Re: Re: [PATCH] KVM: x86: Fix uninitialized eoi_exit_bitmap usage in vcpu_load_eoi_exitmap()

From: Vitaly Kuznetsov
Date: Mon Nov 15 2021 - 08:03:11 EST


黄乐 <huangle1@xxxxxx> writes:

>> 黄乐 <huangle1@xxxxxx> writes:
>>
>> > In vcpu_load_eoi_exitmap(), currently the eoi_exit_bitmap[4] array is
>> > initialized only when Hyper-V context is available, in other path it is
>> > just passed to kvm_x86_ops.load_eoi_exitmap() directly from on the stack,
>> > which would cause unexpected interrupt delivery/handling issues, e.g. an
>> > *old* linux kernel that relies on PIT to do clock calibration on KVM might
>> > randomly fail to boot.
>> >
>> > Fix it by passing ioapic_handled_vectors to load_eoi_exitmap() when Hyper-V
>> > context is not available.
>> >
>> > Signed-off-by: Huang Le <huangle1@xxxxxx>
>>
>> Fixes: f2bc14b69c38 ("KVM: x86: hyper-v: Prepare to meet unallocated Hyper-V context")
>> Cc: stable@xxxxxxxxxxxxxxx
>
> Commit f2bc14b69c38 is not in stable tree I guess, it was merged in from 5.12,
> do we still need Cc this patch to stable maintainers?
>

There are multiple stable trees, one for each major release. Not all of
them are still supported but you don't need to care about it, 'Cc:
stable@xxxxxxxxxxxxxxx' is just an indication for everyone who has
f2bc14b69c38 in his tree (5.12+) that there's a fix available.

--
Vitaly