arm64: KVM: Skip HYP setup when already running in HYP
With the kernel running at EL2, there is no point trying to
configure page tables for HYP, as the kernel is already mapped.
Take this opportunity to refactor the whole init a bit, allowing
the various parts of the hypervisor bringup to be split across
multiple functions.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index fcf6c13..686350d 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -967,6 +967,11 @@
}
}
+static void cpu_init_stage2(void *dummy)
+{
+ __cpu_init_stage2();
+}
+
static void cpu_init_hyp_mode(void *dummy)
{
phys_addr_t boot_pgd_ptr;
@@ -1036,6 +1041,82 @@
}
#endif
+static void teardown_common_resources(void)
+{
+ free_percpu(kvm_host_cpu_state);
+}
+
+static int init_common_resources(void)
+{
+ kvm_host_cpu_state = alloc_percpu(kvm_cpu_context_t);
+ if (!kvm_host_cpu_state) {
+ kvm_err("Cannot allocate host CPU state\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int init_subsystems(void)
+{
+ int err;
+
+ /*
+ * Init HYP view of VGIC
+ */
+ err = kvm_vgic_hyp_init();
+ switch (err) {
+ case 0:
+ vgic_present = true;
+ break;
+ case -ENODEV:
+ case -ENXIO:
+ vgic_present = false;
+ break;
+ default:
+ return err;
+ }
+
+ /*
+ * Init HYP architected timer support
+ */
+ err = kvm_timer_hyp_init();
+ if (err)
+ return err;
+
+ kvm_perf_init();
+ kvm_coproc_table_init();
+
+ return 0;
+}
+
+static void teardown_hyp_mode(void)
+{
+ int cpu;
+
+ if (is_kernel_in_hyp_mode())
+ return;
+
+ free_hyp_pgds();
+ for_each_possible_cpu(cpu)
+ free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
+}
+
+static int init_vhe_mode(void)
+{
+ /*
+ * Execute the init code on each CPU.
+ */
+ on_each_cpu(cpu_init_stage2, NULL, 1);
+
+ /* set size of VMID supported by CPU */
+ kvm_vmid_bits = kvm_get_vmid_bits();
+ kvm_info("%d-bit VMID\n", kvm_vmid_bits);
+
+ kvm_info("VHE mode initialized successfully\n");
+ return 0;
+}
+
/**
* Inits Hyp-mode on all online CPUs
*/
@@ -1066,7 +1147,7 @@
stack_page = __get_free_page(GFP_KERNEL);
if (!stack_page) {
err = -ENOMEM;
- goto out_free_stack_pages;
+ goto out_err;
}
per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
@@ -1078,13 +1159,13 @@
err = create_hyp_mappings(__hyp_text_start, __hyp_text_end);
if (err) {
kvm_err("Cannot map world-switch code\n");
- goto out_free_mappings;
+ goto out_err;
}
err = create_hyp_mappings(__start_rodata, __end_rodata);
if (err) {
kvm_err("Cannot map rodata section\n");
- goto out_free_mappings;
+ goto out_err;
}
/*
@@ -1096,20 +1177,10 @@
if (err) {
kvm_err("Cannot map hyp stack\n");
- goto out_free_mappings;
+ goto out_err;
}
}
- /*
- * Map the host CPU structures
- */
- kvm_host_cpu_state = alloc_percpu(kvm_cpu_context_t);
- if (!kvm_host_cpu_state) {
- err = -ENOMEM;
- kvm_err("Cannot allocate host CPU state\n");
- goto out_free_mappings;
- }
-
for_each_possible_cpu(cpu) {
kvm_cpu_context_t *cpu_ctxt;
@@ -1118,7 +1189,7 @@
if (err) {
kvm_err("Cannot map host CPU state: %d\n", err);
- goto out_free_context;
+ goto out_err;
}
}
@@ -1127,34 +1198,22 @@
*/
on_each_cpu(cpu_init_hyp_mode, NULL, 1);
- /*
- * Init HYP view of VGIC
- */
- err = kvm_vgic_hyp_init();
- switch (err) {
- case 0:
- vgic_present = true;
- break;
- case -ENODEV:
- case -ENXIO:
- vgic_present = false;
- break;
- default:
- goto out_free_context;
- }
-
- /*
- * Init HYP architected timer support
- */
- err = kvm_timer_hyp_init();
- if (err)
- goto out_free_context;
-
#ifndef CONFIG_HOTPLUG_CPU
free_boot_hyp_pgd();
#endif
- kvm_perf_init();
+ cpu_notifier_register_begin();
+
+ err = __register_cpu_notifier(&hyp_init_cpu_nb);
+
+ cpu_notifier_register_done();
+
+ if (err) {
+ kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);
+ goto out_err;
+ }
+
+ hyp_cpu_pm_init();
/* set size of VMID supported by CPU */
kvm_vmid_bits = kvm_get_vmid_bits();
@@ -1163,14 +1222,9 @@
kvm_info("Hyp mode initialized successfully\n");
return 0;
-out_free_context:
- free_percpu(kvm_host_cpu_state);
-out_free_mappings:
- free_hyp_pgds();
-out_free_stack_pages:
- for_each_possible_cpu(cpu)
- free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
+
out_err:
+ teardown_hyp_mode();
kvm_err("error initializing Hyp mode: %d\n", err);
return err;
}
@@ -1214,26 +1268,27 @@
}
}
- cpu_notifier_register_begin();
+ err = init_common_resources();
+ if (err)
+ return err;
- err = init_hyp_mode();
+ if (is_kernel_in_hyp_mode())
+ err = init_vhe_mode();
+ else
+ err = init_hyp_mode();
if (err)
goto out_err;
- err = __register_cpu_notifier(&hyp_init_cpu_nb);
- if (err) {
- kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);
- goto out_err;
- }
+ err = init_subsystems();
+ if (err)
+ goto out_hyp;
- cpu_notifier_register_done();
-
- hyp_cpu_pm_init();
-
- kvm_coproc_table_init();
return 0;
+
+out_hyp:
+ teardown_hyp_mode();
out_err:
- cpu_notifier_register_done();
+ teardown_common_resources();
return err;
}