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/*
* Copyright 2017 The Chromium OS Authors. All rights reserved.
* 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 LOAD_ADDRESS 0x1000
#define STACK_BASE (LOAD_ADDRESS + 0x1000)
#define STACK_SIZE 0x1000
#define SUCCESS_ADDRESS 0x3000
#define KILL_ADDRESS 0x4000
/*
org 0x1000
bits 16
cli
; Set entry 0x0 in the interrupt vector table
mov word [0x0], handle
mov word [0x2], 0x0
sti
; Loop until interrupt is handled
loop:
cmp byte [si], 0x01
jne loop
cli
; Signal that we are ready to end
end:
mov byte [es:0], 0x01
hlt
; Handle the interrupt by halting
handle:
mov byte [si], 0x01
iret
*/
const uint8_t g_code[] = {
0xfa, 0xc7, 0x06, 0x00, 0x00, 0x1b, 0x10, 0xc7, 0x06, 0x02, 0x00, 0x00,
0x00, 0xfb, 0x80, 0x3c, 0x01, 0x75, 0xfb, 0xfa, 0x26, 0xc6, 0x06, 0x00,
0x00, 0x01, 0xf4, 0xc6, 0x04, 0x01, 0xcf
};
struct vcpu_context {
struct crosvm_vcpu *vcpu;
int irqeventfd;
int kill_evt;
};
void *vcpu_thread(void *arg) {
struct vcpu_context *ctx = arg;
struct crosvm_vcpu *vcpu = ctx->vcpu;
struct crosvm_vcpu_event evt;
uint64_t dummy = 1;
int i = 0;
int ret;
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 = 0x0;
sregs.ss.base = 0;
sregs.ss.selector = 0x0;
sregs.es.base = KILL_ADDRESS;
sregs.es.selector = 0x0;
crosvm_vcpu_set_sregs(vcpu, &sregs);
struct kvm_regs regs;
crosvm_vcpu_get_regs(vcpu, ®s);
regs.rflags = 2;
regs.rip = LOAD_ADDRESS;
regs.rsp = STACK_BASE + STACK_SIZE;
regs.rsi = SUCCESS_ADDRESS;
crosvm_vcpu_set_regs(vcpu, ®s);
write(ctx->irqeventfd, &dummy, sizeof(dummy));
}
if (evt.kind == CROSVM_VCPU_EVENT_KIND_IO_ACCESS &&
evt.io_access.address_space == CROSVM_ADDRESS_SPACE_MMIO &&
evt.io_access.address == KILL_ADDRESS &&
evt.io_access.is_write &&
evt.io_access.length == 1 &&
evt.io_access.data[0] == 1)
{
write(ctx->kill_evt, &dummy, sizeof(dummy));
return NULL;
}
crosvm_vcpu_resume(vcpu);
}
return NULL;
}
int main(int argc, char** argv) {
int i;
uint64_t dummy = 1;
struct crosvm *crosvm;
int ret = crosvm_connect(&crosvm);
if (ret) {
fprintf(stderr, "failed to connect to crosvm: %d\n", ret);
return 1;
}
int kill_evt = crosvm_get_shutdown_eventfd(crosvm);
if (kill_evt < 0) {
fprintf(stderr, "failed to get kill eventfd: %d\n", kill_evt);
return 1;
}
crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_MMIO, KILL_ADDRESS, 1);
struct crosvm_irq *irq;
ret = crosvm_create_irq_event(crosvm, 0, &irq);
if (ret) {
fprintf(stderr, "failed to create irq event: %d\n", ret);
return 1;
}
int irqeventfd = crosvm_irq_event_get_fd(irq);
int mem_size = 0x4000;
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, 0);
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 + LOAD_ADDRESS, g_code, sizeof(g_code));
struct crosvm_memory *mem_obj;
ret = crosvm_create_memory(crosvm, mem_fd, 0, mem_size, 0, false, false, &mem_obj);
if (ret) {
fprintf(stderr, "failed to create memory in crosvm: %d\n", ret);
return 1;
}
struct crosvm_vcpu *vcpus[32];
struct vcpu_context ctxs[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;
}
ctxs[vcpu_count].vcpu = vcpus[vcpu_count];
ctxs[vcpu_count].irqeventfd = irqeventfd;
ctxs[vcpu_count].kill_evt = kill_evt;
pthread_create(&vcpu_threads[vcpu_count], NULL, vcpu_thread, &ctxs[vcpu_count]);
}
ret = crosvm_start(crosvm);
if (ret) {
fprintf(stderr, "failed to tell crosvm to start: %d\n", ret);
return 1;
}
ret = read(kill_evt, &dummy, sizeof(dummy));
if (ret == -1) {
fprintf(stderr, "failed to read kill eventfd: %d\n", errno);
return 1;
}
if (mem[SUCCESS_ADDRESS] != 0x01) {
fprintf(stderr, "interrupt was not handled: 0x%x\n", mem[SUCCESS_ADDRESS]);
return 1;
}
return 0;
}
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