x86/sgx: Move provisioning device creation out of SGX driver

And extract sgx_set_attribute() out of sgx_ioc_enclave_provision() and
export it as symbol for KVM to use.

The provisioning key is sensitive. The SGX driver only allows to create
an enclave which can access the provisioning key when the enclave
creator has permission to open /dev/sgx_provision. It should apply to
a VM as well, as the provisioning key is platform-specific, thus an
unrestricted VM can also potentially compromise the provisioning key.

Move the provisioning device creation out of sgx_drv_init() to
sgx_init() as a preparation for adding SGX virtualization support,
so that even if the SGX driver is not enabled due to flexible launch
control not being available, SGX virtualization can still be enabled,
and use it to restrict a VM's capability of being able to access the
provisioning key.

 [ bp: Massage commit message. ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/0f4d044d621561f26d5f4ef73e8dc6cd18cc7e79.1616136308.git.kai.huang@intel.com
This commit is contained in:
Sean Christopherson
2021-03-19 20:23:09 +13:00
committed by Borislav Petkov
parent d155030b1e
commit b3754e5d3d
4 changed files with 61 additions and 32 deletions

View File

@@ -372,4 +372,7 @@ int sgx_virt_einit(void __user *sigstruct, void __user *token,
void __user *secs, u64 *lepubkeyhash, int *trapnr);
#endif
int sgx_set_attribute(unsigned long *allowed_attributes,
unsigned int attribute_fd);
#endif /* _ASM_X86_SGX_H */