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@xxxxxxxxx>
---
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 | 4 ++--
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(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h
index 7cdc351bc273..59fbd4ed5c64 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 {
@@ -112,8 +113,7 @@ int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write);
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 68c8d65a8dee..c0725111cc25 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -753,6 +753,7 @@ 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.
*
@@ -760,12 +761,12 @@ 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 a4df72f715d7..b77343eb2d49 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);
--
2.17.1
