[PATCH RFC v2 10/22] KVM: arm64: Add support for TPIDR2_EL0

[Mark Brown]

SME adds a new user register TPIDR2_EL0, implement support for mananging
this for guests. We provide system register access to it, disable traps
and context switch it along with the other TPIDRs for guests with SME.

Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 arch/arm64/include/asm/kvm_host.h          | 3 +++
 arch/arm64/kvm/hyp/include/hyp/switch.h    | 5 ++++-
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 6 ++++++
 arch/arm64/kvm/sys_regs.c                  | 2 +-
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4be5dda9734d..36bf9d7e92e1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -347,6 +347,7 @@ enum vcpu_sysreg {
 	CONTEXTIDR_EL1,	/* Context ID Register */
 	TPIDR_EL0,	/* Thread ID, User R/W */
 	TPIDRRO_EL0,	/* Thread ID, User R/O */
+	TPIDR2_EL0,	/* Thread ID 2, User R/W */
 	TPIDR_EL1,	/* Thread ID, Privileged */
 	AMAIR_EL1,	/* Aux Memory Attribute Indirection Register */
 	CNTKCTL_EL1,	/* Timer Control Register (EL1) */
@@ -885,6 +886,7 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
 	case CONTEXTIDR_EL1:	*val = read_sysreg_s(SYS_CONTEXTIDR_EL12);break;
 	case TPIDR_EL0:		*val = read_sysreg_s(SYS_TPIDR_EL0);	break;
 	case TPIDRRO_EL0:	*val = read_sysreg_s(SYS_TPIDRRO_EL0);	break;
+	case TPIDR2_EL0:	*val = read_sysreg_s(SYS_TPIDR2_EL0);	break;
 	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;
@@ -928,6 +930,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
 	case VBAR_EL1:		write_sysreg_s(val, SYS_VBAR_EL12);	break;
 	case CONTEXTIDR_EL1:	write_sysreg_s(val, SYS_CONTEXTIDR_EL12);break;
 	case TPIDR_EL0:		write_sysreg_s(val, SYS_TPIDR_EL0);	break;
+	case TPIDR2_EL0:	write_sysreg_s(val, SYS_TPIDR2_EL0);	break;
 	case TPIDRRO_EL0:	write_sysreg_s(val, SYS_TPIDRRO_EL0);	break;
 	case TPIDR_EL1:		write_sysreg_s(val, SYS_TPIDR_EL1);	break;
 	case AMAIR_EL1:		write_sysreg_s(val, SYS_AMAIR_EL12);	break;
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 9601212bd3ce..72982e752972 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -93,7 +93,10 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	ctxt_sys_reg(hctxt, HFGWTR_EL2) = read_sysreg_s(SYS_HFGWTR_EL2);
 
 	if (cpus_have_final_cap(ARM64_SME)) {
-		tmp = HFGxTR_EL2_nSMPRI_EL1_MASK | HFGxTR_EL2_nTPIDR2_EL0_MASK;
+		tmp = HFGxTR_EL2_nSMPRI_EL1_MASK;
+
+		if (!vcpu_has_sme(vcpu))
+			tmp |= HFGxTR_EL2_nTPIDR2_EL0_MASK;
 
 		r_clr |= tmp;
 		w_clr |= tmp;
diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index fb84834cd2a0..5436b33d50b7 100644
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
@@ -35,6 +35,9 @@ static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
 {
 	ctxt_sys_reg(ctxt, TPIDR_EL0)	= read_sysreg(tpidr_el0);
 	ctxt_sys_reg(ctxt, TPIDRRO_EL0)	= read_sysreg(tpidrro_el0);
+
+	if (ctxt_has_sme(ctxt))
+		ctxt_sys_reg(ctxt, TPIDR2_EL0) = read_sysreg_s(SYS_TPIDR2_EL0);
 }
 
 static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt)
@@ -105,6 +108,9 @@ static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
 {
 	write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL0),	tpidr_el0);
 	write_sysreg(ctxt_sys_reg(ctxt, TPIDRRO_EL0),	tpidrro_el0);
+
+	if (ctxt_has_sme(ctxt))
+		write_sysreg_s(ctxt_sys_reg(ctxt, TPIDR2_EL0), SYS_TPIDR2_EL0);
 }
 
 static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e6339ca1d8dc..a33ad12dc3ab 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2369,7 +2369,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 
 	{ SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
 	{ SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },
-	{ SYS_DESC(SYS_TPIDR2_EL0), undef_access },
+	{ SYS_DESC(SYS_TPIDR2_EL0), NULL, reset_unknown, TPIDR2_EL0, 0, .visibility = sme_visibility },
 
 	{ SYS_DESC(SYS_SCXTNUM_EL0), undef_access },
 

-- 
2.30.2