Patch "arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accesses" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accesses

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arm64-kvm-fix-decoding-of-rt-rt2-when-trapping-aarch32-cp-accesses.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Marc Zyngier <[email protected]>
Date: Thu, 27 Apr 2017 19:06:48 +0100
Subject: arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accesses

From: Marc Zyngier <[email protected]>

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.

---
 arch/arm64/include/asm/kvm_emulate.h |    6 ++++++
 arch/arm64/kvm/sys_regs.c            |    8 ++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

@@ -240,6 +240,12 @@ static inline u8 kvm_vcpu_trap_get_fault
 	return kvm_vcpu_get_hsr(vcpu) & ESR_ELx_FSC_TYPE;
 }
 
+static inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
+{
+	u32 esr = kvm_vcpu_get_hsr(vcpu);
+	return (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT;
+}
+
 static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
 {
 	return vcpu_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;

@@ -1573,8 +1573,8 @@ 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 = kvm_vcpu_sys_get_rt(vcpu);
+	int Rt2 = (hsr >> 10) & 0x1f;
 
 	params.is_aarch32 = true;
 	params.is_32bit = false;

@@ -1625,7 +1625,7 @@ 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  = kvm_vcpu_sys_get_rt(vcpu);
 
 	params.is_aarch32 = true;
 	params.is_32bit = true;

@@ -1740,7 +1740,7 @@ int kvm_handle_sys_reg(struct kvm_vcpu *
 {
 	struct sys_reg_params params;
 	unsigned long esr = kvm_vcpu_get_hsr(vcpu);
-	int Rt = (esr >> 5) & 0x1f;
+	int Rt = kvm_vcpu_sys_get_rt(vcpu);
 	int ret;
 
 	trace_kvm_handle_sys_reg(esr);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/arm64-kvm-fix-decoding-of-rt-rt2-when-trapping-aarch32-cp-accesses.patch queue-4.9/kvm-arm-arm64-fix-races-in-kvm_psci_vcpu_on.patch