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.d...@linaro.org>
---
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
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