    /******************************************************************************
     * vm_event.h
     *
     * Memory event common structures.
     *
     * Copyright (c) 2009 by Citrix Systems, Inc. (Patrick Colp)
     *
     * Permission is hereby granted, free of charge, to any person obtaining a copy
     * of this software and associated documentation files (the "Software"), to
     * deal in the Software without restriction, including without limitation the
     * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     * sell copies of the Software, and to permit persons to whom the Software is
     * furnished to do so, subject to the following conditions:
     *
     * The above copyright notice and this permission notice shall be included in
     * all copies or substantial portions of the Software.
     *
     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     * DEALINGS IN THE SOFTWARE.
     */

    #ifndef _XEN_PUBLIC_VM_EVENT_H
    #define _XEN_PUBLIC_VM_EVENT_H

    #include "xen.h"

    #define VM_EVENT_INTERFACE_VERSION 0x00000002

    #if defined(__XEN__) || defined(__XEN_TOOLS__)

    #include "io/ring.h"

    /*
     * Memory event flags
     */

    /*
     * VCPU_PAUSED in a request signals that the vCPU triggering the event has been
     *  paused
     * VCPU_PAUSED in a response signals to unpause the vCPU
     */
    #define VM_EVENT_FLAG_VCPU_PAUSED        (1 << 0)
    /* Flags to aid debugging vm_event */
    #define VM_EVENT_FLAG_FOREIGN            (1 << 1)
    /*
     * The following flags can be set in response to a mem_access event.
     *
     * Emulate the fault-causing instruction (if set in the event response flags).
     * This will allow the guest to continue execution without lifting the page
     * access restrictions.
     */
    #define VM_EVENT_FLAG_EMULATE            (1 << 2)
    /*
     * Same as VM_EVENT_FLAG_EMULATE, but with write operations or operations
     * potentially having side effects (like memory mapped or port I/O) disabled.
     */
    #define VM_EVENT_FLAG_EMULATE_NOWRITE    (1 << 3)
    /*
     * Toggle singlestepping on vm_event response.
     * Requires the vCPU to be paused already (synchronous events only).
     */
    #define VM_EVENT_FLAG_TOGGLE_SINGLESTEP  (1 << 4)
    /*
     * Data is being sent back to the hypervisor in the event response, to be
     * returned by the read function when emulating an instruction.
     * This flag is only useful when combined with VM_EVENT_FLAG_EMULATE
     * and takes precedence if combined with VM_EVENT_FLAG_EMULATE_NOWRITE
     * (i.e. if both VM_EVENT_FLAG_EMULATE_NOWRITE and
     * VM_EVENT_FLAG_SET_EMUL_READ_DATA are set, only the latter will be honored).
     */
    #define VM_EVENT_FLAG_SET_EMUL_READ_DATA (1 << 5)
    /*
     * Deny completion of the operation that triggered the event.
     * Currently only useful for MSR and control-register write events.
     * Requires the vCPU to be paused already (synchronous events only).
     */
    #define VM_EVENT_FLAG_DENY               (1 << 6)
    /*
     * This flag can be set in a request or a response
     *
     * On a request, indicates that the event occurred in the alternate p2m
     * specified by the altp2m_idx request field.
     *
     * On a response, indicates that the VCPU should resume in the alternate p2m
     * specified by the altp2m_idx response field if possible.
     */
    #define VM_EVENT_FLAG_ALTERNATE_P2M      (1 << 7)
    /*
     * Set the vCPU registers to the values in the  vm_event response.
     * At the moment x86-only, applies to EAX-EDX, ESP, EBP, ESI, EDI, R8-R15,
     * EFLAGS, and EIP.
     * Requires the vCPU to be paused already (synchronous events only).
     */
    #define VM_EVENT_FLAG_SET_REGISTERS      (1 << 8)
    /*
     * Instruction cache is being sent back to the hypervisor in the event response
     * to be used by the emulator. This flag is only useful when combined with
     * VM_EVENT_FLAG_EMULATE and does not take presedence if combined with
     * VM_EVENT_FLAG_EMULATE_NOWRITE or VM_EVENT_FLAG_SET_EMUL_READ_DATA, (i.e.
     * if any of those flags are set, only those will be honored).
     */
    #define VM_EVENT_FLAG_SET_EMUL_INSN_DATA (1 << 9)
    /*
     * Have a one-shot VM_EVENT_REASON_INTERRUPT event sent for the first
     * interrupt pending after resuming the VCPU.
     */
    #define VM_EVENT_FLAG_GET_NEXT_INTERRUPT (1 << 10)

    /*
     * Reasons for the vm event request
     */

    /* Default case */
    #define VM_EVENT_REASON_UNKNOWN                 0
    /* Memory access violation */
    #define VM_EVENT_REASON_MEM_ACCESS              1
    /* Memory sharing event */
    #define VM_EVENT_REASON_MEM_SHARING             2
    /* Memory paging event */
    #define VM_EVENT_REASON_MEM_PAGING              3
    /* A control register was updated */
    #define VM_EVENT_REASON_WRITE_CTRLREG           4
    /* An MSR was updated. */
    #define VM_EVENT_REASON_MOV_TO_MSR              5
    /* Debug operation executed (e.g. int3) */
    #define VM_EVENT_REASON_SOFTWARE_BREAKPOINT     6
    /* Single-step (e.g. MTF) */
    #define VM_EVENT_REASON_SINGLESTEP              7
    /* An event has been requested via HVMOP_guest_request_vm_event. */
    #define VM_EVENT_REASON_GUEST_REQUEST           8
    /* A debug exception was caught */
    #define VM_EVENT_REASON_DEBUG_EXCEPTION         9
    /* CPUID executed */
    #define VM_EVENT_REASON_CPUID                   10
    /*
     * Privileged call executed (e.g. SMC).
     * Note: event may be generated even if SMC condition check fails on some CPUs.
     *       As this behavior is CPU-specific, users are advised to not rely on it.
     *       These kinds of events will be filtered out in future versions.
     */
    #define VM_EVENT_REASON_PRIVILEGED_CALL         11
    /* An interrupt has been delivered. */
    #define VM_EVENT_REASON_INTERRUPT               12
    /* A descriptor table register was accessed. */
    #define VM_EVENT_REASON_DESCRIPTOR_ACCESS       13

    /* Supported values for the vm_event_write_ctrlreg index. */
    #define VM_EVENT_X86_CR0    0
    #define VM_EVENT_X86_CR3    1
    #define VM_EVENT_X86_CR4    2
    #define VM_EVENT_X86_XCR0   3

    /*
     * Using custom vCPU structs (i.e. not hvm_hw_cpu) for both x86 and ARM
     * so as to not fill the vm_event ring buffer too quickly.
     */
    struct vm_event_regs_x86 {
        uint64_t rax;
        uint64_t rcx;
        uint64_t rdx;
        uint64_t rbx;
        uint64_t rsp;
        uint64_t rbp;
        uint64_t rsi;
        uint64_t rdi;
        uint64_t r8;
        uint64_t r9;
        uint64_t r10;
        uint64_t r11;
        uint64_t r12;
        uint64_t r13;
        uint64_t r14;
        uint64_t r15;
        uint64_t rflags;
        uint64_t dr7;
        uint64_t rip;
        uint64_t cr0;
        uint64_t cr2;
        uint64_t cr3;
        uint64_t cr4;
        uint64_t sysenter_cs;
        uint64_t sysenter_esp;
        uint64_t sysenter_eip;
        uint64_t msr_efer;
        uint64_t msr_star;
        uint64_t msr_lstar;
        uint64_t fs_base;
        uint64_t gs_base;
        uint32_t cs_arbytes;
        uint32_t _pad;
    };

    /*
     * Only the register 'pc' can be set on a vm_event response using the
     * VM_EVENT_FLAG_SET_REGISTERS flag.
     */
    struct vm_event_regs_arm {
        uint64_t ttbr0;
        uint64_t ttbr1;
        uint64_t ttbcr;
        uint64_t pc;
        uint32_t cpsr;
        uint32_t _pad;
    };

    /*
     * mem_access flag definitions
     *
     * These flags are set only as part of a mem_event request.
     *
     * R/W/X: Defines the type of violation that has triggered the event
     *        Multiple types can be set in a single violation!
     * GLA_VALID: If the gla field holds a guest VA associated with the event
     * FAULT_WITH_GLA: If the violation was triggered by accessing gla
     * FAULT_IN_GPT: If the violation was triggered during translating gla
     */
    #define MEM_ACCESS_R                (1 << 0)
    #define MEM_ACCESS_W                (1 << 1)
    #define MEM_ACCESS_X                (1 << 2)
    #define MEM_ACCESS_RWX              (MEM_ACCESS_R | MEM_ACCESS_W | MEM_ACCESS_X)
    #define MEM_ACCESS_RW               (MEM_ACCESS_R | MEM_ACCESS_W)
    #define MEM_ACCESS_RX               (MEM_ACCESS_R | MEM_ACCESS_X)
    #define MEM_ACCESS_WX               (MEM_ACCESS_W | MEM_ACCESS_X)
    #define MEM_ACCESS_GLA_VALID        (1 << 3)
    #define MEM_ACCESS_FAULT_WITH_GLA   (1 << 4)
    #define MEM_ACCESS_FAULT_IN_GPT     (1 << 5)

    struct vm_event_mem_access {
        uint64_t gfn;
        uint64_t offset;
        uint64_t gla;   /* if flags has MEM_ACCESS_GLA_VALID set */
        uint32_t flags; /* MEM_ACCESS_* */
        uint32_t _pad;
    };

    struct vm_event_write_ctrlreg {
        uint32_t index;
        uint32_t _pad;
        uint64_t new_value;
        uint64_t old_value;
    };

    struct vm_event_singlestep {
        uint64_t gfn;
    };

    struct vm_event_debug {
        uint64_t gfn;
        uint32_t insn_length;
        uint8_t type;        /* HVMOP_TRAP_* */
        uint8_t _pad[3];
    };

    struct vm_event_mov_to_msr {
        uint64_t msr;
        uint64_t value;
    };

    #define VM_EVENT_DESC_IDTR           1
    #define VM_EVENT_DESC_GDTR           2
    #define VM_EVENT_DESC_LDTR           3
    #define VM_EVENT_DESC_TR             4

    struct vm_event_desc_access {
        union {
            struct {
                uint32_t instr_info;         /* VMX: VMCS Instruction-Information */
                uint32_t _pad1;
                uint64_t exit_qualification; /* VMX: VMCS Exit Qualification */
            } vmx;
            struct {
                uint64_t exitinfo;           /* SVM: VMCB EXITINFO */
                uint64_t _pad2;
            } svm;
        } arch;
        uint8_t descriptor;                  /* VM_EVENT_DESC_* */
        uint8_t is_write;
        uint8_t _pad[6];
    };

    struct vm_event_cpuid {
        uint32_t insn_length;
        uint32_t leaf;
        uint32_t subleaf;
        uint32_t _pad;
    };

    struct vm_event_interrupt_x86 {
        uint32_t vector;
        uint32_t type;
        uint32_t error_code;
        uint32_t _pad;
        uint64_t cr2;
    };

    #define MEM_PAGING_DROP_PAGE       (1 << 0)
    #define MEM_PAGING_EVICT_FAIL      (1 << 1)

    struct vm_event_paging {
        uint64_t gfn;
        uint32_t p2mt;
        uint32_t flags;
    };

    struct vm_event_sharing {
        uint64_t gfn;
        uint32_t p2mt;
        uint32_t _pad;
    };

    struct vm_event_emul_read_data {
        uint32_t size;
        /* The struct is used in a union with vm_event_regs_x86. */
        uint8_t  data[sizeof(struct vm_event_regs_x86) - sizeof(uint32_t)];
    };

    struct vm_event_emul_insn_data {
        uint8_t data[16]; /* Has to be completely filled */
    };

    typedef struct vm_event_st {
        uint32_t version;   /* VM_EVENT_INTERFACE_VERSION */
        uint32_t flags;     /* VM_EVENT_FLAG_* */
        uint32_t reason;    /* VM_EVENT_REASON_* */
        uint32_t vcpu_id;
        uint16_t altp2m_idx; /* may be used during request and response */
        uint16_t _pad[3];

        union {
            struct vm_event_paging                mem_paging;
            struct vm_event_sharing               mem_sharing;
            struct vm_event_mem_access            mem_access;
            struct vm_event_write_ctrlreg         write_ctrlreg;
            struct vm_event_mov_to_msr            mov_to_msr;
            struct vm_event_desc_access           desc_access;
            struct vm_event_singlestep            singlestep;
            struct vm_event_debug                 software_breakpoint;
            struct vm_event_debug                 debug_exception;
            struct vm_event_cpuid                 cpuid;
            union {
                struct vm_event_interrupt_x86     x86;
            } interrupt;
        } u;

        union {
            union {
                struct vm_event_regs_x86 x86;
                struct vm_event_regs_arm arm;
            } regs;

            union {
                struct vm_event_emul_read_data read;
                struct vm_event_emul_insn_data insn;
            } emul;
        } data;
    } vm_event_request_t, vm_event_response_t;

    DEFINE_RING_TYPES(vm_event, vm_event_request_t, vm_event_response_t);

    #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
    #endif /* _XEN_PUBLIC_VM_EVENT_H */

    /*
     * Local variables:
     * mode: C
     * c-file-style: "BSD"
     * c-basic-offset: 4
     * tab-width: 4
     * indent-tabs-mode: nil
     * End:
     */