From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43803) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gP0mQ-00038p-Qw for qemu-devel@nongnu.org; Tue, 20 Nov 2018 02:49:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gP0mO-0001el-Rn for qemu-devel@nongnu.org; Tue, 20 Nov 2018 02:49:06 -0500 Received: from mga01.intel.com ([192.55.52.88]:7646) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gP0mO-0001e4-Jx for qemu-devel@nongnu.org; Tue, 20 Nov 2018 02:49:04 -0500 From: Zhang Yi Date: Tue, 20 Nov 2018 15:48:39 +0800 Message-Id: <904316e1b1eb22d7a2d19fa00ffba17e65acda3b.1542699775.git.yi.z.zhang@linux.intel.com> In-Reply-To: References: Subject: [Qemu-devel] [PATCH V5_resend 5/7] util/mmap-alloc: Switch the RAM_SYNC flags to OnOffAuto List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xiaoguangrong.eric@gmail.com, dan.j.williams@intel.com, stefanha@redhat.com, pbonzini@redhat.com, yu.c.zhang@linux.intel.com Cc: mst@redhat.com, qemu-devel@nongnu.org, imammedo@redhat.com, ehabkost@redhat.com, Zhang Yi Signed-off-by: Zhang Yi A set of RAM_SYNC_ON_OFF_AUTO{AUTO,ON,OFF} flags are added to qemu_ram_mmap(): - If RAM_SYNC_ON_OFF_AUTO_ON is present, qemu_ram_mmap() will try to pass MAP_SYNC to mmap(). It will then fail if the host OS or the backend file do not support MAP_SYNC, or MAP_SYNC is conflict with other flags. - If RAM_SYNC_ON_OFF_AUTO_OFF is present, qemu_ram_mmap() will never pass MAP_SYNC to mmap(). - If RAM_SYNC_ON_OFF_AUTO_AUTO is present, and * if the host OS and the backend file support MAP_SYNC, and MAP_SYNC is not conflict with other flags, qemu_ram_mmap() will work as if RAM_SYNC_ON_OFF_AUTO_ON is present; * otherwise, qemu_ram_mmap() will work as if RAM_SYNC_ON_OFF_AUTO_OFF is present. --- include/exec/memory.h | 9 ++++++++- util/mmap-alloc.c | 12 ++++++++++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/include/exec/memory.h b/include/exec/memory.h index 33a4e2c..c74c467 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -127,7 +127,14 @@ typedef struct IOMMUNotifier IOMMUNotifier; #define RAM_PMEM (1 << 5) /* RAM can be mmap by a MAP_SYNC flag */ -#define RAM_SYNC (1 << 6) +#define RAM_SYNC_SHIFT 6 +#define RAM_SYNC_SHIFT_AUTO 7 + +#define RAM_SYNC_ON_OFF_AUTO_ON (1UL << RAM_SYNC_SHIFT) +#define RAM_SYNC_ON_OFF_AUTO_OFF (0UL << RAM_SYNC_SHIFT) +#define RAM_SYNC_ON_OFF_AUTO_AUTO (1UL << RAM_SYNC_SHIFT_AUTO) + +#define RAM_SYNC (RAM_SYNC_ON_OFF_AUTO_ON | RAM_SYNC_ON_OFF_AUTO_AUTO) static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn, IOMMUNotifierFlag flags, diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index f411df7..fe9303f 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -111,6 +111,10 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, uint32_t flags) assert(is_power_of_2(align)); /* Always align to host page size */ assert(align >= getpagesize()); + if ((flags & RAM_SYNC_ON_OFF_AUTO_ON) && + (!shared || !MAP_SYNC_FLAGS)) { + return MAP_FAILED; + } if ((flags & RAM_SYNC) && shared) { mmap_xflags |= MAP_SYNC_FLAGS; } @@ -123,8 +127,12 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, uint32_t flags) (shared ? MAP_SHARED : MAP_PRIVATE) | mmap_xflags, fd, 0); if ((ptr1 == MAP_FAILED) && (mmap_xflags & MAP_SYNC_FLAGS)) { - mmap_xflags &= ~MAP_SYNC_FLAGS; - goto retry_mmap_fd; + if (flags & RAM_SYNC_ON_OFF_AUTO_AUTO) { + mmap_xflags &= ~MAP_SYNC_FLAGS; + goto retry_mmap_fd; + } + munmap(ptr, total); + return MAP_FAILED; } if (offset > 0) { -- 2.7.4