[Qemu-devel] [PATCH] kvm: add detail error message when fail to add ioeventfd

[Amos Kong <akong@redhat.com>]

I try to hotplug 28 * 8 multiple-function devices to guest with
old host kernel, ioeventfds in host kernel will be exhausted, then
qemu fails to allocate ioeventfds for blk/nic devices.

It's better to add detail error here.

Signed-off-by: Amos Kong <akong@redhat.com>
---
 kvm-all.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 8222729..3d5f7b7 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -813,6 +813,8 @@ static void kvm_mem_ioeventfd_add(MemoryListener *listener,
     r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
                                data, true, section->size, match_data);
     if (r < 0) {
+        fprintf(stderr, "%s: error adding ioeventfd: %s\n",
+                __func__, strerror(-r));
         abort();
     }
 }
@@ -843,6 +845,8 @@ static void kvm_io_ioeventfd_add(MemoryListener *listener,
     r = kvm_set_ioeventfd_pio(fd, section->offset_within_address_space,
                               data, true, section->size, match_data);
     if (r < 0) {
+        fprintf(stderr, "%s: error adding ioeventfd: %s\n",
+                __func__, strerror(-r));
         abort();
     }
 }
-- 
1.7.1