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Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_radix.c')
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_radix.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 9091407fbfd4..865ea9bca364 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -137,3 +137,388 @@ int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
return 0;
}
+#ifdef CONFIG_PPC_64K_PAGES
+#define MMU_BASE_PSIZE MMU_PAGE_64K
+#else
+#define MMU_BASE_PSIZE MMU_PAGE_4K
+#endif
+
+static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
+ unsigned int pshift)
+{
+ int psize = MMU_BASE_PSIZE;
+
+ if (pshift >= PMD_SHIFT)
+ psize = MMU_PAGE_2M;
+ addr &= ~0xfffUL;
+ addr |= mmu_psize_defs[psize].ap << 5;
+ asm volatile("ptesync": : :"memory");
+ asm volatile(PPC_TLBIE_5(%0, %1, 0, 0, 1)
+ : : "r" (addr), "r" (kvm->arch.lpid) : "memory");
+ asm volatile("ptesync": : :"memory");
+}
+
+void kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep, unsigned long clr,
+ unsigned long set, unsigned long addr,
+ unsigned int shift)
+{
+ if (!(clr & _PAGE_PRESENT) && cpu_has_feature(CPU_FTR_POWER9_DD1) &&
+ pte_present(*ptep)) {
+ /* have to invalidate it first */
+ __radix_pte_update(ptep, _PAGE_PRESENT, 0);
+ kvmppc_radix_tlbie_page(kvm, addr, shift);
+ set |= _PAGE_PRESENT;
+ }
+ __radix_pte_update(ptep, clr, set);
+}
+
+void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
+}
+
+static struct kmem_cache *kvm_pte_cache;
+
+static pte_t *kvmppc_pte_alloc(void)
+{
+ return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
+}
+
+static void kvmppc_pte_free(pte_t *ptep)
+{
+ kmem_cache_free(kvm_pte_cache, ptep);
+}
+
+static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
+ unsigned int level, unsigned long mmu_seq)
+{
+ pgd_t *pgd;
+ pud_t *pud, *new_pud = NULL;
+ pmd_t *pmd, *new_pmd = NULL;
+ pte_t *ptep, *new_ptep = NULL;
+ int ret;
+
+ /* Traverse the guest's 2nd-level tree, allocate new levels needed */
+ pgd = kvm->arch.pgtable + pgd_index(gpa);
+ pud = NULL;
+ if (pgd_present(*pgd))
+ pud = pud_offset(pgd, gpa);
+ else
+ new_pud = pud_alloc_one(kvm->mm, gpa);
+
+ pmd = NULL;
+ if (pud && pud_present(*pud))
+ pmd = pmd_offset(pud, gpa);
+ else
+ new_pmd = pmd_alloc_one(kvm->mm, gpa);
+
+ if (level == 0 && !(pmd && pmd_present(*pmd)))
+ new_ptep = kvmppc_pte_alloc();
+
+ /* Check if we might have been invalidated; let the guest retry if so */
+ spin_lock(&kvm->mmu_lock);
+ ret = -EAGAIN;
+ if (mmu_notifier_retry(kvm, mmu_seq))
+ goto out_unlock;
+
+ /* Now traverse again under the lock and change the tree */
+ ret = -ENOMEM;
+ if (pgd_none(*pgd)) {
+ if (!new_pud)
+ goto out_unlock;
+ pgd_populate(kvm->mm, pgd, new_pud);
+ new_pud = NULL;
+ }
+ pud = pud_offset(pgd, gpa);
+ if (pud_none(*pud)) {
+ if (!new_pmd)
+ goto out_unlock;
+ pud_populate(kvm->mm, pud, new_pmd);
+ new_pmd = NULL;
+ }
+ pmd = pmd_offset(pud, gpa);
+ if (pmd_large(*pmd)) {
+ /* Someone else has instantiated a large page here; retry */
+ ret = -EAGAIN;
+ goto out_unlock;
+ }
+ if (level == 1 && !pmd_none(*pmd)) {
+ /*
+ * There's a page table page here, but we wanted
+ * to install a large page. Tell the caller and let
+ * it try installing a normal page if it wants.
+ */
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (level == 0) {
+ if (pmd_none(*pmd)) {
+ if (!new_ptep)
+ goto out_unlock;
+ pmd_populate(kvm->mm, pmd, new_ptep);
+ new_ptep = NULL;
+ }
+ ptep = pte_offset_kernel(pmd, gpa);
+ if (pte_present(*ptep)) {
+ /* PTE was previously valid, so invalidate it */
+ kvmppc_radix_update_pte(kvm, ptep, _PAGE_PRESENT,
+ 0, gpa, 0);
+ kvmppc_radix_tlbie_page(kvm, gpa, 0);
+ }
+ kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
+ } else {
+ kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
+ }
+ ret = 0;
+
+ out_unlock:
+ spin_unlock(&kvm->mmu_lock);
+ if (new_pud)
+ pud_free(kvm->mm, new_pud);
+ if (new_pmd)
+ pmd_free(kvm->mm, new_pmd);
+ if (new_ptep)
+ kvmppc_pte_free(new_ptep);
+ return ret;
+}
+
+int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ unsigned long ea, unsigned long dsisr)
+{
+ struct kvm *kvm = vcpu->kvm;
+ unsigned long mmu_seq, pte_size;
+ unsigned long gpa, gfn, hva, pfn;
+ struct kvm_memory_slot *memslot;
+ struct page *page = NULL, *pages[1];
+ long ret, npages, ok;
+ unsigned int writing;
+ struct vm_area_struct *vma;
+ unsigned long flags;
+ pte_t pte, *ptep;
+ unsigned long pgflags;
+ unsigned int shift, level;
+
+ /* Check for unusual errors */
+ if (dsisr & DSISR_UNSUPP_MMU) {
+ pr_err("KVM: Got unsupported MMU fault\n");
+ return -EFAULT;
+ }
+ if (dsisr & DSISR_BADACCESS) {
+ /* Reflect to the guest as DSI */
+ pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
+ kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
+ return RESUME_GUEST;
+ }
+
+ /* Translate the logical address and get the page */
+ gpa = vcpu->arch.fault_gpa & ~0xfffUL;
+ gpa &= ~0xF000000000000000ul;
+ gfn = gpa >> PAGE_SHIFT;
+ if (!(dsisr & DSISR_PGDIRFAULT))
+ gpa |= ea & 0xfff;
+ memslot = gfn_to_memslot(kvm, gfn);
+
+ /* No memslot means it's an emulated MMIO region */
+ if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
+ if (dsisr & (DSISR_PGDIRFAULT | DSISR_BADACCESS |
+ DSISR_SET_RC)) {
+ /*
+ * Bad address in guest page table tree, or other
+ * unusual error - reflect it to the guest as DSI.
+ */
+ kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
+ return RESUME_GUEST;
+ }
+ return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
+ dsisr & DSISR_ISSTORE);
+ }
+
+ /* used to check for invalidations in progress */
+ mmu_seq = kvm->mmu_notifier_seq;
+ smp_rmb();
+
+ writing = (dsisr & DSISR_ISSTORE) != 0;
+ hva = gfn_to_hva_memslot(memslot, gfn);
+ if (dsisr & DSISR_SET_RC) {
+ /*
+ * Need to set an R or C bit in the 2nd-level tables;
+ * if the relevant bits aren't already set in the linux
+ * page tables, fall through to do the gup_fast to
+ * set them in the linux page tables too.
+ */
+ ok = 0;
+ pgflags = _PAGE_ACCESSED;
+ if (writing)
+ pgflags |= _PAGE_DIRTY;
+ local_irq_save(flags);
+ ptep = __find_linux_pte_or_hugepte(current->mm->pgd, hva,
+ NULL, NULL);
+ if (ptep) {
+ pte = READ_ONCE(*ptep);
+ if (pte_present(pte) &&
+ (pte_val(pte) & pgflags) == pgflags)
+ ok = 1;
+ }
+ local_irq_restore(flags);
+ if (ok) {
+ spin_lock(&kvm->mmu_lock);
+ if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
+ spin_unlock(&kvm->mmu_lock);
+ return RESUME_GUEST;
+ }
+ ptep = __find_linux_pte_or_hugepte(kvm->arch.pgtable,
+ gpa, NULL, &shift);
+ if (ptep && pte_present(*ptep)) {
+ kvmppc_radix_update_pte(kvm, ptep, 0, pgflags,
+ gpa, shift);
+ spin_unlock(&kvm->mmu_lock);
+ return RESUME_GUEST;
+ }
+ spin_unlock(&kvm->mmu_lock);
+ }
+ }
+
+ ret = -EFAULT;
+ pfn = 0;
+ pte_size = PAGE_SIZE;
+ pgflags = _PAGE_READ | _PAGE_EXEC;
+ level = 0;
+ npages = get_user_pages_fast(hva, 1, writing, pages);
+ if (npages < 1) {
+ /* Check if it's an I/O mapping */
+ down_read(&current->mm->mmap_sem);
+ vma = find_vma(current->mm, hva);
+ if (vma && vma->vm_start <= hva && hva < vma->vm_end &&
+ (vma->vm_flags & VM_PFNMAP)) {
+ pfn = vma->vm_pgoff +
+ ((hva - vma->vm_start) >> PAGE_SHIFT);
+ pgflags = pgprot_val(vma->vm_page_prot);
+ }
+ up_read(&current->mm->mmap_sem);
+ if (!pfn)
+ return -EFAULT;
+ } else {
+ page = pages[0];
+ pfn = page_to_pfn(page);
+ if (PageHuge(page)) {
+ page = compound_head(page);
+ pte_size <<= compound_order(page);
+ /* See if we can insert a 2MB large-page PTE here */
+ if (pte_size >= PMD_SIZE &&
+ (gpa & PMD_MASK & PAGE_MASK) ==
+ (hva & PMD_MASK & PAGE_MASK)) {
+ level = 1;
+ pfn &= ~((PMD_SIZE >> PAGE_SHIFT) - 1);
+ }
+ }
+ /* See if we can provide write access */
+ if (writing) {
+ /*
+ * We assume gup_fast has set dirty on the host PTE.
+ */
+ pgflags |= _PAGE_WRITE;
+ } else {
+ local_irq_save(flags);
+ ptep = __find_linux_pte_or_hugepte(current->mm->pgd,
+ hva, NULL, NULL);
+ if (ptep && pte_write(*ptep) && pte_dirty(*ptep))
+ pgflags |= _PAGE_WRITE;
+ local_irq_restore(flags);
+ }
+ }
+
+ /*
+ * Compute the PTE value that we need to insert.
+ */
+ pgflags |= _PAGE_PRESENT | _PAGE_PTE | _PAGE_ACCESSED;
+ if (pgflags & _PAGE_WRITE)
+ pgflags |= _PAGE_DIRTY;
+ pte = pfn_pte(pfn, __pgprot(pgflags));
+
+ /* Allocate space in the tree and write the PTE */
+ ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq);
+ if (ret == -EBUSY) {
+ /*
+ * There's already a PMD where wanted to install a large page;
+ * for now, fall back to installing a small page.
+ */
+ level = 0;
+ pfn |= gfn & ((PMD_SIZE >> PAGE_SHIFT) - 1);
+ pte = pfn_pte(pfn, __pgprot(pgflags));
+ ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq);
+ }
+ if (ret == 0 || ret == -EAGAIN)
+ ret = RESUME_GUEST;
+
+ if (page) {
+ /*
+ * We drop pages[0] here, not page because page might
+ * have been set to the head page of a compound, but
+ * we have to drop the reference on the correct tail
+ * page to match the get inside gup()
+ */
+ put_page(pages[0]);
+ }
+ return ret;
+}
+
+void kvmppc_free_radix(struct kvm *kvm)
+{
+ unsigned long ig, iu, im;
+ pte_t *pte;
+ pmd_t *pmd;
+ pud_t *pud;
+ pgd_t *pgd;
+
+ if (!kvm->arch.pgtable)
+ return;
+ pgd = kvm->arch.pgtable;
+ for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
+ if (!pgd_present(*pgd))
+ continue;
+ pud = pud_offset(pgd, 0);
+ for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++pud) {
+ if (!pud_present(*pud))
+ continue;
+ pmd = pmd_offset(pud, 0);
+ for (im = 0; im < PTRS_PER_PMD; ++im, ++pmd) {
+ if (pmd_huge(*pmd)) {
+ pmd_clear(pmd);
+ continue;
+ }
+ if (!pmd_present(*pmd))
+ continue;
+ pte = pte_offset_map(pmd, 0);
+ memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
+ kvmppc_pte_free(pte);
+ pmd_clear(pmd);
+ }
+ pmd_free(kvm->mm, pmd_offset(pud, 0));
+ pud_clear(pud);
+ }
+ pud_free(kvm->mm, pud_offset(pgd, 0));
+ pgd_clear(pgd);
+ }
+ pgd_free(kvm->mm, kvm->arch.pgtable);
+}
+
+static void pte_ctor(void *addr)
+{
+ memset(addr, 0, PTE_TABLE_SIZE);
+}
+
+int kvmppc_radix_init(void)
+{
+ unsigned long size = sizeof(void *) << PTE_INDEX_SIZE;
+
+ kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
+ if (!kvm_pte_cache)
+ return -ENOMEM;
+ return 0;
+}
+
+void kvmppc_radix_exit(void)
+{
+ kmem_cache_destroy(kvm_pte_cache);
+}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-21 22:16:41 +0200