diff mbox series

[RFC,v5,07/26] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled

Message ID 1ab775bbf5212cd0b85d7a41234cccf710cb1656.1613221549.git.kai.huang@intel.com (mailing list archive)
State New, archived
Headers show
Series KVM SGX virtualization support | expand

Commit Message

Huang, Kai Feb. 13, 2021, 1:29 p.m. UTC
Modify sgx_init() to always try to initialize the virtual EPC driver,
even if the SGX driver is disabled.  The SGX driver might be disabled
if SGX Launch Control is in locked mode, or not supported in the
hardware at all.  This allows (non-Linux) guests that support non-LC
configurations to use SGX.

Signed-off-by: Kai Huang <kai.huang@intel.com>
---
v4->v5:

 - No code change.

v3->v4:

 - Added comment to explain virtual EPC driver can be supported in both cases
   that SGX driver is not supported, or failed to initialize, per Dave and
   Jarkko.
 - Removed "virt.h" inclusion since it was removed in previous patch, per Dave.

v2->v3:

 - Changed from sgx_virt_epc_init() to sgx_vepc_init().

---
 arch/x86/kernel/cpu/sgx/main.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

Comments

Dave Hansen Feb. 16, 2021, 6:41 p.m. UTC | #1
On 2/13/21 5:29 AM, Kai Huang wrote:
> Modify sgx_init() to always try to initialize the virtual EPC driver,
> even if the SGX driver is disabled.  The SGX driver might be disabled
> if SGX Launch Control is in locked mode, or not supported in the
> hardware at all.  This allows (non-Linux) guests that support non-LC
> configurations to use SGX.
> 
> Signed-off-by: Kai Huang <kai.huang@intel.com>
...
> +	ret = !!sgx_drv_init() & !!sgx_vepc_init();

That little nugget is starting to grow on me.

Acked-by: Dave Hansen <dave.hansen@intel.com>
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 44fe91a5bfb3..8c922e68274d 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -712,7 +712,15 @@  static int __init sgx_init(void)
 		goto err_page_cache;
 	}
 
-	ret = sgx_drv_init();
+	/*
+	 * Always try to initialize the native *and* KVM drivers.
+	 * The KVM driver is less picky than the native one and
+	 * can function if the native one is not supported on the
+	 * current system or fails to initialize.
+	 *
+	 * Error out only if both fail to initialize.
+	 */
+	ret = !!sgx_drv_init() & !!sgx_vepc_init();
 	if (ret)
 		goto err_kthread;