From 34ff13c0974bf94c3e61b0b8af8134a6933194ea Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 15 Nov 2018 09:45:19 +0100 Subject: [PATCH 1/5] qga: ignore non present cpus when handling qmp_guest_get_vcpus() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Marc-André Lureau Message-id: <20181115094519.22641-1-marcandre.lureau@redhat.com> Patchwork-id: 83030 O-Subject: [RHEL-7.7 qemu-guest-agent PATCH] qga: ignore non present cpus when handling qmp_guest_get_vcpus() Bugzilla: 1611062 RH-Acked-by: Laszlo Ersek RH-Acked-by: Igor Mammedov RH-Acked-by: Markus Armbruster 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 BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1611062 Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=19189361 (cherry picked from commit b4bf912a6c19449e68af7b4173a8c6da21904d99) Signed-off-by: Marc-André Lureau Signed-off-by: Miroslav Rezanina --- 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 26c1863..f4d9380 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -1913,61 +1913,56 @@ 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) @@ -1985,17 +1980,21 @@ 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) { @@ -2016,7 +2015,11 @@ 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; } -- 1.8.3.1