Hi Gleb,
Sorry for the delay. Please see below.
On 07/15/2014 10:40 PM, Gleb Natapov wrote:
......
We can request APIC_ACCESS_ADDR reload during L2->L1 vmexit emulation, so
if APIC_ACCESS_ADDR changes while L2 is running it will be reloaded for L1 too.
apic pages for L2 and L1 are not the same page, right ?
If L2 guest enable apic access page then they are different, otherwise
they are the same.
I think, just like we are doing in patch 5/5, we cannot wait for the next
L2->L1 vmexit.
We should enforce a L2->L1 vmexit in mmu_notifier, just like
make_all_cpus_request() does.
Am I right ?
I do not see why forcing APIC_ACCESS_ADDR reload during L2->L1 exit is not
enough.
Yes, you are right. APIC_ACCESS_ADDR reload should be done during L2->L1
vmexit.
I mean, before the page is moved to other place, we have to enforce a
L2->L1 vmexit,
but not wait for the next L2->L1 vmexit. Since when the page is being
moved, if the
L2 vm is still running, it could access apic page directly. And the vm
may corrupt.
In the mmu_notifier called before the page is moved, we have to enforce
a L2->L1
vmexit, and ask vcpus to reload APIC_ACCESS_ADDR for L2 vm. The process
will wait
till the page migration is completed, and update the APIC_ACCESS_ADDR,
and re-enter
guest mode.
Thanks.
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