On 14.08.19 12:44, Alex Bennée wrote: > > David Hildenbrand <da...@redhat.com> writes: > >> On 14.08.19 12:06, Alex Bennée wrote: >>> >>> David Hildenbrand <da...@redhat.com> writes: >>> >>>> Whenever we modify a storage key, we shuld flush the TLBs of all CPUs, >>>> so the MMU fault handling code can properly consider the changed storage >>>> key (to e.g., properly set the reference and change bit on the next >>>> accesses). >>>> >>>> These functions are barely used in modern Linux guests, so the performance >>>> implications are neglectable for now. >>>> >>>> This is a preparation for better reference and change bit handling for >>>> TCG, which will require more MMU changes. >>>> >>>> Reviewed-by: Cornelia Huck <coh...@redhat.com> >>>> Signed-off-by: David Hildenbrand <da...@redhat.com> >>>> --- >>>> target/s390x/mem_helper.c | 4 ++++ >>>> 1 file changed, 4 insertions(+) >>>> >>>> diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c >>>> index 29d9eaa5b7..ed54265e03 100644 >>>> --- a/target/s390x/mem_helper.c >>>> +++ b/target/s390x/mem_helper.c >>>> @@ -1815,6 +1815,8 @@ void HELPER(sske)(CPUS390XState *env, uint64_t r1, >>>> uint64_t r2) >>>> >>>> key = (uint8_t) r1; >>>> skeyclass->set_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key); >>>> + /* TODO: Flush only entries with this target address */ >>>> + tlb_flush_all_cpus_synced(env_cpu(env)); >>> >>> Doesn't: >>> >>> tlb_flush_page_all_cpus_synced(env_cpu(env), addr & TARGET_PAGE_MASK); >>> >>> do what you want here? >> >> I would have to flush all TLB entries that target this physical page, >> not the entry of the single virtual page. So that does, unfortunately, >> not work. > > Ahh I see. Well maybe that should be the comment instead: > > /* > * As we can only flush by virtual address and not all the entries > * that point to a physical address we have to flush the whole TLB > * here. > */ > tlb_flush_all_cpus_synced(env_cpu(env)); > > ?
I think "entries that target this address" makes it clear that we are talking about the TLB entry target address, not the virtual source address. But I can adjust it. Thanks. -- Thanks, David / dhildenb