KVM: arm64: Context switch SCTLR2_ELx when advertised to the guest

Restore SCTLR2_EL1 with the correct value for the given context when
FEAT_SCTLR2 is advertised to the guest.

Reviewed-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Oliver Upton <[email protected]>

Author: oupton

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

@@ -120,6 +120,17 @@ static inline bool ctxt_has_ras(struct kvm_cpu_context *ctxt)
 	return kvm_has_ras(kern_hyp_va(vcpu->kvm));
 }
 
+static inline bool ctxt_has_sctlr2(struct kvm_cpu_context *ctxt)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (!cpus_have_final_cap(ARM64_HAS_SCTLR2))
+		return false;
+
+	vcpu = ctxt_to_vcpu(ctxt);
+	return kvm_has_sctlr2(kern_hyp_va(vcpu->kvm));
+}
+
 static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 {
 	ctxt_sys_reg(ctxt, SCTLR_EL1)	= read_sysreg_el1(SYS_SCTLR);
@@ -158,6 +169,9 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 	ctxt_sys_reg(ctxt, SP_EL1)	= read_sysreg(sp_el1);
 	ctxt_sys_reg(ctxt, ELR_EL1)	= read_sysreg_el1(SYS_ELR);
 	ctxt_sys_reg(ctxt, SPSR_EL1)	= read_sysreg_el1(SYS_SPSR);
+
+	if (ctxt_has_sctlr2(ctxt))
+		ctxt_sys_reg(ctxt, SCTLR2_EL1) = read_sysreg_el1(SYS_SCTLR2);
 }
 
 static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
@@ -268,6 +282,9 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt,
 	write_sysreg(ctxt_sys_reg(ctxt, SP_EL1),	sp_el1);
 	write_sysreg_el1(ctxt_sys_reg(ctxt, ELR_EL1),	SYS_ELR);
 	write_sysreg_el1(ctxt_sys_reg(ctxt, SPSR_EL1),	SYS_SPSR);
+
+	if (ctxt_has_sctlr2(ctxt))
+		write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR2_EL1), SYS_SCTLR2);
 }
 
 /* Read the VCPU state's PSTATE, but translate (v)EL2 to EL1. */

arch/arm64/kvm/hyp/vhe/sysreg-sr.c

@@ -77,6 +77,9 @@ static void __sysreg_save_vel2_state(struct kvm_vcpu *vcpu)
 	__vcpu_assign_sys_reg(vcpu, SP_EL2,	 read_sysreg(sp_el1));
 	__vcpu_assign_sys_reg(vcpu, ELR_EL2,	 read_sysreg_el1(SYS_ELR));
 	__vcpu_assign_sys_reg(vcpu, SPSR_EL2,	 read_sysreg_el1(SYS_SPSR));
+
+	if (ctxt_has_sctlr2(&vcpu->arch.ctxt))
+		__vcpu_assign_sys_reg(vcpu, SCTLR2_EL2, read_sysreg_el1(SYS_SCTLR2));
 }
 
 static void __sysreg_restore_vel2_state(struct kvm_vcpu *vcpu)
@@ -139,6 +142,9 @@ static void __sysreg_restore_vel2_state(struct kvm_vcpu *vcpu)
 	write_sysreg(__vcpu_sys_reg(vcpu, SP_EL2),		sp_el1);
 	write_sysreg_el1(__vcpu_sys_reg(vcpu, ELR_EL2),		SYS_ELR);
 	write_sysreg_el1(__vcpu_sys_reg(vcpu, SPSR_EL2),	SYS_SPSR);
+
+	if (ctxt_has_sctlr2(&vcpu->arch.ctxt))
+		write_sysreg_el1(__vcpu_sys_reg(vcpu, SCTLR2_EL2), SYS_SCTLR2);
 }
 
 /*