KVM: arm64: Move ELR_EL1 to the system register array

As ELR-EL1 is a VNCR-capable register with ARMv8.4-NV, let's move it to
the sys_regs array and repaint the accessors. While we're at it, let's
kill the now useless accessors used only on the fault injection path.
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_emulate.h

@@ -127,27 +127,6 @@ static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
 	return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
 }
 
-static inline unsigned long *__vcpu_elr_el1(const struct kvm_vcpu *vcpu)
-{
-	return (unsigned long *)&vcpu->arch.ctxt.elr_el1;
-}
-
-static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
-{
-	if (vcpu->arch.sysregs_loaded_on_cpu)
-		return read_sysreg_el1(SYS_ELR);
-	else
-		return *__vcpu_elr_el1(vcpu);
-}
-
-static inline void vcpu_write_elr_el1(const struct kvm_vcpu *vcpu, unsigned long v)
-{
-	if (vcpu->arch.sysregs_loaded_on_cpu)
-		write_sysreg_el1(v, SYS_ELR);
-	else
-		*__vcpu_elr_el1(vcpu) = v;
-}
-
 static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
 {
 	return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;

arch/arm64/include/asm/kvm_host.h

@@ -185,6 +185,8 @@ enum vcpu_sysreg {
 	APGAKEYLO_EL1,
 	APGAKEYHI_EL1,
 
+	ELR_EL1,
+
 	/* 32bit specific registers. Keep them at the end of the range */
 	DACR32_EL2,	/* Domain Access Control Register */
 	IFSR32_EL2,	/* Instruction Fault Status Register */
@@ -239,7 +241,6 @@ struct kvm_cpu_context {
 	struct user_pt_regs regs;	/* sp = sp_el0 */
 
 	u64	sp_el1;
-	u64	elr_el1;
 
 	u64	spsr[KVM_NR_SPSR];
 

arch/arm64/kvm/guest.c

@@ -132,7 +132,7 @@ static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 		return &vcpu->arch.ctxt.sp_el1;
 
 	case KVM_REG_ARM_CORE_REG(elr_el1):
-		return &vcpu->arch.ctxt.elr_el1;
+		return __ctxt_sys_reg(&vcpu->arch.ctxt, ELR_EL1);
 
 	case KVM_REG_ARM_CORE_REG(spsr[0]) ...
 	     KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):

arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h

@@ -47,7 +47,7 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 	ctxt_sys_reg(ctxt, TPIDR_EL1)	= read_sysreg(tpidr_el1);
 
 	ctxt->sp_el1			= read_sysreg(sp_el1);
-	ctxt->elr_el1			= read_sysreg_el1(SYS_ELR);
+	ctxt_sys_reg(ctxt, ELR_EL1)	= read_sysreg_el1(SYS_ELR);
 	ctxt->spsr[KVM_SPSR_EL1]	= read_sysreg_el1(SYS_SPSR);
 }
 
@@ -126,7 +126,7 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
 	}
 
 	write_sysreg(ctxt->sp_el1,			sp_el1);
-	write_sysreg_el1(ctxt->elr_el1,			SYS_ELR);
+	write_sysreg_el1(ctxt_sys_reg(ctxt, ELR_EL1),	SYS_ELR);
 	write_sysreg_el1(ctxt->spsr[KVM_SPSR_EL1],	SYS_SPSR);
 }
 

arch/arm64/kvm/inject_fault.c

@@ -64,7 +64,7 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode,
 	case PSR_MODE_EL1h:
 		vbar = vcpu_read_sys_reg(vcpu, VBAR_EL1);
 		sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
-		vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu));
+		vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL1);
 		break;
 	default:
 		/* Don't do that */

arch/arm64/kvm/sys_regs.c

@@ -94,6 +94,7 @@ static bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
 	case TPIDR_EL1:		*val = read_sysreg_s(SYS_TPIDR_EL1);	break;
 	case AMAIR_EL1:		*val = read_sysreg_s(SYS_AMAIR_EL12);	break;
 	case CNTKCTL_EL1:	*val = read_sysreg_s(SYS_CNTKCTL_EL12);	break;
+	case ELR_EL1:		*val = read_sysreg_s(SYS_ELR_EL12);	break;
 	case PAR_EL1:		*val = read_sysreg_s(SYS_PAR_EL1);	break;
 	case DACR32_EL2:	*val = read_sysreg_s(SYS_DACR32_EL2);	break;
 	case IFSR32_EL2:	*val = read_sysreg_s(SYS_IFSR32_EL2);	break;
@@ -133,6 +134,7 @@ static bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
 	case TPIDR_EL1:		write_sysreg_s(val, SYS_TPIDR_EL1);	break;
 	case AMAIR_EL1:		write_sysreg_s(val, SYS_AMAIR_EL12);	break;
 	case CNTKCTL_EL1:	write_sysreg_s(val, SYS_CNTKCTL_EL12);	break;
+	case ELR_EL1:		write_sysreg_s(val, SYS_ELR_EL12);	break;
 	case PAR_EL1:		write_sysreg_s(val, SYS_PAR_EL1);	break;
 	case DACR32_EL2:	write_sysreg_s(val, SYS_DACR32_EL2);	break;
 	case IFSR32_EL2:	write_sysreg_s(val, SYS_IFSR32_EL2);	break;