[PATCH RFC v9 30/51] KVM: Add HVA range operator

Michael Roth
2023-06-12T04:41:06Z

From: Vishal Annapurve <vannapurve@google.com>

Introduce HVA range operator so that other KVM subsystems
can operate on HVA range.

Signed-off-by: Vishal Annapurve <vannapurve@google.com>
[mdr: minor checkpatch alignment fixups]
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
include/linux/kvm_host.h | 6 +++++
virt/kvm/kvm_main.c | 49 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7de06add2235..9a9d4141ba74 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1400,6 +1400,12 @@ void kvm_mmu_invalidate_begin(struct kvm *kvm);
void kvm_mmu_invalidate_range_add(struct kvm *kvm, gfn_t start, gfn_t end);
void kvm_mmu_invalidate_end(struct kvm *kvm);

+typedef int (*kvm_hva_range_op_t)(struct kvm *kvm,
+ struct kvm_gfn_range *range, void *data);
+
+int kvm_vm_do_hva_range_op(struct kvm *kvm, unsigned long hva_start,
+ unsigned long hva_end, kvm_hva_range_op_t handler, void *data);
+
long kvm_arch_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg);
long kvm_arch_vcpu_ioctl(struct file *filp,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 422d49634c56..48beffca6b67 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -642,6 +642,55 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
return (int)ret;
}

+int kvm_vm_do_hva_range_op(struct kvm *kvm, unsigned long hva_start,
+ unsigned long hva_end, kvm_hva_range_op_t handler, void *data)
+{
+ int ret = 0;
+ struct kvm_gfn_range gfn_range;
+ struct kvm_memory_slot *slot;
+ struct kvm_memslots *slots;
+ int i, idx;
+
+ if (WARN_ON_ONCE(hva_end <= hva_start))
+ return -EINVAL;
+
+ idx = srcu_read_lock(&kvm->srcu);
+
+ for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
+ struct interval_tree_node *node;
+
+ slots = __kvm_memslots(kvm, i);
+ kvm_for_each_memslot_in_hva_range(node, slots,
+ hva_start, hva_end - 1) {
+ unsigned long start, end;
+
+ slot = container_of(node, struct kvm_memory_slot,
+ hva_node[slots->node_idx]);
+ start = max(hva_start, slot->userspace_addr);
+ end = min(hva_end, slot->userspace_addr +
+ (slot->npages << PAGE_SHIFT));
+
+ /*
+ * {gfn(page) | page intersects with [hva_start, hva_end)} =
+ * {gfn_start, gfn_start+1, ..., gfn_end-1}.
+ */
+ gfn_range.start = hva_to_gfn_memslot(start, slot);
+ gfn_range.end = hva_to_gfn_memslot(end + PAGE_SIZE - 1, slot);
+ gfn_range.slot = slot;
+
+ ret = handler(kvm, &gfn_range, data);
+ if (ret)
+ goto e_ret;
+ }
+ }
+
+e_ret:
+ srcu_read_unlock(&kvm->srcu, idx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_vm_do_hva_range_op);
+
static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
unsigned long start,
unsigned long end,
--
2.25.1