[PATCH 4.4 43/56] arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accesses

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marc Zyngier <marc.zyngier@xxxxxxx>

commit c667186f1c01ca8970c785888868b7ffd74e51ee upstream.

Our 32bit CP14/15 handling inherited some of the ARMv7 code for handling
the trapped system registers, completely missing the fact that the
fields for Rt and Rt2 are now 5 bit wide, and not 4...

Let's fix it, and provide an accessor for the most common Rt case.

Reviewed-by: Christoffer Dall <cdall@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <cdall@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/arm64/kvm/sys_regs.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1054,8 +1054,8 @@ static int kvm_handle_cp_64(struct kvm_v
 {
 	struct sys_reg_params params;
 	u32 hsr = kvm_vcpu_get_hsr(vcpu);
-	int Rt = (hsr >> 5) & 0xf;
-	int Rt2 = (hsr >> 10) & 0xf;
+	int Rt = (hsr >> 5) & 0x1f;
+	int Rt2 = (hsr >> 10) & 0x1f;
 
 	params.is_aarch32 = true;
 	params.is_32bit = false;
@@ -1106,7 +1106,7 @@ static int kvm_handle_cp_32(struct kvm_v
 {
 	struct sys_reg_params params;
 	u32 hsr = kvm_vcpu_get_hsr(vcpu);
-	int Rt  = (hsr >> 5) & 0xf;
+	int Rt  = (hsr >> 5) & 0x1f;
 
 	params.is_aarch32 = true;
 	params.is_32bit = true;