/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
 *
 * Authors:
 *     Anup Patel <anup.patel@wdc.com>
 */

#ifndef __RISCV_KVM_HOST_H__
#define __RISCV_KVM_HOST_H__

#include <linux/types.h>
#include <linux/kvm.h>
#include <linux/kvm_types.h>
#include <linux/spinlock.h>
#include <asm/hwcap.h>
#include <asm/kvm_aia.h>
#include <asm/ptrace.h>
#include <asm/kvm_tlb.h>
#include <asm/kvm_vmid.h>
#include <asm/kvm_vcpu_fp.h>
#include <asm/kvm_vcpu_insn.h>
#include <asm/kvm_vcpu_sbi.h>
#include <asm/kvm_vcpu_sbi_fwft.h>
#include <asm/kvm_vcpu_timer.h>
#include <asm/kvm_vcpu_pmu.h>

#define KVM_MAX_VCPUS                   1024

#define KVM_HALT_POLL_NS_DEFAULT        500000

#define KVM_VCPU_MAX_FEATURES           0

#define KVM_IRQCHIP_NUM_PINS            1024

#define KVM_REQ_SLEEP \
        KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_VCPU_RESET              KVM_ARCH_REQ(1)
#define KVM_REQ_UPDATE_HGATP            KVM_ARCH_REQ(2)
#define KVM_REQ_FENCE_I                 \
        KVM_ARCH_REQ_FLAGS(3, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_HFENCE_VVMA_ALL         \
        KVM_ARCH_REQ_FLAGS(4, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_HFENCE                  \
        KVM_ARCH_REQ_FLAGS(5, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_STEAL_UPDATE            KVM_ARCH_REQ(6)

#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE

#define KVM_HEDELEG_DEFAULT             (BIT(EXC_INST_MISALIGNED) | \
                                         BIT(EXC_INST_ILLEGAL)     | \
                                         BIT(EXC_BREAKPOINT)      | \
                                         BIT(EXC_SYSCALL)         | \
                                         BIT(EXC_INST_PAGE_FAULT) | \
                                         BIT(EXC_LOAD_PAGE_FAULT) | \
                                         BIT(EXC_STORE_PAGE_FAULT))

#define KVM_HIDELEG_DEFAULT             (BIT(IRQ_VS_SOFT)  | \
                                         BIT(IRQ_VS_TIMER) | \
                                         BIT(IRQ_VS_EXT))

#define KVM_DIRTY_LOG_MANUAL_CAPS       (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \
                                         KVM_DIRTY_LOG_INITIALLY_SET)

struct kvm_vm_stat {
        struct kvm_vm_stat_generic generic;
};

struct kvm_vcpu_stat {
        struct kvm_vcpu_stat_generic generic;
        u64 ecall_exit_stat;
        u64 wfi_exit_stat;
        u64 wrs_exit_stat;
        u64 mmio_exit_user;
        u64 mmio_exit_kernel;
        u64 csr_exit_user;
        u64 csr_exit_kernel;
        u64 signal_exits;
        u64 exits;
        u64 instr_illegal_exits;
        u64 load_misaligned_exits;
        u64 store_misaligned_exits;
        u64 load_access_exits;
        u64 store_access_exits;
};

struct kvm_arch_memory_slot {
};

struct kvm_arch {
        /* G-stage vmid */
        struct kvm_vmid vmid;

        /* G-stage page table */
        pgd_t *pgd;
        phys_addr_t pgd_phys;

        /* Guest Timer */
        struct kvm_guest_timer timer;

        /* AIA Guest/VM context */
        struct kvm_aia aia;

        /* KVM_CAP_RISCV_MP_STATE_RESET */
        bool mp_state_reset;
};

struct kvm_cpu_trap {
        unsigned long sepc;
        unsigned long scause;
        unsigned long stval;
        unsigned long htval;
        unsigned long htinst;
};

struct kvm_cpu_context {
        unsigned long zero;
        unsigned long ra;
        unsigned long sp;
        unsigned long gp;
        unsigned long tp;
        unsigned long t0;
        unsigned long t1;
        unsigned long t2;
        unsigned long s0;
        unsigned long s1;
        unsigned long a0;
        unsigned long a1;
        unsigned long a2;
        unsigned long a3;
        unsigned long a4;
        unsigned long a5;
        unsigned long a6;
        unsigned long a7;
        unsigned long s2;
        unsigned long s3;
        unsigned long s4;
        unsigned long s5;
        unsigned long s6;
        unsigned long s7;
        unsigned long s8;
        unsigned long s9;
        unsigned long s10;
        unsigned long s11;
        unsigned long t3;
        unsigned long t4;
        unsigned long t5;
        unsigned long t6;
        unsigned long sepc;
        unsigned long sstatus;
        unsigned long hstatus;
        union __riscv_fp_state fp;
        struct __riscv_v_ext_state vector;
};

struct kvm_vcpu_csr {
        unsigned long vsstatus;
        unsigned long vsie;
        unsigned long vstvec;
        unsigned long vsscratch;
        unsigned long vsepc;
        unsigned long vscause;
        unsigned long vstval;
        unsigned long hvip;
        unsigned long vsatp;
        unsigned long scounteren;
        unsigned long senvcfg;
};

struct kvm_vcpu_config {
        u64 henvcfg;
        u64 hstateen0;
        unsigned long hedeleg;
};

struct kvm_vcpu_smstateen_csr {
        unsigned long sstateen0;
};

struct kvm_vcpu_reset_state {
        spinlock_t lock;
        unsigned long pc;
        unsigned long a1;
};

struct kvm_vcpu_arch {
        /* VCPU ran at least once */
        bool ran_atleast_once;

        /* Last Host CPU on which Guest VCPU exited */
        int last_exit_cpu;

        /* ISA feature bits (similar to MISA) */
        DECLARE_BITMAP(isa, RISCV_ISA_EXT_MAX);

        /* Vendor, Arch, and Implementation details */
        unsigned long mvendorid;
        unsigned long marchid;
        unsigned long mimpid;

        /* SSCRATCH, STVEC, and SCOUNTEREN of Host */
        unsigned long host_sscratch;
        unsigned long host_stvec;
        unsigned long host_scounteren;
        unsigned long host_senvcfg;
        unsigned long host_sstateen0;

        /* CPU context of Host */
        struct kvm_cpu_context host_context;

        /* CPU context of Guest VCPU */
        struct kvm_cpu_context guest_context;

        /* CPU CSR context of Guest VCPU */
        struct kvm_vcpu_csr guest_csr;

        /* CPU Smstateen CSR context of Guest VCPU */
        struct kvm_vcpu_smstateen_csr smstateen_csr;

        /* CPU reset state of Guest VCPU */
        struct kvm_vcpu_reset_state reset_state;

        /*
         * VCPU interrupts
         *
         * We have a lockless approach for tracking pending VCPU interrupts
         * implemented using atomic bitops. The irqs_pending bitmap represent
         * pending interrupts whereas irqs_pending_mask represent bits changed
         * in irqs_pending. Our approach is modeled around multiple producer
         * and single consumer problem where the consumer is the VCPU itself.
         */
#define KVM_RISCV_VCPU_NR_IRQS  64
        DECLARE_BITMAP(irqs_pending, KVM_RISCV_VCPU_NR_IRQS);
        DECLARE_BITMAP(irqs_pending_mask, KVM_RISCV_VCPU_NR_IRQS);

        /* VCPU Timer */
        struct kvm_vcpu_timer timer;

        /* HFENCE request queue */
        spinlock_t hfence_lock;
        unsigned long hfence_head;
        unsigned long hfence_tail;
        struct kvm_riscv_hfence hfence_queue[KVM_RISCV_VCPU_MAX_HFENCE];

        /* MMIO instruction details */
        struct kvm_mmio_decode mmio_decode;

        /* CSR instruction details */
        struct kvm_csr_decode csr_decode;

        /* SBI context */
        struct kvm_vcpu_sbi_context sbi_context;

        /* AIA VCPU context */
        struct kvm_vcpu_aia aia_context;

        /* Cache pages needed to program page tables with spinlock held */
        struct kvm_mmu_memory_cache mmu_page_cache;

        /* VCPU power state */
        struct kvm_mp_state mp_state;
        spinlock_t mp_state_lock;

        /* Don't run the VCPU (blocked) */
        bool pause;

        /* Performance monitoring context */
        struct kvm_pmu pmu_context;

        /* Firmware feature SBI extension context */
        struct kvm_sbi_fwft fwft_context;

        /* 'static' configurations which are set only once */
        struct kvm_vcpu_config cfg;

        /* SBI steal-time accounting */
        struct {
                gpa_t shmem;
                u64 last_steal;
        } sta;
};

/*
 * Returns true if a Performance Monitoring Interrupt (PMI), a.k.a. perf event,
 * arrived in guest context.  For riscv, any event that arrives while a vCPU is
 * loaded is considered to be "in guest".
 */
static inline bool kvm_arch_pmi_in_guest(struct kvm_vcpu *vcpu)
{
        return IS_ENABLED(CONFIG_GUEST_PERF_EVENTS) && !!vcpu;
}

static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}

int kvm_riscv_setup_default_irq_routing(struct kvm *kvm, u32 lines);

void __kvm_riscv_unpriv_trap(void);

unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
                                         bool read_insn,
                                         unsigned long guest_addr,
                                         struct kvm_cpu_trap *trap);
void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
                                  struct kvm_cpu_trap *trap);
int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
                        struct kvm_cpu_trap *trap);

void __kvm_riscv_switch_to(struct kvm_vcpu_arch *vcpu_arch);

void kvm_riscv_vcpu_setup_isa(struct kvm_vcpu *vcpu);
unsigned long kvm_riscv_vcpu_num_regs(struct kvm_vcpu *vcpu);
int kvm_riscv_vcpu_copy_reg_indices(struct kvm_vcpu *vcpu,
                                    u64 __user *uindices);
int kvm_riscv_vcpu_get_reg(struct kvm_vcpu *vcpu,
                           const struct kvm_one_reg *reg);
int kvm_riscv_vcpu_set_reg(struct kvm_vcpu *vcpu,
                           const struct kvm_one_reg *reg);

int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq);
int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq);
void kvm_riscv_vcpu_flush_interrupts(struct kvm_vcpu *vcpu);
void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu);
bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask);
void __kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu);
void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu);
void __kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu);
void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu);
bool kvm_riscv_vcpu_stopped(struct kvm_vcpu *vcpu);

void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu);

/* Flags representing implementation specific details */
DECLARE_STATIC_KEY_FALSE(kvm_riscv_vsstage_tlb_no_gpa);

#endif /* __RISCV_KVM_HOST_H__ */