[PATCH 01/31] arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accesses

Marc Zyngier
2017-05-03T10:43:13Z

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.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/include/asm/kvm_emulate.h | 6 ++++++
arch/arm64/kvm/sys_regs.c | 8 ++++----
2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index f5ea0ba70f07..fe39e6841326 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -240,6 +240,12 @@ static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
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;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index efbe9e8e7a78..0fe27024a2e1 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1529,8 +1529,8 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
{
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;
@@ -1586,7 +1586,7 @@ static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
{
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;
@@ -1688,7 +1688,7 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
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);
--
2.11.0