other: 0.258
semantic: 0.191
KVM: 0.121
vnc: 0.058
device: 0.057
graphic: 0.054
performance: 0.046
PID: 0.043
network: 0.040
files: 0.032
socket: 0.031
permissions: 0.031
boot: 0.019
debug: 0.018
KVM: 0.692
debug: 0.098
files: 0.059
other: 0.035
PID: 0.022
performance: 0.015
device: 0.014
semantic: 0.013
network: 0.012
boot: 0.010
socket: 0.009
vnc: 0.009
graphic: 0.007
permissions: 0.005

migration wrong handling of KVM_GET_DIRTY_LOG ioctl

In the code below kvm_vm_ioctl(...) can return --errno != -1 from ioctl call,  but return only checks for -1. 
Found during KVM-ARM migration which apperead to go through but was actually failing getting 
memslot dirty bitmap.

static int kvm_physical_sync_dirty_bitmap(....)
{
 ....
 if(kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
   - err out
 }
 ... continue
}

Sent patch for error handling:
http://lists.nongnu.org/archive/html/qemu-devel/2014-09/msg05633.html

The apparently obvious fix was applied as commit b533f658a98325d0e4 but then reverted in commit 50212d6346f33d6e19, because not all errno returns from this ioctl should be treated as errors.

That commit message said "Revert that patch instead of fixing it properly this late in the release process.  I disagree with this approach, but let's make things move _somewhere_, instead of arguing endlessly whch of the 2 proposed fixes is better." -- and then we never did a proper fix, so 5 years later we're still making an incorrect == -1 check...



Moving this bug back to Confirmed to move it out of "In progress" state. We still check for only -1 upstream.

Yet another try to fix this issue:
https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg07557.html

Patch has been merged here:
https://gitlab.com/qemu-project/qemu/-/commit/38e0b7904eca7cd32