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Re: [Xen-ia64-devel] [PATCH]: vcpu_match_tr_entry & vcpu_ptc_ga



Thank you for your comments.

The race condition you pointed is in fact for ia64_do_page_fault:

        fault = vcpu_translate(current,address,is_data,0,&pteval,&itir,&iha);
        if (fault == IA64_NO_FAULT) {
                pteval = translate_domain_pte(pteval,address,itir);
                
vcpu_itc_no_srlz(current,is_data?2:1,address,pteval,-1UL,(itir>>2)&0x3f);
                return;
        }
Between vcpu_translate and vcpu_itc_no_srlz, a ptc.ga must be taken into 
account.  I am looking for other possible races, but currently I don't see 
other race point.

The obivous solution is a lock: between these two points, the tr_purge must be 
delayed.  We could add a 'tlb_protected' field in each vcpu.
This solution is quite simple but maybe heavy weight.

Any other solution ?

Tristan.



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