diff options
Diffstat (limited to 'arch/arm64/include/asm/kvm_mmu.h')
-rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 127 |
1 files changed, 117 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index a030d16..0caf7a5 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -41,6 +41,18 @@ */ #define TRAMPOLINE_VA (HYP_PAGE_OFFSET_MASK & PAGE_MASK) +/* + * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation + * levels in addition to the PGD and potentially the PUD which are + * pre-allocated (we pre-allocate the fake PGD and the PUD when the Stage-2 + * tables use one level of tables less than the kernel. + */ +#ifdef CONFIG_ARM64_64K_PAGES +#define KVM_MMU_CACHE_MIN_PAGES 1 +#else +#define KVM_MMU_CACHE_MIN_PAGES 2 +#endif + #ifdef __ASSEMBLY__ /* @@ -53,6 +65,7 @@ #else +#include <asm/pgalloc.h> #include <asm/cachetype.h> #include <asm/cacheflush.h> @@ -65,10 +78,6 @@ #define KVM_PHYS_SIZE (1UL << KVM_PHYS_SHIFT) #define KVM_PHYS_MASK (KVM_PHYS_SIZE - 1UL) -/* Make sure we get the right size, and thus the right alignment */ -#define PTRS_PER_S2_PGD (1 << (KVM_PHYS_SHIFT - PGDIR_SHIFT)) -#define S2_PGD_ORDER get_order(PTRS_PER_S2_PGD * sizeof(pgd_t)) - int create_hyp_mappings(void *from, void *to); int create_hyp_io_mappings(void *from, void *to, phys_addr_t); void free_boot_hyp_pgd(void); @@ -77,7 +86,7 @@ void free_hyp_pgds(void); int kvm_alloc_stage2_pgd(struct kvm *kvm); void kvm_free_stage2_pgd(struct kvm *kvm); int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, - phys_addr_t pa, unsigned long size); + phys_addr_t pa, unsigned long size, bool writable); int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run); @@ -93,6 +102,7 @@ void kvm_clear_hyp_idmap(void); #define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) static inline void kvm_clean_pgd(pgd_t *pgd) {} +static inline void kvm_clean_pmd(pmd_t *pmd) {} static inline void kvm_clean_pmd_entry(pmd_t *pmd) {} static inline void kvm_clean_pte(pte_t *pte) {} static inline void kvm_clean_pte_entry(pte_t *pte) {} @@ -111,19 +121,116 @@ static inline void kvm_set_s2pmd_writable(pmd_t *pmd) #define kvm_pud_addr_end(addr, end) pud_addr_end(addr, end) #define kvm_pmd_addr_end(addr, end) pmd_addr_end(addr, end) +/* + * In the case where PGDIR_SHIFT is larger than KVM_PHYS_SHIFT, we can address + * the entire IPA input range with a single pgd entry, and we would only need + * one pgd entry. Note that in this case, the pgd is actually not used by + * the MMU for Stage-2 translations, but is merely a fake pgd used as a data + * structure for the kernel pgtable macros to work. + */ +#if PGDIR_SHIFT > KVM_PHYS_SHIFT +#define PTRS_PER_S2_PGD_SHIFT 0 +#else +#define PTRS_PER_S2_PGD_SHIFT (KVM_PHYS_SHIFT - PGDIR_SHIFT) +#endif +#define PTRS_PER_S2_PGD (1 << PTRS_PER_S2_PGD_SHIFT) +#define S2_PGD_ORDER get_order(PTRS_PER_S2_PGD * sizeof(pgd_t)) + +/* + * If we are concatenating first level stage-2 page tables, we would have less + * than or equal to 16 pointers in the fake PGD, because that's what the + * architecture allows. In this case, (4 - CONFIG_ARM64_PGTABLE_LEVELS) + * represents the first level for the host, and we add 1 to go to the next + * level (which uses contatenation) for the stage-2 tables. + */ +#if PTRS_PER_S2_PGD <= 16 +#define KVM_PREALLOC_LEVEL (4 - CONFIG_ARM64_PGTABLE_LEVELS + 1) +#else +#define KVM_PREALLOC_LEVEL (0) +#endif + +/** + * kvm_prealloc_hwpgd - allocate inital table for VTTBR + * @kvm: The KVM struct pointer for the VM. + * @pgd: The kernel pseudo pgd + * + * When the kernel uses more levels of page tables than the guest, we allocate + * a fake PGD and pre-populate it to point to the next-level page table, which + * will be the real initial page table pointed to by the VTTBR. + * + * When KVM_PREALLOC_LEVEL==2, we allocate a single page for the PMD and + * the kernel will use folded pud. When KVM_PREALLOC_LEVEL==1, we + * allocate 2 consecutive PUD pages. + */ +static inline int kvm_prealloc_hwpgd(struct kvm *kvm, pgd_t *pgd) +{ + unsigned int i; + unsigned long hwpgd; + + if (KVM_PREALLOC_LEVEL == 0) + return 0; + + hwpgd = __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTRS_PER_S2_PGD_SHIFT); + if (!hwpgd) + return -ENOMEM; + + for (i = 0; i < PTRS_PER_S2_PGD; i++) { + if (KVM_PREALLOC_LEVEL == 1) + pgd_populate(NULL, pgd + i, + (pud_t *)hwpgd + i * PTRS_PER_PUD); + else if (KVM_PREALLOC_LEVEL == 2) + pud_populate(NULL, pud_offset(pgd, 0) + i, + (pmd_t *)hwpgd + i * PTRS_PER_PMD); + } + + return 0; +} + +static inline void *kvm_get_hwpgd(struct kvm *kvm) +{ + pgd_t *pgd = kvm->arch.pgd; + pud_t *pud; + + if (KVM_PREALLOC_LEVEL == 0) + return pgd; + + pud = pud_offset(pgd, 0); + if (KVM_PREALLOC_LEVEL == 1) + return pud; + + BUG_ON(KVM_PREALLOC_LEVEL != 2); + return pmd_offset(pud, 0); +} + +static inline void kvm_free_hwpgd(struct kvm *kvm) +{ + if (KVM_PREALLOC_LEVEL > 0) { + unsigned long hwpgd = (unsigned long)kvm_get_hwpgd(kvm); + free_pages(hwpgd, PTRS_PER_S2_PGD_SHIFT); + } +} + static inline bool kvm_page_empty(void *ptr) { struct page *ptr_page = virt_to_page(ptr); return page_count(ptr_page) == 1; } -#define kvm_pte_table_empty(ptep) kvm_page_empty(ptep) -#ifndef CONFIG_ARM64_64K_PAGES -#define kvm_pmd_table_empty(pmdp) kvm_page_empty(pmdp) +#define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep) + +#ifdef __PAGETABLE_PMD_FOLDED +#define kvm_pmd_table_empty(kvm, pmdp) (0) +#else +#define kvm_pmd_table_empty(kvm, pmdp) \ + (kvm_page_empty(pmdp) && (!(kvm) || KVM_PREALLOC_LEVEL < 2)) +#endif + +#ifdef __PAGETABLE_PUD_FOLDED +#define kvm_pud_table_empty(kvm, pudp) (0) #else -#define kvm_pmd_table_empty(pmdp) (0) +#define kvm_pud_table_empty(kvm, pudp) \ + (kvm_page_empty(pudp) && (!(kvm) || KVM_PREALLOC_LEVEL < 1)) #endif -#define kvm_pud_table_empty(pudp) (0) struct kvm; |