From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58821) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQySW-0007Oy-NH for qemu-devel@nongnu.org; Fri, 30 Jun 2017 12:07:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dQySR-0006zO-UJ for qemu-devel@nongnu.org; Fri, 30 Jun 2017 12:07:52 -0400 Received: from smtp.ctxuk.citrix.com ([185.25.65.24]:62995 helo=SMTP.EU.CITRIX.COM) by eggs.gnu.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1dQySR-0006vm-K5 for qemu-devel@nongnu.org; Fri, 30 Jun 2017 12:07:47 -0400 From: Igor Druzhinin Date: Fri, 30 Jun 2017 17:07:03 +0100 Message-ID: <1498838825-23701-3-git-send-email-igor.druzhinin@citrix.com> In-Reply-To: <1498838825-23701-1-git-send-email-igor.druzhinin@citrix.com> References: <1498838825-23701-1-git-send-email-igor.druzhinin@citrix.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH 2/4] xen/mapcache: add an ability to create dummy mappings List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xen-devel@lists.xenproject.org, qemu-devel@nongnu.org Cc: Igor Druzhinin , sstabellini@kernel.org, anthony.perard@citrix.com, paul.durrant@citrix.com, pbonzini@redhat.com 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 --- hw/i386/xen/xen-mapcache.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c index e60156c..05050de 100644 --- a/hw/i386/xen/xen-mapcache.c +++ b/hw/i386/xen/xen-mapcache.c @@ -150,7 +150,8 @@ 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 +178,25 @@ 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; @@ -211,6 +226,7 @@ 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 +278,14 @@ 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 +298,10 @@ tryagain: translated = true; goto tryagain; } + if (!dummy && runstate_check(RUN_STATE_INMIGRATE)) { + dummy = true; + goto tryagain; + } trace_xen_map_cache_return(NULL); return NULL; } -- 2.7.4