| Message ID | afae5980fd4adf52932a9d639a0b0bfe83255c0a.1655761627.git.ashish.kalra@amd.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add AMD Secure Nested Paging (SEV-SNP) | expand |
On Mon, Jun 20, 2022 at 5:06 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote: > > From: Brijesh Singh <brijesh.singh@amd.com> > > Version 2 of the GHCB specification defines VMGEXIT that is used to get > the extended attestation report. The extended attestation report includes > the certificate blobs provided through the SNP_SET_EXT_CONFIG. > > The snp_guest_ext_guest_request() will be used by the hypervisor to get > the extended attestation report. See the GHCB specification for more > details. > > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > --- > drivers/crypto/ccp/sev-dev.c | 43 ++++++++++++++++++++++++++++++++++++ > include/linux/psp-sev.h | 24 ++++++++++++++++++++ > 2 files changed, 67 insertions(+) > > diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c > index 97b479d5aa86..f6306b820b86 100644 > --- a/drivers/crypto/ccp/sev-dev.c > +++ b/drivers/crypto/ccp/sev-dev.c > @@ -25,6 +25,7 @@ > #include <linux/fs.h> > > #include <asm/smp.h> > +#include <asm/sev.h> > > #include "psp-dev.h" > #include "sev-dev.h" > @@ -1857,6 +1858,48 @@ int snp_guest_dbg_decrypt(struct sev_data_snp_dbg *data, int *error) > } > EXPORT_SYMBOL_GPL(snp_guest_dbg_decrypt); > > +int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, > + unsigned long vaddr, unsigned long *npages, unsigned long *fw_err) > +{ > + unsigned long expected_npages; > + struct sev_device *sev; > + int rc; > + > + if (!psp_master || !psp_master->sev_data) > + return -ENODEV; > + > + sev = psp_master->sev_data; > + > + if (!sev->snp_inited) > + return -EINVAL; > + > + /* > + * Check if there is enough space to copy the certificate chain. Otherwise > + * return ERROR code defined in the GHCB specification. > + */ > + expected_npages = sev->snp_certs_len >> PAGE_SHIFT; > + if (*npages < expected_npages) { > + *npages = expected_npages; > + *fw_err = SNP_GUEST_REQ_INVALID_LEN; > + return -EINVAL; > + } > + > + rc = sev_do_cmd(SEV_CMD_SNP_GUEST_REQUEST, data, (int *)&fw_err); We can just pass |fw_error| here (with the cast) here right? Not need to do &fw_err. rc = sev_do_cmd(SEV_CMD_SNP_GUEST_REQUEST, data, (int *)fw_err); > + if (rc) > + return rc; > + > + /* Copy the certificate blob */ > + if (sev->snp_certs_data) { > + *npages = expected_npages; > + memcpy((void *)vaddr, sev->snp_certs_data, *npages << PAGE_SHIFT); Why don't we just make |vaddr| into a void* instead of an unsigned long? > + } else { > + *npages = 0; > + } > + > + return rc; > +} > +EXPORT_SYMBOL_GPL(snp_guest_ext_guest_request); > + > static void sev_exit(struct kref *ref) > { > misc_deregister(&misc_dev->misc); > diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h > index a3bb792bb842..cd37ccd1fa1f 100644 > --- a/include/linux/psp-sev.h > +++ b/include/linux/psp-sev.h > @@ -945,6 +945,23 @@ void *psp_copy_user_blob(u64 uaddr, u32 len); > void *snp_alloc_firmware_page(gfp_t mask); > void snp_free_firmware_page(void *addr); > > +/** > + * snp_guest_ext_guest_request - perform the SNP extended guest request command > + * defined in the GHCB specification. > + * > + * @data: the input guest request structure > + * @vaddr: address where the certificate blob need to be copied. > + * @npages: number of pages for the certificate blob. > + * If the specified page count is less than the certificate blob size, then the > + * required page count is returned with error code defined in the GHCB spec. > + * If the specified page count is more than the certificate blob size, then > + * page count is updated to reflect the amount of valid data copied in the > + * vaddr. > + */ > +int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, > + unsigned long vaddr, unsigned long *npages, > + unsigned long *error); > + > #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ > > static inline int > @@ -992,6 +1009,13 @@ static inline void *snp_alloc_firmware_page(gfp_t mask) > > static inline void snp_free_firmware_page(void *addr) { } > > +static inline int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, > + unsigned long vaddr, unsigned long *n, > + unsigned long *error) > +{ > + return -ENODEV; > +} > + > #endif /* CONFIG_CRYPTO_DEV_SP_PSP */ > > #endif /* __PSP_SEV_H__ */ > -- > 2.25.1 >
I'd rephrase "Provide in-kernel API..." (e.g. not uapi). On Mon, Jun 20, 2022 at 11:06:06PM +0000, Ashish Kalra wrote: > From: Brijesh Singh <brijesh.singh@amd.com> > > Version 2 of the GHCB specification defines VMGEXIT that is used to get > the extended attestation report. The extended attestation report includes > the certificate blobs provided through the SNP_SET_EXT_CONFIG. > > The snp_guest_ext_guest_request() will be used by the hypervisor to get > the extended attestation report. See the GHCB specification for more > details. What is "the hypersivor"? Could it be replaced with e.g. KVM for clarity? > > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > --- > drivers/crypto/ccp/sev-dev.c | 43 ++++++++++++++++++++++++++++++++++++ > include/linux/psp-sev.h | 24 ++++++++++++++++++++ > 2 files changed, 67 insertions(+) > > diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c > index 97b479d5aa86..f6306b820b86 100644 > --- a/drivers/crypto/ccp/sev-dev.c > +++ b/drivers/crypto/ccp/sev-dev.c > @@ -25,6 +25,7 @@ > #include <linux/fs.h> > > #include <asm/smp.h> > +#include <asm/sev.h> > > #include "psp-dev.h" > #include "sev-dev.h" > @@ -1857,6 +1858,48 @@ int snp_guest_dbg_decrypt(struct sev_data_snp_dbg *data, int *error) > } > EXPORT_SYMBOL_GPL(snp_guest_dbg_decrypt); > > +int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, > + unsigned long vaddr, unsigned long *npages, unsigned long *fw_err) > +{ > + unsigned long expected_npages; > + struct sev_device *sev; > + int rc; > + > + if (!psp_master || !psp_master->sev_data) > + return -ENODEV; > + > + sev = psp_master->sev_data; > + > + if (!sev->snp_inited) > + return -EINVAL; > + > + /* > + * Check if there is enough space to copy the certificate chain. Otherwise > + * return ERROR code defined in the GHCB specification. > + */ > + expected_npages = sev->snp_certs_len >> PAGE_SHIFT; > + if (*npages < expected_npages) { > + *npages = expected_npages; > + *fw_err = SNP_GUEST_REQ_INVALID_LEN; > + return -EINVAL; > + } > + > + rc = sev_do_cmd(SEV_CMD_SNP_GUEST_REQUEST, data, (int *)&fw_err); > + if (rc) > + return rc; > + > + /* Copy the certificate blob */ > + if (sev->snp_certs_data) { > + *npages = expected_npages; > + memcpy((void *)vaddr, sev->snp_certs_data, *npages << PAGE_SHIFT); > + } else { > + *npages = 0; > + } > + > + return rc; > +} > +EXPORT_SYMBOL_GPL(snp_guest_ext_guest_request); Undocumented export. > + > static void sev_exit(struct kref *ref) > { > misc_deregister(&misc_dev->misc); > diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h > index a3bb792bb842..cd37ccd1fa1f 100644 > --- a/include/linux/psp-sev.h > +++ b/include/linux/psp-sev.h > @@ -945,6 +945,23 @@ void *psp_copy_user_blob(u64 uaddr, u32 len); > void *snp_alloc_firmware_page(gfp_t mask); > void snp_free_firmware_page(void *addr); > > +/** > + * snp_guest_ext_guest_request - perform the SNP extended guest request command > + * defined in the GHCB specification. > + * > + * @data: the input guest request structure > + * @vaddr: address where the certificate blob need to be copied. > + * @npages: number of pages for the certificate blob. > + * If the specified page count is less than the certificate blob size, then the > + * required page count is returned with error code defined in the GHCB spec. > + * If the specified page count is more than the certificate blob size, then > + * page count is updated to reflect the amount of valid data copied in the > + * vaddr. > + */ This kdoc is misplaced: it should be in sev-dev.c, right before the implementation. Also it does not say anything about return value, and still the return type is "int". > +int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, > + unsigned long vaddr, unsigned long *npages, > + unsigned long *error); > + > #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ > > static inline int > @@ -992,6 +1009,13 @@ static inline void *snp_alloc_firmware_page(gfp_t mask) > > static inline void snp_free_firmware_page(void *addr) { } > > +static inline int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, > + unsigned long vaddr, unsigned long *n, > + unsigned long *error) > +{ > + return -ENODEV; > +} > + > #endif /* CONFIG_CRYPTO_DEV_SP_PSP */ > > #endif /* __PSP_SEV_H__ */ > -- > 2.25.1 > BR, Jarkko
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 97b479d5aa86..f6306b820b86 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -25,6 +25,7 @@ #include <linux/fs.h> #include <asm/smp.h> +#include <asm/sev.h> #include "psp-dev.h" #include "sev-dev.h" @@ -1857,6 +1858,48 @@ int snp_guest_dbg_decrypt(struct sev_data_snp_dbg *data, int *error) } EXPORT_SYMBOL_GPL(snp_guest_dbg_decrypt); +int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, + unsigned long vaddr, unsigned long *npages, unsigned long *fw_err) +{ + unsigned long expected_npages; + struct sev_device *sev; + int rc; + + if (!psp_master || !psp_master->sev_data) + return -ENODEV; + + sev = psp_master->sev_data; + + if (!sev->snp_inited) + return -EINVAL; + + /* + * Check if there is enough space to copy the certificate chain. Otherwise + * return ERROR code defined in the GHCB specification. + */ + expected_npages = sev->snp_certs_len >> PAGE_SHIFT; + if (*npages < expected_npages) { + *npages = expected_npages; + *fw_err = SNP_GUEST_REQ_INVALID_LEN; + return -EINVAL; + } + + rc = sev_do_cmd(SEV_CMD_SNP_GUEST_REQUEST, data, (int *)&fw_err); + if (rc) + return rc; + + /* Copy the certificate blob */ + if (sev->snp_certs_data) { + *npages = expected_npages; + memcpy((void *)vaddr, sev->snp_certs_data, *npages << PAGE_SHIFT); + } else { + *npages = 0; + } + + return rc; +} +EXPORT_SYMBOL_GPL(snp_guest_ext_guest_request); + static void sev_exit(struct kref *ref) { misc_deregister(&misc_dev->misc); diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h index a3bb792bb842..cd37ccd1fa1f 100644 --- a/include/linux/psp-sev.h +++ b/include/linux/psp-sev.h @@ -945,6 +945,23 @@ void *psp_copy_user_blob(u64 uaddr, u32 len); void *snp_alloc_firmware_page(gfp_t mask); void snp_free_firmware_page(void *addr); +/** + * snp_guest_ext_guest_request - perform the SNP extended guest request command + * defined in the GHCB specification. + * + * @data: the input guest request structure + * @vaddr: address where the certificate blob need to be copied. + * @npages: number of pages for the certificate blob. + * If the specified page count is less than the certificate blob size, then the + * required page count is returned with error code defined in the GHCB spec. + * If the specified page count is more than the certificate blob size, then + * page count is updated to reflect the amount of valid data copied in the + * vaddr. + */ +int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, + unsigned long vaddr, unsigned long *npages, + unsigned long *error); + #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ static inline int @@ -992,6 +1009,13 @@ static inline void *snp_alloc_firmware_page(gfp_t mask) static inline void snp_free_firmware_page(void *addr) { } +static inline int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data, + unsigned long vaddr, unsigned long *n, + unsigned long *error) +{ + return -ENODEV; +} + #endif /* CONFIG_CRYPTO_DEV_SP_PSP */ #endif /* __PSP_SEV_H__ */