[tip: x86/sgx] x86/sgx: Add encls_faulted() helper

[tip-bot2 for Sean Christopherson]

The following commit has been merged into the x86/sgx branch of tip:

Commit-ID:     a67136b458e5e63822b19c35794451122fe2bf3e
Gitweb:        https://git.kernel.org/tip/a67136b458e5e63822b19c35794451122fe2bf3e
Author:        Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
AuthorDate:    Fri, 19 Mar 2021 20:23:06 +13:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Tue, 06 Apr 2021 09:43:42 +02:00

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@xxxxxxxxx>
Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx>
Link: https://lkml.kernel.org/r/c1f955898110de2f669da536fc6cf62e003dff88.1616136308.git.kai.huang@xxxxxxxxx
---
 arch/x86/kernel/cpu/sgx/encls.h | 15 ++++++++++++++-
 arch/x86/kernel/cpu/sgx/ioctl.c |  2 +-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
index be5c496..9b20484 100644
--- 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
--- 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");