From cbd8c958be54abdf2c0f9b9c3eac971428b9d4b1 Mon Sep 17 00:00:00 2001 From: Sascha Bischoff Date: Thu, 19 Mar 2026 15:50:28 +0000 Subject: [PATCH] KVM: arm64: Return early from kvm_finalize_sys_regs() if guest has run If the guest has already run, we have no business finalizing the system register state - it is too late. Therefore, check early and bail if the VM has already run. This change also stops kvm_init_nv_sysregs() from being called once the RM has run once. Although this looks like a behavioural change, the function returns early once it has been called the first time. Signed-off-by: Sascha Bischoff Link: https://patch.msgid.link/20260319154937.3619520-4-sascha.bischoff@arm.com Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 0acd10e50aab..42c84b7900ff 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -5659,11 +5659,14 @@ int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu) guard(mutex)(&kvm->arch.config_lock); + if (kvm_vm_has_ran_once(kvm)) + return 0; + /* * This hacks into the ID registers, so only perform it when the * first vcpu runs, or the kvm_set_vm_id_reg() helper will scream. */ - if (!irqchip_in_kernel(kvm) && !kvm_vm_has_ran_once(kvm)) { + if (!irqchip_in_kernel(kvm)) { u64 val; val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;