From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33184) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJJy1-0000QF-AM for qemu-devel@nongnu.org; Thu, 17 May 2018 10:33:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fJJxr-0000F8-FN for qemu-devel@nongnu.org; Thu, 17 May 2018 10:33:17 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:44914 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fJJxr-0000Et-A0 for qemu-devel@nongnu.org; Thu, 17 May 2018 10:33:07 -0400 References: <20180504030811.28111-1-peterx@redhat.com> <20180504030811.28111-6-peterx@redhat.com> From: Auger Eric Message-ID: <99897d3c-ee46-977d-c886-5d23996c7f04@redhat.com> Date: Thu, 17 May 2018 16:32:58 +0200 MIME-Version: 1.0 In-Reply-To: <20180504030811.28111-6-peterx@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 05/10] intel-iommu: introduce vtd_page_walk_info List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu , qemu-devel@nongnu.org Cc: Tian Kevin , "Michael S . Tsirkin" , Jason Wang , Alex Williamson , Jintack Lim Hi Peter, On 05/04/2018 05:08 AM, Peter Xu wrote: > 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 Reviewed-by: Eric Auger Thanks Eric > --- > 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 9a418abfb6..b2b2a0a441 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -747,9 +747,27 @@ 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); > @@ -762,17 +780,13 @@ 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; > @@ -822,24 +836,24 @@ 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; > } > @@ -848,10 +862,9 @@ 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; > } > @@ -880,6 +893,12 @@ 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; > @@ -890,8 +909,7 @@ 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) */ >