[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC 19/22] xen/arm: p2m: Re-implement p2m_remove_using using p2m_set_entry
On Thu, 28 Jul 2016, Julien Grall wrote: > The function p2m_insert_mapping can be re-implemented using the generic > function p2m_set_entry. > > Also drop the operation REMOVE in apply_* as nobody is using it anymore. > Note that the functions could have been dropped in one go at the end, > however I find easier to drop the operations one by one avoiding a big > deletion in the patch that converts the last operation. > > Signed-off-by: Julien Grall <julien.grall@xxxxxxx> Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx> > xen/arch/arm/p2m.c | 127 > ++++++----------------------------------------------- > 1 file changed, 13 insertions(+), 114 deletions(-) > > diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c > index 297b176..0920222 100644 > --- a/xen/arch/arm/p2m.c > +++ b/xen/arch/arm/p2m.c > @@ -725,7 +725,6 @@ static int p2m_mem_access_radix_set(struct p2m_domain > *p2m, gfn_t gfn, > > enum p2m_operation { > INSERT, > - REMOVE, > MEMACCESS, > }; > > @@ -750,7 +749,6 @@ static void p2m_put_l3_page(mfn_t mfn, p2m_type_t type) > } > } > > -#if 0 > /* Free lpae sub-tree behind an entry */ > static void p2m_free_entry(struct p2m_domain *p2m, > lpae_t entry, unsigned int level) > @@ -1083,7 +1081,6 @@ static int p2m_set_entry(struct p2m_domain *p2m, > > return rc; > } > -#endif > > /* > * Returns true if start_gpaddr..end_gpaddr contains at least one > @@ -1161,7 +1158,6 @@ static int apply_one_level(struct domain *d, > p2m_access_t a) > { > const paddr_t level_size = level_sizes[level]; > - const paddr_t level_mask = level_masks[level]; > > struct p2m_domain *p2m = &d->arch.p2m; > lpae_t pte; > @@ -1247,74 +1243,6 @@ static int apply_one_level(struct domain *d, > > break; > > - case REMOVE: > - if ( !p2m_valid(orig_pte) ) > - { > - /* Progress up to next boundary */ > - *addr = (*addr + level_size) & level_mask; > - *maddr = (*maddr + level_size) & level_mask; > - return P2M_ONE_PROGRESS_NOP; > - } > - > - if ( level < 3 ) > - { > - 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) ) > - { > - /* > - * Removing a mapping from the middle of a superpage. Shatter > - * and descend. > - */ > - *flush = true; > - rc = p2m_shatter_page(p2m, entry, level); > - if ( rc < 0 ) > - return rc; > - > - return P2M_ONE_DESCEND; > - } > - } > - > - /* > - * 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 > - * orig_pte.p2m.base is the machine frame number actually > - * mapped to the guest address: check if the two correspond. > - */ > - if ( op == REMOVE && > - pfn_to_paddr(orig_pte.p2m.base) != *maddr ) > - printk(XENLOG_G_WARNING > - "p2m_remove dom%d: mapping at %"PRIpaddr" is of maddr > %"PRIpaddr" not %"PRIpaddr" as expected\n", > - d->domain_id, *addr, pfn_to_paddr(orig_pte.p2m.base), > - *maddr); > - > - *flush = true; > - > - p2m_remove_pte(entry, p2m->clean_pte); > - p2m_mem_access_radix_set(p2m, _gfn(paddr_to_pfn(*addr)), > - p2m_access_rwx); > - > - *addr += level_size; > - *maddr += level_size; > - > - p2m->stats.mappings[level]--; > - > - if ( level == 3 ) > - p2m_put_l3_page(_mfn(orig_pte.p2m.base), orig_pte.p2m.type); > - > - /* > - * This is still a single pte write, no matter the level, so no need > to > - * scale. > - */ > - return P2M_ONE_PROGRESS; > - > case MEMACCESS: > if ( level < 3 ) > { > @@ -1526,43 +1454,6 @@ static int apply_p2m_changes(struct domain *d, > } > > BUG_ON(level > 3); > - > - if ( op == REMOVE ) > - { > - for ( ; level > P2M_ROOT_LEVEL; level-- ) > - { > - lpae_t old_entry; > - lpae_t *entry; > - unsigned int offset; > - > - pg = pages[level]; > - > - /* > - * No need to try the previous level if the current one > - * still contains some mappings. > - */ > - if ( pg->u.inuse.p2m_refcount ) > - break; > - > - offset = offsets[level - 1]; > - entry = &mappings[level - 1][offset]; > - old_entry = *entry; > - > - page_list_del(pg, &p2m->pages); > - > - p2m_remove_pte(entry, p2m->clean_pte); > - > - p2m->stats.mappings[level - 1]--; > - update_reference_mapping(pages[level - 1], old_entry, > *entry); > - > - /* > - * We can't free the page now because it may be present > - * in the guest TLB. Queue it and free it after the TLB > - * has been flushed. > - */ > - page_list_add(pg, &free_pages); > - } > - } > } > > if ( op == INSERT ) > @@ -1604,8 +1495,10 @@ out: > * addr keeps the address of the end of the last > successfully-inserted > * mapping. > */ > - apply_p2m_changes(d, REMOVE, sgfn, gfn - gfn_x(sgfn), smfn, > - 0, p2m_invalid, d->arch.p2m.default_access); > + p2m_write_lock(p2m); > + p2m_set_entry(p2m, sgfn, gfn - gfn_x(sgfn), INVALID_MFN, > + p2m_invalid, p2m_access_rwx); > + p2m_write_unlock(p2m); > } > > return rc; > @@ -1626,9 +1519,15 @@ static inline int p2m_remove_mapping(struct domain *d, > unsigned long nr, > mfn_t mfn) > { > - return apply_p2m_changes(d, REMOVE, start_gfn, nr, mfn, > - /* arguments below not used when removing > mapping */ > - 0, p2m_invalid, d->arch.p2m.default_access); > + struct p2m_domain *p2m = &d->arch.p2m; > + int rc; > + > + p2m_write_lock(p2m); > + rc = p2m_set_entry(p2m, start_gfn, nr, INVALID_MFN, > + p2m_invalid, p2m_access_rwx); > + p2m_write_unlock(p2m); > + > + return rc; > } > > int map_regions_rw_cache(struct domain *d, > -- > 1.9.1 > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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