From 68e0eb83ef62a4bbbd4837c3759bada65a62b71b Mon Sep 17 00:00:00 2001 From: Volodymyr Babchuk Date: Wed, 19 Jun 2019 17:54:24 +0000 Subject: [PATCH] xen/arm: optee: check if OP-TEE is virtualization-aware This is workaround for OP-TEE 3.5. This is the first OP-TEE release which supports virtualization, but there is no way to tell if OP-TEE was built with that support enabled. We can probe for it by calling SMC that is available only when OP-TEE is built with virtualization support. Signed-off-by: Volodymyr Babchuk Acked-by: Julien Grall --- xen/arch/arm/tee/optee.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c index 1d79c2c159..ec5402e89b 100644 --- a/xen/arch/arm/tee/optee.c +++ b/xen/arch/arm/tee/optee.c @@ -172,6 +172,16 @@ static bool optee_probe(void) return false; } + /* + * Workaround: OP-TEE 3.5 have no way to tell if it is build with + * virtualization support. But we can probe for OPTEE_SMC_VM_DESTROYED + * call. It will return OPTEE_SMC_RETURN_UNKNOWN_FUNCTION if + * OP-TEE have no virtualization support enabled. + */ + arm_smccc_smc(OPTEE_SMC_VM_DESTROYED, 0, 0, 0, 0, 0, 0, 0, &resp); + if ( resp.a0 == OPTEE_SMC_RETURN_UNKNOWN_FUNCTION ) + return false; + return true; } -- 2.30.2