| Message ID | 20230220183847.59159-28-michael.roth@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support | expand |
On Mon, 20 Feb 2023 12:38:18 -0600 Michael Roth <michael.roth@amd.com> wrote: > From: Brijesh Singh <brijesh.singh@amd.com> > > The SEV-SNP firmware provides the SNP_CONFIG command used to set the > system-wide configuration value for SNP guests. The information includes > the TCB version string to be reported in guest attestation reports. > > Version 2 of the GHCB specification adds an NAE (SNP extended guest > request) that a guest can use to query the reports that include additional > certificates. > > In both cases, userspace provided additional data is included in the > attestation reports. The userspace will use the SNP_SET_EXT_CONFIG > command to give the certificate blob and the reported TCB version string > at once. Note that the specification defines certificate blob with a > specific GUID format; the userspace is responsible for building the > proper certificate blob. The ioctl treats it an opaque blob. > > While it is not defined in the spec, but let's add SNP_GET_EXT_CONFIG > command that can be used to obtain the data programmed through the > SNP_SET_EXT_CONFIG. > > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > Signed-off-by: Michael Roth <michael.roth@amd.com> > --- > Documentation/virt/coco/sev-guest.rst | 27 ++++++ > drivers/crypto/ccp/sev-dev.c | 123 ++++++++++++++++++++++++++ > drivers/crypto/ccp/sev-dev.h | 4 + > include/uapi/linux/psp-sev.h | 17 ++++ > 4 files changed, 171 insertions(+) > > diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst > index 11ea67c944df..6cad4226c348 100644 > --- a/Documentation/virt/coco/sev-guest.rst > +++ b/Documentation/virt/coco/sev-guest.rst > @@ -145,6 +145,33 @@ The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The > status includes API major, minor version and more. See the SEV-SNP > specification for further details. > > +2.5 SNP_SET_EXT_CONFIG > +---------------------- > +:Technology: sev-snp > +:Type: hypervisor ioctl cmd > +:Parameters (in): struct sev_data_snp_ext_config > +:Returns (out): 0 on success, -negative on error > + > +The SNP_SET_EXT_CONFIG is used to set the system-wide configuration such as > +reported TCB version in the attestation report. The command is similar to > +SNP_CONFIG command defined in the SEV-SNP spec. The main difference is the > +command also accepts an additional certificate blob defined in the GHCB > +specification. > + > +If the certs_address is zero, then the previous certificate blob will deleted. > +For more information on the certificate blob layout, see the GHCB spec > +(extended guest request message). > + > +2.6 SNP_GET_EXT_CONFIG > +---------------------- > +:Technology: sev-snp > +:Type: hypervisor ioctl cmd > +:Parameters (in): struct sev_data_snp_ext_config > +:Returns (out): 0 on success, -negative on error > + > +The SNP_GET_EXT_CONFIG is used to query the system-wide configuration set > +through the SNP_SET_EXT_CONFIG. > + > 3. SEV-SNP CPUID Enforcement > ============================ > > diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c > index 65e13a562f3b..b56b00ca2cd4 100644 > --- a/drivers/crypto/ccp/sev-dev.c > +++ b/drivers/crypto/ccp/sev-dev.c > @@ -1481,6 +1481,10 @@ static int __sev_snp_shutdown_locked(int *error) > data.length = sizeof(data); > data.iommu_snp_shutdown = 1; > > + /* Free the memory used for caching the certificate data */ > + kfree(sev->snp_certs_data); > + sev->snp_certs_data = NULL; > + > wbinvd_on_all_cpus(); > > retry: > @@ -1793,6 +1797,118 @@ static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp) > return ret; > } > > +static int sev_ioctl_snp_get_config(struct sev_issue_cmd *argp) > +{ > + struct sev_device *sev = psp_master->sev_data; > + struct sev_user_data_ext_snp_config input; > + int ret; > + > + if (!sev->snp_initialized || !argp->data) > + return -EINVAL; > + > + memset(&input, 0, sizeof(input)); > + > + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) > + return -EFAULT; > + > + /* Copy the TCB version programmed through the SET_CONFIG to userspace */ > + if (input.config_address) { > + if (copy_to_user((void * __user)input.config_address, > + &sev->snp_config, sizeof(struct sev_user_data_snp_config))) > + return -EFAULT; > + } > + > + /* Copy the extended certs programmed through the SNP_SET_CONFIG */ > + if (input.certs_address && sev->snp_certs_data) { > + if (input.certs_len < sev->snp_certs_len) { > + /* Return the certs length to userspace */ > + input.certs_len = sev->snp_certs_len; > + > + ret = -ENOSR; > + goto e_done; > + } > + What about if input.certs_len > sev->snp_certs_len? Is it possbile for the userspace to know the length of data in the buffer? (I guess it might be able to know the certs len through the blob data, but a comment here would be nice) > + if (copy_to_user((void * __user)input.certs_address, > + sev->snp_certs_data, sev->snp_certs_len)) > + return -EFAULT; > + } > + > + ret = 0; > + > +e_done: > + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) > + ret = -EFAULT; > + > + return ret; > +} > + > +static int sev_ioctl_snp_set_config(struct sev_issue_cmd *argp, bool writable) > +{ > + struct sev_device *sev = psp_master->sev_data; > + struct sev_user_data_ext_snp_config input; > + struct sev_user_data_snp_config config; > + void *certs = NULL; > + int ret = 0; > + > + if (!sev->snp_initialized || !argp->data) > + return -EINVAL; > + > + if (!writable) > + return -EPERM; > + > + memset(&input, 0, sizeof(input)); > + > + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) > + return -EFAULT; > + > + /* Copy the certs from userspace */ > + if (input.certs_address) { > + if (!input.certs_len || !IS_ALIGNED(input.certs_len, PAGE_SIZE)) > + return -EINVAL; > + > + certs = psp_copy_user_blob(input.certs_address, input.certs_len); > + if (IS_ERR(certs)) > + return PTR_ERR(certs); > + } > + > + /* Issue the PSP command to update the TCB version using the SNP_CONFIG. */ > + if (input.config_address) { > + memset(&config, 0, sizeof(config)); > + if (copy_from_user(&config, > + (void __user *)input.config_address, sizeof(config))) { > + ret = -EFAULT; > + goto e_free; > + } > + > + ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error); > + if (ret) > + goto e_free; > + > + memcpy(&sev->snp_config, &config, sizeof(config)); > + } > + > + /* > + * If the new certs are passed then cache it else free the old certs. > + */ > + mutex_lock(&sev->snp_certs_lock); > + if (certs) { > + kfree(sev->snp_certs_data); > + sev->snp_certs_data = certs; > + sev->snp_certs_len = input.certs_len; > + } else { > + kfree(sev->snp_certs_data); > + sev->snp_certs_data = NULL; > + sev->snp_certs_len = 0; > + } > + mutex_unlock(&sev->snp_certs_lock); > + > + return 0; > + > +e_free: > + kfree(certs); > + return ret; > +} > + > static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > { > void __user *argp = (void __user *)arg; > @@ -1847,6 +1963,12 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > case SNP_PLATFORM_STATUS: > ret = sev_ioctl_snp_platform_status(&input); > break; > + case SNP_SET_EXT_CONFIG: > + ret = sev_ioctl_snp_set_config(&input, writable); > + break; > + case SNP_GET_EXT_CONFIG: > + ret = sev_ioctl_snp_get_config(&input); > + break; > default: > ret = -EINVAL; > goto out; > @@ -1962,6 +2084,7 @@ int sev_dev_init(struct psp_device *psp) > goto e_sev; > > sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE; > + mutex_init(&sev->snp_certs_lock); > > psp->sev_data = sev; > > diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h > index 19d79f9d4212..41d5353d5bab 100644 > --- a/drivers/crypto/ccp/sev-dev.h > +++ b/drivers/crypto/ccp/sev-dev.h > @@ -66,6 +66,10 @@ struct sev_device { > > bool snp_initialized; > struct snp_host_map snp_host_map[MAX_SNP_HOST_MAP_BUFS]; > + void *snp_certs_data; > + u32 snp_certs_len; > + struct mutex snp_certs_lock; > + struct sev_user_data_snp_config snp_config; > }; > > int sev_dev_init(struct psp_device *psp); > diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h > index 5adfaea7df97..c20d37586d21 100644 > --- a/include/uapi/linux/psp-sev.h > +++ b/include/uapi/linux/psp-sev.h > @@ -29,6 +29,8 @@ enum { > SEV_GET_ID, /* This command is deprecated, use SEV_GET_ID2 */ > SEV_GET_ID2, > SNP_PLATFORM_STATUS, > + SNP_SET_EXT_CONFIG, > + SNP_GET_EXT_CONFIG, > > SEV_MAX, > }; > @@ -192,6 +194,21 @@ struct sev_user_data_snp_config { > __u8 rsvd1[52]; > } __packed; > > +/** > + * struct sev_data_snp_ext_config - system wide configuration value for SNP. > + * > + * @config_address: address of the struct sev_user_data_snp_config or 0 when > + * reported_tcb does not need to be updated. > + * @certs_address: address of extended guest request certificate chain or > + * 0 when previous certificate should be removed on SNP_SET_EXT_CONFIG. > + * @certs_len: length of the certs > + */ > +struct sev_user_data_ext_snp_config { > + __u64 config_address; /* In */ > + __u64 certs_address; /* In */ > + __u32 certs_len; /* In */ > +}; > + > /** > * struct sev_issue_cmd - SEV ioctl parameters > *
On 2/22/23 06:32, Zhi Wang wrote: > On Mon, 20 Feb 2023 12:38:18 -0600 > Michael Roth <michael.roth@amd.com> wrote: > >> From: Brijesh Singh <brijesh.singh@amd.com> >> >> The SEV-SNP firmware provides the SNP_CONFIG command used to set the >> system-wide configuration value for SNP guests. The information includes >> the TCB version string to be reported in guest attestation reports. >> >> Version 2 of the GHCB specification adds an NAE (SNP extended guest >> request) that a guest can use to query the reports that include additional >> certificates. >> >> In both cases, userspace provided additional data is included in the >> attestation reports. The userspace will use the SNP_SET_EXT_CONFIG >> command to give the certificate blob and the reported TCB version string >> at once. Note that the specification defines certificate blob with a >> specific GUID format; the userspace is responsible for building the >> proper certificate blob. The ioctl treats it an opaque blob. >> >> While it is not defined in the spec, but let's add SNP_GET_EXT_CONFIG >> command that can be used to obtain the data programmed through the >> SNP_SET_EXT_CONFIG. >> >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> >> Signed-off-by: Michael Roth <michael.roth@amd.com> >> --- >> Documentation/virt/coco/sev-guest.rst | 27 ++++++ >> drivers/crypto/ccp/sev-dev.c | 123 ++++++++++++++++++++++++++ >> drivers/crypto/ccp/sev-dev.h | 4 + >> include/uapi/linux/psp-sev.h | 17 ++++ >> 4 files changed, 171 insertions(+) >> >> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c >> index 65e13a562f3b..b56b00ca2cd4 100644 >> --- a/drivers/crypto/ccp/sev-dev.c >> +++ b/drivers/crypto/ccp/sev-dev.c >> @@ -1481,6 +1481,10 @@ static int __sev_snp_shutdown_locked(int *error) >> data.length = sizeof(data); >> data.iommu_snp_shutdown = 1; >> >> + /* Free the memory used for caching the certificate data */ >> + kfree(sev->snp_certs_data); >> + sev->snp_certs_data = NULL; >> + >> wbinvd_on_all_cpus(); >> >> retry: >> @@ -1793,6 +1797,118 @@ static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp) >> return ret; >> } >> >> +static int sev_ioctl_snp_get_config(struct sev_issue_cmd *argp) >> +{ >> + struct sev_device *sev = psp_master->sev_data; >> + struct sev_user_data_ext_snp_config input; >> + int ret; >> + >> + if (!sev->snp_initialized || !argp->data) >> + return -EINVAL; >> + >> + memset(&input, 0, sizeof(input)); >> + >> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) >> + return -EFAULT; >> + >> + /* Copy the TCB version programmed through the SET_CONFIG to userspace */ >> + if (input.config_address) { >> + if (copy_to_user((void * __user)input.config_address, >> + &sev->snp_config, sizeof(struct sev_user_data_snp_config))) >> + return -EFAULT; >> + } >> + >> + /* Copy the extended certs programmed through the SNP_SET_CONFIG */ >> + if (input.certs_address && sev->snp_certs_data) { >> + if (input.certs_len < sev->snp_certs_len) { >> + /* Return the certs length to userspace */ >> + input.certs_len = sev->snp_certs_len; >> + >> + ret = -ENOSR; We should be consistent with the other SEV ioctls that return required lengths and return -EIO here instead -ENOSR. Thanks, Tom >> + goto e_done; >> + } >> + > > What about if input.certs_len > sev->snp_certs_len? Is it possbile for the > userspace to know the length of data in the buffer? (I guess it might be able > to know the certs len through the blob data, but a comment here would be nice) > >> + if (copy_to_user((void * __user)input.certs_address, >> + sev->snp_certs_data, sev->snp_certs_len)) >> + return -EFAULT; >> + } >> + >> + ret = 0; >> + >> +e_done: >> + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) >> + ret = -EFAULT; >> + >> + return ret; >> +}
On 2/22/2023 6:32 AM, Zhi Wang wrote: > On Mon, 20 Feb 2023 12:38:18 -0600 > Michael Roth <michael.roth@amd.com> wrote: > >> From: Brijesh Singh <brijesh.singh@amd.com> >> >> The SEV-SNP firmware provides the SNP_CONFIG command used to set the >> system-wide configuration value for SNP guests. The information includes >> the TCB version string to be reported in guest attestation reports. >> >> Version 2 of the GHCB specification adds an NAE (SNP extended guest >> request) that a guest can use to query the reports that include additional >> certificates. >> >> In both cases, userspace provided additional data is included in the >> attestation reports. The userspace will use the SNP_SET_EXT_CONFIG >> command to give the certificate blob and the reported TCB version string >> at once. Note that the specification defines certificate blob with a >> specific GUID format; the userspace is responsible for building the >> proper certificate blob. The ioctl treats it an opaque blob. >> >> While it is not defined in the spec, but let's add SNP_GET_EXT_CONFIG >> command that can be used to obtain the data programmed through the >> SNP_SET_EXT_CONFIG. >> >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> >> Signed-off-by: Michael Roth <michael.roth@amd.com> >> --- >> Documentation/virt/coco/sev-guest.rst | 27 ++++++ >> drivers/crypto/ccp/sev-dev.c | 123 ++++++++++++++++++++++++++ >> drivers/crypto/ccp/sev-dev.h | 4 + >> include/uapi/linux/psp-sev.h | 17 ++++ >> 4 files changed, 171 insertions(+) >> >> diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst >> index 11ea67c944df..6cad4226c348 100644 >> --- a/Documentation/virt/coco/sev-guest.rst >> +++ b/Documentation/virt/coco/sev-guest.rst >> @@ -145,6 +145,33 @@ The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The >> status includes API major, minor version and more. See the SEV-SNP >> specification for further details. >> >> +2.5 SNP_SET_EXT_CONFIG >> +---------------------- >> +:Technology: sev-snp >> +:Type: hypervisor ioctl cmd >> +:Parameters (in): struct sev_data_snp_ext_config >> +:Returns (out): 0 on success, -negative on error >> + >> +The SNP_SET_EXT_CONFIG is used to set the system-wide configuration such as >> +reported TCB version in the attestation report. The command is similar to >> +SNP_CONFIG command defined in the SEV-SNP spec. The main difference is the >> +command also accepts an additional certificate blob defined in the GHCB >> +specification. >> + >> +If the certs_address is zero, then the previous certificate blob will deleted. >> +For more information on the certificate blob layout, see the GHCB spec >> +(extended guest request message). >> + >> +2.6 SNP_GET_EXT_CONFIG >> +---------------------- >> +:Technology: sev-snp >> +:Type: hypervisor ioctl cmd >> +:Parameters (in): struct sev_data_snp_ext_config >> +:Returns (out): 0 on success, -negative on error >> + >> +The SNP_GET_EXT_CONFIG is used to query the system-wide configuration set >> +through the SNP_SET_EXT_CONFIG. >> + >> 3. SEV-SNP CPUID Enforcement >> ============================ >> >> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c >> index 65e13a562f3b..b56b00ca2cd4 100644 >> --- a/drivers/crypto/ccp/sev-dev.c >> +++ b/drivers/crypto/ccp/sev-dev.c >> @@ -1481,6 +1481,10 @@ static int __sev_snp_shutdown_locked(int *error) >> data.length = sizeof(data); >> data.iommu_snp_shutdown = 1; >> >> + /* Free the memory used for caching the certificate data */ >> + kfree(sev->snp_certs_data); >> + sev->snp_certs_data = NULL; >> + >> wbinvd_on_all_cpus(); >> >> retry: >> @@ -1793,6 +1797,118 @@ static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp) >> return ret; >> } >> >> +static int sev_ioctl_snp_get_config(struct sev_issue_cmd *argp) >> +{ >> + struct sev_device *sev = psp_master->sev_data; >> + struct sev_user_data_ext_snp_config input; >> + int ret; >> + >> + if (!sev->snp_initialized || !argp->data) >> + return -EINVAL; >> + >> + memset(&input, 0, sizeof(input)); >> + >> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) >> + return -EFAULT; >> + >> + /* Copy the TCB version programmed through the SET_CONFIG to userspace */ >> + if (input.config_address) { >> + if (copy_to_user((void * __user)input.config_address, >> + &sev->snp_config, sizeof(struct sev_user_data_snp_config))) >> + return -EFAULT; >> + } >> + >> + /* Copy the extended certs programmed through the SNP_SET_CONFIG */ >> + if (input.certs_address && sev->snp_certs_data) { >> + if (input.certs_len < sev->snp_certs_len) { >> + /* Return the certs length to userspace */ >> + input.certs_len = sev->snp_certs_len; >> + >> + ret = -ENOSR; >> + goto e_done; >> + } >> + > > What about if input.certs_len > sev->snp_certs_len? Is it possbile for the > userspace to know the length of data in the buffer? (I guess it might be able > to know the certs len through the blob data, but a comment here would be nice) > If userspace provides an input buffer/length smaller then snp_certs_len, then the above returns the "required" certs length back to userspace. And what is the issue if input.certs_len > sev->snp_certs_len, the buffer returned back to userspace is sev->snp_certs_len as below. Thanks, Ashish >> + if (copy_to_user((void * __user)input.certs_address, >> + sev->snp_certs_data, sev->snp_certs_len)) >> + return -EFAULT; >> + } >> + >> + ret = 0; >> + >> +e_done: >> + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) >> + ret = -EFAULT; >> + >> + return ret; >> +} >> + >> +static int sev_ioctl_snp_set_config(struct sev_issue_cmd *argp, bool writable) >> +{ >> + struct sev_device *sev = psp_master->sev_data; >> + struct sev_user_data_ext_snp_config input; >> + struct sev_user_data_snp_config config; >> + void *certs = NULL; >> + int ret = 0; >> + >> + if (!sev->snp_initialized || !argp->data) >> + return -EINVAL; >> + >> + if (!writable) >> + return -EPERM; >> + >> + memset(&input, 0, sizeof(input)); >> + >> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) >> + return -EFAULT; >> + >> + /* Copy the certs from userspace */ >> + if (input.certs_address) { >> + if (!input.certs_len || !IS_ALIGNED(input.certs_len, PAGE_SIZE)) >> + return -EINVAL; >> + >> + certs = psp_copy_user_blob(input.certs_address, input.certs_len); >> + if (IS_ERR(certs)) >> + return PTR_ERR(certs); >> + } >> + >> + /* Issue the PSP command to update the TCB version using the SNP_CONFIG. */ >> + if (input.config_address) { >> + memset(&config, 0, sizeof(config)); >> + if (copy_from_user(&config, >> + (void __user *)input.config_address, sizeof(config))) { >> + ret = -EFAULT; >> + goto e_free; >> + } >> + >> + ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error); >> + if (ret) >> + goto e_free; >> + >> + memcpy(&sev->snp_config, &config, sizeof(config)); >> + } >> + >> + /* >> + * If the new certs are passed then cache it else free the old certs. >> + */ >> + mutex_lock(&sev->snp_certs_lock); >> + if (certs) { >> + kfree(sev->snp_certs_data); >> + sev->snp_certs_data = certs; >> + sev->snp_certs_len = input.certs_len; >> + } else { >> + kfree(sev->snp_certs_data); >> + sev->snp_certs_data = NULL; >> + sev->snp_certs_len = 0; >> + } >> + mutex_unlock(&sev->snp_certs_lock); >> + >> + return 0; >> + >> +e_free: >> + kfree(certs); >> + return ret; >> +} >> + >> static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) >> { >> void __user *argp = (void __user *)arg; >> @@ -1847,6 +1963,12 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) >> case SNP_PLATFORM_STATUS: >> ret = sev_ioctl_snp_platform_status(&input); >> break; >> + case SNP_SET_EXT_CONFIG: >> + ret = sev_ioctl_snp_set_config(&input, writable); >> + break; >> + case SNP_GET_EXT_CONFIG: >> + ret = sev_ioctl_snp_get_config(&input); >> + break; >> default: >> ret = -EINVAL; >> goto out; >> @@ -1962,6 +2084,7 @@ int sev_dev_init(struct psp_device *psp) >> goto e_sev; >> >> sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE; >> + mutex_init(&sev->snp_certs_lock); >> >> psp->sev_data = sev; >> >> diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h >> index 19d79f9d4212..41d5353d5bab 100644 >> --- a/drivers/crypto/ccp/sev-dev.h >> +++ b/drivers/crypto/ccp/sev-dev.h >> @@ -66,6 +66,10 @@ struct sev_device { >> >> bool snp_initialized; >> struct snp_host_map snp_host_map[MAX_SNP_HOST_MAP_BUFS]; >> + void *snp_certs_data; >> + u32 snp_certs_len; >> + struct mutex snp_certs_lock; >> + struct sev_user_data_snp_config snp_config; >> }; >> >> int sev_dev_init(struct psp_device *psp); >> diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h >> index 5adfaea7df97..c20d37586d21 100644 >> --- a/include/uapi/linux/psp-sev.h >> +++ b/include/uapi/linux/psp-sev.h >> @@ -29,6 +29,8 @@ enum { >> SEV_GET_ID, /* This command is deprecated, use SEV_GET_ID2 */ >> SEV_GET_ID2, >> SNP_PLATFORM_STATUS, >> + SNP_SET_EXT_CONFIG, >> + SNP_GET_EXT_CONFIG, >> >> SEV_MAX, >> }; >> @@ -192,6 +194,21 @@ struct sev_user_data_snp_config { >> __u8 rsvd1[52]; >> } __packed; >> >> +/** >> + * struct sev_data_snp_ext_config - system wide configuration value for SNP. >> + * >> + * @config_address: address of the struct sev_user_data_snp_config or 0 when >> + * reported_tcb does not need to be updated. >> + * @certs_address: address of extended guest request certificate chain or >> + * 0 when previous certificate should be removed on SNP_SET_EXT_CONFIG. >> + * @certs_len: length of the certs >> + */ >> +struct sev_user_data_ext_snp_config { >> + __u64 config_address; /* In */ >> + __u64 certs_address; /* In */ >> + __u32 certs_len; /* In */ >> +}; >> + >> /** >> * struct sev_issue_cmd - SEV ioctl parameters >> * >
On Wed, 22 Feb 2023 16:43:54 -0600 "Kalra, Ashish" <ashish.kalra@amd.com> wrote: > On 2/22/2023 6:32 AM, Zhi Wang wrote: > > On Mon, 20 Feb 2023 12:38:18 -0600 > > Michael Roth <michael.roth@amd.com> wrote: > > > >> From: Brijesh Singh <brijesh.singh@amd.com> > >> > >> The SEV-SNP firmware provides the SNP_CONFIG command used to set the > >> system-wide configuration value for SNP guests. The information includes > >> the TCB version string to be reported in guest attestation reports. > >> > >> Version 2 of the GHCB specification adds an NAE (SNP extended guest > >> request) that a guest can use to query the reports that include additional > >> certificates. > >> > >> In both cases, userspace provided additional data is included in the > >> attestation reports. The userspace will use the SNP_SET_EXT_CONFIG > >> command to give the certificate blob and the reported TCB version string > >> at once. Note that the specification defines certificate blob with a > >> specific GUID format; the userspace is responsible for building the > >> proper certificate blob. The ioctl treats it an opaque blob. > >> > >> While it is not defined in the spec, but let's add SNP_GET_EXT_CONFIG > >> command that can be used to obtain the data programmed through the > >> SNP_SET_EXT_CONFIG. > >> > >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > >> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > >> Signed-off-by: Michael Roth <michael.roth@amd.com> > >> --- > >> Documentation/virt/coco/sev-guest.rst | 27 ++++++ > >> drivers/crypto/ccp/sev-dev.c | 123 ++++++++++++++++++++++++++ > >> drivers/crypto/ccp/sev-dev.h | 4 + > >> include/uapi/linux/psp-sev.h | 17 ++++ > >> 4 files changed, 171 insertions(+) > >> > >> diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst > >> index 11ea67c944df..6cad4226c348 100644 > >> --- a/Documentation/virt/coco/sev-guest.rst > >> +++ b/Documentation/virt/coco/sev-guest.rst > >> @@ -145,6 +145,33 @@ The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The > >> status includes API major, minor version and more. See the SEV-SNP > >> specification for further details. > >> > >> +2.5 SNP_SET_EXT_CONFIG > >> +---------------------- > >> +:Technology: sev-snp > >> +:Type: hypervisor ioctl cmd > >> +:Parameters (in): struct sev_data_snp_ext_config > >> +:Returns (out): 0 on success, -negative on error > >> + > >> +The SNP_SET_EXT_CONFIG is used to set the system-wide configuration such as > >> +reported TCB version in the attestation report. The command is similar to > >> +SNP_CONFIG command defined in the SEV-SNP spec. The main difference is the > >> +command also accepts an additional certificate blob defined in the GHCB > >> +specification. > >> + > >> +If the certs_address is zero, then the previous certificate blob will deleted. > >> +For more information on the certificate blob layout, see the GHCB spec > >> +(extended guest request message). > >> + > >> +2.6 SNP_GET_EXT_CONFIG > >> +---------------------- > >> +:Technology: sev-snp > >> +:Type: hypervisor ioctl cmd > >> +:Parameters (in): struct sev_data_snp_ext_config > >> +:Returns (out): 0 on success, -negative on error > >> + > >> +The SNP_GET_EXT_CONFIG is used to query the system-wide configuration set > >> +through the SNP_SET_EXT_CONFIG. > >> + > >> 3. SEV-SNP CPUID Enforcement > >> ============================ > >> > >> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c > >> index 65e13a562f3b..b56b00ca2cd4 100644 > >> --- a/drivers/crypto/ccp/sev-dev.c > >> +++ b/drivers/crypto/ccp/sev-dev.c > >> @@ -1481,6 +1481,10 @@ static int __sev_snp_shutdown_locked(int *error) > >> data.length = sizeof(data); > >> data.iommu_snp_shutdown = 1; > >> > >> + /* Free the memory used for caching the certificate data */ > >> + kfree(sev->snp_certs_data); > >> + sev->snp_certs_data = NULL; > >> + > >> wbinvd_on_all_cpus(); > >> > >> retry: > >> @@ -1793,6 +1797,118 @@ static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp) > >> return ret; > >> } > >> > >> +static int sev_ioctl_snp_get_config(struct sev_issue_cmd *argp) > >> +{ > >> + struct sev_device *sev = psp_master->sev_data; > >> + struct sev_user_data_ext_snp_config input; > >> + int ret; > >> + > >> + if (!sev->snp_initialized || !argp->data) > >> + return -EINVAL; > >> + > >> + memset(&input, 0, sizeof(input)); > >> + > >> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) > >> + return -EFAULT; > >> + > >> + /* Copy the TCB version programmed through the SET_CONFIG to userspace */ > >> + if (input.config_address) { > >> + if (copy_to_user((void * __user)input.config_address, > >> + &sev->snp_config, sizeof(struct sev_user_data_snp_config))) > >> + return -EFAULT; > >> + } > >> + > >> + /* Copy the extended certs programmed through the SNP_SET_CONFIG */ > >> + if (input.certs_address && sev->snp_certs_data) { > >> + if (input.certs_len < sev->snp_certs_len) { > >> + /* Return the certs length to userspace */ > >> + input.certs_len = sev->snp_certs_len; > >> + > >> + ret = -ENOSR; > >> + goto e_done; > >> + } > >> + > > > > What about if input.certs_len > sev->snp_certs_len? Is it possbile for the > > userspace to know the length of data in the buffer? (I guess it might be able > > to know the certs len through the blob data, but a comment here would be nice) > > > > If userspace provides an input buffer/length smaller then snp_certs_len, > then the above returns the "required" certs length back to userspace. > > And what is the issue if input.certs_len > sev->snp_certs_len, the > buffer returned back to userspace is sev->snp_certs_len as below. > My point is: How can the userspace know the length of return data is shorter than input.certs_len when input.certs_len > sev->snp_serts_len? as the length is only returned when input.certs_len < sev->snp_certs_len. > Thanks, > Ashish > > >> + if (copy_to_user((void * __user)input.certs_address, > >> + sev->snp_certs_data, sev->snp_certs_len)) > >> + return -EFAULT; > >> + } > >> + > >> + ret = 0; > >> + > >> +e_done: > >> + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) > >> + ret = -EFAULT; > >> + > >> + return ret; > >> +} > >> + > >> +static int sev_ioctl_snp_set_config(struct sev_issue_cmd *argp, bool writable) > >> +{ > >> + struct sev_device *sev = psp_master->sev_data; > >> + struct sev_user_data_ext_snp_config input; > >> + struct sev_user_data_snp_config config; > >> + void *certs = NULL; > >> + int ret = 0; > >> + > >> + if (!sev->snp_initialized || !argp->data) > >> + return -EINVAL; > >> + > >> + if (!writable) > >> + return -EPERM; > >> + > >> + memset(&input, 0, sizeof(input)); > >> + > >> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) > >> + return -EFAULT; > >> + > >> + /* Copy the certs from userspace */ > >> + if (input.certs_address) { > >> + if (!input.certs_len || !IS_ALIGNED(input.certs_len, PAGE_SIZE)) > >> + return -EINVAL; > >> + > >> + certs = psp_copy_user_blob(input.certs_address, input.certs_len); > >> + if (IS_ERR(certs)) > >> + return PTR_ERR(certs); > >> + } > >> + > >> + /* Issue the PSP command to update the TCB version using the SNP_CONFIG. */ > >> + if (input.config_address) { > >> + memset(&config, 0, sizeof(config)); > >> + if (copy_from_user(&config, > >> + (void __user *)input.config_address, sizeof(config))) { > >> + ret = -EFAULT; > >> + goto e_free; > >> + } > >> + > >> + ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error); > >> + if (ret) > >> + goto e_free; > >> + > >> + memcpy(&sev->snp_config, &config, sizeof(config)); > >> + } > >> + > >> + /* > >> + * If the new certs are passed then cache it else free the old certs. > >> + */ > >> + mutex_lock(&sev->snp_certs_lock); > >> + if (certs) { > >> + kfree(sev->snp_certs_data); > >> + sev->snp_certs_data = certs; > >> + sev->snp_certs_len = input.certs_len; > >> + } else { > >> + kfree(sev->snp_certs_data); > >> + sev->snp_certs_data = NULL; > >> + sev->snp_certs_len = 0; > >> + } > >> + mutex_unlock(&sev->snp_certs_lock); > >> + > >> + return 0; > >> + > >> +e_free: > >> + kfree(certs); > >> + return ret; > >> +} > >> + > >> static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > >> { > >> void __user *argp = (void __user *)arg; > >> @@ -1847,6 +1963,12 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > >> case SNP_PLATFORM_STATUS: > >> ret = sev_ioctl_snp_platform_status(&input); > >> break; > >> + case SNP_SET_EXT_CONFIG: > >> + ret = sev_ioctl_snp_set_config(&input, writable); > >> + break; > >> + case SNP_GET_EXT_CONFIG: > >> + ret = sev_ioctl_snp_get_config(&input); > >> + break; > >> default: > >> ret = -EINVAL; > >> goto out; > >> @@ -1962,6 +2084,7 @@ int sev_dev_init(struct psp_device *psp) > >> goto e_sev; > >> > >> sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE; > >> + mutex_init(&sev->snp_certs_lock); > >> > >> psp->sev_data = sev; > >> > >> diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h > >> index 19d79f9d4212..41d5353d5bab 100644 > >> --- a/drivers/crypto/ccp/sev-dev.h > >> +++ b/drivers/crypto/ccp/sev-dev.h > >> @@ -66,6 +66,10 @@ struct sev_device { > >> > >> bool snp_initialized; > >> struct snp_host_map snp_host_map[MAX_SNP_HOST_MAP_BUFS]; > >> + void *snp_certs_data; > >> + u32 snp_certs_len; > >> + struct mutex snp_certs_lock; > >> + struct sev_user_data_snp_config snp_config; > >> }; > >> > >> int sev_dev_init(struct psp_device *psp); > >> diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h > >> index 5adfaea7df97..c20d37586d21 100644 > >> --- a/include/uapi/linux/psp-sev.h > >> +++ b/include/uapi/linux/psp-sev.h > >> @@ -29,6 +29,8 @@ enum { > >> SEV_GET_ID, /* This command is deprecated, use SEV_GET_ID2 */ > >> SEV_GET_ID2, > >> SNP_PLATFORM_STATUS, > >> + SNP_SET_EXT_CONFIG, > >> + SNP_GET_EXT_CONFIG, > >> > >> SEV_MAX, > >> }; > >> @@ -192,6 +194,21 @@ struct sev_user_data_snp_config { > >> __u8 rsvd1[52]; > >> } __packed; > >> > >> +/** > >> + * struct sev_data_snp_ext_config - system wide configuration value for SNP. > >> + * > >> + * @config_address: address of the struct sev_user_data_snp_config or 0 when > >> + * reported_tcb does not need to be updated. > >> + * @certs_address: address of extended guest request certificate chain or > >> + * 0 when previous certificate should be removed on SNP_SET_EXT_CONFIG. > >> + * @certs_len: length of the certs > >> + */ > >> +struct sev_user_data_ext_snp_config { > >> + __u64 config_address; /* In */ > >> + __u64 certs_address; /* In */ > >> + __u32 certs_len; /* In */ > >> +}; > >> + > >> /** > >> * struct sev_issue_cmd - SEV ioctl parameters > >> * > >
On 2/23/23 00:38, Zhi Wang wrote: > On Wed, 22 Feb 2023 16:43:54 -0600 > "Kalra, Ashish" <ashish.kalra@amd.com> wrote: > >> On 2/22/2023 6:32 AM, Zhi Wang wrote: >>> On Mon, 20 Feb 2023 12:38:18 -0600 >>> Michael Roth <michael.roth@amd.com> wrote: >>> >>>> From: Brijesh Singh <brijesh.singh@amd.com> >>>> >>>> The SEV-SNP firmware provides the SNP_CONFIG command used to set the >>>> system-wide configuration value for SNP guests. The information includes >>>> the TCB version string to be reported in guest attestation reports. >>>> >>>> Version 2 of the GHCB specification adds an NAE (SNP extended guest >>>> request) that a guest can use to query the reports that include additional >>>> certificates. >>>> >>>> In both cases, userspace provided additional data is included in the >>>> attestation reports. The userspace will use the SNP_SET_EXT_CONFIG >>>> command to give the certificate blob and the reported TCB version string >>>> at once. Note that the specification defines certificate blob with a >>>> specific GUID format; the userspace is responsible for building the >>>> proper certificate blob. The ioctl treats it an opaque blob. >>>> >>>> While it is not defined in the spec, but let's add SNP_GET_EXT_CONFIG >>>> command that can be used to obtain the data programmed through the >>>> SNP_SET_EXT_CONFIG. >>>> >>>> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >>>> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> >>>> Signed-off-by: Michael Roth <michael.roth@amd.com> >>>> --- >>>> Documentation/virt/coco/sev-guest.rst | 27 ++++++ >>>> drivers/crypto/ccp/sev-dev.c | 123 ++++++++++++++++++++++++++ >>>> drivers/crypto/ccp/sev-dev.h | 4 + >>>> include/uapi/linux/psp-sev.h | 17 ++++ >>>> 4 files changed, 171 insertions(+) >>>> >>>> diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst >>>> index 11ea67c944df..6cad4226c348 100644 >>>> --- a/Documentation/virt/coco/sev-guest.rst >>>> +++ b/Documentation/virt/coco/sev-guest.rst >>>> @@ -145,6 +145,33 @@ The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The >>>> status includes API major, minor version and more. See the SEV-SNP >>>> specification for further details. >>>> >>>> +2.5 SNP_SET_EXT_CONFIG >>>> +---------------------- >>>> +:Technology: sev-snp >>>> +:Type: hypervisor ioctl cmd >>>> +:Parameters (in): struct sev_data_snp_ext_config >>>> +:Returns (out): 0 on success, -negative on error >>>> + >>>> +The SNP_SET_EXT_CONFIG is used to set the system-wide configuration such as >>>> +reported TCB version in the attestation report. The command is similar to >>>> +SNP_CONFIG command defined in the SEV-SNP spec. The main difference is the >>>> +command also accepts an additional certificate blob defined in the GHCB >>>> +specification. >>>> + >>>> +If the certs_address is zero, then the previous certificate blob will deleted. >>>> +For more information on the certificate blob layout, see the GHCB spec >>>> +(extended guest request message). >>>> + >>>> +2.6 SNP_GET_EXT_CONFIG >>>> +---------------------- >>>> +:Technology: sev-snp >>>> +:Type: hypervisor ioctl cmd >>>> +:Parameters (in): struct sev_data_snp_ext_config >>>> +:Returns (out): 0 on success, -negative on error >>>> + >>>> +The SNP_GET_EXT_CONFIG is used to query the system-wide configuration set >>>> +through the SNP_SET_EXT_CONFIG. >>>> + >>>> 3. SEV-SNP CPUID Enforcement >>>> ============================ >>>> >>>> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c >>>> index 65e13a562f3b..b56b00ca2cd4 100644 >>>> --- a/drivers/crypto/ccp/sev-dev.c >>>> +++ b/drivers/crypto/ccp/sev-dev.c >>>> @@ -1481,6 +1481,10 @@ static int __sev_snp_shutdown_locked(int *error) >>>> data.length = sizeof(data); >>>> data.iommu_snp_shutdown = 1; >>>> >>>> + /* Free the memory used for caching the certificate data */ >>>> + kfree(sev->snp_certs_data); >>>> + sev->snp_certs_data = NULL; >>>> + >>>> wbinvd_on_all_cpus(); >>>> >>>> retry: >>>> @@ -1793,6 +1797,118 @@ static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp) >>>> return ret; >>>> } >>>> >>>> +static int sev_ioctl_snp_get_config(struct sev_issue_cmd *argp) >>>> +{ >>>> + struct sev_device *sev = psp_master->sev_data; >>>> + struct sev_user_data_ext_snp_config input; >>>> + int ret; >>>> + >>>> + if (!sev->snp_initialized || !argp->data) >>>> + return -EINVAL; >>>> + >>>> + memset(&input, 0, sizeof(input)); >>>> + >>>> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) >>>> + return -EFAULT; >>>> + >>>> + /* Copy the TCB version programmed through the SET_CONFIG to userspace */ >>>> + if (input.config_address) { >>>> + if (copy_to_user((void * __user)input.config_address, >>>> + &sev->snp_config, sizeof(struct sev_user_data_snp_config))) >>>> + return -EFAULT; >>>> + } >>>> + >>>> + /* Copy the extended certs programmed through the SNP_SET_CONFIG */ >>>> + if (input.certs_address && sev->snp_certs_data) { >>>> + if (input.certs_len < sev->snp_certs_len) { >>>> + /* Return the certs length to userspace */ >>>> + input.certs_len = sev->snp_certs_len; >>>> + >>>> + ret = -ENOSR; >>>> + goto e_done; >>>> + } >>>> + >>> >>> What about if input.certs_len > sev->snp_certs_len? Is it possbile for the >>> userspace to know the length of data in the buffer? (I guess it might be able >>> to know the certs len through the blob data, but a comment here would be nice) >>> >> >> If userspace provides an input buffer/length smaller then snp_certs_len, >> then the above returns the "required" certs length back to userspace. >> >> And what is the issue if input.certs_len > sev->snp_certs_len, the >> buffer returned back to userspace is sev->snp_certs_len as below. >> > > My point is: How can the userspace know the length of return data is shorter > than input.certs_len when input.certs_len > sev->snp_serts_len? as the length > is only returned when input.certs_len < sev->snp_certs_len. The returned data has a defined format that can be used to calculate the overall length. Thanks, Tom > >> Thanks, >> Ashish >> >>>> + if (copy_to_user((void * __user)input.certs_address, >>>> + sev->snp_certs_data, sev->snp_certs_len)) >>>> + return -EFAULT; >>>> + } >>>> + >>>> + ret = 0; >>>> + >>>> +e_done: >>>> + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) >>>> + ret = -EFAULT; >>>> + >>>> + return ret; >>>> +} >>>> + >>>> +static int sev_ioctl_snp_set_config(struct sev_issue_cmd *argp, bool writable) >>>> +{ >>>> + struct sev_device *sev = psp_master->sev_data; >>>> + struct sev_user_data_ext_snp_config input; >>>> + struct sev_user_data_snp_config config; >>>> + void *certs = NULL; >>>> + int ret = 0; >>>> + >>>> + if (!sev->snp_initialized || !argp->data) >>>> + return -EINVAL; >>>> + >>>> + if (!writable) >>>> + return -EPERM; >>>> + >>>> + memset(&input, 0, sizeof(input)); >>>> + >>>> + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) >>>> + return -EFAULT; >>>> + >>>> + /* Copy the certs from userspace */ >>>> + if (input.certs_address) { >>>> + if (!input.certs_len || !IS_ALIGNED(input.certs_len, PAGE_SIZE)) >>>> + return -EINVAL; >>>> + >>>> + certs = psp_copy_user_blob(input.certs_address, input.certs_len); >>>> + if (IS_ERR(certs)) >>>> + return PTR_ERR(certs); >>>> + } >>>> + >>>> + /* Issue the PSP command to update the TCB version using the SNP_CONFIG. */ >>>> + if (input.config_address) { >>>> + memset(&config, 0, sizeof(config)); >>>> + if (copy_from_user(&config, >>>> + (void __user *)input.config_address, sizeof(config))) { >>>> + ret = -EFAULT; >>>> + goto e_free; >>>> + } >>>> + >>>> + ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error); >>>> + if (ret) >>>> + goto e_free; >>>> + >>>> + memcpy(&sev->snp_config, &config, sizeof(config)); >>>> + } >>>> + >>>> + /* >>>> + * If the new certs are passed then cache it else free the old certs. >>>> + */ >>>> + mutex_lock(&sev->snp_certs_lock); >>>> + if (certs) { >>>> + kfree(sev->snp_certs_data); >>>> + sev->snp_certs_data = certs; >>>> + sev->snp_certs_len = input.certs_len; >>>> + } else { >>>> + kfree(sev->snp_certs_data); >>>> + sev->snp_certs_data = NULL; >>>> + sev->snp_certs_len = 0; >>>> + } >>>> + mutex_unlock(&sev->snp_certs_lock); >>>> + >>>> + return 0; >>>> + >>>> +e_free: >>>> + kfree(certs); >>>> + return ret; >>>> +} >>>> + >>>> static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) >>>> { >>>> void __user *argp = (void __user *)arg; >>>> @@ -1847,6 +1963,12 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) >>>> case SNP_PLATFORM_STATUS: >>>> ret = sev_ioctl_snp_platform_status(&input); >>>> break; >>>> + case SNP_SET_EXT_CONFIG: >>>> + ret = sev_ioctl_snp_set_config(&input, writable); >>>> + break; >>>> + case SNP_GET_EXT_CONFIG: >>>> + ret = sev_ioctl_snp_get_config(&input); >>>> + break; >>>> default: >>>> ret = -EINVAL; >>>> goto out; >>>> @@ -1962,6 +2084,7 @@ int sev_dev_init(struct psp_device *psp) >>>> goto e_sev; >>>> >>>> sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE; >>>> + mutex_init(&sev->snp_certs_lock); >>>> >>>> psp->sev_data = sev; >>>> >>>> diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h >>>> index 19d79f9d4212..41d5353d5bab 100644 >>>> --- a/drivers/crypto/ccp/sev-dev.h >>>> +++ b/drivers/crypto/ccp/sev-dev.h >>>> @@ -66,6 +66,10 @@ struct sev_device { >>>> >>>> bool snp_initialized; >>>> struct snp_host_map snp_host_map[MAX_SNP_HOST_MAP_BUFS]; >>>> + void *snp_certs_data; >>>> + u32 snp_certs_len; >>>> + struct mutex snp_certs_lock; >>>> + struct sev_user_data_snp_config snp_config; >>>> }; >>>> >>>> int sev_dev_init(struct psp_device *psp); >>>> diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h >>>> index 5adfaea7df97..c20d37586d21 100644 >>>> --- a/include/uapi/linux/psp-sev.h >>>> +++ b/include/uapi/linux/psp-sev.h >>>> @@ -29,6 +29,8 @@ enum { >>>> SEV_GET_ID, /* This command is deprecated, use SEV_GET_ID2 */ >>>> SEV_GET_ID2, >>>> SNP_PLATFORM_STATUS, >>>> + SNP_SET_EXT_CONFIG, >>>> + SNP_GET_EXT_CONFIG, >>>> >>>> SEV_MAX, >>>> }; >>>> @@ -192,6 +194,21 @@ struct sev_user_data_snp_config { >>>> __u8 rsvd1[52]; >>>> } __packed; >>>> >>>> +/** >>>> + * struct sev_data_snp_ext_config - system wide configuration value for SNP. >>>> + * >>>> + * @config_address: address of the struct sev_user_data_snp_config or 0 when >>>> + * reported_tcb does not need to be updated. >>>> + * @certs_address: address of extended guest request certificate chain or >>>> + * 0 when previous certificate should be removed on SNP_SET_EXT_CONFIG. >>>> + * @certs_len: length of the certs >>>> + */ >>>> +struct sev_user_data_ext_snp_config { >>>> + __u64 config_address; /* In */ >>>> + __u64 certs_address; /* In */ >>>> + __u32 certs_len; /* In */ >>>> +}; >>>> + >>>> /** >>>> * struct sev_issue_cmd - SEV ioctl parameters >>>> * >>> >
diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst index 11ea67c944df..6cad4226c348 100644 --- a/Documentation/virt/coco/sev-guest.rst +++ b/Documentation/virt/coco/sev-guest.rst @@ -145,6 +145,33 @@ The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The status includes API major, minor version and more. See the SEV-SNP specification for further details. +2.5 SNP_SET_EXT_CONFIG +---------------------- +:Technology: sev-snp +:Type: hypervisor ioctl cmd +:Parameters (in): struct sev_data_snp_ext_config +:Returns (out): 0 on success, -negative on error + +The SNP_SET_EXT_CONFIG is used to set the system-wide configuration such as +reported TCB version in the attestation report. The command is similar to +SNP_CONFIG command defined in the SEV-SNP spec. The main difference is the +command also accepts an additional certificate blob defined in the GHCB +specification. + +If the certs_address is zero, then the previous certificate blob will deleted. +For more information on the certificate blob layout, see the GHCB spec +(extended guest request message). + +2.6 SNP_GET_EXT_CONFIG +---------------------- +:Technology: sev-snp +:Type: hypervisor ioctl cmd +:Parameters (in): struct sev_data_snp_ext_config +:Returns (out): 0 on success, -negative on error + +The SNP_GET_EXT_CONFIG is used to query the system-wide configuration set +through the SNP_SET_EXT_CONFIG. + 3. SEV-SNP CPUID Enforcement ============================ diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 65e13a562f3b..b56b00ca2cd4 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -1481,6 +1481,10 @@ static int __sev_snp_shutdown_locked(int *error) data.length = sizeof(data); data.iommu_snp_shutdown = 1; + /* Free the memory used for caching the certificate data */ + kfree(sev->snp_certs_data); + sev->snp_certs_data = NULL; + wbinvd_on_all_cpus(); retry: @@ -1793,6 +1797,118 @@ static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp) return ret; } +static int sev_ioctl_snp_get_config(struct sev_issue_cmd *argp) +{ + struct sev_device *sev = psp_master->sev_data; + struct sev_user_data_ext_snp_config input; + int ret; + + if (!sev->snp_initialized || !argp->data) + return -EINVAL; + + memset(&input, 0, sizeof(input)); + + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) + return -EFAULT; + + /* Copy the TCB version programmed through the SET_CONFIG to userspace */ + if (input.config_address) { + if (copy_to_user((void * __user)input.config_address, + &sev->snp_config, sizeof(struct sev_user_data_snp_config))) + return -EFAULT; + } + + /* Copy the extended certs programmed through the SNP_SET_CONFIG */ + if (input.certs_address && sev->snp_certs_data) { + if (input.certs_len < sev->snp_certs_len) { + /* Return the certs length to userspace */ + input.certs_len = sev->snp_certs_len; + + ret = -ENOSR; + goto e_done; + } + + if (copy_to_user((void * __user)input.certs_address, + sev->snp_certs_data, sev->snp_certs_len)) + return -EFAULT; + } + + ret = 0; + +e_done: + if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) + ret = -EFAULT; + + return ret; +} + +static int sev_ioctl_snp_set_config(struct sev_issue_cmd *argp, bool writable) +{ + struct sev_device *sev = psp_master->sev_data; + struct sev_user_data_ext_snp_config input; + struct sev_user_data_snp_config config; + void *certs = NULL; + int ret = 0; + + if (!sev->snp_initialized || !argp->data) + return -EINVAL; + + if (!writable) + return -EPERM; + + memset(&input, 0, sizeof(input)); + + if (copy_from_user(&input, (void __user *)argp->data, sizeof(input))) + return -EFAULT; + + /* Copy the certs from userspace */ + if (input.certs_address) { + if (!input.certs_len || !IS_ALIGNED(input.certs_len, PAGE_SIZE)) + return -EINVAL; + + certs = psp_copy_user_blob(input.certs_address, input.certs_len); + if (IS_ERR(certs)) + return PTR_ERR(certs); + } + + /* Issue the PSP command to update the TCB version using the SNP_CONFIG. */ + if (input.config_address) { + memset(&config, 0, sizeof(config)); + if (copy_from_user(&config, + (void __user *)input.config_address, sizeof(config))) { + ret = -EFAULT; + goto e_free; + } + + ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error); + if (ret) + goto e_free; + + memcpy(&sev->snp_config, &config, sizeof(config)); + } + + /* + * If the new certs are passed then cache it else free the old certs. + */ + mutex_lock(&sev->snp_certs_lock); + if (certs) { + kfree(sev->snp_certs_data); + sev->snp_certs_data = certs; + sev->snp_certs_len = input.certs_len; + } else { + kfree(sev->snp_certs_data); + sev->snp_certs_data = NULL; + sev->snp_certs_len = 0; + } + mutex_unlock(&sev->snp_certs_lock); + + return 0; + +e_free: + kfree(certs); + return ret; +} + static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) { void __user *argp = (void __user *)arg; @@ -1847,6 +1963,12 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) case SNP_PLATFORM_STATUS: ret = sev_ioctl_snp_platform_status(&input); break; + case SNP_SET_EXT_CONFIG: + ret = sev_ioctl_snp_set_config(&input, writable); + break; + case SNP_GET_EXT_CONFIG: + ret = sev_ioctl_snp_get_config(&input); + break; default: ret = -EINVAL; goto out; @@ -1962,6 +2084,7 @@ int sev_dev_init(struct psp_device *psp) goto e_sev; sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE; + mutex_init(&sev->snp_certs_lock); psp->sev_data = sev; diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h index 19d79f9d4212..41d5353d5bab 100644 --- a/drivers/crypto/ccp/sev-dev.h +++ b/drivers/crypto/ccp/sev-dev.h @@ -66,6 +66,10 @@ struct sev_device { bool snp_initialized; struct snp_host_map snp_host_map[MAX_SNP_HOST_MAP_BUFS]; + void *snp_certs_data; + u32 snp_certs_len; + struct mutex snp_certs_lock; + struct sev_user_data_snp_config snp_config; }; int sev_dev_init(struct psp_device *psp); diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h index 5adfaea7df97..c20d37586d21 100644 --- a/include/uapi/linux/psp-sev.h +++ b/include/uapi/linux/psp-sev.h @@ -29,6 +29,8 @@ enum { SEV_GET_ID, /* This command is deprecated, use SEV_GET_ID2 */ SEV_GET_ID2, SNP_PLATFORM_STATUS, + SNP_SET_EXT_CONFIG, + SNP_GET_EXT_CONFIG, SEV_MAX, }; @@ -192,6 +194,21 @@ struct sev_user_data_snp_config { __u8 rsvd1[52]; } __packed; +/** + * struct sev_data_snp_ext_config - system wide configuration value for SNP. + * + * @config_address: address of the struct sev_user_data_snp_config or 0 when + * reported_tcb does not need to be updated. + * @certs_address: address of extended guest request certificate chain or + * 0 when previous certificate should be removed on SNP_SET_EXT_CONFIG. + * @certs_len: length of the certs + */ +struct sev_user_data_ext_snp_config { + __u64 config_address; /* In */ + __u64 certs_address; /* In */ + __u32 certs_len; /* In */ +}; + /** * struct sev_issue_cmd - SEV ioctl parameters *