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)); ? -- Alex Bennée