@@ -423,6 +423,7 @@ static bool sgx_should_reclaim(unsigned long watermark)
!list_empty(&sgx_active_page_list);
}
+void sgx_update_cpusvn_intel(void);
static int ksgxd(void *p)
{
int srcu_idx;
@@ -437,7 +438,14 @@ static int ksgxd(void *p)
__sgx_sanitize_pages(&sgx_dirty_page_list);
/* sanity check: */
- WARN_ON(!list_empty(&sgx_dirty_page_list));
+ if (!WARN_ON(!list_empty(&sgx_dirty_page_list))) {
+ /*
+ * Do SVN update for kexec(). It should complete without error, for
+ * all EPC pages are unused at this point.
+ */
+ if (cpuid_eax(SGX_CPUID) & SGX_CPUID_EUPDATESVN)
+ sgx_update_cpusvn_intel();
+ }
while (!kthread_should_stop()) {
if (try_to_freeze())
A snapshot of the processor microcode SVN is taken each boot cycle at the time when Intel SGX is first used. This results in microcode updates being loadable at any time, fixing microcode issues. However, if system boot up through kexec() from error recovery, no hardware reset happens, any SGX leaf execution during boot up is not assumed as the first use in such case, and no snapshot of SVN is taken. So, it's necessary to call ENCLS[EUPDATESVN] to update SVN automatically, rather than waiting for the admin to do it when he/she is even not aware of that. Call ENCLS[EUPDATESVN] after sanitizing pages will increase the chance of success, for it requires that EPC is empty. Signed-off-by: Cathy Zhang <cathy.zhang@intel.com> --- Changes since v3: - Rename as sgx_update_cpusvn_intel(). Changes since v1: - Update accordingly for update_cpusvn_intel() return *void*. --- arch/x86/kernel/cpu/sgx/main.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)