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SubjectRe: [PATCH] crypto: ccp - Consolidate sev INIT logic
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On 10/12/21 7:34 AM, Peter Gonda wrote:
> On Fri, Oct 8, 2021 at 9:52 AM Brijesh Singh <brijesh.singh@amd.com> wrote:
>>
>> On 10/5/21 12:52 PM, Peter Gonda wrote:
>>> +static int sev_init_if_required(int cmd_id, bool writable,
>>> + struct sev_issue_cmd *argp)
>>> +{
>>> + struct sev_device *sev = psp_master->sev_data;
>>> +
>>> + lockdep_assert_held(&sev_cmd_mutex);
>>> +
>>> + if (!writable)
>>> + return -EPERM;
>>> +
>>> + if (cmd_id == SEV_FACTORY_RESET || cmd_id == SEV_PLATFORM_STATUS ||
>>> + cmd_id == SEV_GET_ID || cmd_id == SEV_GET_ID2)
>>> + return 0;
>>> +
>>> + if (sev->state == SEV_STATE_UNINIT)
>>> + return __sev_platform_init_locked(&argp->error);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
>>> {
>>> void __user *argp = (void __user *)arg;
>>> @@ -840,8 +825,11 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
>>>
>>> mutex_lock(&sev_cmd_mutex);
>>>
>>> - switch (input.cmd) {
>>> + ret = sev_init_if_required(input.cmd, writable, &input);
>>> + if (ret)
>>> + goto copy_out;
>> We need to call this function only for the SEV commands (i.e input.cmd
>>> =0 && input.cmd <= SEV_GET_ID2). Otherwise a invalid command may
>> trigger SEV_INIT. e.g below sequence:
>>
>> 1) SEV_FACTORY_RESET // this will transition the fw to UNINIT state.
>>
>> 2) <INVALID_CMD_ID> // since fw was in uninit this invalid command
>> will initialize the fw and then later switch will fail.
> Good catch, I took Marc's suggested approach for a V2. Does that sound
> reasonable?

Yes, that works.

thanks


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