[RFC PATCH 0/1] accel/kvm: implement KVM_SET_USER_MEMORY_REGION_LIST

[RFC PATCH 0/1] accel/kvm: implement KVM_SET_USER_MEMORY_REGION_LIST

[Emanuele Giuseppe Esposito]

Use the new KVM ioctl KVM_SET_USER_MEMORY_REGION_LIST.
Based on my QEMU serie "[RFC PATCH v2 0/3] accel/kvm: extend kvm memory listener to support".

Based-on: 20220909081150.709060-1-eesposit@redhat.com

Requires my KVM serie "[RFC PATCH 0/9] kvm: implement atomic memslot updates"
https://lkml.org/lkml/2022/9/9/533

Emanuele Giuseppe Esposito (1):
  kvm/kvm-all.c: implement KVM_SET_USER_MEMORY_REGION_LIST ioctl

 accel/kvm/kvm-all.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

-- 
2.31.1

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

[Emanuele Giuseppe Esposito]

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 <eesposit@redhat.com>
---
 accel/kvm/kvm-all.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

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;
-- 
2.31.1