1 use super::{vcpu::Vcpu, vm}; 2 use crate::{ 3 kdebug, 4 mm::{kernel_mapper::KernelMapper, page::PageFlags, VirtAddr}, 5 syscall::SystemError, 6 }; 7 8 /* 9 * Address types: 10 * 11 * gva - guest virtual address 12 * gpa - guest physical address 13 * gfn - guest frame number 14 * hva - host virtual address 15 * hpa - host physical address 16 * hfn - host frame number 17 */ 18 pub const KVM_USER_MEM_SLOTS: u32 = 16; 19 pub const KVM_PRIVATE_MEM_SLOTS: u32 = 3; 20 pub const KVM_MEM_SLOTS_NUM: u32 = KVM_USER_MEM_SLOTS + KVM_PRIVATE_MEM_SLOTS; 21 pub const KVM_ADDRESS_SPACE_NUM: usize = 2; 22 23 pub const KVM_MEM_LOG_DIRTY_PAGES: u32 = 1 << 0; 24 pub const KVM_MEM_READONLY: u32 = 1 << 1; 25 pub const KVM_MEM_MAX_NR_PAGES: u32 = (1 << 31) - 1; 26 27 /* 28 * The bit 16 ~ bit 31 of kvm_memory_region::flags are internally used 29 * in kvm, other bits are visible for userspace which are defined in 30 * include/linux/kvm_h. 31 */ 32 pub const KVM_MEMSLOT_INVALID: u32 = 1 << 16; 33 // pub const KVM_MEMSLOT_INCOHERENT:u32 = 1 << 17; 34 35 // pub const KVM_PERMILLE_MMU_PAGES: u32 = 20; // the proportion of MMU pages required per thousand (out of 1000) memory pages. 36 // pub const KVM_MIN_ALLOC_MMU_PAGES: u32 = 64; 37 38 pub const PAGE_SHIFT: u32 = 12; 39 pub const PAGE_SIZE: u32 = 1 << PAGE_SHIFT; 40 pub const PAGE_MASK: u32 = !(PAGE_SIZE - 1); 41 42 #[repr(C)] 43 /// 通过这个结构可以将虚拟机的物理地址对应到用户进程的虚拟地址 44 /// 用来表示虚拟机的一段物理内存 45 pub struct KvmUserspaceMemoryRegion { 46 pub slot: u32, // 要在哪个slot上注册内存区间 47 // 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。 48 // KVM_MEM_LOG_DIRTY_PAGES用来开启内存脏页，KVM_MEM_READONLY用来开启内存只读。 49 pub flags: u32, 50 pub guest_phys_addr: u64, // 虚机内存区间起始物理地址 51 pub memory_size: u64, // 虚机内存区间大小 52 pub userspace_addr: u64, // 虚机内存区间对应的主机虚拟地址 53 } 54 55 #[derive(Default, Clone, Copy, Debug)] 56 pub struct KvmMemorySlot { 57 pub base_gfn: u64, // 虚机内存区间起始物理页框号 58 pub npages: u64, // 虚机内存区间页数，即内存区间的大小 59 pub userspace_addr: u64, // 虚机内存区间对应的主机虚拟地址 60 pub flags: u32, // 虚机内存区间属性 61 pub id: u16, // 虚机内存区间id 62 // 用来记录虚机内存区间的脏页信息，每个bit对应一个页，如果bit为1，表示对应的页是脏页，如果bit为0，表示对应的页是干净页。 63 // pub dirty_bitmap: *mut u8, 64 // unsigned long *rmap[KVM_NR_PAGE_SIZES]; 反向映射相关的结构, 创建EPT页表项时就记录GPA对应的页表项地址(GPA-->页表项地址)，暂时不需要 65 } 66 67 #[derive(Default, Clone, Copy, Debug)] 68 pub struct KvmMemorySlots { 69 pub memslots: [KvmMemorySlot; KVM_MEM_SLOTS_NUM as usize], // 虚机内存区间数组 70 pub used_slots: u32, // 已经使用的slot数量 71 } 72 73 #[derive(PartialEq, Eq, Debug)] 74 pub enum KvmMemoryChange { 75 Create, 76 Delete, 77 Move, 78 FlagsOnly, 79 } 80 81 impl Default for KvmUserspaceMemoryRegion { 82 fn default() -> KvmUserspaceMemoryRegion { 83 KvmUserspaceMemoryRegion { 84 slot: 0, 85 flags: 0, 86 guest_phys_addr: 0, 87 memory_size: 0, 88 userspace_addr: 0, 89 } 90 } 91 } 92 93 pub fn kvm_vcpu_memslots(_vcpu: &mut dyn Vcpu) -> KvmMemorySlots { 94 let kvm = vm(0).unwrap(); 95 let as_id = 0; 96 return kvm.memslots[as_id]; 97 } 98 99 fn __gfn_to_memslot(slots: KvmMemorySlots, gfn: u64) -> Option<KvmMemorySlot> { 100 kdebug!("__gfn_to_memslot"); 101 // TODO: 使用二分查找的方式优化 102 for i in 0..slots.used_slots { 103 let memslot = slots.memslots[i as usize]; 104 if gfn >= memslot.base_gfn && gfn < memslot.base_gfn + memslot.npages { 105 return Some(memslot); 106 } 107 } 108 return None; 109 } 110 111 fn __gfn_to_hva(slot: KvmMemorySlot, gfn: u64) -> u64 { 112 return slot.userspace_addr + (gfn - slot.base_gfn) * (PAGE_SIZE as u64); 113 } 114 fn __gfn_to_hva_many( 115 slot: Option<KvmMemorySlot>, 116 gfn: u64, 117 nr_pages: Option<&mut u64>, 118 write: bool, 119 ) -> Result<u64, SystemError> { 120 kdebug!("__gfn_to_hva_many"); 121 if slot.is_none() { 122 return Err(SystemError::KVM_HVA_ERR_BAD); 123 } 124 let slot = slot.unwrap(); 125 if slot.flags & KVM_MEMSLOT_INVALID != 0 || (slot.flags & KVM_MEM_READONLY != 0) && write { 126 return Err(SystemError::KVM_HVA_ERR_BAD); 127 } 128 129 if nr_pages.is_some() { 130 let nr_pages = nr_pages.unwrap(); 131 *nr_pages = slot.npages - (gfn - slot.base_gfn); 132 } 133 return Ok(__gfn_to_hva(slot, gfn)); 134 } 135 136 /* From Linux kernel 137 * Pin guest page in memory and return its pfn. 138 * @addr: host virtual address which maps memory to the guest 139 * @atomic: whether this function can sleep 140 * @async: whether this function need to wait IO complete if the 141 * host page is not in the memory 142 * @write_fault: whether we should get a writable host page 143 * @writable: whether it allows to map a writable host page for !@write_fault 144 * 145 * The function will map a writable host page for these two cases: 146 * 1): @write_fault = true 147 * 2): @write_fault = false && @writable, @writable will tell the caller 148 * whether the mapping is writable. 149 */ 150 // 计算 HVA 对应的 pfn，同时确保该物理页在内存中 151 // host端虚拟地址到物理地址的转换，有两种方式，hva_to_pfn_fast、hva_to_pfn_slow 152 // 正确性待验证 153 fn hva_to_pfn(addr: u64, _atomic: bool, _writable: &mut bool) -> Result<u64, SystemError> { 154 kdebug!("hva_to_pfn"); 155 unsafe { 156 let raw = addr as *const i32; 157 kdebug!("raw={:x}", *raw); 158 } 159 // let hpa = MMArch::virt_2_phys(VirtAddr::new(addr)).unwrap().data() as u64; 160 let hva = VirtAddr::new(addr as usize); 161 let mut mapper = KernelMapper::lock(); 162 let mapper = mapper.as_mut().unwrap(); 163 if let Some((hpa, _)) = mapper.translate(hva) { 164 return Ok(hpa.data() as u64 >> PAGE_SHIFT); 165 } 166 unsafe { 167 mapper.map(hva, PageFlags::mmio_flags()); 168 } 169 let (hpa, _) = mapper.translate(hva).unwrap(); 170 return Ok(hpa.data() as u64 >> PAGE_SHIFT); 171 } 172 173 pub fn __gfn_to_pfn( 174 slot: Option<KvmMemorySlot>, 175 gfn: u64, 176 atomic: bool, 177 write: bool, 178 writable: &mut bool, 179 ) -> Result<u64, SystemError> { 180 kdebug!("__gfn_to_pfn"); 181 let mut nr_pages = 0; 182 let addr = __gfn_to_hva_many(slot, gfn, Some(&mut nr_pages), write)?; 183 let pfn = hva_to_pfn(addr, atomic, writable)?; 184 kdebug!("hva={}, pfn={}", addr, pfn); 185 return Ok(pfn); 186 } 187 188 pub fn kvm_vcpu_gfn_to_memslot(vcpu: &mut dyn Vcpu, gfn: u64) -> Option<KvmMemorySlot> { 189 return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn); 190 } 191