Re: [RFC KVM 06/27] KVM: x86: Exit KVM isolation on IRQ entry

From: Alexandre Chartre
Date: Mon May 13 2019 - 12:30:16 EST




On 5/13/19 5:51 PM, Andy Lutomirski wrote:
On Mon, May 13, 2019 at 7:39 AM Alexandre Chartre
<alexandre.chartre@xxxxxxxxxx> wrote:

From: Liran Alon <liran.alon@xxxxxxxxxx>

Next commits will change most of KVM #VMExit handlers to run
in KVM isolated address space. Any interrupt handler raised
during execution in KVM address space needs to switch back
to host address space.

This patch makes sure that IRQ handlers will run in full
host address space instead of KVM isolated address space.

IMO this needs to be somewhere a lot more central. What about NMI and
MCE? Or async page faults? Or any other entry?


Actually, I am not sure this is effectively useful because the IRQ
handler is probably faulting before it tries to exit isolation, so
the isolation exit will be done by the kvm page fault handler. I need
to check that.

alex.