1*40314b30SXiaoye Zheng use crate::arch::mm::PageMapper; 2*40314b30SXiaoye Zheng use crate::arch::MMArch; 3*40314b30SXiaoye Zheng use crate::mm::page::PageFlags; 4*40314b30SXiaoye Zheng use crate::mm::{PageTableKind, PhysAddr, VirtAddr}; 5*40314b30SXiaoye Zheng use crate::smp::core::smp_get_processor_id; 6*40314b30SXiaoye Zheng use crate::{arch::mm::LockedFrameAllocator, syscall::SystemError}; 7*40314b30SXiaoye Zheng use core::sync::atomic::{compiler_fence, AtomicUsize, Ordering}; 8*40314b30SXiaoye Zheng use x86::msr; 9*40314b30SXiaoye Zheng 10*40314b30SXiaoye Zheng /// Check if MTRR is supported 11*40314b30SXiaoye Zheng pub fn check_ept_features() -> Result<(), SystemError> { 12*40314b30SXiaoye Zheng const MTRR_ENABLE_BIT: u64 = 1 << 11; 13*40314b30SXiaoye Zheng let ia32_mtrr_def_type = unsafe { msr::rdmsr(msr::IA32_MTRR_DEF_TYPE) }; 14*40314b30SXiaoye Zheng if (ia32_mtrr_def_type & MTRR_ENABLE_BIT) == 0 { 15*40314b30SXiaoye Zheng return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP); 16*40314b30SXiaoye Zheng } 17*40314b30SXiaoye Zheng Ok(()) 18*40314b30SXiaoye Zheng } 19*40314b30SXiaoye Zheng 20*40314b30SXiaoye Zheng // pub fn ept_build_mtrr_map() -> Result<(), SystemError> { 21*40314b30SXiaoye Zheng // let ia32_mtrr_cap = unsafe { msr::rdmsr(msr::IA32_MTRRCAP) }; 22*40314b30SXiaoye Zheng // Ok(()) 23*40314b30SXiaoye Zheng // } 24*40314b30SXiaoye Zheng 25*40314b30SXiaoye Zheng /// 标志当前没有处理器持有内核映射器的锁 26*40314b30SXiaoye Zheng /// 之所以需要这个标志,是因为AtomicUsize::new(0)会把0当作一个处理器的id 27*40314b30SXiaoye Zheng const EPT_MAPPER_NO_PROCESSOR: usize = !0; 28*40314b30SXiaoye Zheng /// 当前持有内核映射器锁的处理器 29*40314b30SXiaoye Zheng static EPT_MAPPER_LOCK_OWNER: AtomicUsize = AtomicUsize::new(EPT_MAPPER_NO_PROCESSOR); 30*40314b30SXiaoye Zheng /// 内核映射器的锁计数器 31*40314b30SXiaoye Zheng static EPT_MAPPER_LOCK_COUNT: AtomicUsize = AtomicUsize::new(0); 32*40314b30SXiaoye Zheng 33*40314b30SXiaoye Zheng pub struct EptMapper { 34*40314b30SXiaoye Zheng /// EPT页表映射器 35*40314b30SXiaoye Zheng mapper: PageMapper, 36*40314b30SXiaoye Zheng /// 标记当前映射器是否为只读 37*40314b30SXiaoye Zheng readonly: bool, 38*40314b30SXiaoye Zheng // EPT页表根地址 39*40314b30SXiaoye Zheng // root_hpa: PhysAddr, 40*40314b30SXiaoye Zheng } 41*40314b30SXiaoye Zheng 42*40314b30SXiaoye Zheng impl EptMapper { 43*40314b30SXiaoye Zheng fn lock_cpu(cpuid: usize, mapper: PageMapper) -> Self { 44*40314b30SXiaoye Zheng loop { 45*40314b30SXiaoye Zheng match EPT_MAPPER_LOCK_OWNER.compare_exchange_weak( 46*40314b30SXiaoye Zheng EPT_MAPPER_NO_PROCESSOR, 47*40314b30SXiaoye Zheng cpuid, 48*40314b30SXiaoye Zheng Ordering::Acquire, 49*40314b30SXiaoye Zheng Ordering::Relaxed, 50*40314b30SXiaoye Zheng ) { 51*40314b30SXiaoye Zheng Ok(_) => break, 52*40314b30SXiaoye Zheng // 当前处理器已经持有了锁 53*40314b30SXiaoye Zheng Err(id) if id == cpuid => break, 54*40314b30SXiaoye Zheng // either CAS failed, or some other hardware thread holds the lock 55*40314b30SXiaoye Zheng Err(_) => core::hint::spin_loop(), 56*40314b30SXiaoye Zheng } 57*40314b30SXiaoye Zheng } 58*40314b30SXiaoye Zheng 59*40314b30SXiaoye Zheng let prev_count = EPT_MAPPER_LOCK_COUNT.fetch_add(1, Ordering::Relaxed); 60*40314b30SXiaoye Zheng compiler_fence(Ordering::Acquire); 61*40314b30SXiaoye Zheng 62*40314b30SXiaoye Zheng // 本地核心已经持有过锁,因此标记当前加锁获得的映射器为只读 63*40314b30SXiaoye Zheng let readonly = prev_count > 0; 64*40314b30SXiaoye Zheng 65*40314b30SXiaoye Zheng return Self { mapper, readonly }; 66*40314b30SXiaoye Zheng } 67*40314b30SXiaoye Zheng 68*40314b30SXiaoye Zheng /// @brief 锁定内核映射器, 并返回一个内核映射器对象 69*40314b30SXiaoye Zheng #[inline(always)] 70*40314b30SXiaoye Zheng pub fn lock() -> Self { 71*40314b30SXiaoye Zheng let cpuid = smp_get_processor_id() as usize; 72*40314b30SXiaoye Zheng let mapper = unsafe { PageMapper::current(PageTableKind::EPT, LockedFrameAllocator) }; 73*40314b30SXiaoye Zheng return Self::lock_cpu(cpuid, mapper); 74*40314b30SXiaoye Zheng } 75*40314b30SXiaoye Zheng 76*40314b30SXiaoye Zheng /// 映射guest physical addr(gpa)到指定的host physical addr(hpa)。 77*40314b30SXiaoye Zheng /// 78*40314b30SXiaoye Zheng /// ## 参数 79*40314b30SXiaoye Zheng /// 80*40314b30SXiaoye Zheng /// - `gpa`: 要映射的guest physical addr 81*40314b30SXiaoye Zheng /// - `hpa`: 要映射的host physical addr 82*40314b30SXiaoye Zheng /// - `flags`: 页面标志 83*40314b30SXiaoye Zheng /// 84*40314b30SXiaoye Zheng /// ## 返回 85*40314b30SXiaoye Zheng /// 86*40314b30SXiaoye Zheng /// - 成功:返回Ok(()) 87*40314b30SXiaoye Zheng /// - 失败: 如果当前映射器为只读,则返回EAGAIN_OR_EWOULDBLOCK 88*40314b30SXiaoye Zheng pub unsafe fn walk( 89*40314b30SXiaoye Zheng &mut self, 90*40314b30SXiaoye Zheng gpa: u64, 91*40314b30SXiaoye Zheng hpa: u64, 92*40314b30SXiaoye Zheng flags: PageFlags<MMArch>, 93*40314b30SXiaoye Zheng ) -> Result<(), SystemError> { 94*40314b30SXiaoye Zheng if self.readonly { 95*40314b30SXiaoye Zheng return Err(SystemError::EAGAIN_OR_EWOULDBLOCK); 96*40314b30SXiaoye Zheng } 97*40314b30SXiaoye Zheng self.mapper 98*40314b30SXiaoye Zheng .map_phys( 99*40314b30SXiaoye Zheng VirtAddr::new(gpa as usize), 100*40314b30SXiaoye Zheng PhysAddr::new(hpa as usize), 101*40314b30SXiaoye Zheng flags, 102*40314b30SXiaoye Zheng ) 103*40314b30SXiaoye Zheng .unwrap() 104*40314b30SXiaoye Zheng .flush(); 105*40314b30SXiaoye Zheng return Ok(()); 106*40314b30SXiaoye Zheng } 107*40314b30SXiaoye Zheng 108*40314b30SXiaoye Zheng // fn get_ept_index(addr: u64, level: usize) -> u64 { 109*40314b30SXiaoye Zheng // let pt64_level_shift = PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS; 110*40314b30SXiaoye Zheng // (addr >> pt64_level_shift) & ((1 << PT64_LEVEL_BITS) - 1) 111*40314b30SXiaoye Zheng // } 112*40314b30SXiaoye Zheng } 113