From 64f324979210d4064adf64f19da40c125c9dd137 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Tue, 22 Mar 2016 18:56:21 +0000 Subject: [PATCH] kvm-arm: Add explicit hyp page table modifiers We have common routines to modify hyp and stage2 page tables based on the 'kvm' parameter. For a smoother transition to using separate routines for each, duplicate the routines and modify the copy to work on hyp. Marks the forked routines with _hyp_ and gets rid of the kvm parameter which is no longer needed and is NULL for hyp. Also, gets rid of calls to kvm_tlb_flush_by_vmid_ipa() calls from the hyp versions. Uses explicit host page table accessors instead of the kvm_* page table helpers. Suggested-by: Christoffer Dall Cc: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Suzuki K Poulose --- arch/arm/kvm/mmu.c | 104 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 99 insertions(+), 5 deletions(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index f93f717b5d8b..af526f67022c 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -388,6 +388,100 @@ static void stage2_flush_vm(struct kvm *kvm) srcu_read_unlock(&kvm->srcu, idx); } +static void clear_hyp_pgd_entry(pgd_t *pgd) +{ + pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL); + pgd_clear(pgd); + pud_free(NULL, pud_table); + put_page(virt_to_page(pgd)); +} + +static void clear_hyp_pud_entry(pud_t *pud) +{ + pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0); + VM_BUG_ON(pud_huge(*pud)); + pud_clear(pud); + pmd_free(NULL, pmd_table); + put_page(virt_to_page(pud)); +} + +static void clear_hyp_pmd_entry(pmd_t *pmd) +{ + pte_t *pte_table = pte_offset_kernel(pmd, 0); + VM_BUG_ON(pmd_thp_or_huge(*pmd)); + pmd_clear(pmd); + pte_free_kernel(NULL, pte_table); + put_page(virt_to_page(pmd)); +} + +static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end) +{ + pte_t *pte, *start_pte; + + start_pte = pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + kvm_set_pte(pte, __pte(0)); + put_page(virt_to_page(pte)); + } + } while (pte++, addr += PAGE_SIZE, addr != end); + + if (hyp_pte_table_empty(start_pte)) + clear_hyp_pmd_entry(pmd); +} + +static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t next; + pmd_t *pmd, *start_pmd; + + start_pmd = pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + /* Hyp doesn't use huge pmds */ + if (!pmd_none(*pmd)) + unmap_hyp_ptes(pmd, addr, next); + } while (pmd++, addr = next, addr != end); + + if (hyp_pmd_table_empty(start_pmd)) + clear_hyp_pud_entry(pud); +} + +static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t next; + pud_t *pud, *start_pud; + + start_pud = pud = pud_offset(pgd, addr); + do { + next = pud_addr_end(addr, end); + /* Hyp doesn't use huge puds */ + if (!pud_none(*pud)) + unmap_hyp_pmds(pud, addr, next); + } while (pud++, addr = next, addr != end); + + if (hyp_pud_table_empty(start_pud)) + clear_hyp_pgd_entry(pgd); +} + +static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size) +{ + pgd_t *pgd; + phys_addr_t addr = start, end = start + size; + phys_addr_t next; + + /* + * We don't unmap anything from HYP, except at the hyp tear down. + * Hence, we don't have to invalidate the TLBs here. + */ + pgd = pgdp + pgd_index(addr); + do { + next = pgd_addr_end(addr, end); + if (!pgd_none(*pgd)) + unmap_hyp_puds(pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} + /** * free_boot_hyp_pgd - free HYP boot page tables * @@ -398,14 +492,14 @@ void free_boot_hyp_pgd(void) mutex_lock(&kvm_hyp_pgd_mutex); if (boot_hyp_pgd) { - unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); - unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); + unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); + unmap_hyp_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order); boot_hyp_pgd = NULL; } if (hyp_pgd) - unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); + unmap_hyp_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); mutex_unlock(&kvm_hyp_pgd_mutex); } @@ -430,9 +524,9 @@ void free_hyp_pgds(void) if (hyp_pgd) { for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE) - unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + unmap_hyp_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE) - unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + unmap_hyp_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); free_pages((unsigned long)hyp_pgd, hyp_pgd_order); hyp_pgd = NULL;