[PATCH] KVM: PPC: Book3S HV: Fix kvm_unmap_gfn_range_hv() for Hash MMU

[Michael Ellerman]

Sean Christopherson <seanjc at google.com> writes:
> On Tue, May 11, 2021, Michael Ellerman wrote:
>> Commit 32b48bf8514c ("KVM: PPC: Book3S HV: Fix conversion to gfn-based
>> MMU notifier callbacks") fixed kvm_unmap_gfn_range_hv() by adding a for
>> loop over each gfn in the range.
>> 
>> But for the Hash MMU it repeatedly calls kvm_unmap_rmapp() with the
>> first gfn of the range, rather than iterating through the range.
>> 
>> This exhibits as strange guest behaviour, sometimes crashing in firmare,
>> or booting and then guest userspace crashing unexpectedly.
>> 
>> Fix it by passing the iterator, gfn, to kvm_unmap_rmapp().
>> 
>> Fixes: 32b48bf8514c ("KVM: PPC: Book3S HV: Fix conversion to gfn-based MMU notifier callbacks")
>> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
>> ---
>>  arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> I plan to take this via the powerpc fixes branch.
>
> FWIW,
>
> Reviewed-by: Sean Christopherson <seanjc at google.com>

Thanks.

cheers