diff options
Diffstat (limited to 'arch/x86/kernel/cpu/sgx/virt.c')
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/virt.c | 95 |
1 files changed, 86 insertions, 9 deletions
diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c index 64511c4a5200..8de1f1a755f2 100644 --- a/arch/x86/kernel/cpu/sgx/virt.c +++ b/arch/x86/kernel/cpu/sgx/virt.c @@ -5,6 +5,7 @@ * Copyright(c) 2021 Intel Corporation. */ +#include <linux/kvm_types.h> #include <linux/miscdevice.h> #include <linux/mm.h> #include <linux/mman.h> @@ -105,16 +106,14 @@ static int sgx_vepc_mmap(struct file *file, struct vm_area_struct *vma) vma->vm_ops = &sgx_vepc_vm_ops; /* Don't copy VMA in fork() */ - vma->vm_flags |= VM_PFNMAP | VM_IO | VM_DONTDUMP | VM_DONTCOPY; + vm_flags_set(vma, VM_PFNMAP | VM_IO | VM_DONTDUMP | VM_DONTCOPY); vma->vm_private_data = vepc; return 0; } -static int sgx_vepc_free_page(struct sgx_epc_page *epc_page) +static int sgx_vepc_remove_page(struct sgx_epc_page *epc_page) { - int ret; - /* * Take a previously guest-owned EPC page and return it to the * general EPC page pool. @@ -124,7 +123,12 @@ static int sgx_vepc_free_page(struct sgx_epc_page *epc_page) * case that a guest properly EREMOVE'd this page, a superfluous * EREMOVE is harmless. */ - ret = __eremove(sgx_get_epc_virt_addr(epc_page)); + return __eremove(sgx_get_epc_virt_addr(epc_page)); +} + +static int sgx_vepc_free_page(struct sgx_epc_page *epc_page) +{ + int ret = sgx_vepc_remove_page(epc_page); if (ret) { /* * Only SGX_CHILD_PRESENT is expected, which is because of @@ -144,10 +148,44 @@ static int sgx_vepc_free_page(struct sgx_epc_page *epc_page) } sgx_free_epc_page(epc_page); - return 0; } +static long sgx_vepc_remove_all(struct sgx_vepc *vepc) +{ + struct sgx_epc_page *entry; + unsigned long index; + long failures = 0; + + xa_for_each(&vepc->page_array, index, entry) { + int ret = sgx_vepc_remove_page(entry); + if (ret) { + if (ret == SGX_CHILD_PRESENT) { + /* The page is a SECS, userspace will retry. */ + failures++; + } else { + /* + * Report errors due to #GP or SGX_ENCLAVE_ACT; do not + * WARN, as userspace can induce said failures by + * calling the ioctl concurrently on multiple vEPCs or + * while one or more CPUs is running the enclave. Only + * a #PF on EREMOVE indicates a kernel/hardware issue. + */ + WARN_ON_ONCE(encls_faulted(ret) && + ENCLS_TRAPNR(ret) != X86_TRAP_GP); + return -EBUSY; + } + } + cond_resched(); + } + + /* + * Return the number of SECS pages that failed to be removed, so + * userspace knows that it has to retry. + */ + return failures; +} + static int sgx_vepc_release(struct inode *inode, struct file *file) { struct sgx_vepc *vepc = file->private_data; @@ -167,6 +205,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) continue; xa_erase(&vepc->page_array, index); + cond_resched(); } /* @@ -185,6 +224,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) list_add_tail(&epc_page->list, &secs_pages); xa_erase(&vepc->page_array, index); + cond_resched(); } /* @@ -206,6 +246,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) if (sgx_vepc_free_page(epc_page)) list_add_tail(&epc_page->list, &secs_pages); + cond_resched(); } if (!list_empty(&secs_pages)) @@ -215,10 +256,11 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) xa_destroy(&vepc->page_array); kfree(vepc); + sgx_dec_usage_count(); return 0; } -static int sgx_vepc_open(struct inode *inode, struct file *file) +static int __sgx_vepc_open(struct inode *inode, struct file *file) { struct sgx_vepc *vepc; @@ -233,9 +275,44 @@ static int sgx_vepc_open(struct inode *inode, struct file *file) return 0; } +static int sgx_vepc_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = sgx_inc_usage_count(); + if (ret) + return ret; + + ret = __sgx_vepc_open(inode, file); + if (ret) { + sgx_dec_usage_count(); + return ret; + } + + return 0; +} + +static long sgx_vepc_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct sgx_vepc *vepc = file->private_data; + + switch (cmd) { + case SGX_IOC_VEPC_REMOVE_ALL: + if (arg) + return -EINVAL; + return sgx_vepc_remove_all(vepc); + + default: + return -ENOTTY; + } +} + static const struct file_operations sgx_vepc_fops = { .owner = THIS_MODULE, .open = sgx_vepc_open, + .unlocked_ioctl = sgx_vepc_ioctl, + .compat_ioctl = sgx_vepc_ioctl, .release = sgx_vepc_release, .mmap = sgx_vepc_mmap, }; @@ -305,7 +382,7 @@ int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, WARN_ON_ONCE(ret); return 0; } -EXPORT_SYMBOL_GPL(sgx_virt_ecreate); +EXPORT_SYMBOL_FOR_KVM(sgx_virt_ecreate); static int __sgx_virt_einit(void __user *sigstruct, void __user *token, void __user *secs) @@ -374,4 +451,4 @@ int sgx_virt_einit(void __user *sigstruct, void __user *token, return ret; } -EXPORT_SYMBOL_GPL(sgx_virt_einit); +EXPORT_SYMBOL_FOR_KVM(sgx_virt_einit); |