[PATCH 25/60] kvm: Move kvm_vcpu->dirty_ring to struct kvm_vcpu_common

From: Jörg Rödel

Date: Mon Jun 08 2026 - 11:15:57 EST


From: Joerg Roedel <joerg.roedel@xxxxxxx>

The dirty tracking should happen across all planes of a given VCPU, so
move the dirty_ring to struct kvm_vcpu_common.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
include/linux/kvm_host.h | 3 ++-
virt/kvm/dirty_ring.c | 4 ++--
virt/kvm/kvm_main.c | 22 ++++++++++------------
3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index f6e8a0b653b3..7d06459a06f3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -373,6 +373,8 @@ struct kvm_vcpu_common {
bool preempted;
bool ready;
bool scheduled_out;
+
+ struct kvm_dirty_ring dirty_ring;
};

struct kvm_vcpu {
@@ -413,7 +415,6 @@ struct kvm_vcpu {
struct kvm_vcpu_arch arch;
struct kvm_vcpu_stat stat;
char stats_id[KVM_STATS_NAME_SIZE];
- struct kvm_dirty_ring dirty_ring;

/*
* The most recently used memslot by this vCPU and the slots generation
diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
index 572b854edf74..c6f46b93bddb 100644
--- a/virt/kvm/dirty_ring.c
+++ b/virt/kvm/dirty_ring.c
@@ -218,7 +218,7 @@ int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring,

void kvm_dirty_ring_push(struct kvm_vcpu *vcpu, u32 slot, u64 offset)
{
- struct kvm_dirty_ring *ring = &vcpu->dirty_ring;
+ struct kvm_dirty_ring *ring = &vcpu->common->dirty_ring;
struct kvm_dirty_gfn *entry;

/* It should never get full */
@@ -250,7 +250,7 @@ bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu)
* the dirty ring is reset by userspace.
*/
if (kvm_check_request(KVM_REQ_DIRTY_RING_SOFT_FULL, vcpu) &&
- kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) {
+ kvm_dirty_ring_soft_full(&vcpu->common->dirty_ring)) {
kvm_make_request(KVM_REQ_DIRTY_RING_SOFT_FULL, vcpu);
vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL;
trace_kvm_dirty_ring_exit(vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 24ff8748a317..f85ddb0fc781 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -483,6 +483,13 @@ static int kvm_vcpu_init_common(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned
common->ready = false;
preempt_notifier_init(&common->preempt_notifier, &kvm_preempt_ops);

+ if (kvm->dirty_ring_size) {
+ r = kvm_dirty_ring_alloc(kvm, &common->dirty_ring,
+ id, kvm->dirty_ring_size);
+ if (r)
+ goto out_drop_counter;
+ }
+
vcpu->common = no_free_ptr(common);

kvm_vcpu_set_in_spin_loop(vcpu, false);
@@ -547,6 +554,7 @@ static void kvm_vcpu_common_destroy(struct kvm_vcpu *vcpu)
* are already gone.
*/
put_pid(common->pid);
+ kvm_dirty_ring_free(&common->dirty_ring);
kfree(common);
}

@@ -555,7 +563,6 @@ static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
kvm_arch_vcpu_destroy(vcpu);

kvm_vcpu_common_destroy(vcpu);
- kvm_dirty_ring_free(&vcpu->dirty_ring);

free_page((unsigned long)vcpu->run);
kmem_cache_free(kvm_vcpu_cache, vcpu);
@@ -4209,7 +4216,7 @@ static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
#endif
else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff))
page = kvm_dirty_ring_get_page(
- &vcpu->dirty_ring,
+ &vcpu->common->dirty_ring,
vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET);
else
return kvm_arch_vcpu_fault(vcpu, vmf);
@@ -4338,13 +4345,6 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
if (r)
goto vcpu_free_run_page;

- if (kvm->dirty_ring_size) {
- r = kvm_dirty_ring_alloc(kvm, &vcpu->dirty_ring,
- id, kvm->dirty_ring_size);
- if (r)
- goto arch_vcpu_destroy;
- }
-
mutex_lock(&kvm->lock);

if (kvm_get_vcpu_by_id(kvm, id)) {
@@ -4385,8 +4385,6 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
xa_erase(&kvm->planes[0]->vcpu_array, vcpu->vcpu_idx);
unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
- kvm_dirty_ring_free(&vcpu->dirty_ring);
-arch_vcpu_destroy:
kvm_arch_vcpu_destroy(vcpu);
vcpu_free_run_page:
free_page((unsigned long)vcpu->run);
@@ -5120,7 +5118,7 @@ static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm)
mutex_lock(&kvm->slots_lock);

kvm_for_each_vcpu(i, vcpu, kvm) {
- r = kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring, &cleared);
+ r = kvm_dirty_ring_reset(vcpu->kvm, &vcpu->common->dirty_ring, &cleared);
if (r)
break;
}
--
2.53.0