From patchwork Tue Jul 18 22:22:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 9849945 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BEA62600CC for ; Tue, 18 Jul 2017 22:27:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A816628433 for ; Tue, 18 Jul 2017 22:27:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9CC3A285B7; Tue, 18 Jul 2017 22:27:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2EA1428433 for ; Tue, 18 Jul 2017 22:27:00 +0000 (UTC) Received: from localhost ([::1]:58915 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dXaxH-0002lW-Ef for patchwork-qemu-devel@patchwork.kernel.org; Tue, 18 Jul 2017 18:26:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58475) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dXatE-00086o-Q8 for qemu-devel@nongnu.org; Tue, 18 Jul 2017 18:22:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dXatD-0004WT-KC for qemu-devel@nongnu.org; Tue, 18 Jul 2017 18:22:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:39870) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dXatD-0004VB-BY for qemu-devel@nongnu.org; Tue, 18 Jul 2017 18:22:47 -0400 Received: from localhost.localdomain (162-198-228-33.lightspeed.wlfrct.sbcglobal.net [162.198.228.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 505AD22BE3; Tue, 18 Jul 2017 22:22:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 505AD22BE3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=sstabellini@kernel.org From: Stefano Stabellini To: peter.maydell@linaro.org, stefanha@gmail.com Date: Tue, 18 Jul 2017 15:22:40 -0700 Message-Id: <1500416562-27337-5-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1500416562-27337-1-git-send-email-sstabellini@kernel.org> References: <1500416562-27337-1-git-send-email-sstabellini@kernel.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 198.145.29.99 Subject: [Qemu-devel] [PULL for-2.10 5/7] xen/mapcache: add an ability to create dummy mappings X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Igor Druzhinin , sstabellini@kernel.org, qemu-devel@nongnu.org, stefanha@redhat.com, anthony.perard@citrix.com, xen-devel@lists.xenproject.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Igor Druzhinin Dummys are simple anonymous mappings that are placed instead of regular foreign mappings in certain situations when we need to postpone the actual mapping but still have to give a memory region to QEMU to play with. This is planned to be used for restore on Xen. Signed-off-by: Igor Druzhinin Reviewed-by: Paul Durrant Reviewed-by: Stefano Stabellini --- hw/i386/xen/xen-mapcache.c | 44 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 36 insertions(+), 8 deletions(-) diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c index e60156c..39cb511 100644 --- a/hw/i386/xen/xen-mapcache.c +++ b/hw/i386/xen/xen-mapcache.c @@ -53,6 +53,8 @@ typedef struct MapCacheEntry { uint8_t *vaddr_base; unsigned long *valid_mapping; uint8_t lock; +#define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) + uint8_t flags; hwaddr size; struct MapCacheEntry *next; } MapCacheEntry; @@ -150,7 +152,8 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) static void xen_remap_bucket(MapCacheEntry *entry, hwaddr size, - hwaddr address_index) + hwaddr address_index, + bool dummy) { uint8_t *vaddr_base; xen_pfn_t *pfns; @@ -177,11 +180,25 @@ static void xen_remap_bucket(MapCacheEntry *entry, pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i; } - vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, PROT_READ|PROT_WRITE, - nb_pfn, pfns, err); - if (vaddr_base == NULL) { - perror("xenforeignmemory_map"); - exit(-1); + if (!dummy) { + vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, + PROT_READ | PROT_WRITE, + nb_pfn, pfns, err); + if (vaddr_base == NULL) { + perror("xenforeignmemory_map"); + exit(-1); + } + } else { + /* + * We create dummy mappings where we are unable to create a foreign + * mapping immediately due to certain circumstances (i.e. on resume now) + */ + vaddr_base = mmap(NULL, size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_SHARED, -1, 0); + if (vaddr_base == NULL) { + perror("mmap"); + exit(-1); + } } entry->vaddr_base = vaddr_base; @@ -190,6 +207,12 @@ static void xen_remap_bucket(MapCacheEntry *entry, entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) * BITS_TO_LONGS(size >> XC_PAGE_SHIFT)); + if (dummy) { + entry->flags |= XEN_MAPCACHE_ENTRY_DUMMY; + } else { + entry->flags &= ~(XEN_MAPCACHE_ENTRY_DUMMY); + } + ram_block_notify_add(entry->vaddr_base, entry->size); bitmap_zero(entry->valid_mapping, nb_pfn); for (i = 0; i < nb_pfn; i++) { @@ -211,6 +234,7 @@ static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size, hwaddr cache_size = size; hwaddr test_bit_size; bool translated = false; + bool dummy = false; tryagain: address_index = phys_addr >> MCACHE_BUCKET_SHIFT; @@ -262,14 +286,14 @@ tryagain: if (!entry) { entry = g_malloc0(sizeof (MapCacheEntry)); pentry->next = entry; - xen_remap_bucket(entry, cache_size, address_index); + xen_remap_bucket(entry, cache_size, address_index, dummy); } else if (!entry->lock) { if (!entry->vaddr_base || entry->paddr_index != address_index || entry->size != cache_size || !test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping)) { - xen_remap_bucket(entry, cache_size, address_index); + xen_remap_bucket(entry, cache_size, address_index, dummy); } } @@ -282,6 +306,10 @@ tryagain: translated = true; goto tryagain; } + if (!dummy && runstate_check(RUN_STATE_INMIGRATE)) { + dummy = true; + goto tryagain; + } trace_xen_map_cache_return(NULL); return NULL; }