/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 static char g_serial_out[16]; static int g_next_evt; static int g_kill_evt; static bool g_paused; static bool g_exit_loop; static pthread_mutex_t g_pause_mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t g_pause_cond = PTHREAD_COND_INITIALIZER; static volatile int count; static void *vcpu_thread_fn(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, ®s); regs.rip = 0x1000; regs.rax = 2; regs.rbx = 7; regs.rflags = 2; crosvm_vcpu_set_regs(vcpu, ®s); /* Signal the main thread that init is done */ uint64_t dummy = 1; write(g_next_evt, &dummy, sizeof(dummy)); } else if (evt.kind == CROSVM_VCPU_EVENT_KIND_IO_ACCESS && 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; } else if (evt.kind == CROSVM_VCPU_EVENT_KIND_PAUSED) { /* Signal that we paused */ uint64_t dummy = 1; write(g_next_evt, &dummy, sizeof(dummy)); /* Wait till we can continue again */ pthread_mutex_lock(&g_pause_mutex); while (g_paused) pthread_cond_wait(&g_pause_cond, &g_pause_mutex); /* Kick the VM from infinite loop if requested */ if (g_exit_loop) { struct kvm_regs regs; crosvm_vcpu_get_regs(vcpu, ®s); regs.rbx = 1; crosvm_vcpu_set_regs(vcpu, ®s); } /* Signal that we are no longer paused */ write(g_next_evt, &dummy, sizeof(dummy)); pthread_mutex_unlock(&g_pause_mutex); } crosvm_vcpu_resume(vcpu); } return NULL; } static int signal_pause(struct crosvm *crosvm) { pthread_mutex_lock(&g_pause_mutex); g_paused = true; pthread_mutex_unlock(&g_pause_mutex); return crosvm_pause_vcpus(crosvm, 1, NULL); } static void signal_unpause(struct crosvm *crosvm, bool exit_loop) { pthread_mutex_lock(&g_pause_mutex); g_paused = false; g_exit_loop = exit_loop; pthread_cond_broadcast(&g_pause_cond); pthread_mutex_unlock(&g_pause_mutex); } int main(int argc, char** argv) { const uint8_t code[] = { /* 0000 00D8 add al,bl 0002 80FB01 cmp bl, 0x1 0005 75F9 jne 0x0 0007 BAF903 mov dx,0x3f8 000A B001 mov al,0x1 000C EE out dx,al 000D F4 hlt */ 0x00, 0xd8, 0x80, 0xfb, 0x01, 0x75, 0xf9, 0xba, 0xf9, 0x03, 0xb0, 0x01, 0xee, 0xf4 }; g_next_evt = eventfd(0, 0); if (g_next_evt == -1) { fprintf(stderr, "failed to create eventfd: %d\n", errno); return 1; } struct crosvm *crosvm; int ret = crosvm_connect(&crosvm); if (ret) { fprintf(stderr, "failed to connect to crosvm: %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, 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 create a thread for the vcpu */ struct crosvm_vcpu *vcpu; ret = crosvm_get_vcpu(crosvm, 0, &vcpu); if (ret) { fprintf(stderr, "error while getting vcpu: %d\n", ret); return 1; } pthread_t vcpu_thread; ret = pthread_create(&vcpu_thread, NULL, vcpu_thread_fn, vcpu); if (ret) { fprintf(stderr, "failed to createvcpu thread\n"); return 1; } ret = crosvm_start(crosvm); if (ret) { fprintf(stderr, "failed to tell crosvm to start: %d\n", ret); return 1; } /* Wait till VCPU thread tells us that its initialization is done */ uint64_t dummy; read(g_next_evt, &dummy, sizeof(dummy)); ret = signal_pause(crosvm); if (ret) { fprintf(stderr, "failed to pause vcpus (1st time): %d\n", ret); return 1; } /* Wait till VCPU thread tells us it is paused */ read(g_next_evt, &dummy, sizeof(dummy)); /* Try pausing VCPUs 2nd time to make sure we do not deadlock */ ret = signal_pause(crosvm); if (ret) { fprintf(stderr, "failed to pause vcpus (2nd time): %d\n", ret); return 1; } signal_unpause(crosvm, false); /* Wait until VCPU thread tells us that it is no longer paused */ read(g_next_evt, &dummy, sizeof(dummy)); /* * Try pausing VCPUs 3rd time to see if we will miss pause * request as we are exiting previous pause. */ ret = signal_pause(crosvm); if (ret) { fprintf(stderr, "failed to pause vcpus (2nd time): %d\n", ret); return 1; } signal_unpause(crosvm, true); /* Wait for crosvm to request that we exit otherwise we will be killed. */ read(g_kill_evt, &dummy, sizeof(dummy)); 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, KILL_ADDRESS, 0); if (ret) { fprintf(stderr, "failed to unreserve mmio range: %d\n", ret); return 1; } return 0; }