x86/sgx: Add encls_faulted() helper

Add a helper to extract the fault indicator from an encoded ENCLS return
value.  SGX virtualization will also need to detect ENCLS faults.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/c1f955898110de2f669da536fc6cf62e003dff88.1616136308.git.kai.huang@intel.com

diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
index be5c496..9b20484 100644 (file)
--- a/arch/x86/kernel/cpu/sgx/encls.h
+++ b/arch/x86/kernel/cpu/sgx/encls.h
@@ -40,6 +40,19 @@
        } while (0);                                                      \
 }
 
+/*
+ * encls_faulted() - Check if an ENCLS leaf faulted given an error code
+ * @ret:       the return value of an ENCLS leaf function call
+ *
+ * Return:
+ * - true:     ENCLS leaf faulted.
+ * - false:    Otherwise.
+ */
+static inline bool encls_faulted(int ret)
+{
+       return ret & ENCLS_FAULT_FLAG;
+}
+
 /**
  * encls_failed() - Check if an ENCLS function failed
  * @ret:       the return value of an ENCLS function call
@@ -50,7 +63,7 @@
  */
 static inline bool encls_failed(int ret)
 {
-       if (ret & ENCLS_FAULT_FLAG)
+       if (encls_faulted(ret))
                return ENCLS_TRAPNR(ret) != X86_TRAP_PF;
 
        return !!ret;

diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 354e309..11e3f96 100644 (file)
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -568,7 +568,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
                }
        }
 
-       if (ret & ENCLS_FAULT_FLAG) {
+       if (encls_faulted(ret)) {
                if (encls_failed(ret))
                        ENCLS_WARN(ret, "EINIT");