| Message ID | 20220520103904.1216-3-cathy.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Support microcode updates affecting SGX | expand |
On Fri, May 20, 2022 at 06:38:57PM +0800, Cathy Zhang wrote: > Tearing down all enclaves is required by SGX SVN update, which > involves running the ENCLS[EREMOVE] instruction on every EPC > page. This (tearing down all enclaves) should be coordinated > with any enclaves that may be in the process of existing and thus > already be running ENCLS[EREMOVE] as part of enclave release. > > In support of this coordination, it is required to know which enclave > owns each in-use EPC page. It is already possible to locate the > owning enclave of SECS and regular pages but not for VA pages. > > Make the following changes for VA pages' location: > 1) Make epc->owner type-agnostic by changing its type to 'void *'. So, > besides "struct sgx_encl_page", it can have other types, like > "struct sgx_va_page". > 2) Save the enclave pointer for each VA page to support locating its > owning enclave. Enumeration lists imply that you would better to split this into two patches. BR, Jarkko
diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index 7311bc40bd1b..52e0a3e52598 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -76,6 +76,7 @@ struct sgx_va_page { struct sgx_epc_page *epc_page; DECLARE_BITMAP(slots, SGX_VA_SLOT_COUNT); struct list_head list; + struct sgx_encl *encl; }; struct sgx_backing { @@ -113,7 +114,7 @@ void sgx_encl_put_backing(struct sgx_backing *backing); int sgx_encl_test_and_clear_young(struct mm_struct *mm, struct sgx_encl_page *page); -struct sgx_epc_page *sgx_alloc_va_page(void); +struct sgx_epc_page *sgx_alloc_va_page(struct sgx_va_page *va_page); unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page); void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset); bool sgx_va_page_full(struct sgx_va_page *va_page); diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index d7a1490d90bb..f8ed9deac18b 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -33,7 +33,7 @@ struct sgx_epc_page { unsigned int section; u16 flags; u16 poison; - struct sgx_encl_page *owner; + void *owner; struct list_head list; }; diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 39f7f5dc09fd..08f39fa03a39 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -888,6 +888,7 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm, /** * sgx_alloc_va_page() - Allocate a Version Array (VA) page + * @va_page: struct sgx_va_page connected to this VA page * * Allocate a free EPC page and convert it to a Version Array (VA) page. * @@ -895,12 +896,12 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm, * a VA page, * -errno otherwise */ -struct sgx_epc_page *sgx_alloc_va_page(void) +struct sgx_epc_page *sgx_alloc_va_page(struct sgx_va_page *va_page) { struct sgx_epc_page *epc_page; int ret; - epc_page = sgx_alloc_epc_page(NULL, true); + epc_page = sgx_alloc_epc_page(va_page, true); if (IS_ERR(epc_page)) return ERR_CAST(epc_page); diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index d62720ed1728..939008c63a84 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -30,7 +30,8 @@ static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl) if (!va_page) return ERR_PTR(-ENOMEM); - va_page->epc_page = sgx_alloc_va_page(); + va_page->encl = encl; + va_page->epc_page = sgx_alloc_va_page(va_page); if (IS_ERR(va_page->epc_page)) { err = ERR_CAST(va_page->epc_page); kfree(va_page);
Tearing down all enclaves is required by SGX SVN update, which involves running the ENCLS[EREMOVE] instruction on every EPC page. This (tearing down all enclaves) should be coordinated with any enclaves that may be in the process of existing and thus already be running ENCLS[EREMOVE] as part of enclave release. In support of this coordination, it is required to know which enclave owns each in-use EPC page. It is already possible to locate the owning enclave of SECS and regular pages but not for VA pages. Make the following changes for VA pages' location: 1) Make epc->owner type-agnostic by changing its type to 'void *'. So, besides "struct sgx_encl_page", it can have other types, like "struct sgx_va_page". 2) Save the enclave pointer for each VA page to support locating its owning enclave. Note: to track 2T EPC memory, this scheme of tracking will use additional 8M memory. Signed-off-by: Cathy Zhang <cathy.zhang@intel.com> --- Changes since v4: - Add back the blank line removed unintenitonally in encl.h. (Jarkko Sakkinen) Changes since v3: - Squash patch "x86/sgx: Provide VA page non-NULL owner" and "x86/sgx: Save enclave pointer for VA page". Update commit log. (Suggested by Jarkko Sakkinen) --- arch/x86/kernel/cpu/sgx/encl.h | 3 ++- arch/x86/kernel/cpu/sgx/sgx.h | 2 +- arch/x86/kernel/cpu/sgx/encl.c | 5 +++-- arch/x86/kernel/cpu/sgx/ioctl.c | 3 ++- 4 files changed, 8 insertions(+), 5 deletions(-)