In order to ensure that slipping HCR_EL2.TGE is done at the right
time when switching translation regime, let insert the required ISBs
that will be patched in when erratum 1165522 is detected.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm64/include/asm/kvm_hyp.h | 7 +++++++
arch/arm64/kvm/hyp/switch.c | 19 +++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 23aca66767f9..ce46bb1c5f4b 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -163,6 +163,13 @@ static __always_inline void __hyp_text __load_guest_stage2(struct kvm *kvm)
{
write_sysreg(kvm->arch.vtcr, vtcr_el2);
write_sysreg(kvm->arch.vttbr, vttbr_el2);
+
+ /*
+ * ARM erratum 1165522 requires the actual execution of the above
+ * before we can switch to the EL1/EL0 translation regime used by
+ * the guest.
+ */
+ asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522));
}
#endif /* __ARM64_KVM_HYP_H__ */
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index a8fa61c68c32..31ee0bfc432f 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -143,6 +143,14 @@ static void deactivate_traps_vhe(void)
{
extern char vectors[]; /* kernel exception vectors */
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
+
+ /*
+ * ARM erratum 1165522 requires the actual execution of the above
+ * before we can switch to the EL2/EL0 translation regime used by
+ * the host.
+ */
+ asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522));
+
write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);
write_sysreg(vectors, vbar_el1);
}
@@ -499,6 +507,17 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
sysreg_save_host_state_vhe(host_ctxt);
+ /*
+ * ARM erratum 1165522 requires us to configure both stage 1 and
+ * stage 2 translation for the guest context before we clear
+ * HCR_EL2.TGE.
+ *
+ * We have already configured the guest's stage 1 translation in
+ * kvm_vcpu_load_sysregs above. We must now call __activate_vm
+ * before __activate_traps, because __activate_vm configures
+ * stage 2 translation, and __activate_traps clear HCR_EL2.TGE
+ * (among other things).
+ */
__activate_vm(vcpu->kvm);
__activate_traps(vcpu);
--
2.19.1
