[v20,01/30] LoongArch: KVM: Add kvm related header files

diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
new file mode 100644
index 0000000000..9f23ddaaae
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -0,0 +1,238 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_LOONGARCH_KVM_HOST_H__
+#define __ASM_LOONGARCH_KVM_HOST_H__
+
+#include <linux/cpumask.h>
+#include <linux/mutex.h>
+#include <linux/hrtimer.h>
+#include <linux/interrupt.h>
+#include <linux/types.h>
+#include <linux/kvm.h>
+#include <linux/kvm_types.h>
+#include <linux/threads.h>
+#include <linux/spinlock.h>
+
+#include <asm/inst.h>
+#include <asm/loongarch.h>
+
+/* Loongarch KVM register ids */
+#define LOONGARCH_CSR_32(_R, _S)	\
+	(KVM_REG_LOONGARCH_CSR | KVM_REG_SIZE_U32 | (8 * (_R) + (_S)))
+
+#define LOONGARCH_CSR_64(_R, _S)	\
+	(KVM_REG_LOONGARCH_CSR | KVM_REG_SIZE_U64 | (8 * (_R) + (_S)))
+
+#define KVM_IOC_CSRID(id)		LOONGARCH_CSR_64(id, 0)
+#define KVM_GET_IOC_CSRIDX(id)		((id & KVM_CSR_IDX_MASK) >> 3)
+
+#define KVM_MAX_VCPUS			256
+/* memory slots that does not exposed to userspace */
+#define KVM_PRIVATE_MEM_SLOTS		0
+
+#define KVM_HALT_POLL_NS_DEFAULT	500000
+
+struct kvm_vm_stat {
+	struct kvm_vm_stat_generic generic;
+};
+
+struct kvm_vcpu_stat {
+	struct kvm_vcpu_stat_generic generic;
+	u64 idle_exits;
+	u64 signal_exits;
+	u64 int_exits;
+	u64 cpucfg_exits;
+};
+
+struct kvm_arch_memory_slot {
+};
+
+struct kvm_context {
+	unsigned long vpid_cache;
+	struct kvm_vcpu *last_vcpu;
+};
+
+struct kvm_world_switch {
+	int (*guest_eentry)(void);
+	int (*enter_guest)(struct kvm_run *run, struct kvm_vcpu *vcpu);
+	unsigned long page_order;
+};
+
+struct kvm_arch {
+	/* Guest physical mm */
+	pgd_t *pgd;
+	unsigned long gpa_size;
+
+	s64 time_offset;
+	struct kvm_context __percpu *vmcs;
+};
+
+#define CSR_MAX_NUMS		0x800
+
+struct loongarch_csrs {
+	unsigned long csrs[CSR_MAX_NUMS];
+};
+
+/* Resume Flags */
+#define RESUME_HOST		0
+#define RESUME_GUEST		1
+
+enum emulation_result {
+	EMULATE_DONE,		/* no further processing */
+	EMULATE_DO_MMIO,	/* kvm_run filled with MMIO request */
+	EMULATE_FAIL,		/* can't emulate this instruction */
+	EMULATE_EXCEPT,		/* A guest exception has been generated */
+	EMULATE_DO_IOCSR,	/* handle IOCSR request */
+};
+
+#define KVM_LARCH_CSR		(0x1 << 1)
+#define KVM_LARCH_FPU		(0x1 << 0)
+
+struct kvm_vcpu_arch {
+	/*
+	 * Switch pointer-to-function type to unsigned long
+	 * for loading the value into register directly.
+	 */
+	unsigned long host_eentry;
+	unsigned long guest_eentry;
+
+	/* Pointers stored here for easy accessing from assembly code */
+	int (*handle_exit)(struct kvm_run *run, struct kvm_vcpu *vcpu);
+
+	/* Host registers preserved across guest mode execution */
+	unsigned long host_sp;
+	unsigned long host_tp;
+	unsigned long host_pgd;
+
+	/* Host CSRs are used when handling exits from guest */
+	unsigned long badi;
+	unsigned long badv;
+	unsigned long host_ecfg;
+	unsigned long host_estat;
+	unsigned long host_percpu;
+
+	/* GPRs */
+	unsigned long gprs[32];
+	unsigned long pc;
+
+	/* Which auxiliary state is loaded (KVM_LOONGARCH_AUX_*) */
+	unsigned int aux_inuse;
+	/* FPU state */
+	struct loongarch_fpu fpu FPU_ALIGN;
+
+	/* CSR state */
+	struct loongarch_csrs *csr;
+
+	/* GPR used as IO source/target */
+	u32 io_gpr;
+
+	struct hrtimer swtimer;
+	/* KVM register to control count timer */
+	u32 count_ctl;
+
+	/* Bitmask of exceptions that are pending */
+	unsigned long irq_pending;
+	/* Bitmask of pending exceptions to be cleared */
+	unsigned long irq_clear;
+
+	/* Cache for pages needed inside spinlock regions */
+	struct kvm_mmu_memory_cache mmu_page_cache;
+
+	/* vcpu's vpid */
+	u64 vpid;
+
+	/* Frequency of stable timer in Hz */
+	u64 timer_mhz;
+	ktime_t expire;
+
+	u64 core_ext_ioisr[4];
+
+	/* Last CPU the vCPU state was loaded on */
+	int last_sched_cpu;
+	/* mp state */
+	struct kvm_mp_state mp_state;
+};
+
+static inline unsigned long readl_sw_gcsr(struct loongarch_csrs *csr, int reg)
+{
+	return csr->csrs[reg];
+}
+
+static inline void writel_sw_gcsr(struct loongarch_csrs *csr, int reg, unsigned long val)
+{
+	csr->csrs[reg] = val;
+}
+
+/* Helpers */
+static inline bool _kvm_guest_has_fpu(struct kvm_vcpu_arch *arch)
+{
+	return cpu_has_fpu;
+}
+
+void _kvm_init_fault(void);
+
+/* Debug: dump vcpu state */
+int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
+
+/* MMU handling */
+int kvm_handle_mm_fault(struct kvm_vcpu *vcpu, unsigned long badv, bool write);
+void kvm_flush_tlb_all(void);
+void _kvm_destroy_mm(struct kvm *kvm);
+pgd_t *kvm_pgd_alloc(void);
+
+#define KVM_ARCH_WANT_MMU_NOTIFIER
+int kvm_unmap_hva_range(struct kvm *kvm,
+			unsigned long start, unsigned long end, bool blockable);
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
+int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
+int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
+
+static inline void update_pc(struct kvm_vcpu_arch *arch)
+{
+	arch->pc += 4;
+}
+
+/**
+ * kvm_is_ifetch_fault() - Find whether a TLBL exception is due to ifetch fault.
+ * @vcpu:	Virtual CPU.
+ *
+ * Returns:	Whether the TLBL exception was likely due to an instruction
+ *		fetch fault rather than a data load fault.
+ */
+static inline bool kvm_is_ifetch_fault(struct kvm_vcpu_arch *arch)
+{
+	return arch->pc == arch->badv;
+}
+
+/* Misc */
+static inline void kvm_arch_hardware_unsetup(void) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_free_memslot(struct kvm *kvm,
+				   struct kvm_memory_slot *slot) {}
+void _kvm_check_vmid(struct kvm_vcpu *vcpu);
+enum hrtimer_restart kvm_swtimer_wakeup(struct hrtimer *timer);
+int kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa);
+void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
+					const struct kvm_memory_slot *memslot);
+void kvm_init_vmcs(struct kvm *kvm);
+void kvm_vector_entry(void);
+int  kvm_enter_guest(struct kvm_run *run, struct kvm_vcpu *vcpu);
+extern const unsigned long kvm_vector_size;
+extern const unsigned long kvm_enter_guest_size;
+extern unsigned long vpid_mask;
+extern struct kvm_world_switch *kvm_loongarch_ops;
+
+#define SW_GCSR		(1 << 0)
+#define HW_GCSR		(1 << 1)
+#define INVALID_GCSR	(1 << 2)
+int get_gcsr_flag(int csr);
+extern void set_hw_gcsr(int csr_id, unsigned long val);
+#endif /* __ASM_LOONGARCH_KVM_HOST_H__ */
diff --git a/arch/loongarch/include/asm/kvm_types.h b/arch/loongarch/include/asm/kvm_types.h
new file mode 100644
index 0000000000..2fe1d4bdff
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_types.h
@@ -0,0 +1,11 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef _ASM_LOONGARCH_KVM_TYPES_H
+#define _ASM_LOONGARCH_KVM_TYPES_H
+
+#define KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE	40
+
+#endif /* _ASM_LOONGARCH_KVM_TYPES_H */
diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
new file mode 100644
index 0000000000..7ec2f34018
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -0,0 +1,101 @@ 
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef __UAPI_ASM_LOONGARCH_KVM_H
+#define __UAPI_ASM_LOONGARCH_KVM_H
+
+#include <linux/types.h>
+
+/*
+ * KVM Loongarch specific structures and definitions.
+ *
+ * Some parts derived from the x86 version of this file.
+ */
+
+#define __KVM_HAVE_READONLY_MEM
+
+#define KVM_COALESCED_MMIO_PAGE_OFFSET	1
+#define KVM_DIRTY_LOG_PAGE_OFFSET	64
+
+/*
+ * for KVM_GET_REGS and KVM_SET_REGS
+ */
+struct kvm_regs {
+	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+	__u64 gpr[32];
+	__u64 pc;
+};
+
+/*
+ * for KVM_GET_FPU and KVM_SET_FPU
+ */
+struct kvm_fpu {
+	__u32 fcsr;
+	__u64 fcc;    /* 8x8 */
+	struct kvm_fpureg {
+		__u64 val64[4];
+	} fpr[32];
+};
+
+/*
+ * For LoongArch, we use KVM_SET_ONE_REG and KVM_GET_ONE_REG to access various
+ * registers.  The id field is broken down as follows:
+ *
+ *  bits[63..52] - As per linux/kvm.h
+ *  bits[51..32] - Must be zero.
+ *  bits[31..16] - Register set.
+ *
+ * Register set = 0: GP registers from kvm_regs (see definitions below).
+ *
+ * Register set = 1: CSR registers.
+ *
+ * Register set = 2: KVM specific registers (see definitions below).
+ *
+ * Register set = 3: FPU / SIMD registers (see definitions below).
+ *
+ * Other sets registers may be added in the future.  Each set would
+ * have its own identifier in bits[31..16].
+ */
+
+#define KVM_REG_LOONGARCH_GPR		(KVM_REG_LOONGARCH | 0x00000ULL)
+#define KVM_REG_LOONGARCH_CSR		(KVM_REG_LOONGARCH | 0x10000ULL)
+#define KVM_REG_LOONGARCH_KVM		(KVM_REG_LOONGARCH | 0x20000ULL)
+#define KVM_REG_LOONGARCH_FPU		(KVM_REG_LOONGARCH | 0x30000ULL)
+#define KVM_REG_LOONGARCH_MASK		(KVM_REG_LOONGARCH | 0x30000ULL)
+#define KVM_CSR_IDX_MASK		(0x10000 - 1)
+
+/*
+ * KVM_REG_LOONGARCH_KVM - KVM specific control registers.
+ */
+
+#define KVM_REG_LOONGARCH_COUNTER	(KVM_REG_LOONGARCH_KVM | KVM_REG_SIZE_U64 | 3)
+#define KVM_REG_LOONGARCH_VCPU_RESET	(KVM_REG_LOONGARCH_KVM | KVM_REG_SIZE_U64 | 4)
+
+struct kvm_debug_exit_arch {
+};
+
+/* for KVM_SET_GUEST_DEBUG */
+struct kvm_guest_debug_arch {
+};
+
+/* definition of registers in kvm_run */
+struct kvm_sync_regs {
+};
+
+/* dummy definition */
+struct kvm_sregs {
+};
+
+struct kvm_iocsr_entry {
+	__u32 addr;
+	__u32 pad;
+	__u64 data;
+};
+
+#define KVM_NR_IRQCHIPS		1
+#define KVM_IRQCHIP_NUM_PINS	64
+#define KVM_MAX_CORES		256
+
+#endif /* __UAPI_ASM_LOONGARCH_KVM_H */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f089ab2909..1184171224 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -264,6 +264,7 @@  struct kvm_xen_exit {
 #define KVM_EXIT_RISCV_SBI        35
 #define KVM_EXIT_RISCV_CSR        36
 #define KVM_EXIT_NOTIFY           37
+#define KVM_EXIT_LOONGARCH_IOCSR  38
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 /* Emulate instruction failed. */
@@ -336,6 +337,13 @@  struct kvm_run {
 			__u32 len;
 			__u8  is_write;
 		} mmio;
+		/* KVM_EXIT_LOONGARCH_IOCSR */
+		struct {
+			__u64 phys_addr;
+			__u8  data[8];
+			__u32 len;
+			__u8  is_write;
+		} iocsr_io;
 		/* KVM_EXIT_HYPERCALL */
 		struct {
 			__u64 nr;
@@ -1362,6 +1370,7 @@  struct kvm_dirty_tlb {
 #define KVM_REG_ARM64		0x6000000000000000ULL
 #define KVM_REG_MIPS		0x7000000000000000ULL
 #define KVM_REG_RISCV		0x8000000000000000ULL
+#define KVM_REG_LOONGARCH	0x9000000000000000ULL
 
 #define KVM_REG_SIZE_SHIFT	52
 #define KVM_REG_SIZE_MASK	0x00f0000000000000ULL