[PATCH 1/5] arm/arm64: KVM: Don't BUG_ON if IT bits are set in ARM mode
From: Marc Zyngier <hidden>
Date: 2016-08-19 12:38:11
Also in:
kvm, kvmarm
Subsystem:
arm port, arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
The ARM ARM asserts that having the IT bits set in ARM mode is unpredictable. But should a CPU do that (and still be able to run correctly), we shouldn't kill the system. So let's drop the BUG_ON that checks for this, as it is not very helpful. Signed-off-by: Marc Zyngier <redacted> --- arch/arm/kvm/emulate.c | 4 +--- arch/arm64/kvm/emulate.c | 4 +--- 2 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index af93e3f..eda9ddd 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c@@ -221,9 +221,7 @@ static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_arm = !(cpsr & PSR_T_BIT); - BUG_ON(is_arm && (cpsr & PSR_IT_MASK)); - - if (!(cpsr & PSR_IT_MASK)) + if (is_arm || !(cpsr & PSR_IT_MASK)) return; cond = (cpsr & 0xe000) >> 13;
diff --git a/arch/arm64/kvm/emulate.c b/arch/arm64/kvm/emulate.c
index f87d8fb..df76590 100644
--- a/arch/arm64/kvm/emulate.c
+++ b/arch/arm64/kvm/emulate.c@@ -120,9 +120,7 @@ static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_arm = !(cpsr & COMPAT_PSR_T_BIT); - BUG_ON(is_arm && (cpsr & COMPAT_PSR_IT_MASK)); - - if (!(cpsr & COMPAT_PSR_IT_MASK)) + if (is_arm || !(cpsr & COMPAT_PSR_IT_MASK)) return; cond = (cpsr & 0xe000) >> 13;
--
2.1.4