[PATCH 04/11] KVM: arm64: Add context-switch of ACCDATA_EL1

[Marc Zyngier <maz@kernel.org>]

Add ACCDATA_EL1 save/restore as part of the EL0 context. This is
conditioned on the guest's view of ID_AA64ISAR1_EL1.LS64 reporting
that this register is supported.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 29 +++++++++++++++++-----
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index 4c0fdabaf8ae..d23d7113261b 100644
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
@@ -21,12 +21,6 @@ static inline void __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
 	ctxt_sys_reg(ctxt, MDSCR_EL1)	= read_sysreg(mdscr_el1);
 }
 
-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);
-}
-
 static inline struct kvm_vcpu *ctxt_to_vcpu(struct kvm_cpu_context *ctxt)
 {
 	struct kvm_vcpu *vcpu = ctxt->__hyp_running_vcpu;
@@ -66,6 +60,26 @@ static inline bool ctxt_has_tcrx(struct kvm_cpu_context *ctxt)
 	return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, TCRX, IMP);
 }
 
+static inline bool ctxt_has_accdata(struct kvm_cpu_context *ctxt)
+{
+	struct kvm_vcpu *vcpu = ctxt_to_vcpu(ctxt);
+
+	return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA);
+}
+
+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);
+
+	/*
+	 * Despite the appearances, ACCDATA_EL1 is part of the EL0
+	 * context, as it can only be used using ST64BV0.
+	 */
+	if (ctxt_has_accdata(ctxt))
+		ctxt_sys_reg(ctxt, ACCDATA_EL1)	= read_sysreg_s(SYS_ACCDATA_EL1);
+}
+
 static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 {
 	ctxt_sys_reg(ctxt, SCTLR_EL1)	= read_sysreg_el1(SYS_SCTLR);
@@ -126,6 +140,9 @@ 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_accdata(ctxt))
+		write_sysreg_s(ctxt_sys_reg(ctxt, ACCDATA_EL1), SYS_ACCDATA_EL1);
 }
 
 static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
-- 
2.39.2