[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v10 01/12] arch/arm: add consistency check to REMOVE p2m changes
On 29/07/14 12:55, Julien Grall wrote: > Hi Arianna, > > On 07/28/2014 11:11 PM, Arianna Avanzini wrote: >> @@ -609,26 +610,42 @@ static int apply_one_level(struct domain *d, >> if ( p2m_table(orig_pte) ) >> return P2M_ONE_DESCEND; >> >> - if ( op == REMOVE && >> - !is_mapping_aligned(*addr, end_gpaddr, >> - 0, /* maddr doesn't matter for remove >> */ >> - level_size) ) >> + if ( op == REMOVE ) >> { >> - /* >> - * Removing a mapping from the middle of a superpage. >> Shatter >> - * and descend. >> - */ >> - *flush = true; >> - rc = p2m_create_table(d, entry, >> - level_shift - PAGE_SHIFT, >> flush_cache); >> - if ( rc < 0 ) >> - return rc; >> - >> - p2m->stats.shattered[level]++; >> - p2m->stats.mappings[level]--; >> - p2m->stats.mappings[level+1] += LPAE_ENTRIES; >> - >> - return P2M_ONE_DESCEND; >> + if ( is_mapping_aligned(*addr, end_gpaddr, *maddr, >> level_size) ) >> + { > You don't cover every case with this solution. This code is only called > when (level < 3). So for single 4k (level 3), Xen will not print a > message when the MFN differ. > > I still think that the best place to check it, is after the if ( level < 3 ) > > The code would look like: > > if ( level < 3 ) > { > .... > } > > if ( op == REMOVE && pfn_to_paddr(orig_pte.p2m.base) != *maddr ) > printk(XENLOG_ERR "p2m_remove"....); > >> + unsigned long mfn = orig_pte.p2m.base; >> + /* >> + * Ensure that the guest address addr currently being >> + * handled (that is in the range given as argument to >> + * this function) is actually mapped to the >> corresponding >> + * machine address in the specified range. maddr here >> is >> + * the machine address given to the function, while >> mfn >> + * is the machine frame number actually mapped to the >> + * guest address: check if the two correspond. >> + */ >> + if ( *maddr != pfn_to_paddr(mfn) ) >> + printk("p2m_remove dom%d: mapping at %"PRIpaddr" >> is of maddr %"PRIpaddr" not %"PRIpaddr" as expected\n", > You have to prefix it at least by XENLOG_WARNING or XENLOG_ERR > > Regards, > XENLOG_G_WARNING or XENLOG_G_ERR Guest printk()s are rate limited differently to core hypervisor printk()s, and have a separate controllable loglevel. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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