When running a 32-bit VM (EL1 in AArch32), the AArch32 system registers can be deferred to vcpu load/put on VHE systems because neither the host kernel nor host userspace uses these registers. Note that we can no longer save/restore DBGVCR32_EL2 conditionally based on the state of the debug dirty flag on VHE, but since we do the load/put pretty rarely, this comes out as a win anyway. Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> --- arch/arm64/kvm/hyp/switch.c | 6 ------ arch/arm64/kvm/hyp/sysreg-sr.c | 12 ++++++++++-- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 2e04d404ac82..05f266b505ce 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -355,11 +355,6 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) __vgic_restore_state(vcpu); - /* - * We must restore the 32-bit state before the sysregs, thanks - * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). - */ - __sysreg32_restore_state(vcpu); sysreg_restore_guest_state_vhe(guest_ctxt); __debug_switch_to_guest(vcpu); @@ -371,7 +366,6 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) } while (fixup_guest_exit(vcpu, &exit_code)); sysreg_save_guest_state_vhe(guest_ctxt); - __sysreg32_save_state(vcpu); __vgic_save_state(vcpu); __deactivate_traps(vcpu); diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index eabd35154232..d225f5797651 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -195,7 +195,7 @@ void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu) sysreg[DACR32_EL2] = read_sysreg(dacr32_el2); sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2); - if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) + if (has_vhe() || vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2); } @@ -217,7 +217,7 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu) write_sysreg(sysreg[DACR32_EL2], dacr32_el2); write_sysreg(sysreg[IFSR32_EL2], ifsr32_el2); - if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) + if (has_vhe() || vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2); } @@ -242,6 +242,13 @@ void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) __sysreg_save_user_state(host_ctxt); + /* + * Load guest EL1 and user state + * + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + */ + __sysreg32_restore_state(vcpu); __sysreg_restore_user_state(guest_ctxt); __sysreg_restore_el1_state(guest_ctxt); @@ -280,6 +287,7 @@ void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) __sysreg_save_el1_state(guest_ctxt); __sysreg_save_user_state(guest_ctxt); + __sysreg32_save_state(vcpu); /* Restore host user state */ __sysreg_restore_user_state(host_ctxt); -- 2.14.2 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
