arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 205 insertions, 0 deletions

diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
new file mode 100644
index 000000000..6b4a118d1
--- /dev/null
+++ b/include/kvm/arm_pmu.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Shannon Zhao <shannon.zhao@linaro.org>
+ */
+
+#ifndef __ASM_ARM_KVM_PMU_H
+#define __ASM_ARM_KVM_PMU_H
+
+#include <linux/perf_event.h>
+#include <linux/perf/arm_pmuv3.h>
+
+#define KVM_ARMV8_PMU_MAX_COUNTERS	32
+
+/* PPI #23 - architecturally specified for GICv5 */
+#define KVM_ARMV8_PMU_GICV5_IRQ		0x20000017
+
+#if IS_ENABLED(CONFIG_HW_PERF_EVENTS) && IS_ENABLED(CONFIG_KVM)
+struct kvm_pmc {
+	u8 idx;	/* index into the pmu->pmc array */
+	struct perf_event *perf_event;
+};
+
+struct kvm_pmu_events {
+	u64 events_host;
+	u64 events_guest;
+};
+
+struct kvm_pmu {
+	struct irq_work overflow_work;
+	struct kvm_pmu_events events;
+	struct kvm_pmc pmc[KVM_ARMV8_PMU_MAX_COUNTERS];
+	int irq_num;
+	bool created;
+};
+
+struct arm_pmu_entry {
+	struct list_head entry;
+	struct arm_pmu *arm_pmu;
+};
+
+bool kvm_supports_guest_pmuv3(void);
+#define kvm_arm_pmu_irq_initialized(v)	((v)->arch.pmu.irq_num != 0)
+u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
+void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
+void kvm_pmu_set_counter_value_user(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
+u64 kvm_pmu_implemented_counter_mask(struct kvm_vcpu *vcpu);
+u64 kvm_pmu_accessible_counter_mask(struct kvm_vcpu *vcpu);
+u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1);
+void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu);
+void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu);
+void kvm_pmu_reprogram_counter_mask(struct kvm_vcpu *vcpu, u64 val);
+void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu);
+void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu);
+bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu);
+bool kvm_pmu_update_run(struct kvm_vcpu *vcpu);
+void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);
+void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);
+void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
+				    u64 select_idx);
+void kvm_vcpu_reload_pmu(struct kvm_vcpu *vcpu);
+int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu,
+			    struct kvm_device_attr *attr);
+int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu,
+			    struct kvm_device_attr *attr);
+int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu,
+			    struct kvm_device_attr *attr);
+int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu);
+
+struct kvm_pmu_events *kvm_get_pmu_events(void);
+void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu);
+void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);
+void kvm_vcpu_pmu_resync_el0(void);
+
+#define kvm_vcpu_has_pmu(vcpu)					\
+	(vcpu_has_feature(vcpu, KVM_ARM_VCPU_PMU_V3))
+
+#define kvm_vcpu_has_pmuv3_strict(vcpu)				\
+	(vcpu_has_feature(vcpu, KVM_ARM_VCPU_PMU_V3_STRICT))
+
+/*
+ * Updates the vcpu's view of the pmu events for this cpu.
+ * Must be called before every vcpu run after disabling interrupts, to ensure
+ * that an interrupt cannot fire and update the structure.
+ */
+#define kvm_pmu_update_vcpu_events(vcpu)				\
+	do {								\
+		if (!has_vhe() && system_supports_pmuv3())		\
+			vcpu->arch.pmu.events = *kvm_get_pmu_events();	\
+	} while (0)
+
+u8 kvm_arm_pmu_get_pmuver_limit(void);
+u64 kvm_pmu_evtyper_mask(struct kvm *kvm);
+int kvm_arm_set_default_pmu(struct kvm *kvm);
+u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm);
+
+u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu);
+bool kvm_pmu_counter_is_hyp(struct kvm_vcpu *vcpu, unsigned int idx);
+void kvm_pmu_nested_transition(struct kvm_vcpu *vcpu);
+#else
+struct kvm_pmu {
+};
+
+static inline bool kvm_supports_guest_pmuv3(void)
+{
+	return false;
+}
+
+#define kvm_arm_pmu_irq_initialized(v)	(false)
+static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu,
+					    u64 select_idx)
+{
+	return 0;
+}
+static inline void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu,
+					     u64 select_idx, u64 val) {}
+static inline void kvm_pmu_set_counter_value_user(struct kvm_vcpu *vcpu,
+						  u64 select_idx, u64 val) {}
+static inline u64 kvm_pmu_implemented_counter_mask(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+static inline u64 kvm_pmu_accessible_counter_mask(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+static inline void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu) {}
+static inline void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu) {}
+static inline void kvm_pmu_reprogram_counter_mask(struct kvm_vcpu *vcpu, u64 val) {}
+static inline void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) {}
+static inline void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) {}
+static inline bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
+{
+	return false;
+}
+static inline bool kvm_pmu_update_run(struct kvm_vcpu *vcpu) { return false; }
+static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}
+static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}
+static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
+						  u64 data, u64 select_idx) {}
+static inline int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu,
+					  struct kvm_device_attr *attr)
+{
+	return -ENXIO;
+}
+static inline int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu,
+					  struct kvm_device_attr *attr)
+{
+	return -ENXIO;
+}
+static inline int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu,
+					  struct kvm_device_attr *attr)
+{
+	return -ENXIO;
+}
+static inline int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
+{
+	return 0;
+}
+
+#define kvm_vcpu_has_pmu(vcpu)		({ false; })
+#define kvm_vcpu_has_pmuv3_strict(vcpu)	({ false; })
+static inline void kvm_pmu_update_vcpu_events(struct kvm_vcpu *vcpu) {}
+static inline void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu) {}
+static inline void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) {}
+static inline void kvm_vcpu_reload_pmu(struct kvm_vcpu *vcpu) {}
+static inline u8 kvm_arm_pmu_get_pmuver_limit(void)
+{
+	return 0;
+}
+static inline u64 kvm_pmu_evtyper_mask(struct kvm *kvm)
+{
+	return 0;
+}
+static inline void kvm_vcpu_pmu_resync_el0(void) {}
+
+static inline int kvm_arm_set_default_pmu(struct kvm *kvm)
+{
+	return -ENODEV;
+}
+
+static inline u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm)
+{
+	return 0;
+}
+
+static inline u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+static inline bool kvm_pmu_counter_is_hyp(struct kvm_vcpu *vcpu, unsigned int idx)
+{
+	return false;
+}
+
+static inline void kvm_pmu_nested_transition(struct kvm_vcpu *vcpu) {}
+
+#endif
+
+#endif