Merge tag 'kvmarm-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.16

- More progress on the protected VM front, now with the full
  fixed feature set as well as the limitation of some hypercalls
  after initialisation.

- Cleanup of the RAZ/WI sysreg handling, which was pointlessly
  complicated

- Fixes for the vgic placement in the IPA space, together with a
  bunch of selftests

- More memcg accounting of the memory allocated on behalf of a guest

- Timer and vgic selftests

- Workarounds for the Apple M1 broken vgic implementation

- KConfig cleanups

- New kvmarm.mode=none option, for those who really dislike us

1 files changed, 72 insertions, 22 deletions

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 7838e9fb693e..f5490afe1ebf 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -291,10 +291,12 @@ long kvm_arch_dev_ioctl(struct file *filp,
 
 struct kvm *kvm_arch_alloc_vm(void)
 {
+	size_t sz = sizeof(struct kvm);
+
 	if (!has_vhe())
-		return kzalloc(sizeof(struct kvm), GFP_KERNEL);
+		return kzalloc(sz, GFP_KERNEL_ACCOUNT);
 
-	return vzalloc(sizeof(struct kvm));
+	return __vmalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM | __GFP_ZERO);
 }
 
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
@@ -612,6 +614,14 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
 
 	ret = kvm_arm_pmu_v3_enable(vcpu);
 
+	/*
+	 * Initialize traps for protected VMs.
+	 * NOTE: Move to run in EL2 directly, rather than via a hypercall, once
+	 * the code is in place for first run initialization at EL2.
+	 */
+	if (kvm_vm_is_protected(kvm))
+		kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu);
+
 	return ret;
 }
 
@@ -1571,25 +1581,33 @@ static void cpu_set_hyp_vector(void)
 		kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot);
 }
 
-static void cpu_hyp_reinit(void)
+static void cpu_hyp_init_context(void)
 {
 	kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt);
 
-	cpu_hyp_reset();
-
-	if (is_kernel_in_hyp_mode())
-		kvm_timer_init_vhe();
-	else
+	if (!is_kernel_in_hyp_mode())
 		cpu_init_hyp_mode();
+}
 
+static void cpu_hyp_init_features(void)
+{
 	cpu_set_hyp_vector();
-
 	kvm_arm_init_debug();
 
+	if (is_kernel_in_hyp_mode())
+		kvm_timer_init_vhe();
+
 	if (vgic_present)
 		kvm_vgic_init_cpu_hardware();
 }
 
+static void cpu_hyp_reinit(void)
+{
+	cpu_hyp_reset();
+	cpu_hyp_init_context();
+	cpu_hyp_init_features();
+}
+
 static void _kvm_arch_hardware_enable(void *discard)
 {
 	if (!__this_cpu_read(kvm_arm_hardware_enabled)) {
@@ -1780,10 +1798,17 @@ static int do_pkvm_init(u32 hyp_va_bits)
 	int ret;
 
 	preempt_disable();
-	hyp_install_host_vector();
+	cpu_hyp_init_context();
 	ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size,
 				num_possible_cpus(), kern_hyp_va(per_cpu_base),
 				hyp_va_bits);
+	cpu_hyp_init_features();
+
+	/*
+	 * The stub hypercalls are now disabled, so set our local flag to
+	 * prevent a later re-init attempt in kvm_arch_hardware_enable().
+	 */
+	__this_cpu_write(kvm_arm_hardware_enabled, 1);
 	preempt_enable();
 
 	return ret;
@@ -1794,8 +1819,13 @@ static int kvm_hyp_init_protection(u32 hyp_va_bits)
 	void *addr = phys_to_virt(hyp_mem_base);
 	int ret;
 
+	kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
+	kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
+	kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1);
+	kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
 	kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
 	kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+	kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1);
 
 	ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP);
 	if (ret)
@@ -1963,9 +1993,25 @@ out_err:
 	return err;
 }
 
-static void _kvm_host_prot_finalize(void *discard)
+static void _kvm_host_prot_finalize(void *arg)
 {
-	WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize));
+	int *err = arg;
+
+	if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)))
+		WRITE_ONCE(*err, -EINVAL);
+}
+
+static int pkvm_drop_host_privileges(void)
+{
+	int ret = 0;
+
+	/*
+	 * Flip the static key upfront as that may no longer be possible
+	 * once the host stage 2 is installed.
+	 */
+	static_branch_enable(&kvm_protected_mode_initialized);
+	on_each_cpu(_kvm_host_prot_finalize, &ret, 1);
+	return ret;
 }
 
 static int finalize_hyp_mode(void)
@@ -1979,15 +2025,7 @@ static int finalize_hyp_mode(void)
 	 * None of other sections should ever be introspected.
 	 */
 	kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);
-
-	/*
-	 * Flip the static key upfront as that may no longer be possible
-	 * once the host stage 2 is installed.
-	 */
-	static_branch_enable(&kvm_protected_mode_initialized);
-	on_each_cpu(_kvm_host_prot_finalize, NULL, 1);
-
-	return 0;
+	return pkvm_drop_host_privileges();
 }
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
@@ -2056,6 +2094,11 @@ int kvm_arch_init(void *opaque)
 		return -ENODEV;
 	}
 
+	if (kvm_get_mode() == KVM_MODE_NONE) {
+		kvm_info("KVM disabled from command line\n");
+		return -ENODEV;
+	}
+
 	in_hyp_mode = is_kernel_in_hyp_mode();
 
 	if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
@@ -2129,8 +2172,15 @@ static int __init early_kvm_mode_cfg(char *arg)
 		return 0;
 	}
 
-	if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode()))
+	if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode())) {
+		kvm_mode = KVM_MODE_DEFAULT;
+		return 0;
+	}
+
+	if (strcmp(arg, "none") == 0) {
+		kvm_mode = KVM_MODE_NONE;
 		return 0;
+	}
 
 	return -EINVAL;
 }