[PATCH v4 30/36] KVM: arm64: Add basic support for POR_EL2

[Marc Zyngier]

S1POE support implies support for POR_EL2, which  we provide by

- adding it to the vcpu_sysreg enum
- advertising it as mapped to its EL1 counterpart in get_el2_to_el1_mapping
- wiring it in the sys_reg_desc table with the correct visibility
- handling POR_EL1 in __vcpu_{read,write}_sys_reg_from_cpu()

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/include/asm/kvm_host.h | 3 +++
 arch/arm64/kvm/sys_regs.c         | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 9a6997827ad49..c6ac6a1ea1ec5 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -473,6 +473,7 @@ enum vcpu_sysreg {
 	TCR_EL2,	/* Translation Control Register (EL2) */
 	PIRE0_EL2,	/* Permission Indirection Register 0 (EL2) */
 	PIR_EL2,	/* Permission Indirection Register 1 (EL2) */
+	POR_EL2,	/* Permission Overlay Register 2 (EL2) */
 	SPSR_EL2,	/* EL2 saved program status register */
 	ELR_EL2,	/* EL2 exception link register */
 	AFSR0_EL2,	/* Auxiliary Fault Status Register 0 (EL2) */
@@ -1043,6 +1044,7 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
 	case TCR2_EL1:		*val = read_sysreg_s(SYS_TCR2_EL12);	break;
 	case PIR_EL1:		*val = read_sysreg_s(SYS_PIR_EL12);	break;
 	case PIRE0_EL1:		*val = read_sysreg_s(SYS_PIRE0_EL12);	break;
+	case POR_EL1:		*val = read_sysreg_s(SYS_POR_EL12);	break;
 	case ESR_EL1:		*val = read_sysreg_s(SYS_ESR_EL12);	break;
 	case AFSR0_EL1:		*val = read_sysreg_s(SYS_AFSR0_EL12);	break;
 	case AFSR1_EL1:		*val = read_sysreg_s(SYS_AFSR1_EL12);	break;
@@ -1092,6 +1094,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
 	case TCR2_EL1:		write_sysreg_s(val, SYS_TCR2_EL12);	break;
 	case PIR_EL1:		write_sysreg_s(val, SYS_PIR_EL12);	break;
 	case PIRE0_EL1:		write_sysreg_s(val, SYS_PIRE0_EL12);	break;
+	case POR_EL1:		write_sysreg_s(val, SYS_POR_EL12);	break;
 	case ESR_EL1:		write_sysreg_s(val, SYS_ESR_EL12);	break;
 	case AFSR0_EL1:		write_sysreg_s(val, SYS_AFSR0_EL12);	break;
 	case AFSR1_EL1:		write_sysreg_s(val, SYS_AFSR1_EL12);	break;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 6c20de8607b2d..c9d8450e51fcd 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -137,6 +137,7 @@ static bool get_el2_to_el1_mapping(unsigned int reg,
 		MAPPED_EL2_SYSREG(TCR2_EL2,    TCR2_EL1,    NULL	     );
 		MAPPED_EL2_SYSREG(PIR_EL2,     PIR_EL1,     NULL	     );
 		MAPPED_EL2_SYSREG(PIRE0_EL2,   PIRE0_EL1,   NULL	     );
+		MAPPED_EL2_SYSREG(POR_EL2,     POR_EL1,     NULL	     );
 		MAPPED_EL2_SYSREG(AMAIR_EL2,   AMAIR_EL1,   NULL	     );
 		MAPPED_EL2_SYSREG(ELR_EL2,     ELR_EL1,	    NULL	     );
 		MAPPED_EL2_SYSREG(SPSR_EL2,    SPSR_EL1,    NULL	     );
@@ -2322,6 +2323,12 @@ static unsigned int s1poe_visibility(const struct kvm_vcpu *vcpu,
 	return REG_HIDDEN;
 }
 
+static unsigned int s1poe_el2_visibility(const struct kvm_vcpu *vcpu,
+					 const struct sys_reg_desc *rd)
+{
+	return __el2_visibility(vcpu, rd, s1poe_visibility);
+}
+
 static unsigned int tcr2_visibility(const struct kvm_vcpu *vcpu,
 				    const struct sys_reg_desc *rd)
 {
@@ -2909,6 +2916,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 			 s1pie_el2_visibility),
 	EL2_REG_FILTERED(PIR_EL2, access_rw, reset_val, 0,
 			 s1pie_el2_visibility),
+	EL2_REG_FILTERED(POR_EL2, access_rw, reset_val, 0,
+			 s1poe_el2_visibility),
 	EL2_REG(AMAIR_EL2, access_rw, reset_val, 0),
 
 	EL2_REG(VBAR_EL2, access_rw, reset_val, 0),
-- 
2.39.2