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 <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-13-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index c9761574f18feeaae95e9381ea062a721fdf62fd..a17cbe7582de90daab66f6c2f26712458c3d6cce 100644 (file)
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/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. */

diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
index 73e4bc7fde9e4c25a898436cb6f5e74e7d7d42e7..f28c6cf4fe1be62dd9a5d3d3fd74c48668c996d4 100644 (file)
--- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
+++ b/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);
 }
 
 /*