From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60549) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHfVF-0000oO-4A for qemu-devel@nongnu.org; Tue, 30 Oct 2018 21:41:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gHfVA-0002Wr-IE for qemu-devel@nongnu.org; Tue, 30 Oct 2018 21:41:01 -0400 Received: from mail-qk1-x741.google.com ([2607:f8b0:4864:20::741]:41763) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gHfVA-0002Va-9y for qemu-devel@nongnu.org; Tue, 30 Oct 2018 21:40:56 -0400 Received: by mail-qk1-x741.google.com with SMTP id 189so7167050qkj.8 for ; Tue, 30 Oct 2018 18:40:56 -0700 (PDT) Sender: fluxion From: Michael Roth Date: Tue, 30 Oct 2018 20:38:00 -0500 Message-Id: <20181031013821.24023-4-mdroth@linux.vnet.ibm.com> In-Reply-To: <20181031013821.24023-1-mdroth@linux.vnet.ibm.com> References: <20181031013821.24023-1-mdroth@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PULL v2 03/24] qga: ignore non present cpus when handling qmp_guest_get_vcpus() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, Igor Mammedov From: Igor Mammedov If VM has VCPUs plugged sparselly (for example a VM started with 3 VCPUs (cpu0, cpu1 and cpu2) and then cpu1 was hotunplugged so only cpu0 and cpu2 are present), QGA will rise a error error: internal error: unable to execute QEMU agent command 'guest-get-vcpus': open("/sys/devices/system/cpu/cpu1/"): No such file or directory when virsh vcpucount FOO --guest is executed. Fix it by ignoring non present CPUs when fetching CPUs status from sysfs. Signed-off-by: Igor Mammedov Reviewed-by: Laszlo Ersek Reviewed-by: Marc-André Lureau Signed-off-by: Michael Roth --- qga/commands-posix.c | 115 ++++++++++++++++++++++--------------------- 1 file changed, 59 insertions(+), 56 deletions(-) diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 37e8a2d791..42d30f078e 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -2035,61 +2035,56 @@ static long sysconf_exact(int name, const char *name_str, Error **errp) * Written members remain unmodified on error. */ static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu, - Error **errp) + char *dirpath, Error **errp) { - char *dirpath; + int fd; + int res; int dirfd; + static const char fn[] = "online"; - dirpath = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/", - vcpu->logical_id); dirfd = open(dirpath, O_RDONLY | O_DIRECTORY); if (dirfd == -1) { error_setg_errno(errp, errno, "open(\"%s\")", dirpath); - } else { - static const char fn[] = "online"; - int fd; - int res; - - fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR); - if (fd == -1) { - if (errno != ENOENT) { - error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn); - } else if (sys2vcpu) { - vcpu->online = true; - vcpu->can_offline = false; - } else if (!vcpu->online) { - error_setg(errp, "logical processor #%" PRId64 " can't be " - "offlined", vcpu->logical_id); - } /* otherwise pretend successful re-onlining */ - } else { - unsigned char status; - - res = pread(fd, &status, 1, 0); - if (res == -1) { - error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn); - } else if (res == 0) { - error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath, - fn); - } else if (sys2vcpu) { - vcpu->online = (status != '0'); - vcpu->can_offline = true; - } else if (vcpu->online != (status != '0')) { - status = '0' + vcpu->online; - if (pwrite(fd, &status, 1, 0) == -1) { - error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath, - fn); - } - } /* otherwise pretend successful re-(on|off)-lining */ + return; + } - res = close(fd); - g_assert(res == 0); - } + fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR); + if (fd == -1) { + if (errno != ENOENT) { + error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn); + } else if (sys2vcpu) { + vcpu->online = true; + vcpu->can_offline = false; + } else if (!vcpu->online) { + error_setg(errp, "logical processor #%" PRId64 " can't be " + "offlined", vcpu->logical_id); + } /* otherwise pretend successful re-onlining */ + } else { + unsigned char status; + + res = pread(fd, &status, 1, 0); + if (res == -1) { + error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn); + } else if (res == 0) { + error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath, + fn); + } else if (sys2vcpu) { + vcpu->online = (status != '0'); + vcpu->can_offline = true; + } else if (vcpu->online != (status != '0')) { + status = '0' + vcpu->online; + if (pwrite(fd, &status, 1, 0) == -1) { + error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath, + fn); + } + } /* otherwise pretend successful re-(on|off)-lining */ - res = close(dirfd); + res = close(fd); g_assert(res == 0); } - g_free(dirpath); + res = close(dirfd); + g_assert(res == 0); } GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp) @@ -2107,17 +2102,21 @@ GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp) while (local_err == NULL && current < sc_max) { GuestLogicalProcessor *vcpu; GuestLogicalProcessorList *entry; - - vcpu = g_malloc0(sizeof *vcpu); - vcpu->logical_id = current++; - vcpu->has_can_offline = true; /* lolspeak ftw */ - transfer_vcpu(vcpu, true, &local_err); - - entry = g_malloc0(sizeof *entry); - entry->value = vcpu; - - *link = entry; - link = &entry->next; + int64_t id = current++; + char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/", + id); + + if (g_file_test(path, G_FILE_TEST_EXISTS)) { + vcpu = g_malloc0(sizeof *vcpu); + vcpu->logical_id = id; + vcpu->has_can_offline = true; /* lolspeak ftw */ + transfer_vcpu(vcpu, true, path, &local_err); + entry = g_malloc0(sizeof *entry); + entry->value = vcpu; + *link = entry; + link = &entry->next; + } + g_free(path); } if (local_err == NULL) { @@ -2138,7 +2137,11 @@ int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp) processed = 0; while (vcpus != NULL) { - transfer_vcpu(vcpus->value, false, &local_err); + char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/", + vcpus->value->logical_id); + + transfer_vcpu(vcpus->value, false, path, &local_err); + g_free(path); if (local_err != NULL) { break; } -- 2.17.1