From cf47f50b5c2e24c4ca1e5c8bbec1c47404a9ac24 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 18 Feb 2020 13:07:23 -0800 Subject: [PATCH] KVM: Move setting of memslot into helper routine MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Split out the core functionality of setting a memslot into a separate helper in preparation for moving memslot deletion into its own routine. Tested-by: Christoffer Dall Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Peter Xu Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 106 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 63 insertions(+), 43 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f5719ce7e2d5..882ea3b70ec0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -983,6 +983,66 @@ static struct kvm_memslots *install_new_memslots(struct kvm *kvm, return old_memslots; } +static int kvm_set_memslot(struct kvm *kvm, + const struct kvm_userspace_memory_region *mem, + const struct kvm_memory_slot *old, + struct kvm_memory_slot *new, int as_id, + enum kvm_mr_change change) +{ + struct kvm_memory_slot *slot; + struct kvm_memslots *slots; + int r; + + slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT); + if (!slots) + return -ENOMEM; + memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots)); + + if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { + /* + * Note, the INVALID flag needs to be in the appropriate entry + * in the freshly allocated memslots, not in @old or @new. + */ + slot = id_to_memslot(slots, old->id); + slot->flags |= KVM_MEMSLOT_INVALID; + + /* + * We can re-use the old memslots, the only difference from the + * newly installed memslots is the invalid flag, which will get + * dropped by update_memslots anyway. We'll also revert to the + * old memslots if preparing the new memory region fails. + */ + slots = install_new_memslots(kvm, as_id, slots); + + /* From this point no new shadow pages pointing to a deleted, + * or moved, memslot will be created. + * + * validation of sp->gfn happens in: + * - gfn_to_hva (kvm_read_guest, gfn_to_pfn) + * - kvm_is_visible_gfn (mmu_check_root) + */ + kvm_arch_flush_shadow_memslot(kvm, slot); + } + + r = kvm_arch_prepare_memory_region(kvm, new, mem, change); + if (r) + goto out_slots; + + update_memslots(slots, new, change); + slots = install_new_memslots(kvm, as_id, slots); + + kvm_arch_commit_memory_region(kvm, mem, old, new, change); + + kvfree(slots); + return 0; + +out_slots: + if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) + slots = install_new_memslots(kvm, as_id, slots); + kvfree(slots); + return r; +} + /* * Allocate some memory and give it an address in the guest physical address * space. @@ -999,7 +1059,6 @@ int __kvm_set_memory_region(struct kvm *kvm, unsigned long npages; struct kvm_memory_slot *slot; struct kvm_memory_slot old, new; - struct kvm_memslots *slots; int as_id, id; enum kvm_mr_change change; @@ -1086,58 +1145,19 @@ int __kvm_set_memory_region(struct kvm *kvm, return r; } - slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT); - if (!slots) { - r = -ENOMEM; - goto out_bitmap; - } - memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots)); - - if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) { - slot = id_to_memslot(slots, id); - slot->flags |= KVM_MEMSLOT_INVALID; - - /* - * We can re-use the old memslots, the only difference from the - * newly installed memslots is the invalid flag, which will get - * dropped by update_memslots anyway. We'll also revert to the - * old memslots if preparing the new memory region fails. - */ - slots = install_new_memslots(kvm, as_id, slots); - - /* From this point no new shadow pages pointing to a deleted, - * or moved, memslot will be created. - * - * validation of sp->gfn happens in: - * - gfn_to_hva (kvm_read_guest, gfn_to_pfn) - * - kvm_is_visible_gfn (mmu_check_root) - */ - kvm_arch_flush_shadow_memslot(kvm, slot); - } - - r = kvm_arch_prepare_memory_region(kvm, &new, mem, change); - if (r) - goto out_slots; - /* actual memory is freed via old in kvm_free_memslot below */ if (change == KVM_MR_DELETE) { new.dirty_bitmap = NULL; memset(&new.arch, 0, sizeof(new.arch)); } - update_memslots(slots, &new, change); - slots = install_new_memslots(kvm, as_id, slots); - - kvm_arch_commit_memory_region(kvm, mem, &old, &new, change); + r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change); + if (r) + goto out_bitmap; kvm_free_memslot(kvm, &old, &new); - kvfree(slots); return 0; -out_slots: - if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) - slots = install_new_memslots(kvm, as_id, slots); - kvfree(slots); out_bitmap: if (new.dirty_bitmap && !old.dirty_bitmap) kvm_destroy_dirty_bitmap(&new); -- 2.11.0