/*
 * This file is part of the Palacios Virtual Machine Monitor developed
 * by the V3VEE Project with funding from the United States National 
 * Science Foundation and the Department of Energy.  
 *
 * The V3VEE Project is a joint project between Northwestern University
 * and the University of New Mexico.  You can find out more at 
 * http://www.v3vee.org
 *
 * Copyright (c) 2008, Andy Gocke <agocke@gmail.com>
 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
 * All rights reserved.
 *
 * Author: Andy Gocke <agocke@gmail.com>
 *
 * This is free software.  You are permitted to use,
 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
 */

#include <palacios/vmx_io.h>
#include <palacios/vmm_io.h>
#include <palacios/vmcs.h>
#include <palacios/vmx_lowlevel.h>
#include <palacios/vmm.h>
#include <palacios/vmx_handler.h>
#include <palacios/vmm_ctrl_regs.h>
#include <palacios/vm_guest_mem.h>
#include <palacios/vmm_decoder.h>

#ifndef CONFIG_DEBUG_IO
#undef PrintDebug
#define PrintDebug(fmt, args...)
#endif


/* Same as SVM */
static int update_map(struct guest_info * info, uint16_t port, int hook_read, int hook_write)
{
    uchar_t * bitmap = (uint8_t *)(info->io_map.arch_data);
    int major = port / 8;
    int minor = port % 8;

    if ((hook_read == 0) && (hook_write == 0)) {
	*(bitmap + major) &= ~(0x1 << minor);
    } else {
	*(bitmap + major) |= (0x1 << minor);
    }

    return 0;
}

int v3_init_vmx_io_map(struct guest_info * info)
{
    info->io_map.update_map = update_map;
    
    info->io_map.arch_data = V3_VAddr(V3_AllocPages(2));
    memset(info->io_map.arch_data, 0, PAGE_SIZE_4KB*2);

    return 0;
}

int v3_handle_vmx_io_in(struct guest_info * info) {
    ulong_t exit_qual;
    uint32_t instr_length = 0;

    vmcs_read(VMCS_EXIT_QUAL, &exit_qual);

    struct vmexit_io_qual * io_qual = (struct vmexit_io_qual *)&exit_qual;

    struct v3_io_hook * hook = v3_get_io_hook(info, io_qual->port);
    int read_size = 0;

    if (hook == NULL) {
        PrintError("Hook not present for IN on port %x\n", io_qual->port);
        return -1;
    }

    read_size = io_qual->access_size + 1;

    PrintDebug("IN of %d bytes on port %d (0x%x)\n", read_size, io_qual->port, io_qual->port);

    if (hook->read(io_qual->port, &(info->vm_regs.rax), read_size, hook->priv_data) != read_size) {
        PrintError("Read failure for IN on port %x\n", io_qual->port);
        return -1;
    }



    if (vmcs_read(VMCS_EXIT_INSTR_LEN, &instr_length) != VMX_SUCCESS) {
        PrintError("Could not read instruction length\n");
        return -1;
    }

    info->rip += instr_length;

    return 0;
}

int v3_handle_vmx_io_ins(struct guest_info * info)
{
    ulong_t exit_qual;

    vmcs_read(VMCS_EXIT_QUAL, &exit_qual);

    struct vmexit_io_qual * io_qual = (struct vmexit_io_qual *)&exit_qual;
    struct v3_io_hook * hook = v3_get_io_hook(info, io_qual->port);
    int read_size;
    addr_t guest_va;
    addr_t host_addr;
    int rdi_change;
    ulong_t rep_num = 1;

    if(hook == NULL) {
        PrintError("Hook not present for INS on port 0x%x\n", io_qual->port);
        return -1;
    }

    PrintDebug("INS on port 0x%x\n", io_qual->port);

    read_size = io_qual->access_size + 1;

    if (io_qual->rep) {
        rep_num = info->vm_regs.rcx & get_gpr_mask(info);
    }
    
    if ( ((struct rflags *)&(info->ctrl_regs.rflags))->df ) {
        rdi_change = -read_size;
    } else {
        rdi_change = read_size;
    }

    PrintDebug("INS size=%d for %ld steps\n", read_size, rep_num);

    vmcs_read(VMCS_GUEST_LINEAR_ADDR, &guest_va);

    if (guest_va_to_host_va(info, guest_va, &host_addr) == -1) {
        PrintError("Could not convert Guest VA to host VA\n");
        return -1;
    }

    do {
        if (hook->read(io_qual->port, (char *)host_addr, read_size, hook->priv_data) != read_size) {
            PrintError("Read Failure for INS on port 0x%x\n", io_qual->port);
            return -1;
        }

        host_addr += rdi_change;
        info->vm_regs.rdi += rdi_change;

        if (io_qual->rep) {
            --info->vm_regs.rcx;
        }
        --rep_num;

    } while (rep_num > 0);

    int instr_len = 0;

    vmcs_read(VMCS_EXIT_INSTR_LEN, &instr_len);

    info->rip += instr_len;

    return 0;
}



int v3_handle_vmx_io_out(struct guest_info * info) {
    ulong_t exit_qual;

    vmcs_read(VMCS_EXIT_QUAL, &exit_qual);

    struct vmexit_io_qual * io_qual = (struct vmexit_io_qual *)&exit_qual;

    struct v3_io_hook * hook = v3_get_io_hook(info, io_qual->port);

    if (hook == NULL) {
        PrintError("Hook not present for out on port %x\n", io_qual->port);
        return -1;
    }

    int write_size = io_qual->access_size + 1;
    
    PrintDebug("OUT of %d bytes on port %d (0x%x)\n", write_size, io_qual->port, io_qual->port);


    if (hook->write(io_qual->port, &(info->vm_regs.rax), write_size, hook->priv_data) != write_size) {
        PrintError("Write failure for out on port %x\n",io_qual->port);
        return -1;
    }

    uint32_t instr_length = 0;

    if (vmcs_read(VMCS_EXIT_INSTR_LEN, &instr_length) != VMX_SUCCESS) {
        PrintError("Could not read instruction length\n");
        return -1;
    } 

    info->rip += instr_length;

    return 0;
}



int v3_handle_vmx_io_outs(struct guest_info * info) {
    ulong_t exit_qual;

    vmcs_read(VMCS_EXIT_QUAL, &exit_qual);

    struct vmexit_io_qual * io_qual = (struct vmexit_io_qual *)&exit_qual;
    struct v3_io_hook * hook = v3_get_io_hook(info, io_qual->port);
    int write_size;
    addr_t guest_va;
    addr_t host_addr;
    int rsi_change;
    ulong_t rep_num = 1;

    if (hook == NULL) {
        PrintError("Hook not present for OUTS on port 0x%x\n", io_qual->port);
        return -1;
    }

    PrintDebug("OUTS on port 0x%x\n", io_qual->port);

    write_size = io_qual->access_size + 1;

    if (io_qual->rep) {
        // Grab the address sized bits of rcx
        rep_num = info->vm_regs.rcx & get_gpr_mask(info);
    }

    if ( ((struct rflags *)&(info->ctrl_regs.rflags))->df ) {
        rsi_change = -write_size;
    } else {
        rsi_change = write_size;
    }

    vmcs_read(VMCS_GUEST_LINEAR_ADDR, &guest_va);

    PrintDebug("OUTS size=%d for %ld steps\n", write_size, rep_num);

    if (guest_va_to_host_va(info, guest_va, &host_addr) == -1) {
        PrintError("Could not convert guest VA to host VA\n");
        return -1;
    }

    do {
       if (hook->write(io_qual->port, (char *)host_addr, write_size, hook->priv_data) != write_size) {
           PrintError("Read failure for INS on port 0x%x\n", io_qual->port);
           return -1;
       }

       host_addr += rsi_change;
       info->vm_regs.rsi += rsi_change;

       if (io_qual->rep) {
           --info->vm_regs.rcx;
       }
       --rep_num;

    } while (rep_num > 0);

    int instr_len = 0;

    vmcs_read(VMCS_EXIT_INSTR_LEN, &instr_len);

    info->rip += instr_len;

    return 0;
}