[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH RFC 7/9] xen: arm: handle variable p2m levels in apply_p2m_changes
As with prervious changes this involves conversion from a linear series of lookups into a loop over the levels. Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx> --- xen/arch/arm/p2m.c | 178 +++++++++++++++++++++++++--------------------------- 1 file changed, 84 insertions(+), 94 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 557663f..e9938ae 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -15,7 +15,6 @@ /* First level P2M is 2 consecutive pages */ #define P2M_ROOT_ORDER 1 -#define P2M_ROOT_ENTRIES (LPAE_ENTRIES<<P2M_ROOT_ORDER) #define P2M_ROOT_PAGES (1<<P2M_ROOT_ORDER) static bool_t p2m_valid(lpae_t pte) @@ -115,31 +114,6 @@ void flush_tlb_domain(struct domain *d) p2m_load_VTTBR(current->domain); } -static int p2m_first_level_index(paddr_t addr) -{ - /* - * 1st pages are concatenated so zeroeth offset gives us the - * index of the 1st page - */ - return zeroeth_table_offset(addr); -} - -/* - * Map whichever of the first pages contain addr. The caller should - * then use first_table_offset as an index. - */ -static lpae_t *p2m_map_first(struct p2m_domain *p2m, paddr_t addr) -{ - struct page_info *page; - - if ( first_linear_offset(addr) >= P2M_ROOT_ENTRIES ) - return NULL; - - page = p2m->root + p2m_first_level_index(addr); - - return __map_domain_page(page); -} - /* * Lookup the MFN corresponding to a domain's PFN. * @@ -707,14 +681,13 @@ static int apply_p2m_changes(struct domain *d, int mattr, p2m_type_t t) { - int rc, ret; + int level, rc, ret; struct p2m_domain *p2m = &d->arch.p2m; - lpae_t *first = NULL, *second = NULL, *third = NULL; + lpae_t *mappings[4] = { NULL, }; paddr_t addr; - unsigned long cur_first_page = ~0, - cur_first_offset = ~0, - cur_second_offset = ~0; - unsigned long count = 0; + unsigned int cur_root_table = ~0; + unsigned int cur_offset[4] = { ~0, }; + unsigned int count = 0; bool_t flush = false; bool_t flush_pt; @@ -726,9 +699,27 @@ static int apply_p2m_changes(struct domain *d, spin_lock(&p2m->lock); + if ( P2M_ROOT_PAGES == 1 ) + { + /* Static mapping. P2M_ROOT_PAGES > 1 are handled below */ + mappings[P2M_ROOT_LEVEL] = __map_domain_page(p2m->root); + { + rc = -EINVAL; + goto out; + } + } + addr = start_gpaddr; while ( addr < end_gpaddr ) { + int root_table; + const unsigned int offsets[4] = { + zeroeth_table_offset(addr), + first_table_offset(addr), + second_table_offset(addr), + third_table_offset(addr) + }; + /* * Arbitrarily, preempt every 512 operations or 8192 nops. * 512*P2M_ONE_PROGRESS == 8192*P2M_ONE_PROGRESS_NOP == 0x2000 @@ -748,73 +739,71 @@ static int apply_p2m_changes(struct domain *d, count = 0; } - if ( cur_first_page != p2m_first_level_index(addr) ) + if ( P2M_ROOT_PAGES > 1 ) { - if ( first ) unmap_domain_page(first); - first = p2m_map_first(p2m, addr); - if ( !first ) + int i; + /* + * Concatenated root-level tables. The table number will be the + * offset at the previous level. It is not possible to concetenate + * a level-0 root. + */ + BUG_ON(P2M_ROOT_LEVEL == 0); + root_table = offsets[P2M_ROOT_LEVEL - 1]; + if ( root_table >= P2M_ROOT_PAGES ) { rc = -EINVAL; goto out; } - cur_first_page = p2m_first_level_index(addr); - /* Any mapping further down is now invalid */ - cur_first_offset = cur_second_offset = ~0; - } - - /* We only use a 3 level p2m at the moment, so no level 0, - * current hardware doesn't support super page mappings at - * level 0 anyway */ - - ret = apply_one_level(d, &first[first_table_offset(addr)], - 1, flush_pt, op, - start_gpaddr, end_gpaddr, - &addr, &maddr, &flush, - mattr, t); - if ( ret < 0 ) { rc = ret ; goto out; } - count += ret; - if ( ret != P2M_ONE_DESCEND ) continue; - - BUG_ON(!p2m_valid(first[first_table_offset(addr)])); - - if ( cur_first_offset != first_table_offset(addr) ) - { - if (second) unmap_domain_page(second); - second = map_domain_page(first[first_table_offset(addr)].p2m.base); - cur_first_offset = first_table_offset(addr); - /* Any mapping further down is now invalid */ - cur_second_offset = ~0; + if ( cur_root_table != root_table ) + { + if ( mappings[P2M_ROOT_LEVEL] ) + unmap_domain_page(mappings[P2M_ROOT_LEVEL]); + mappings[P2M_ROOT_LEVEL] = + __map_domain_page(p2m->root + root_table); + if ( !mappings[P2M_ROOT_LEVEL] ) + { + rc = -EINVAL; + goto out; + } + cur_root_table = root_table; + /* Any mapping further down is now invalid */ + for ( i = P2M_ROOT_LEVEL; i < 4; i++ ) + cur_offset[i] = ~0; + } } - /* else: second already valid */ - - ret = apply_one_level(d,&second[second_table_offset(addr)], - 2, flush_pt, op, - start_gpaddr, end_gpaddr, - &addr, &maddr, &flush, - mattr, t); - if ( ret < 0 ) { rc = ret ; goto out; } - count += ret; - if ( ret != P2M_ONE_DESCEND ) continue; - - BUG_ON(!p2m_valid(second[second_table_offset(addr)])); - if ( cur_second_offset != second_table_offset(addr) ) + for ( level = P2M_ROOT_LEVEL; level < 4; level++ ) { - /* map third level */ - if (third) unmap_domain_page(third); - third = map_domain_page(second[second_table_offset(addr)].p2m.base); - cur_second_offset = second_table_offset(addr); + unsigned offset = offsets[level]; + lpae_t *entry = &mappings[level][offset]; + + ret = apply_one_level(d, entry, + level, flush_pt, op, + start_gpaddr, end_gpaddr, + &addr, &maddr, &flush, + mattr, t); + if ( ret < 0 ) { rc = ret ; goto out; } + count += ret; + /* L3 had better have done something! We cannot descend any further */ + BUG_ON(level == 3 && ret == P2M_ONE_DESCEND); + if ( ret != P2M_ONE_DESCEND ) break; + + BUG_ON(!p2m_valid(*entry)); + + if ( cur_offset[level] != offset ) + { + /* Update mapping for next level */ + int i; + if ( mappings[level+1] ) + unmap_domain_page(mappings[level+1]); + mappings[level+1] = map_domain_page(entry->p2m.base); + cur_offset[level] = offset; + /* Any mapping further down is now invalid */ + for ( i = level+1; i < 4; i++ ) + cur_offset[i] = ~0; + } + /* else: next level already valid */ } - - ret = apply_one_level(d, &third[third_table_offset(addr)], - 3, flush_pt, op, - start_gpaddr, end_gpaddr, - &addr, &maddr, &flush, - mattr, t); - if ( ret < 0 ) { rc = ret ; goto out; } - /* L3 had better have done something! We cannot descend any further */ - BUG_ON(ret == P2M_ONE_DESCEND); - count += ret; } if ( flush ) @@ -838,10 +827,11 @@ static int apply_p2m_changes(struct domain *d, rc = 0; out: - if (third) unmap_domain_page(third); - if (second) unmap_domain_page(second); - if (first) unmap_domain_page(first); - + for ( level = P2M_ROOT_LEVEL; level < 4; level ++ ) + { + if ( mappings[level] ) + unmap_domain_page(mappings[level]); + } spin_unlock(&p2m->lock); return rc; -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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