Add a new field to struct kvm that keeps track of the number of memslots
with dirty logging enabled. This will be used in a future commit to
cheaply check if any memslot is doing dirty logging.
Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
---
include/linux/kvm_host.h | 2 ++
virt/kvm/kvm_main.c | 10 ++++++++++
2 files changed, 12 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 32f259fa5801..25ed8c1725ff 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -709,6 +709,8 @@ struct kvm {
struct kvm_memslots __memslots[KVM_ADDRESS_SPACE_NUM][2];
/* The current active memslot set for each address space */
struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
+ /* The number of memslots with dirty logging enabled. */
+ int nr_memslots_dirty_logging;
struct xarray vcpu_array;
/* Used to wait for completion of MMU notifiers. */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e30f1b4ecfa5..57e4406005cd 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1641,6 +1641,9 @@ static void kvm_commit_memory_region(struct kvm *kvm,
const struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
+ int old_flags = old ? old->flags : 0;
+ int new_flags = new ? new->flags : 0;
+
/*
* Update the total number of memslot pages before calling the arch
* hook so that architectures can consume the result directly.
@@ -1650,6 +1653,13 @@ static void kvm_commit_memory_region(struct kvm *kvm,
else if (change == KVM_MR_CREATE)
kvm->nr_memslot_pages += new->npages;
+ if ((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES) {
+ if (new_flags & KVM_MEM_LOG_DIRTY_PAGES)
+ kvm->nr_memslots_dirty_logging++;
+ else
+ kvm->nr_memslots_dirty_logging--;
+ }
+
kvm_arch_commit_memory_region(kvm, old, new, change);
switch (change) {
--
2.38.1.273.g43a17bfeac-goog
