diff mbox

[02/14] arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls

Message ID 20180126142847.31240-3-marc.zyngier@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Marc Zyngier Jan. 26, 2018, 2:28 p.m. UTC
KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.

Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.

Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/kvm/handle_exit.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c
index cf8bf6bf87c4..d15ac772d186 100644
--- a/arch/arm/kvm/handle_exit.c
+++ b/arch/arm/kvm/handle_exit.c
@@ -38,7 +38,7 @@  static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 	ret = kvm_psci_call(vcpu);
 	if (ret < 0) {
-		kvm_inject_undefined(vcpu);
+		vcpu_set_reg(vcpu, 0, ~0UL);
 		return 1;
 	}
 
@@ -47,7 +47,7 @@  static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	kvm_inject_undefined(vcpu);
+	vcpu_set_reg(vcpu, 0, ~0UL);
 	return 1;
 }