On 07/07/21 00:22, stsp wrote:
I confirm that this works, thanks.
Sadly the problematic patch was
CCed to -stable, and is now present
in all kernels, like ubuntu's 5.8.0-55-generic.
Since AFAICT it didn't contain the
important/security fix, I think it
shouldn't have been CCed to -stable.
Can we revert it from -stable?
That will mean a relatively quick
fix for most of current users.
It was a bugfix, see the commit message:
when userspace requests an IRQ window vmexit, an interrupt in the
local APIC can cause kvm_cpu_has_interrupt() to be true and thus
kvm_vcpu_ready_for_interrupt_injection() to return false. When this
happens, vcpu_run does not exit to userspace but the interrupt window
vmexits keep occurring. The VM loops without any hope of making progress.
Thanks for the testing!
Paolo
