>> doesn't really serve any purpose from what I can tell.
>>>>>
>>>>> Just make this "if (rc) {"
>>>>
>>>> My bad... -ENODEV is returned if cc_platform_has(CC_ATTR_HOST_SEV_SNP) is
>>>> false, never mind.
>>>
>>> Yes, that's what i was going to reply with ... we want to continue with
>>> SEV INIT if SNP host support is not enabled.
>>
>> Although we could get rid of that awkward if statement by doing...
>>
>> if (cc_platform_has(CC_ATTR_HOST_SEV_SNP)) {
>> rc = __sev_snp_init_locked(&args->error);
>> if (rc) {
>> dev_err(sev->dev, ...
>> return rc;
>> }
>> }
>>
>> And deleting the cc_platform_has() check from __sev_snp_init_locked().
>
> We probably have to keep the cc_platform_has() check in
> __sev_snp_init_locked() for the implicit SNP INIT being issued
> for various SNP specific ioctl's (via snp_move_to_init_state()).
Oh, yeah, the very next patch calls into __sev_snp_init_locked() now.
Thanks,
Tom
>
> Thanks,
> Ashish
>
>>>>>
>>>>>> - /*
>>>>>> - * Don't abort the probe if SNP INIT failed,
>>>>>> - * continue to initialize the legacy SEV firmware.
>>>>>> - */
>>>>>> dev_err(sev->dev, "SEV-SNP: failed to INIT rc %d, error %#x\n",
>>>>>> rc, args->error);
>>>>>> + return rc;
>>>>>> }
>>>>>>
>>>>>> /* Defer legacy SEV/SEV-ES support if allowed by caller/module. */
>>>
>
