[RFCv1,8/8] kvm: Enable dirty ring for arm64

Commit Message

Gavin Shan Feb. 6, 2023, 11:20 a.m. UTC

arm64 has different capability from x86 to enable the dirty ring, which
is KVM_CAP_DIRTY_LOG_RING_ACQ_REL. To enable it in kvm_dirty_ring_init()
when KVM_CAP_DIRTY_LOG_RING isn't supported.

Signed-off-by: Gavin Shan <[e-mail]>
---
 accel/kvm/kvm-all.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Juan Quintela Feb. 8, 2023, 10:15 p.m. UTC | #1

Gavin Shan <[e-mail]> wrote:
> arm64 has different capability from x86 to enable the dirty ring, which
> is KVM_CAP_DIRTY_LOG_RING_ACQ_REL. To enable it in kvm_dirty_ring_init()
> when KVM_CAP_DIRTY_LOG_RING isn't supported.
>
> Signed-off-by: Gavin Shan <[e-mail]>

Reviewed-by: Juan Quintela <[e-mail]>

Patch

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 399ef0f7e6..8ab31865eb 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1479,13 +1479,19 @@  static int kvm_dirty_ring_reaper_init(KVMState *s)
 static int kvm_dirty_ring_init(KVMState *s)
 {
     uint64_t ring_bytes;
+    unsigned int capability = KVM_CAP_DIRTY_LOG_RING;
     int ret;
 
     /*
      * Read the max supported pages. Fall back to dirty logging mode
      * if the dirty ring isn't supported.
      */
-    ret = kvm_vm_check_extension(s, KVM_CAP_DIRTY_LOG_RING);
+    ret = kvm_vm_check_extension(s, capability);
+    if (ret <= 0) {
+        capability = KVM_CAP_DIRTY_LOG_RING_ACQ_REL;
+        ret = kvm_vm_check_extension(s, capability);
+    }
+
     if (ret <= 0) {
         warn_report("KVM dirty ring not available, using bitmap method");
         s->kvm_dirty_ring_size = 0;
@@ -1502,7 +1508,7 @@  static int kvm_dirty_ring_init(KVMState *s)
         goto out;
     }
 
-    ret = kvm_vm_enable_cap(s, KVM_CAP_DIRTY_LOG_RING, 0, ring_bytes);
+    ret = kvm_vm_enable_cap(s, capability, 0, ring_bytes);
     if (ret) {
         error_report("Enabling of KVM dirty ring failed: %s. "
                      "Suggested minimum value is 1024.", strerror(-ret));