crosvm/tests/plugin_adder.c

/*
 * Copyright 2017 The ChromiumOS Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include <errno.h>
#include <fcntl.h>
#include <linux/memfd.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <time.h>
#include <unistd.h>

#include "crosvm.h"

#ifndef F_LINUX_SPECIFIC_BASE
#define F_LINUX_SPECIFIC_BASE 1024
#endif

#ifndef F_ADD_SEALS
#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
#endif

#ifndef F_SEAL_SHRINK
#define F_SEAL_SHRINK 0x0002
#endif

#define SERIAL_ADDRESS 0x3f8
#define KILL_ADDRESS 0x3f9

char g_serial_out[16];
int g_kill_evt;

void *vcpu_thread(void *arg) {
    struct crosvm_vcpu *vcpu = arg;
    struct crosvm_vcpu_event evt;
    int i = 0;
    while (crosvm_vcpu_wait(vcpu, &evt) == 0) {
        if (evt.kind == CROSVM_VCPU_EVENT_KIND_INIT) {
            struct kvm_sregs sregs;
            crosvm_vcpu_get_sregs(vcpu, &sregs);
            sregs.cs.base = 0;
            sregs.cs.selector = 0;
            sregs.es.base = KILL_ADDRESS;
            sregs.es.selector = 0;
            crosvm_vcpu_set_sregs(vcpu, &sregs);

            struct kvm_regs regs;
            crosvm_vcpu_get_regs(vcpu, &regs);
            regs.rip = 0x1000;
            regs.rax = 2;
            regs.rbx = 7;
            regs.rflags = 2;
            crosvm_vcpu_set_regs(vcpu, &regs);
        }
        if (evt.kind == CROSVM_VCPU_EVENT_KIND_IO_ACCESS) {
            if (evt.io_access.address_space == CROSVM_ADDRESS_SPACE_IOPORT &&
                evt.io_access.address == SERIAL_ADDRESS &&
                evt.io_access.is_write &&
                evt.io_access.length == 1) {
                g_serial_out[i] = evt.io_access.data[0];
                i++;
            }
            if (evt.io_access.address_space == CROSVM_ADDRESS_SPACE_IOPORT &&
                evt.io_access.address == KILL_ADDRESS &&
                evt.io_access.is_write &&
                evt.io_access.length == 1 &&
                evt.io_access.data[0] == 1)
            {
                uint64_t dummy = 1;
                write(g_kill_evt, &dummy, sizeof(dummy));
                return NULL;
            }
        }

        crosvm_vcpu_resume(vcpu);
    }

    return NULL;
}

int main(int argc, char** argv) {
    const uint8_t code[] = {
    /*
    0000  BAF803  mov dx,0x3f8
    0003  00D8    add al,bl
    0005  0430    add al,0x30
    0007  EE      out dx,al
    0008  B05C    mov al,0x0a
    000A  EE      out dx,al
    000B  BAF903  mov dx,0x3f9
    000E  B001    mov al,0x1
    0010  EE      out dx,al
    0011  F4      hlt
    */
        0xba, 0xf8, 0x03,
        0x00, 0xd8,
        0x04, '0',
        0xee,
        0xb0, '\n',
        0xee,
        0xba, 0xf9, 0x03,
        0xb0, 0x01,
        0xee,
        0xf4
    };

    struct crosvm *crosvm;
    int ret = crosvm_connect(&crosvm);
    if (ret) {
        fprintf(stderr, "failed to connect to crosvm: %d\n", ret);
        return 1;
    }

    /*
     * Not strictly necessary, but demonstrates we can have as many connections
     * as we please.
     */
    struct crosvm *extra_crosvm;
    ret = crosvm_new_connection(crosvm, &extra_crosvm);
    if (ret) {
        fprintf(stderr, "failed to make new socket: %d\n", ret);
        return 1;
    }

    /* We needs this eventfd to know when to exit before being killed. */
    g_kill_evt = crosvm_get_shutdown_eventfd(crosvm);
    if (g_kill_evt < 0) {
        fprintf(stderr, "failed to get kill eventfd: %d\n", g_kill_evt);
        return 1;
    }

    ret = crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_IOPORT, SERIAL_ADDRESS, 1);
    if (ret) {
        fprintf(stderr, "failed to reserve ioport range: %d\n", ret);
        return 1;
    }

    ret = crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_IOPORT, KILL_ADDRESS, 1);
    if (ret) {
        fprintf(stderr, "failed to reserve mmio range: %d\n", ret);
        return 1;
    }

    int mem_size = 0x2000;
    int mem_fd = syscall(SYS_memfd_create, "guest_mem", MFD_CLOEXEC | MFD_ALLOW_SEALING);
    if (mem_fd < 0) {
        fprintf(stderr, "failed to create guest memfd: %d\n", errno);
        return 1;
    }
    ret = ftruncate(mem_fd, mem_size);
    if (ret) {
        fprintf(stderr, "failed to set size of guest memory: %d\n", errno);
        return 1;
    }
    uint8_t *mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, 0x1000);
    if (mem == MAP_FAILED) {
        fprintf(stderr, "failed to mmap guest memory: %d\n", errno);
        return 1;
    }
    fcntl(mem_fd, F_ADD_SEALS, F_SEAL_SHRINK);
    memcpy(mem, code, sizeof(code));

    struct crosvm_memory *mem_obj;
    ret = crosvm_create_memory(crosvm, mem_fd, 0x1000, 0x1000, 0x1000, false, false, &mem_obj);
    if (ret) {
        fprintf(stderr, "failed to create memory in crosvm: %d\n", ret);
        return 1;
    }

    /* get and creat a thread for each vcpu */
    struct crosvm_vcpu *vcpus[32];
    pthread_t vcpu_threads[32];
    uint32_t vcpu_count;
    for (vcpu_count = 0; vcpu_count < 32; vcpu_count++) {
        ret = crosvm_get_vcpu(crosvm, vcpu_count, &vcpus[vcpu_count]);
        if (ret == -ENOENT)
            break;

        if (ret) {
            fprintf(stderr, "error while getting all vcpus: %d\n", ret);
            return 1;
        }
        pthread_create(&vcpu_threads[vcpu_count], NULL, vcpu_thread, vcpus[vcpu_count]);
    }

    ret = crosvm_start(extra_crosvm);
    if (ret) {
        fprintf(stderr, "failed to tell crosvm to start: %d\n", ret);
        return 1;
    }

    /* Wait for crosvm to request that we exit otherwise we will be killed. */
    uint64_t dummy;
    read(g_kill_evt, &dummy, 8);

    ret = crosvm_destroy_memory(crosvm, &mem_obj);
    if (ret) {
        fprintf(stderr, "failed to destroy memory in crosvm: %d\n", ret);
        return 1;
    }

    ret = crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_IOPORT, SERIAL_ADDRESS, 0);
    if (ret) {
        fprintf(stderr, "failed to unreserve ioport range: %d\n", ret);
        return 1;
    }

    ret = crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_IOPORT, KILL_ADDRESS, 0);
    if (ret) {
        fprintf(stderr, "failed to unreserve mmio range: %d\n", ret);
        return 1;
    }

    return strcmp(g_serial_out, "9\n");
}