From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55008) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xx9Lz-0006EB-QW for qemu-devel@nongnu.org; Sat, 06 Dec 2014 02:00:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xx9Ln-0005mx-It for qemu-devel@nongnu.org; Sat, 06 Dec 2014 02:00:31 -0500 Received: from szxga01-in.huawei.com ([119.145.14.64]:14073) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xx9Lm-0005Nw-Tl for qemu-devel@nongnu.org; Sat, 06 Dec 2014 02:00:19 -0500 From: zhanghailiang Date: Sat, 6 Dec 2014 14:59:15 +0800 Message-ID: <1417849159-6568-3-git-send-email-zhang.zhanghailiang@huawei.com> In-Reply-To: <1417849159-6568-1-git-send-email-zhang.zhanghailiang@huawei.com> References: <1417849159-6568-1-git-send-email-zhang.zhanghailiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH RFC for-2.3 2/6] qga: introduce three help functions for memory block functions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: zhanghailiang , mdroth@linux.vnet.ibm.com, peter.huangpeng@huawei.com Signed-off-by: zhanghailiang --- qga/commands-posix.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) diff --git a/qga/commands-posix.c b/qga/commands-posix.c index b0d6a5d..8917dca 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -1875,6 +1875,136 @@ int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp) return processed; } +static void ga_read_sysfs_file(int dirfd, const char *pathname, char *buf, + int size, Error **errp) +{ + int fd; + int res; + + errno = 0; + fd = openat(dirfd, pathname, O_RDONLY); + if (fd == -1) { + error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname); + return; + } + + res = pread(fd, buf, size, 0); + if (res == -1) { + error_setg_errno(errp, errno, "pread sysfs file \"%s\"", pathname); + } else if (res == 0) { + error_setg(errp, "pread sysfs file \"%s\": unexpected EOF", pathname); + } + res = close(fd); + g_assert(res == 0); +} + +static void ga_write_sysfs_file(int dirfd, const char *pathname, + const char *buf, int size, Error **errp) +{ + int fd; + int res; + + errno = 0; + fd = openat(dirfd, pathname, O_WRONLY); + if (fd == -1) { + error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname); + return; + } + + if (pwrite(fd, buf, size, 0) == -1) { + error_setg_errno(errp, errno, "pwrite sysfs file \"%s\"", pathname); + } + + res = close(fd); + g_assert(res == 0); +} + +/* Transfer online/offline status between @mem_blk and the guest system. + * + * On input either @errp or *@errp must be NULL. + * + * In system-to-@mem_blk direction, the following @mem_blk fields are accessed: + * - R: mem_blk->phys_index + * - W: mem_blk->online + * - W: mem_blk->can_offline + * + * In @mem_blk-to-system direction, the following @mem_blk fields are accessed: + * - R: mem_blk->phys_index + * - R: mem_blk->online + *- R: mem_blk->can_offline + * Written members remain unmodified on error. + */ +static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk, + Error **errp) +{ + char *dirpath; + int dirfd; + int res; + char *status; + Error *local_err = NULL; + + dirpath = g_strdup_printf("/sys/devices/system/memory/memory%" PRId64 "/", + mem_blk->phys_index); + dirfd = open(dirpath, O_RDONLY | O_DIRECTORY); + if (dirfd == -1) { + error_setg_errno(errp, errno, "open(\"%s\")", dirpath); + g_free(dirpath); + return; + } + g_free(dirpath); + + status = g_malloc0(10); + ga_read_sysfs_file(dirfd, "state", status, 10, &local_err); + if (local_err) { + /* treat with sysfs file that not exist in old kernel */ + if (errno == ENOENT) { + error_free(local_err); + if (sys2memblk) { + mem_blk->online = true; + mem_blk->can_offline = false; + } else if (!mem_blk->online) { + error_setg(errp, "memory block #%" PRId64 " can't be " + "offlined", mem_blk->phys_index); + } + } else { + error_propagate(errp, local_err); + } + return; + } + + if (sys2memblk) { + char removable = '0'; + + mem_blk->online = (strncmp(status, "online", 6) == 0); + + ga_read_sysfs_file(dirfd, "removable", &removable, 1, &local_err); + if (local_err) { + /* if no 'removable' file, it does't support offline mem blk */ + if (errno == ENOENT) { + error_free(local_err); + mem_blk->can_offline = false; + } else { + error_propagate(errp, local_err); + } + } else { + mem_blk->can_offline = (removable != '0'); + } + } else { + if (mem_blk->online != (strncmp(status, "online", 6) == 0)) { + char *new_state = mem_blk->online ? g_strdup("online") : + g_strdup("offline"); + + ga_write_sysfs_file(dirfd, "state", new_state, strlen(new_state), + errp); + g_free(new_state); + } /* otherwise pretend successful re-(on|off)-lining */ + } + + g_free(status); + res = close(dirfd); + g_assert(res == 0); +} + #else /* defined(__linux__) */ void qmp_guest_suspend_disk(Error **errp) -- 1.7.12.4