Draining a CPU-side dirty log buffer into the dirty ring requires sizing that buffer against the ring, which reserves room for a full flush. Add a kvm_arch_dirty_ring_size_updated() hook called right after kvm->dirty_ring_size is recorded, with a __weak no-op default.
arm64 will use it to pin its HDBSS buffer size in dirty-ring mode. Signed-off-by: Tian Zheng <[email protected]> --- include/linux/kvm_dirty_ring.h | 1 + virt/kvm/dirty_ring.c | 4 ++++ virt/kvm/kvm_main.c | 1 + 3 files changed, 6 insertions(+) diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h index eb10d87adf7d..c2b922791530 100644 --- a/include/linux/kvm_dirty_ring.h +++ b/include/linux/kvm_dirty_ring.h @@ -73,6 +73,7 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) #else /* CONFIG_HAVE_KVM_DIRTY_RING */ int kvm_cpu_dirty_log_size(struct kvm *kvm); +void kvm_arch_dirty_ring_size_updated(struct kvm *kvm); bool kvm_use_dirty_bitmap(struct kvm *kvm); bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm); u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm); diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c index 572b854edf74..784f53c95b54 100644 --- a/virt/kvm/dirty_ring.c +++ b/virt/kvm/dirty_ring.c @@ -16,6 +16,10 @@ int __weak kvm_cpu_dirty_log_size(struct kvm *kvm) return 0; } +void __weak kvm_arch_dirty_ring_size_updated(struct kvm *kvm) +{ +} + u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm) { return KVM_DIRTY_RING_RSVD_ENTRIES + kvm_cpu_dirty_log_size(kvm); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 85f42289748d..d109062f6a1c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5011,6 +5011,7 @@ static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size) r = -EINVAL; } else { kvm->dirty_ring_size = size; + kvm_arch_dirty_ring_size_updated(kvm); r = 0; } -- 2.43.0
