From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42033) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1auf7O-0003Y2-UR for qemu-devel@nongnu.org; Mon, 25 Apr 2016 07:55:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1auf7J-00080I-Ry for qemu-devel@nongnu.org; Mon, 25 Apr 2016 07:55:58 -0400 Received: from e06smtp08.uk.ibm.com ([195.75.94.104]:52180) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1auf7J-00080A-IX for qemu-devel@nongnu.org; Mon, 25 Apr 2016 07:55:53 -0400 Received: from localhost by e06smtp08.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 25 Apr 2016 12:55:50 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id BD8DD1B0807A for ; Mon, 25 Apr 2016 12:56:28 +0100 (BST) Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u3PBtg876685172 for ; Mon, 25 Apr 2016 11:55:42 GMT Received: from d06av04.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u3PBteMS007447 for ; Mon, 25 Apr 2016 05:55:41 -0600 From: Dominik Dingel Date: Mon, 25 Apr 2016 13:55:38 +0200 Message-Id: <1461585338-45863-1-git-send-email-dingel@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH] exec.c: Ensure right alignment also for file backed ram List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Peter Crosthwaite , Richard Henderson , Halil Pasic While in the anonymous ram case we already take care of the right alignment such an alignment gurantee does not exist for file backed ram allocation. Instead, pagesize is used for alignment. On s390 this is not enough for gmap, as we need to satisfy an alignment up to segments. Reported-by: Halil Pasic Signed-off-by: Dominik Dingel --- v2 -> v3: Skipping additional variable and just use alignment of memory region. As memory will not be backpropagated it is enough to round up to page_sizes. v1 -> v2: While enforcing alignments we allow memory sizes on page_size. On mmap the memory size will be round up to alignments. I thought about moving this alignment into qemu_ram_mmap but the result was a lot of code churn, the other possibility was to create an additional define ending up with two defines with the same semantics. --- exec.c | 5 +++-- include/qemu/osdep.h | 13 +++++++++++++ util/oslib-posix.c | 13 ------------- 3 files changed, 16 insertions(+), 15 deletions(-) diff --git a/exec.c b/exec.c index c4f9036..fc75266 100644 --- a/exec.c +++ b/exec.c @@ -1296,7 +1296,7 @@ static void *file_ram_alloc(RAMBlock *block, } page_size = qemu_fd_getpagesize(fd); - block->mr->align = page_size; + block->mr->align = MAX(page_size, QEMU_VMALLOC_ALIGN); if (memory < page_size) { error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to " @@ -1317,7 +1317,8 @@ static void *file_ram_alloc(RAMBlock *block, perror("ftruncate"); } - area = qemu_ram_mmap(fd, memory, page_size, block->flags & RAM_SHARED); + area = qemu_ram_mmap(fd, memory, block->mr->align, + block->flags & RAM_SHARED); if (area == MAP_FAILED) { error_setg_errno(errp, errno, "unable to map backing store for guest RAM"); diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 408783f..783270f 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -247,6 +247,19 @@ void qemu_anon_ram_free(void *ptr, size_t size); #endif +#if defined(__linux__) && \ + (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)) + /* Use 2 MiB alignment so transparent hugepages can be used by KVM. + Valgrind does not support alignments larger than 1 MiB, + therefore we need special code which handles running on Valgrind. */ +# define QEMU_VMALLOC_ALIGN (512 * 4096) +#elif defined(__linux__) && defined(__s390x__) + /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ +# define QEMU_VMALLOC_ALIGN (256 * 4096) +#else +# define QEMU_VMALLOC_ALIGN getpagesize() +#endif + int qemu_madvise(void *addr, size_t len, int advice); int qemu_open(const char *name, int flags, ...); diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 6cc4b8f..4adde93 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -26,19 +26,6 @@ * THE SOFTWARE. */ -#if defined(__linux__) && \ - (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)) - /* Use 2 MiB alignment so transparent hugepages can be used by KVM. - Valgrind does not support alignments larger than 1 MiB, - therefore we need special code which handles running on Valgrind. */ -# define QEMU_VMALLOC_ALIGN (512 * 4096) -#elif defined(__linux__) && defined(__s390x__) - /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ -# define QEMU_VMALLOC_ALIGN (256 * 4096) -#else -# define QEMU_VMALLOC_ALIGN getpagesize() -#endif - #include "qemu/osdep.h" #include #include -- 2.6.6