diff options
Diffstat (limited to 'pk/mmap.c')
-rw-r--r-- | pk/mmap.c | 66 |
1 files changed, 66 insertions, 0 deletions
@@ -25,6 +25,7 @@ typedef struct vmr_t { static vmr_t* vmr_freelist_head; static pte_t* root_page_table; +static pte_t* g_root_page_table; #define RISCV_PGLEVELS ((VA_BITS - RISCV_PGSHIFT) / RISCV_PGLEVEL_BITS) @@ -36,6 +37,7 @@ static size_t free_pages; static size_t pages_promised; int demand_paging = 1; // unless -p flag is given +int have_hypervisor; uint64_t randomize_mapping; // set by --randomize-mapping typedef struct freelist_node_t { @@ -293,6 +295,8 @@ int __valid_user_range(uintptr_t vaddr, size_t len) static void flush_tlb_entry(uintptr_t vaddr) { + if (have_hypervisor) + asm (".insn r 0x73, 0x0, 0x11, x0, %0, x0" : : "r" (vaddr)); // hfence.vvma vaddr asm volatile ("sfence.vma %0" : : "r" (vaddr) : "memory"); } @@ -558,6 +562,65 @@ static void init_early_alloc() free_pages = (mem_size - (first_free_page - MEM_START)) / RISCV_PGSIZE; } +static bool __make_host_mapping(uintptr_t paddr) +{ + pte_t* hpte = __walk_internal(g_root_page_table, paddr, 1, 0); + kassert(hpte); + + if (!*hpte) { + *hpte = pte_create(paddr >> RISCV_PGSHIFT, prot_to_type(PROT_READ | PROT_WRITE | PROT_EXEC, 1)); + asm (".insn r 0x73, 0x0, 0x31, x0, %0, x0" : : "r" (paddr / 4)); // hfence.gvma paddr, x0 + return true; + } + return false; +} + +static int __handle_guest_page_fault(uintptr_t vaddr) +{ + for (int level = RISCV_PGLEVELS - 1; level >= 0; level--) { + pte_t* vpte = __walk_internal(root_page_table, vaddr, 0, level); + if (!vpte) + return -1; + + if (__make_host_mapping(kva2pa(vpte))) + return 0; + + if (level == 0 && (*vpte & PTE_V)) { + if (__make_host_mapping(pte_ppn(*vpte) << RISCV_PGSHIFT)) + return 0; + } + } + + return -1; +} + +int handle_guest_page_fault(uintptr_t addr) +{ + spinlock_lock(&vm_lock); + int ret = __handle_guest_page_fault(addr); + spinlock_unlock(&vm_lock); + return ret; +} + +static void hypervisor_vm_init() +{ + have_hypervisor = sizeof(uintptr_t) == 8 && ((read_csr(misa) >> ('H' - 'A')) & 1); + if (!have_hypervisor) + return; + + size_t root_pages = 4; + g_root_page_table = (uintptr_t*)__early_pgalloc_align(root_pages, root_pages); + memset(g_root_page_table, 0, root_pages * RISCV_PGSIZE); + + asm ("csrw %0, %1" : : "I" (CSR_HEDELEG), "r" (0)); + asm ("csrw %0, %1" : : "I" (CSR_HIDELEG), "r" (0)); + asm ("csrw %0, %1" : : "I" (CSR_VSSTATUS), "r" (SSTATUS_FS)); + asm ("csrw %0, %1" : : "I" (CSR_HSTATUS), "r" (HSTATUS_SPV)); + asm ("csrw %0, %1" : : "I" (CSR_HGATP), "r" (SATP_MODE_CHOICE | ((uintptr_t)g_root_page_table >> RISCV_PGSHIFT))); + asm ("csrw %0, %1" : : "I" (CSR_VSATP), "r" (SATP_MODE_CHOICE | ((uintptr_t)root_page_table >> RISCV_PGSHIFT))); + asm (".insn r 0x73, 0x0, 0x31, x0, x0, x0"); // hfence.gvma x0, x0 +} + uintptr_t pk_vm_init() { init_early_alloc(); @@ -571,12 +634,15 @@ uintptr_t pk_vm_init() flush_tlb(); write_csr(satp, ((uintptr_t)root_page_table >> RISCV_PGSHIFT) | SATP_MODE_CHOICE); + hypervisor_vm_init(); + uintptr_t kernel_stack_top = __page_alloc_assert() + RISCV_PGSIZE; // relocate kva2pa_offset = KVA_START - MEM_START; page_freelist_storage = (void*)pa2kva(page_freelist_storage); root_page_table = (void*)pa2kva(root_page_table); + g_root_page_table = (void*)pa2kva(g_root_page_table); return kernel_stack_top; } |