From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39176) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZvjrR-000475-Ur for qemu-devel@nongnu.org; Mon, 09 Nov 2015 05:39:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZvjrM-0005wW-RM for qemu-devel@nongnu.org; Mon, 09 Nov 2015 05:39:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51387) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZvjrM-0005wS-Jy for qemu-devel@nongnu.org; Mon, 09 Nov 2015 05:39:36 -0500 Date: Mon, 9 Nov 2015 12:39:31 +0200 From: "Michael S. Tsirkin" Message-ID: <20151109103931.GA3324@redhat.com> References: <1446184587-142784-1-git-send-email-guangrong.xiao@linux.intel.com> <1446184587-142784-9-git-send-email-guangrong.xiao@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1446184587-142784-9-git-send-email-guangrong.xiao@linux.intel.com> Subject: Re: [Qemu-devel] [PATCH v6 08/33] exec: allow memory to be allocated from any kind of path List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Xiao Guangrong Cc: ehabkost@redhat.com, kvm@vger.kernel.org, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, imammedo@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, rth@twiddle.net On Fri, Oct 30, 2015 at 01:56:02PM +0800, Xiao Guangrong wrote: > Currently file_ram_alloc() is designed for hugetlbfs, however, the memory > of nvdimm can come from either raw pmem device eg, /dev/pmem, or the file > locates at DAX enabled filesystem > > So this patch let it work on any kind of path > > Signed-off-by: Xiao Guangrong So this allows regular memory to be specified directly. This needs to be split out and merged separately from acpi/nvdimm bits. Alternatively, if it's possible to use nvdimm with DAX fs (similar to hugetlbfs), leave these patches off for now. > --- > exec.c | 56 +++++++++++++++++--------------------------------------- > 1 file changed, 17 insertions(+), 39 deletions(-) > > diff --git a/exec.c b/exec.c > index 8af2570..3ca7e50 100644 > --- a/exec.c > +++ b/exec.c > @@ -1174,32 +1174,6 @@ void qemu_mutex_unlock_ramlist(void) > } > > #ifdef __linux__ > - > -#include > - > -#define HUGETLBFS_MAGIC 0x958458f6 > - > -static long gethugepagesize(const char *path, Error **errp) > -{ > - struct statfs fs; > - int ret; > - > - do { > - ret = statfs(path, &fs); > - } while (ret != 0 && errno == EINTR); > - > - if (ret != 0) { > - error_setg_errno(errp, errno, "failed to get page size of file %s", > - path); > - return 0; > - } > - > - if (fs.f_type != HUGETLBFS_MAGIC) > - fprintf(stderr, "Warning: path not on HugeTLBFS: %s\n", path); > - > - return fs.f_bsize; > -} > - > static void *file_ram_alloc(RAMBlock *block, > ram_addr_t memory, > const char *path, > @@ -1210,20 +1184,24 @@ static void *file_ram_alloc(RAMBlock *block, > char *c; > void *area; > int fd; > - uint64_t hpagesize; > - Error *local_err = NULL; > + uint64_t pagesize; > > - hpagesize = gethugepagesize(path, &local_err); > - if (local_err) { > - error_propagate(errp, local_err); > + pagesize = qemu_file_get_page_size(path); > + if (!pagesize) { > + error_setg(errp, "can't get page size for %s", path); > goto error; > } > - block->mr->align = hpagesize; > > - if (memory < hpagesize) { > + if (pagesize == getpagesize()) { > + fprintf(stderr, "Memory is not allocated from HugeTlbfs.\n"); > + } > + > + block->mr->align = pagesize; > + > + if (memory < pagesize) { > error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to " > - "or larger than huge page size 0x%" PRIx64, > - memory, hpagesize); > + "or larger than page size 0x%" PRIx64, > + memory, pagesize); > goto error; > } > > @@ -1247,14 +1225,14 @@ static void *file_ram_alloc(RAMBlock *block, > fd = mkstemp(filename); > if (fd < 0) { > error_setg_errno(errp, errno, > - "unable to create backing store for hugepages"); > + "unable to create backing store for path %s", path); > g_free(filename); > goto error; > } > unlink(filename); > g_free(filename); Looks like we are still calling mkstemp/unlink here. How does this work? > > - memory = ROUND_UP(memory, hpagesize); > + memory = ROUND_UP(memory, pagesize); > > /* > * ftruncate is not supported by hugetlbfs in older > @@ -1266,10 +1244,10 @@ static void *file_ram_alloc(RAMBlock *block, > perror("ftruncate"); > } > > - area = qemu_ram_mmap(fd, memory, hpagesize, block->flags & RAM_SHARED); > + area = qemu_ram_mmap(fd, memory, pagesize, block->flags & RAM_SHARED); > if (area == MAP_FAILED) { > error_setg_errno(errp, errno, > - "unable to map backing store for hugepages"); > + "unable to map backing store for path %s", path); > close(fd); > goto error; > } > -- > 1.8.3.1