[RFC,1/1] kvm/kvm-all.c: implement KVM_SET_USER_MEMORY_REGION_LIST ioctl

Commit Message

Emanuele Giuseppe Esposito Sept. 9, 2022, 11 a.m. UTC

Instead of sending memslot updates in each callback, kvm listener
already takes care of sending them in the commit phase, as multiple
ioctls.

Using the new KVM_SET_USER_MEMORY_REGION_LIST, we just need a single
call containing all memory regions to update.

Signed-off-by: Emanuele Giuseppe Esposito <[e-mail]>
---
 accel/kvm/kvm-all.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

Patch

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 9780f3d2da..6a7f7b4567 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1547,30 +1547,25 @@  static void kvm_commit(MemoryListener *listener)
     KVMMemoryListener *kml = container_of(listener, KVMMemoryListener,
                                           listener);
     KVMState *s = kvm_state;
-    int i;
+    int i, ret;
 
     for (i = 0; i < kml->mem_array.list->nent; i++) {
         struct kvm_userspace_memory_region_entry *mem;
-        int ret;
 
         mem = &kml->mem_array.list->entries[i];
 
-        /*
-         * Note that mem is struct kvm_userspace_memory_region_entry, while the
-         * kernel expects a kvm_userspace_memory_region, so it will currently
-         * ignore mem->invalidate_slot and mem->padding.
-         */
-        ret = kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, mem);
-
         trace_kvm_set_user_memory(mem->slot, mem->flags, mem->guest_phys_addr,
                                   mem->memory_size, mem->userspace_addr, 0);
+    }
 
-        if (ret < 0) {
-            error_report("%s: KVM_SET_USER_MEMORY_REGION failed, slot=%d,"
-                         " start=0x%" PRIx64 ": %s",
-                         __func__, mem->slot,
-                         (uint64_t)mem->memory_size, strerror(errno));
-        }
+    ret = kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION_LIST, kml->mem_array.list);
+
+    if (ret < 0) {
+        error_report("%s: KVM_SET_USER_MEMORY_REGION_LIST failed, size=0x%"
+                     PRIx64 " flags=0x%" PRIx64 ": %s",
+                     __func__, (uint64_t)kml->mem_array.list->nent,
+                     (uint64_t)kml->mem_array.list->flags,
+                     strerror(errno));
     }
 
     kml->mem_array.list->nent = 0;