Re: [PATCH v3 2/7] crypto: ccp: Fix implicit SEV/SNP init and shutdown in ioctls

Kalra, Ashish
2025-01-07T18:53:45Z

On 1/6/2025 9:29 PM, Alexey Kardashevskiy wrote:
> On 4/1/25 07:00, Ashish Kalra wrote:
>> From: Ashish Kalra <ashish.kalra@amd.com>
>>
>> Modify the behavior of implicit SEV initialization in some of the
>> SEV ioctls to do both SEV initialization and shutdown and adds
>> implicit SNP initialization and shutdown to some of the SNP ioctls
>> so that the change of SEV/SNP platform initialization not being
>> done during PSP driver probe time does not break userspace tools
>> such as sevtool, etc.
>>
>> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
>> ---
>>   drivers/crypto/ccp/sev-dev.c | 149 +++++++++++++++++++++++++++++------
>>   1 file changed, 125 insertions(+), 24 deletions(-)
>>
>> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
>> index 1c1c33d3ed9a..0ec2e8191583 100644
>> --- a/drivers/crypto/ccp/sev-dev.c
>> +++ b/drivers/crypto/ccp/sev-dev.c
>> @@ -1454,7 +1454,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
>>   static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
>>   {
>>       struct sev_device *sev = psp_master->sev_data;
>> -    int rc;
>> +    bool shutdown_required = false;
>> +    int rc, ret, error;
>>         if (!writable)
>>           return -EPERM;
>> @@ -1463,19 +1464,30 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
>>           rc = __sev_platform_init_locked(&argp->error);
>>           if (rc)
>>               return rc;
>> +        shutdown_required = true;
>> +    }
>> +
>> +    rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
>> +
>> +    if (shutdown_required) {
>> +        ret = __sev_platform_shutdown_locked(&error);
>> +        if (ret)
>> +            dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, ret);
>>       }
>>   -    return __sev_do_cmd_locked(cmd, NULL, &argp->error);
>> +    return rc;
>>   }
>>     static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
>>   {
>>       struct sev_device *sev = psp_master->sev_data;
>>       struct sev_user_data_pek_csr input;
>> +    bool shutdown_required = false;
>>       struct sev_data_pek_csr data;
>>       void __user *input_address;
>> +    int ret, rc, error;
>>       void *blob = NULL;
>> -    int ret;
>>         if (!writable)
>>           return -EPERM;
>> @@ -1506,6 +1518,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
>>           ret = __sev_platform_init_locked(&argp->error);
>>           if (ret)
>>               goto e_free_blob;
>> +        shutdown_required = true;
>>       }
>>         ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);
>> @@ -1524,6 +1537,13 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
>>       }
>>     e_free_blob:
>> +    if (shutdown_required) {
>> +        rc = __sev_platform_shutdown_locked(&error);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>>       kfree(blob);
>>       return ret;
>>   }
>> @@ -1739,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
>>       struct sev_device *sev = psp_master->sev_data;
>>       struct sev_user_data_pek_cert_import input;
>>       struct sev_data_pek_cert_import data;
>> +    bool shutdown_required = false;
>>       void *pek_blob, *oca_blob;
>> -    int ret;
>> +    int ret, rc, error;
>>         if (!writable)
>>           return -EPERM;
>> @@ -1772,11 +1793,19 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
>>           ret = __sev_platform_init_locked(&argp->error);
>>           if (ret)
>>               goto e_free_oca;
>> +        shutdown_required = true;
>>       }
>>         ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
>>     e_free_oca:
>> +    if (shutdown_required) {
>> +        rc = __sev_platform_shutdown_locked(&error);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>>       kfree(oca_blob);
>>   e_free_pek:
>>       kfree(pek_blob);
>> @@ -1893,17 +1922,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>>       struct sev_data_pdh_cert_export data;
>>       void __user *input_cert_chain_address;
>>       void __user *input_pdh_cert_address;
>> -    int ret;
>> -
>> -    /* If platform is not in INIT state then transition it to INIT. */
>> -    if (sev->state != SEV_STATE_INIT) {
>> -        if (!writable)
>> -            return -EPERM;
>> -
>> -        ret = __sev_platform_init_locked(&argp->error);
>> -        if (ret)
>> -            return ret;
>> -    }
>> +    bool shutdown_required = false;
>> +    int ret, rc, error;
>>         if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
>>           return -EFAULT;
>> @@ -1944,6 +1964,16 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>>       data.cert_chain_len = input.cert_chain_len;
>>     cmd:
>> +    /* If platform is not in INIT state then transition it to INIT. */
>> +    if (sev->state != SEV_STATE_INIT) {
>> +        if (!writable)
>> +            return -EPERM;
>
> same comment as in v2:
>
> goto e_free_cert, not return, otherwise leaks memory.
>
>
>
>> +        ret = __sev_platform_init_locked(&argp->error);
>> +        if (ret)
>> +            goto e_free_cert;
>> +        shutdown_required = true;
>> +    }
>> +
>>       ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
>>         /* If we query the length, FW responded with expected data. */
>> @@ -1970,6 +2000,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>>       }
>>     e_free_cert:
>> +    if (shutdown_required) {
>> +        rc = __sev_platform_shutdown_locked(&error);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>>       kfree(cert_blob);
>>   e_free_pdh:
>>       kfree(pdh_blob);
>> @@ -1979,12 +2016,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>>   static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>>   {
>>       struct sev_device *sev = psp_master->sev_data;
>> +    bool shutdown_required = false;
>>       struct sev_data_snp_addr buf;
>>       struct page *status_page;
>> +    int ret, rc, error;
>>       void *data;
>> -    int ret;
>>   -    if (!sev->snp_initialized || !argp->data)
>> +    if (!argp->data)
>>           return -EINVAL;
>>         status_page = alloc_page(GFP_KERNEL_ACCOUNT);
>> @@ -1993,6 +2031,13 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>>         data = page_address(status_page);
>>   +    if (!sev->snp_initialized) {
>> +        ret = __sev_snp_init_locked(&argp->error);
>> +        if (ret)
>> +            goto cleanup;
>> +        shutdown_required = true;
>> +    }
>> +
>>       /*
>>        * Firmware expects status page to be in firmware-owned state, otherwise
>>        * it will report firmware error code INVALID_PAGE_STATE (0x1A).
>> @@ -2021,6 +2066,13 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>>           ret = -EFAULT;
>>     cleanup:
>> +    if (shutdown_required) {
>> +        rc = __sev_snp_shutdown_locked(&error, false);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>>       __free_pages(status_page, 0);
>>       return ret;
>>   }
>> @@ -2029,21 +2081,38 @@ static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp)
>>   {
>>       struct sev_device *sev = psp_master->sev_data;
>>       struct sev_data_snp_commit buf;
>> +    bool shutdown_required = false;
>> +    int ret, rc, error;
>>   -    if (!sev->snp_initialized)
>> -        return -EINVAL;
>> +    if (!sev->snp_initialized) {
>> +        ret = __sev_snp_init_locked(&argp->error);
>> +        if (ret)
>> +            return ret;
>> +        shutdown_required = true;
>> +    }
>>         buf.len = sizeof(buf);
>>   -    return __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
>> +    ret = __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
>> +
>> +    if (shutdown_required) {
>> +        rc = __sev_snp_shutdown_locked(&error, false);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>> +    return ret;
>>   }
>>     static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable)
>>   {
>>       struct sev_device *sev = psp_master->sev_data;
>>       struct sev_user_data_snp_config config;
>> +    bool shutdown_required = false;
>> +    int ret, rc, error;
>>   -    if (!sev->snp_initialized || !argp->data)
>> +    if (!argp->data)
>>           return -EINVAL;
>>         if (!writable)
>> @@ -2052,17 +2121,34 @@ static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable
>>       if (copy_from_user(&config, (void __user *)argp->data, sizeof(config)))
>>           return -EFAULT;
>>   -    return __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
>> +    if (!sev->snp_initialized) {
>> +        ret = __sev_snp_init_locked(&argp->error);
>> +        if (ret)
>> +            return ret;
>> +        shutdown_required = true;
>> +    }
>> +
>> +    ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
>> +
>> +    if (shutdown_required) {
>> +        rc = __sev_snp_shutdown_locked(&error, false);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>> +    return ret;
>>   }
>>     static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
>>   {
>>       struct sev_device *sev = psp_master->sev_data;
>>       struct sev_user_data_snp_vlek_load input;
>> +    bool shutdown_required = false;
>> +    int ret, rc, error;
>>       void *blob;
>> -    int ret;
>>   -    if (!sev->snp_initialized || !argp->data)
>> +    if (!argp->data)
>>           return -EINVAL;
>>         if (!writable)
>> @@ -2081,8 +2167,23 @@ static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
>>         input.vlek_wrapped_address = __psp_pa(blob);
>>   +    if (!sev->snp_initialized) {
>> +        ret = __sev_snp_init_locked(&argp->error);
>> +        if (ret)
>> +            goto cleanup;
>> +        shutdown_required = true;
>> +    }
>> +
>>       ret = __sev_do_cmd_locked(SEV_CMD_SNP_VLEK_LOAD, &input, &argp->error);
>>   +    if (shutdown_required) {
>> +        rc = __sev_snp_shutdown_locked(&error, false);
>> +        if (rc)
>> +            dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
>> +                error, rc);
>> +    }
>> +
>
> same comment as in v2:
>
>
> It is the same template 8 (?) times, I'd declare rc and error inside the "if (shutdown_required)" scope or even drop them and error messages as __sev_snp_shutdown_locked() prints dev_err() anyway.
>
> if (shutdown_required)
>     __sev_snp_shutdown_locked(&error, false);
>
> and that's it. Thanks,

Yes, makes sense to use the dev_err() in __sev_snp_shutdown_locked() as that is the whole purpose of the first patch in this series, but will
still have to declare error as a local as we can't use argp->error here.

Thanks,
Ashish

>
>> +cleanup:
>>       kfree(blob);
>>         return ret;
>