DragonOS虚拟化 (#389)

* try some ioctl flow & kvm device

* add sys ioctl

* 删掉一些debug信息

* 修改run-qemu.sh脚本，在QEMU中enable vmx

* 修改cr0,cr4,msr寄存器enable VMX operations

* enable vmx operation

* allocate memory for vmcs with bug

* allocate memory for vmcs

* cpu virt-50%

* single vcpu virt

* add vmcs fields

* CPU virt overall flow with bug

* run vmlaunch success

* run CPU virt with bug

* 成功运行non-root模式的guest

* 成功运行vmexit,进入vmx_return函数

* 成功运行vmlaunch, vmexit, vmresume

* vmexit handler with bug

* 完成vmexit cpuid handler

* fix vmresume guest状态恢复的bug

* 增加vm ioctl

* refactor kvm 50%

* refactor kvm 80%

* FIXME: kvm vmlaunch failed

* vmlaunch success

* FIXME: output error

* update guest_rsp

* cpu virt refactor

* add mmu related struct

* add usermemory region workflow

* add mem-virt workflow

* add mem-virt

* refactor code

* add vcpu ioctl set_regs

* rename hypervisor to vm & solve some deadlock bugs

* workout mem pipeline

* fix vmcs control setting bugs

* refactor segment regs initialization

* resovle conficts

* resovle conficts

* format code

user/apps/test_kvm/main.c

@@ -0,0 +1,114 @@
+/**
+ * @file main.c
+ * @author xiaoyez (xiaoyez@zju.edu.cn)
+ * @brief 测试kvm的程序
+ * @version 0.1
+ * @date 2023-07-13
+ *
+ * @copyright Copyright (c) 2023
+ *
+ */
+
+/**
+ * 测试kvm命令的方法:
+ * 1.在DragonOS的控制台输入 exec bin/test_kvm.elf
+ *
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#define KVM_CREATE_VCPU 0x00
+#define KVM_SET_USER_MEMORY_REGION 0x01
+
+#define KVM_RUN 0x00
+#define KVM_GET_REGS 0x01
+#define KVM_SET_REGS 0x02
+
+struct kvm_userspace_memory_region {
+    uint32_t slot; // 要在哪个slot上注册内存区间
+    // flags有两个取值，KVM_MEM_LOG_DIRTY_PAGES和KVM_MEM_READONLY，用来指示kvm针对这段内存应该做的事情。
+    // KVM_MEM_LOG_DIRTY_PAGES用来开启内存脏页，KVM_MEM_READONLY用来开启内存只读。
+    uint32_t flags;
+    uint64_t guest_phys_addr; // 虚机内存区间起始物理地址
+    uint64_t memory_size;     // 虚机内存区间大小
+    uint64_t userspace_addr;  // 虚机内存区间对应的主机虚拟地址
+};
+
+struct kvm_regs {
+	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+	uint64_t rax, rbx, rcx, rdx;
+	uint64_t rsi, rdi, rsp, rbp;
+	uint64_t r8,  r9,  r10, r11;
+	uint64_t r12, r13, r14, r15;
+	uint64_t rip, rflags;
+};
+
+int guest_code(){
+    while (1)
+    {
+        // printf("guest code\n");
+        __asm__ __volatile__ (
+            "mov %rax, 0\n\t"
+            "mov %rcx, 0\n\t"
+            "cpuid\n\t"
+        );
+    }
+    return 0;
+}
+
+int main()
+{
+    printf("Test kvm running...\n");
+    printf("Open /dev/kvm\n");
+    int kvm_fd = open("/dev/kvm", O_RDWR|O_CLOEXEC);
+    int vmfd = ioctl(kvm_fd, 0x01, 0);
+    printf("vmfd=%d\n", vmfd);
+
+    /*
+         __asm__ __volatile__ (
+            "mov %rax, 0\n\t"
+            "mov %rcx, 0\n\t"
+            "cpuid\n\t"
+        ); 
+    */
+    const uint8_t code[] = {
+        0xba, 0xf8, 0x03, /* mov $0x3f8, %dx */
+        0x00, 0xd8,       /* add %bl, %al */
+        0x04, '0',        /* add $'0', %al */
+        0xee,             /* out %al, (%dx) */
+        0xb0, '\n',       /* mov $'\n', %al */
+        0xee,             /* out %al, (%dx) */
+        0xf4,             /* hlt */
+    };
+
+    size_t mem_size = 0x4000; // size of user memory you want to assign
+    printf("code=%p\n", code);
+    // void *mem = mmap(0, mem_size, 0x7, -1, 0);
+    // memcpy(mem, code, sizeof(code));
+    struct kvm_userspace_memory_region region = {
+        .slot = 0,
+        .flags = 0,
+        .guest_phys_addr = 0,
+        .memory_size = mem_size,
+        .userspace_addr = (size_t)code
+    };
+    ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &region);
+
+    int vcpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
+    printf("vcpufd=%d\n", vcpufd);
+    int user_entry = 0x0;
+
+    struct kvm_regs regs = {0};
+    regs.rip = user_entry;
+    regs.rsp = 0x3000; // stack address
+    regs.rflags = 0x2; // in x86 the 0x2 bit should always be set
+    ioctl(vcpufd, KVM_SET_REGS, &regs); // set registers
+
+    ioctl(vcpufd, KVM_RUN, 0);
+
+    return 0;
+}
+
+