kvm: arm64: Create separate instances of kvm_host_data for VHE/nVHE

Host CPU context is stored in a global per-cpu variable `kvm_host_data`.
In preparation for introducing independent per-CPU region for nVHE hyp,
create two separate instances of `kvm_host_data`, one for VHE and one
for nVHE.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-9-dbrazdil@google.com

arch/arm64/include/asm/kvm_host.h

@@ -565,7 +565,7 @@ void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
 
-DECLARE_PER_CPU(kvm_host_data_t, kvm_host_data);
+DECLARE_KVM_HYP_PER_CPU(kvm_host_data_t, kvm_host_data);
 
 static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt)
 {

arch/arm64/kernel/image-vars.h

@@ -67,7 +67,6 @@ KVM_NVHE_ALIAS(kvm_patch_vector_branch);
 KVM_NVHE_ALIAS(kvm_update_va_mask);
 
 /* Global kernel state accessed by nVHE hyp code. */
-KVM_NVHE_ALIAS(kvm_host_data);
 KVM_NVHE_ALIAS(kvm_vgic_global_state);
 
 /* Kernel constant needed to compute idmap addresses. */

arch/arm64/kvm/arm.c

@@ -46,7 +46,6 @@
 __asm__(".arch_extension	virt");
 #endif
 
-DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
 static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
 
 /* The VMID used in the VTTBR */
@@ -1308,7 +1307,7 @@ static void cpu_hyp_reset(void)
 
 static void cpu_hyp_reinit(void)
 {
-	kvm_init_host_cpu_context(&this_cpu_ptr(&kvm_host_data)->host_ctxt);
+	kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt);
 
 	cpu_hyp_reset();
 
@@ -1543,7 +1542,7 @@ static int init_hyp_mode(void)
 	for_each_possible_cpu(cpu) {
 		kvm_host_data_t *cpu_data;
 
-		cpu_data = per_cpu_ptr(&kvm_host_data, cpu);
+		cpu_data = per_cpu_ptr_hyp_sym(kvm_host_data, cpu);
 		err = create_hyp_mappings(cpu_data, cpu_data + 1, PAGE_HYP);
 
 		if (err) {

arch/arm64/kvm/hyp/nvhe/switch.c

@@ -30,6 +30,9 @@
 /* Non-VHE copy of the kernel symbol. */
 DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
 
+/* Non-VHE instance of kvm_host_data. */
+DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
+
 static void __activate_traps(struct kvm_vcpu *vcpu)
 {
 	u64 val;

arch/arm64/kvm/hyp/vhe/switch.c

@@ -28,6 +28,9 @@
 
 const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n";
 
+/* VHE instance of kvm_host_data. */
+DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data);
+
 static void __activate_traps(struct kvm_vcpu *vcpu)
 {
 	u64 val;

arch/arm64/kvm/pmu.c

@@ -31,7 +31,7 @@ static bool kvm_pmu_switch_needed(struct perf_event_attr *attr)
  */
 void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr)
 {
-	struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data);
+	struct kvm_host_data *ctx = this_cpu_ptr_hyp_sym(kvm_host_data);
 
 	if (!kvm_pmu_switch_needed(attr))
 		return;
@@ -47,7 +47,7 @@ void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr)
  */
 void kvm_clr_pmu_events(u32 clr)
 {
-	struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data);
+	struct kvm_host_data *ctx = this_cpu_ptr_hyp_sym(kvm_host_data);
 
 	ctx->pmu_events.events_host &= ~clr;
 	ctx->pmu_events.events_guest &= ~clr;
@@ -173,7 +173,7 @@ void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu)
 		return;
 
 	preempt_disable();
-	host = this_cpu_ptr(&kvm_host_data);
+	host = this_cpu_ptr_hyp_sym(kvm_host_data);
 	events_guest = host->pmu_events.events_guest;
 	events_host = host->pmu_events.events_host;
 
@@ -193,7 +193,7 @@ void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu)
 	if (!has_vhe())
 		return;
 
-	host = this_cpu_ptr(&kvm_host_data);
+	host = this_cpu_ptr_hyp_sym(kvm_host_data);
 	events_guest = host->pmu_events.events_guest;
 	events_host = host->pmu_events.events_host;