diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 4c5c8a386baf703eb5c9a26de19467b33ae81b36..b0b0cde77ca66c8b37388bd695e0056a784aff3e 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -49,6 +49,9 @@ #include #include +/* Ensure compatibility with arm64 */ +#define VA_BITS 32 + int create_hyp_mappings(void *from, void *to, pgprot_t prot); int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, void __iomem **kaddr, diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index f7fe724c14f4eda3485bb0821637f1dd1acb5797..d8ea68b78e9cb59b6a8b31cdfcf6aa397deedcc7 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -43,6 +43,8 @@ static unsigned long hyp_idmap_start; static unsigned long hyp_idmap_end; static phys_addr_t hyp_idmap_vector; +static unsigned long io_map_base; + #define S2_PGD_SIZE (PTRS_PER_S2_PGD * sizeof(pgd_t)) #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t)) @@ -518,27 +520,35 @@ static void unmap_hyp_idmap_range(pgd_t *pgdp, phys_addr_t start, u64 size) * * Assumes hyp_pgd is a page table used strictly in Hyp-mode and * therefore contains either mappings in the kernel memory area (above - * PAGE_OFFSET), or device mappings in the vmalloc range (from - * VMALLOC_START to VMALLOC_END). + * PAGE_OFFSET), or device mappings in the idmap range. * - * boot_hyp_pgd should only map two pages for the init code. + * boot_hyp_pgd should only map the idmap range, and is only used in + * the extended idmap case. */ void free_hyp_pgds(void) { + pgd_t *id_pgd; + mutex_lock(&kvm_hyp_pgd_mutex); + id_pgd = boot_hyp_pgd ? boot_hyp_pgd : hyp_pgd; + + if (id_pgd) { + /* In case we never called hyp_mmu_init() */ + if (!io_map_base) + io_map_base = hyp_idmap_start; + unmap_hyp_idmap_range(id_pgd, io_map_base, + hyp_idmap_start + PAGE_SIZE - io_map_base); + } + if (boot_hyp_pgd) { - unmap_hyp_idmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order); boot_hyp_pgd = NULL; } if (hyp_pgd) { - unmap_hyp_idmap_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE); unmap_hyp_range(hyp_pgd, kern_hyp_va(PAGE_OFFSET), (uintptr_t)high_memory - PAGE_OFFSET); - unmap_hyp_range(hyp_pgd, kern_hyp_va(VMALLOC_START), - VMALLOC_END - VMALLOC_START); free_pages((unsigned long)hyp_pgd, hyp_pgd_order); hyp_pgd = NULL; @@ -735,8 +745,9 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, void __iomem **kaddr, void __iomem **haddr) { - unsigned long start, end; - int ret; + pgd_t *pgd = hyp_pgd; + unsigned long base; + int ret = 0; *kaddr = ioremap(phys_addr, size); if (!*kaddr) @@ -747,19 +758,52 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, return 0; } + mutex_lock(&kvm_hyp_pgd_mutex); - start = kern_hyp_va((unsigned long)*kaddr); - end = kern_hyp_va((unsigned long)*kaddr + size); - ret = __create_hyp_mappings(hyp_pgd, PTRS_PER_PGD, start, end, - __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE); + /* + * This assumes that we we have enough space below the idmap + * page to allocate our VAs. If not, the check below will + * kick. A potential alternative would be to detect that + * overflow and switch to an allocation above the idmap. + * + * The allocated size is always a multiple of PAGE_SIZE. + */ + size = PAGE_ALIGN(size + offset_in_page(phys_addr)); + base = io_map_base - size; + /* + * Verify that BIT(VA_BITS - 1) hasn't been flipped by + * allocating the new area, as it would indicate we've + * overflowed the idmap/IO address range. + */ + if ((base ^ io_map_base) & BIT(VA_BITS - 1)) + ret = -ENOMEM; + else + io_map_base = base; + + mutex_unlock(&kvm_hyp_pgd_mutex); + + if (ret) + goto out; + + if (__kvm_cpu_uses_extended_idmap()) + pgd = boot_hyp_pgd; + + ret = __create_hyp_mappings(pgd, __kvm_idmap_ptrs_per_pgd(), + base, base + size, + __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE); + if (ret) + goto out; + + *haddr = (void __iomem *)base + offset_in_page(phys_addr); + +out: if (ret) { iounmap(*kaddr); *kaddr = NULL; return ret; } - *haddr = (void __iomem *)start; return 0; } @@ -1892,6 +1936,7 @@ int kvm_mmu_init(void) goto out; } + io_map_base = hyp_idmap_start; return 0; out: free_hyp_pgds();