Patch "arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accesses" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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 4.4-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-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From c667186f1c01ca8970c785888868b7ffd74e51ee Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
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 <marc.zyngier@arm.com>

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@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -217,6 +217,12 @@ 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;
--- 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 = kvm_vcpu_sys_get_rt(vcpu);
+	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  = kvm_vcpu_sys_get_rt(vcpu);
 
 	params.is_aarch32 = true;
 	params.is_32bit = true;
@@ -1221,7 +1221,7 @@ 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 marc.zyngier@arm.com are

queue-4.4/arm64-kvm-fix-decoding-of-rt-rt2-when-trapping-aarch32-cp-accesses.patch
queue-4.4/kvm-arm-arm64-fix-races-in-kvm_psci_vcpu_on.patch