[PATCH v2 3/4] KVM: arm64: pkvm: Reset GICv3 LRs in the hypervisor

[Vincent Donnefort]

After the host is deprivileged, pKVM can't trust the host for resetting
the vGIC LRs whose value is architecturally UNKNOWN when the CPU boots
or resumes. Add a blanket cover in the CPU_ON/CPU_SUSPEND path.

Fixes: cdf367192766 ("KVM: arm64: Intercept host's CPU_ON SMCs")
Signed-off-by: Vincent Donnefort <vdonnefort at google.com>
---
 arch/arm64/kvm/hyp/nvhe/psci-relay.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index e20db999e328..890ced64fb18 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -213,6 +213,10 @@ static void __noreturn __kvm_host_psci_cpu_entry(unsigned long pc, unsigned long
 	write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
 	write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
 
+	/* We can't trust the host to reset those registers */
+	if (hyp_gicv3_nr_lr)
+		__vgic_v3_init_lrs();
+
 	trace_hyp_exit(host_ctxt, HYP_REASON_PSCI);
 	__host_enter(host_ctxt);
 }
-- 
2.56.0.257.gf7497c7d27-goog