| Message ID | 20200121223157.15263-10-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Dynamically size memslot arrays | expand |
On Tue, Jan 21, 2020 at 02:31:47PM -0800, Sean Christopherson wrote: > 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 <christoffer.dall@arm.com> > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > 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 fdf045a5d240..64f6c5d35260 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -982,6 +982,66 @@ 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. > @@ -998,7 +1058,6 @@ 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; > > @@ -1085,58 +1144,19 @@ 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)); > } It's not extremely clear to me on why this single block is leftover here instead of putting into kvm_set_memslot(). I see that after all it'll be removed in patch 12, so it seems OK: Reviewed-by: Peter Xu <peterx@redhat.com> > > - 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); > -- > 2.24.1 >
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fdf045a5d240..64f6c5d35260 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -982,6 +982,66 @@ 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. @@ -998,7 +1058,6 @@ 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; @@ -1085,58 +1144,19 @@ 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);