On Mon, Jan 18, 2021 at 04:28:07PM +1300, Kai Huang wrote: > From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > And extract sgx_set_attribute() out of sgx_ioc_enclave_provision() and > export it as symbol for KVM to use. > > Provisioning key is sensitive. SGX driver only allows to create enclave > which can access provisioning key when enclave creator has permission to > open /dev/sgx_provision. It should apply to VM as well, as provisioning > key is platform specific, thus unrestricted VM can also potentially > compromise provisioning key. > > Move provisioning device creation out of sgx_drv_init() to sgx_init() as > preparation for adding SGX virtualization support, so that even SGX > driver is not enabled due to flexible launch control is not available, > SGX virtualization can still be enabled, and use it to restrict VM's > capability of being able to access provisioning key. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx> > --- > arch/x86/include/asm/sgx.h | 3 +++ > arch/x86/kernel/cpu/sgx/driver.c | 17 ------------ > arch/x86/kernel/cpu/sgx/ioctl.c | 16 ++---------- > arch/x86/kernel/cpu/sgx/main.c | 45 +++++++++++++++++++++++++++++++- > 4 files changed, 49 insertions(+), 32 deletions(-) > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > index 0d643b985085..795d724fab87 100644 > --- a/arch/x86/include/asm/sgx.h > +++ b/arch/x86/include/asm/sgx.h > @@ -4,6 +4,9 @@ > > #include <linux/types.h> > > +int sgx_set_attribute(unsigned long *allowed_attributes, > + unsigned int attribute_fd); > + > #ifdef CONFIG_X86_SGX_VIRTUALIZATION > struct sgx_pageinfo; > > diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c > index f2eac41bb4ff..4f3241109bda 100644 > --- a/arch/x86/kernel/cpu/sgx/driver.c > +++ b/arch/x86/kernel/cpu/sgx/driver.c > @@ -133,10 +133,6 @@ static const struct file_operations sgx_encl_fops = { > .get_unmapped_area = sgx_get_unmapped_area, > }; > > -const struct file_operations sgx_provision_fops = { > - .owner = THIS_MODULE, > -}; > - > static struct miscdevice sgx_dev_enclave = { > .minor = MISC_DYNAMIC_MINOR, > .name = "sgx_enclave", > @@ -144,13 +140,6 @@ static struct miscdevice sgx_dev_enclave = { > .fops = &sgx_encl_fops, > }; > > -static struct miscdevice sgx_dev_provision = { > - .minor = MISC_DYNAMIC_MINOR, > - .name = "sgx_provision", > - .nodename = "sgx_provision", > - .fops = &sgx_provision_fops, > -}; > - > int __init sgx_drv_init(void) > { > unsigned int eax, ebx, ecx, edx; > @@ -184,11 +173,5 @@ int __init sgx_drv_init(void) > if (ret) > return ret; > > - ret = misc_register(&sgx_dev_provision); > - if (ret) { > - misc_deregister(&sgx_dev_enclave); > - return ret; > - } > - > return 0; > } > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c > index 1bae754268d1..4714de12422d 100644 > --- a/arch/x86/kernel/cpu/sgx/ioctl.c > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c > @@ -2,6 +2,7 @@ > /* Copyright(c) 2016-20 Intel Corporation. */ > > #include <asm/mman.h> > +#include <asm/sgx.h> > #include <linux/mman.h> > #include <linux/delay.h> > #include <linux/file.h> > @@ -664,24 +665,11 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) > static long sgx_ioc_enclave_provision(struct sgx_encl *encl, void __user *arg) > { > struct sgx_enclave_provision params; > - struct file *file; > > if (copy_from_user(¶ms, arg, sizeof(params))) > return -EFAULT; > > - file = fget(params.fd); > - if (!file) > - return -EINVAL; > - > - if (file->f_op != &sgx_provision_fops) { > - fput(file); > - return -EINVAL; > - } > - > - encl->attributes_mask |= SGX_ATTR_PROVISIONKEY; > - > - fput(file); > - return 0; > + return sgx_set_attribute(&encl->attributes_mask, params.fd); > } > > long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > index 1cf1f0f058b8..e14ddfa9b78b 100644 > --- a/arch/x86/kernel/cpu/sgx/main.c > +++ b/arch/x86/kernel/cpu/sgx/main.c > @@ -1,14 +1,18 @@ > // SPDX-License-Identifier: GPL-2.0 > /* Copyright(c) 2016-20 Intel Corporation. */ > > +#include <linux/file.h> > #include <linux/freezer.h> > #include <linux/highmem.h> > #include <linux/kthread.h> > +#include <linux/miscdevice.h> > #include <linux/pagemap.h> > #include <linux/ratelimit.h> > #include <linux/sched/mm.h> > #include <linux/sched/signal.h> > #include <linux/slab.h> > +#include <asm/sgx_arch.h> > +#include <asm/sgx.h> > #include "driver.h" > #include "encl.h" > #include "encls.h" > @@ -705,6 +709,38 @@ void sgx_update_lepubkeyhash(u64 *lepubkeyhash) > wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]); > } > > +const struct file_operations sgx_provision_fops = { > + .owner = THIS_MODULE, > +}; > + > +static struct miscdevice sgx_dev_provision = { > + .minor = MISC_DYNAMIC_MINOR, > + .name = "sgx_provision", > + .nodename = "sgx_provision", > + .fops = &sgx_provision_fops, > +}; > + > +int sgx_set_attribute(unsigned long *allowed_attributes, > + unsigned int attribute_fd) kdoc > +{ > + struct file *file; > + > + file = fget(attribute_fd); > + if (!file) > + return -EINVAL; > + > + if (file->f_op != &sgx_provision_fops) { > + fput(file); > + return -EINVAL; > + } > + > + *allowed_attributes |= SGX_ATTR_PROVISIONKEY; > + > + fput(file); > + return 0; > +} > +EXPORT_SYMBOL_GPL(sgx_set_attribute); > + > static void __init sgx_init(void) > { > int ret; > @@ -719,13 +755,20 @@ static void __init sgx_init(void) > if (!sgx_page_reclaimer_init()) > goto err_page_cache; > > + ret = misc_register(&sgx_dev_provision); > + if (ret) > + goto err_kthread; > + > /* Success if the native *or* virtual EPC driver initialized cleanly. */ > ret = !!sgx_drv_init() & !!sgx_virt_epc_init(); > if (ret) > - goto err_kthread; > + goto err_provision; > > return; > > +err_provision: > + misc_deregister(&sgx_dev_provision); > + > err_kthread: > kthread_stop(ksgxd_tsk); > > -- > 2.29.2 > > /Jarkko