During the recursive page walking of IOVA page tables, some stack variables are constant variables and never changed during the whole page walking procedure. Isolate them into a struct so that we don't need to pass those contants down the stack every time and multiple times.
Signed-off-by: Peter Xu <pet...@redhat.com> --- hw/i386/intel_iommu.c | 56 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 19 deletions(-) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 1c252414a9..42f607676c 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -750,9 +750,27 @@ static int vtd_iova_to_slpte(VTDContextEntry *ce, uint64_t iova, bool is_write, typedef int (*vtd_page_walk_hook)(IOMMUTLBEntry *entry, void *private); +/** + * Constant information used during page walking + * + * @hook_fn: hook func to be called when detected page + * @private: private data to be passed into hook func + * @notify_unmap: whether we should notify invalid entries + * @aw: maximum address width + */ +typedef struct { + vtd_page_walk_hook hook_fn; + void *private; + bool notify_unmap; + uint8_t aw; +} vtd_page_walk_info; + static int vtd_page_walk_one(IOMMUTLBEntry *entry, int level, - vtd_page_walk_hook hook_fn, void *private) + vtd_page_walk_info *info) { + vtd_page_walk_hook hook_fn = info->hook_fn; + void *private = info->private; + assert(hook_fn); trace_vtd_page_walk_one(level, entry->iova, entry->translated_addr, entry->addr_mask, entry->perm); @@ -765,17 +783,13 @@ static int vtd_page_walk_one(IOMMUTLBEntry *entry, int level, * @addr: base GPA addr to start the walk * @start: IOVA range start address * @end: IOVA range end address (start <= addr < end) - * @hook_fn: hook func to be called when detected page - * @private: private data to be passed into hook func * @read: whether parent level has read permission * @write: whether parent level has write permission - * @notify_unmap: whether we should notify invalid entries - * @aw: maximum address width + * @info: constant information for the page walk */ static int vtd_page_walk_level(dma_addr_t addr, uint64_t start, - uint64_t end, vtd_page_walk_hook hook_fn, - void *private, uint32_t level, bool read, - bool write, bool notify_unmap, uint8_t aw) + uint64_t end, uint32_t level, bool read, + bool write, vtd_page_walk_info *info) { bool read_cur, write_cur, entry_valid; uint32_t offset; @@ -825,24 +839,24 @@ static int vtd_page_walk_level(dma_addr_t addr, uint64_t start, if (vtd_is_last_slpte(slpte, level)) { /* NOTE: this is only meaningful if entry_valid == true */ - entry.translated_addr = vtd_get_slpte_addr(slpte, aw); - if (!entry_valid && !notify_unmap) { + entry.translated_addr = vtd_get_slpte_addr(slpte, info->aw); + if (!entry_valid && !info->notify_unmap) { trace_vtd_page_walk_skip_perm(iova, iova_next); goto next; } - ret = vtd_page_walk_one(&entry, level, hook_fn, private); + ret = vtd_page_walk_one(&entry, level, info); if (ret < 0) { return ret; } } else { if (!entry_valid) { - if (notify_unmap) { + if (info->notify_unmap) { /* * The whole entry is invalid; unmap it all. * Translated address is meaningless, zero it. */ entry.translated_addr = 0x0; - ret = vtd_page_walk_one(&entry, level, hook_fn, private); + ret = vtd_page_walk_one(&entry, level, info); if (ret < 0) { return ret; } @@ -851,10 +865,9 @@ static int vtd_page_walk_level(dma_addr_t addr, uint64_t start, } goto next; } - ret = vtd_page_walk_level(vtd_get_slpte_addr(slpte, aw), iova, - MIN(iova_next, end), hook_fn, private, - level - 1, read_cur, write_cur, - notify_unmap, aw); + ret = vtd_page_walk_level(vtd_get_slpte_addr(slpte, info->aw), + iova, MIN(iova_next, end), level - 1, + read_cur, write_cur, info); if (ret < 0) { return ret; } @@ -883,6 +896,12 @@ static int vtd_page_walk(VTDContextEntry *ce, uint64_t start, uint64_t end, { dma_addr_t addr = vtd_ce_get_slpt_base(ce); uint32_t level = vtd_ce_get_level(ce); + vtd_page_walk_info info = { + .hook_fn = hook_fn, + .private = private, + .notify_unmap = notify_unmap, + .aw = aw, + }; if (!vtd_iova_range_check(start, ce, aw)) { return -VTD_FR_ADDR_BEYOND_MGAW; @@ -893,8 +912,7 @@ static int vtd_page_walk(VTDContextEntry *ce, uint64_t start, uint64_t end, end = vtd_iova_limit(ce, aw); } - return vtd_page_walk_level(addr, start, end, hook_fn, private, - level, true, true, notify_unmap, aw); + return vtd_page_walk_level(addr, start, end, level, true, true, &info); } /* Map a device to its corresponding domain (context-entry) */ -- 2.14.3