ARM: KVM: move kvm_condition_valid to emulate.c
This is really hardware emulation, and as such it better be with
its little friends.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index d3094eb..04dbac6 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -20,6 +20,7 @@
#include <linux/kvm_host.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_emulate.h>
+#include <asm/opcodes.h>
#include <trace/events/kvm.h>
#include "trace.h"
@@ -176,6 +177,50 @@
return 1;
}
+/*
+ * A conditional instruction is allowed to trap, even though it
+ * wouldn't be executed. So let's re-implement the hardware, in
+ * software!
+ */
+bool kvm_condition_valid(struct kvm_vcpu *vcpu)
+{
+ unsigned long cpsr, cond, insn;
+
+ /*
+ * Exception Code 0 can only happen if we set HCR.TGE to 1, to
+ * catch undefined instructions, and then we won't get past
+ * the arm_exit_handlers test anyway.
+ */
+ BUG_ON(!kvm_vcpu_trap_get_class(vcpu));
+
+ /* Top two bits non-zero? Unconditional. */
+ if (kvm_vcpu_get_hsr(vcpu) >> 30)
+ return true;
+
+ cpsr = *vcpu_cpsr(vcpu);
+
+ /* Is condition field valid? */
+ if ((kvm_vcpu_get_hsr(vcpu) & HSR_CV) >> HSR_CV_SHIFT)
+ cond = (kvm_vcpu_get_hsr(vcpu) & HSR_COND) >> HSR_COND_SHIFT;
+ else {
+ /* This can happen in Thumb mode: examine IT state. */
+ unsigned long it;
+
+ it = ((cpsr >> 8) & 0xFC) | ((cpsr >> 25) & 0x3);
+
+ /* it == 0 => unconditional. */
+ if (it == 0)
+ return true;
+
+ /* The cond for this insn works out as the top 4 bits. */
+ cond = (it >> 4);
+ }
+
+ /* Shift makes it look like an ARM-mode instruction */
+ insn = cond << 28;
+ return arm_check_condition(insn, cpsr) != ARM_OPCODE_CONDTEST_FAIL;
+}
+
/**
* adjust_itstate - adjust ITSTATE when emulating instructions in IT-block
* @vcpu: The VCPU pointer