[libvirt] [PATCH] qemu: Search binaries in PATH instead of hardcoding /usr/bin
--- src/qemu/qemu_conf.c | 137 ++++++++++++++++++++++++++++++-------------------- 1 files changed, 82 insertions(+), 55 deletions(-) diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 92a9348..6141ec6 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -379,20 +379,20 @@ static const struct qemu_feature_flags const arch_info_x86_64_flags [] = { /* The archicture tables for supported QEMU archs */ static const struct qemu_arch_info const arch_info_hvm[] = { - { "i686", 32, NULL, "/usr/bin/qemu", - "/usr/bin/qemu-system-x86_64", arch_info_i686_flags, 4 }, - { "x86_64", 64, NULL, "/usr/bin/qemu-system-x86_64", + { "i686", 32, NULL, "qemu", + "qemu-system-x86_64", arch_info_i686_flags, 4 }, + { "x86_64", 64, NULL, "qemu-system-x86_64", NULL, arch_info_x86_64_flags, 2 }, - { "arm", 32, NULL, "/usr/bin/qemu-system-arm", NULL, NULL, 0 }, - { "mips", 32, NULL, "/usr/bin/qemu-system-mips", NULL, NULL, 0 }, - { "mipsel", 32, NULL, "/usr/bin/qemu-system-mipsel", NULL, NULL, 0 }, - { "sparc", 32, NULL, "/usr/bin/qemu-system-sparc", NULL, NULL, 0 }, - { "ppc", 32, NULL, "/usr/bin/qemu-system-ppc", NULL, NULL, 0 }, + { "arm", 32, NULL, "qemu-system-arm", NULL, NULL, 0 }, + { "mips", 32, NULL, "qemu-system-mips", NULL, NULL, 0 }, + { "mipsel", 32, NULL, "qemu-system-mipsel", NULL, NULL, 0 }, + { "sparc", 32, NULL, "qemu-system-sparc", NULL, NULL, 0 }, + { "ppc", 32, NULL, "qemu-system-ppc", NULL, NULL, 0 }, }; static const struct qemu_arch_info const arch_info_xen[] = { - { "i686", 32, "xenner", "/usr/bin/xenner", NULL, arch_info_i686_flags, 4 }, - { "x86_64", 64, "xenner", "/usr/bin/xenner", NULL, arch_info_x86_64_flags, 2 }, + { "i686", 32, "xenner", "xenner", NULL, arch_info_i686_flags, 4 }, + { "x86_64", 64, "xenner", "xenner", NULL, arch_info_x86_64_flags, 2 }, }; @@ -768,8 +768,8 @@ qemudCapsInitGuest(virCapsPtr caps, int i; int haskvm = 0; int haskqemu = 0; - const char *kvmbin = NULL; - const char *binary = NULL; + char *kvmbin = NULL; + char *binary = NULL; time_t binary_mtime; virCapsGuestMachinePtr *machines = NULL; int nmachines = 0; @@ -779,10 +779,15 @@ qemudCapsInitGuest(virCapsPtr caps, /* Check for existance of base emulator, or alternate base * which can be used with magic cpu choice */ - if (access(info->binary, X_OK) == 0) - binary = info->binary; - else if (info->altbinary && access(info->altbinary, X_OK) == 0) - binary = info->altbinary; + binary = virFindFileInPath(info->binary); + + if (binary == NULL || access(binary, X_OK) != 0) { + VIR_FREE(binary); + binary = virFindFileInPath(info->altbinary); + + if (binary != NULL && access(binary, X_OK) != 0) + VIR_FREE(binary); + } /* Can use acceleration for KVM/KQEMU if * - host & guest arches match @@ -792,16 +797,30 @@ qemudCapsInitGuest(virCapsPtr caps, */ if (STREQ(info->arch, hostmachine) || (STREQ(hostmachine, "x86_64") && STREQ(info->arch, "i686"))) { - const char *const kvmbins[] = { "/usr/bin/qemu-kvm", /* Fedora */ - "/usr/bin/kvm" }; /* Upstream .spec */ + if (access("/dev/kvm", F_OK) == 0) { + const char *const kvmbins[] = { "qemu-kvm", /* Fedora */ + "kvm" }; /* Upstream .spec */ + + for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { + kvmbin = virFindFileInPath(kvmbins[i]); + + if (kvmbin == NULL || access(kvmbin, X_OK) != 0) { + VIR_FREE(kvmbin); + continue; + } - for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { - if (access(kvmbins[i], X_OK) == 0 && - access("/dev/kvm", F_OK) == 0) { haskvm = 1; - kvmbin = kvmbins[i]; - if (!binary) - binary = kvmbin; + + if (binary == NULL) { + binary = strdup(kvmbin); + + if (binary == NULL) { + virReportOOMError(NULL); + VIR_FREE(kvmbin); + return -1; + } + } + break; } } @@ -826,21 +845,18 @@ qemudCapsInitGuest(virCapsPtr caps, virCapsGuestMachinePtr machine; if (VIR_ALLOC(machine) < 0) { - virReportOOMError(NULL); - return -1; + goto no_memory; } if (!(machine->name = strdup(info->machine))) { - virReportOOMError(NULL); VIR_FREE(machine); - return -1; + goto no_memory; } if (VIR_ALLOC_N(machines, 1) < 0) { - virReportOOMError(NULL); VIR_FREE(machine->name); VIR_FREE(machine); - return -1; + goto no_memory; } machines[0] = machine; @@ -853,7 +869,7 @@ qemudCapsInitGuest(virCapsPtr caps, old_caps, &machines, &nmachines); if (probe && qemudProbeMachineTypes(binary, &machines, &nmachines) < 0) - return -1; + goto error; } /* We register kvm as the base emulator too, since we can @@ -865,21 +881,18 @@ qemudCapsInitGuest(virCapsPtr caps, binary, NULL, nmachines, - machines)) == NULL) { - for (i = 0; i < nmachines; i++) { - VIR_FREE(machines[i]->name); - VIR_FREE(machines[i]); - } - VIR_FREE(machines); - return -1; - } + machines)) == NULL) + goto error; + + machines = NULL; + nmachines = 0; guest->arch.defaultInfo.emulator_mtime = binary_mtime; if (qemudProbeCPUModels(binary, info->arch, &ncpus, NULL) == 0 && ncpus > 0 && !virCapabilitiesAddGuestFeature(guest, "cpuselection", 1, 0)) - return -1; + goto error; if (hvm) { if (virCapabilitiesAddGuestDomain(guest, @@ -888,7 +901,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error; if (haskqemu && virCapabilitiesAddGuestDomain(guest, @@ -897,7 +910,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error; if (haskvm) { virCapsGuestDomainPtr dom; @@ -911,9 +924,6 @@ qemudCapsInitGuest(virCapsPtr caps, binary_mtime = 0; } - machines = NULL; - nmachines = 0; - if (!STREQ(binary, kvmbin)) { int probe = 1; if (old_caps && binary_mtime) @@ -922,7 +932,7 @@ qemudCapsInitGuest(virCapsPtr caps, old_caps, &machines, &nmachines); if (probe && qemudProbeMachineTypes(kvmbin, &machines, &nmachines) < 0) - return -1; + goto error; } if ((dom = virCapabilitiesAddGuestDomain(guest, @@ -931,14 +941,12 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, nmachines, machines)) == NULL) { - for (i = 0; i < nmachines; i++) { - VIR_FREE(machines[i]->name); - VIR_FREE(machines[i]); - } - VIR_FREE(machines); - return -1; + goto error; } + machines = NULL; + nmachines = 0; + dom->info.emulator_mtime = binary_mtime; } } else { @@ -948,7 +956,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error; } if (info->nflags) { @@ -957,11 +965,24 @@ qemudCapsInitGuest(virCapsPtr caps, info->flags[i].name, info->flags[i].default_on, info->flags[i].toggle) == NULL) - return -1; + goto error; } } + VIR_FREE(binary); + VIR_FREE(kvmbin); + return 0; + +no_memory: + virReportOOMError(NULL); + +error: + VIR_FREE(binary); + VIR_FREE(kvmbin); + virCapabilitiesFreeMachines(machines, nmachines); + + return -1; } @@ -1011,6 +1032,7 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { struct utsname utsname; virCapsPtr caps; int i; + char *xenner = NULL; /* Really, this never fails - look at the man-page. */ uname (&utsname); @@ -1051,7 +1073,9 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { goto no_memory; /* Then possibly the Xen paravirt guests (ie Xenner */ - if (access("/usr/bin/xenner", X_OK) == 0 && + xenner = virFindFileInPath("xenner"); + + if (xenner != NULL && access(xenner, X_OK) == 0 && access("/dev/kvm", F_OK) == 0) { for (i = 0 ; i < ARRAY_CARDINALITY(arch_info_xen) ; i++) /* Allow Xen 32-on-32, 32-on-64 and 64-on-64 */ @@ -1065,12 +1089,15 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { } } + VIR_FREE(xenner); + /* QEMU Requires an emulator in the XML */ virCapabilitiesSetEmulatorRequired(caps); return caps; no_memory: + VIR_FREE(xenner); virCapabilitiesFree(caps); return NULL; } -- 1.6.3.3
On Wed, Jan 20, 2010 at 02:46:10AM +0100, Matthias Bolte wrote:
--- src/qemu/qemu_conf.c | 137 ++++++++++++++++++++++++++++++-------------------- 1 files changed, 82 insertions(+), 55 deletions(-)
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 92a9348..6141ec6 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -379,20 +379,20 @@ static const struct qemu_feature_flags const arch_info_x86_64_flags [] = {
/* The archicture tables for supported QEMU archs */ static const struct qemu_arch_info const arch_info_hvm[] = { - { "i686", 32, NULL, "/usr/bin/qemu", - "/usr/bin/qemu-system-x86_64", arch_info_i686_flags, 4 }, - { "x86_64", 64, NULL, "/usr/bin/qemu-system-x86_64", + { "i686", 32, NULL, "qemu", + "qemu-system-x86_64", arch_info_i686_flags, 4 }, + { "x86_64", 64, NULL, "qemu-system-x86_64", NULL, arch_info_x86_64_flags, 2 }, - { "arm", 32, NULL, "/usr/bin/qemu-system-arm", NULL, NULL, 0 }, - { "mips", 32, NULL, "/usr/bin/qemu-system-mips", NULL, NULL, 0 }, - { "mipsel", 32, NULL, "/usr/bin/qemu-system-mipsel", NULL, NULL, 0 }, - { "sparc", 32, NULL, "/usr/bin/qemu-system-sparc", NULL, NULL, 0 }, - { "ppc", 32, NULL, "/usr/bin/qemu-system-ppc", NULL, NULL, 0 }, + { "arm", 32, NULL, "qemu-system-arm", NULL, NULL, 0 }, + { "mips", 32, NULL, "qemu-system-mips", NULL, NULL, 0 }, + { "mipsel", 32, NULL, "qemu-system-mipsel", NULL, NULL, 0 }, + { "sparc", 32, NULL, "qemu-system-sparc", NULL, NULL, 0 }, + { "ppc", 32, NULL, "qemu-system-ppc", NULL, NULL, 0 }, };
static const struct qemu_arch_info const arch_info_xen[] = { - { "i686", 32, "xenner", "/usr/bin/xenner", NULL, arch_info_i686_flags, 4 }, - { "x86_64", 64, "xenner", "/usr/bin/xenner", NULL, arch_info_x86_64_flags, 2 }, + { "i686", 32, "xenner", "xenner", NULL, arch_info_i686_flags, 4 }, + { "x86_64", 64, "xenner", "xenner", NULL, arch_info_x86_64_flags, 2 }, };
@@ -768,8 +768,8 @@ qemudCapsInitGuest(virCapsPtr caps, int i; int haskvm = 0; int haskqemu = 0; - const char *kvmbin = NULL; - const char *binary = NULL; + char *kvmbin = NULL; + char *binary = NULL; time_t binary_mtime; virCapsGuestMachinePtr *machines = NULL; int nmachines = 0; @@ -779,10 +779,15 @@ qemudCapsInitGuest(virCapsPtr caps, /* Check for existance of base emulator, or alternate base * which can be used with magic cpu choice */ - if (access(info->binary, X_OK) == 0) - binary = info->binary; - else if (info->altbinary && access(info->altbinary, X_OK) == 0) - binary = info->altbinary; + binary = virFindFileInPath(info->binary); + + if (binary == NULL || access(binary, X_OK) != 0) { + VIR_FREE(binary); + binary = virFindFileInPath(info->altbinary); + + if (binary != NULL && access(binary, X_OK) != 0) + VIR_FREE(binary); + }
/* Can use acceleration for KVM/KQEMU if * - host & guest arches match @@ -792,16 +797,30 @@ qemudCapsInitGuest(virCapsPtr caps, */ if (STREQ(info->arch, hostmachine) || (STREQ(hostmachine, "x86_64") && STREQ(info->arch, "i686"))) { - const char *const kvmbins[] = { "/usr/bin/qemu-kvm", /* Fedora */ - "/usr/bin/kvm" }; /* Upstream .spec */ + if (access("/dev/kvm", F_OK) == 0) { + const char *const kvmbins[] = { "qemu-kvm", /* Fedora */ + "kvm" }; /* Upstream .spec */ + + for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { + kvmbin = virFindFileInPath(kvmbins[i]); + + if (kvmbin == NULL || access(kvmbin, X_OK) != 0) { + VIR_FREE(kvmbin); + continue; + }
- for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { - if (access(kvmbins[i], X_OK) == 0 && - access("/dev/kvm", F_OK) == 0) { haskvm = 1; - kvmbin = kvmbins[i]; - if (!binary) - binary = kvmbin; + + if (binary == NULL) { + binary = strdup(kvmbin); + + if (binary == NULL) { + virReportOOMError(NULL); + VIR_FREE(kvmbin); + return -1; + } + } + break; } } @@ -826,21 +845,18 @@ qemudCapsInitGuest(virCapsPtr caps, virCapsGuestMachinePtr machine;
if (VIR_ALLOC(machine) < 0) { - virReportOOMError(NULL); - return -1; + goto no_memory; }
if (!(machine->name = strdup(info->machine))) { - virReportOOMError(NULL); VIR_FREE(machine); - return -1; + goto no_memory; }
if (VIR_ALLOC_N(machines, 1) < 0) { - virReportOOMError(NULL); VIR_FREE(machine->name); VIR_FREE(machine); - return -1; + goto no_memory; }
machines[0] = machine; @@ -853,7 +869,7 @@ qemudCapsInitGuest(virCapsPtr caps, old_caps, &machines, &nmachines); if (probe && qemudProbeMachineTypes(binary, &machines, &nmachines) < 0) - return -1; + goto error; }
/* We register kvm as the base emulator too, since we can @@ -865,21 +881,18 @@ qemudCapsInitGuest(virCapsPtr caps, binary, NULL, nmachines, - machines)) == NULL) { - for (i = 0; i < nmachines; i++) { - VIR_FREE(machines[i]->name); - VIR_FREE(machines[i]); - } - VIR_FREE(machines); - return -1; - } + machines)) == NULL) + goto error; + + machines = NULL; + nmachines = 0;
guest->arch.defaultInfo.emulator_mtime = binary_mtime;
if (qemudProbeCPUModels(binary, info->arch, &ncpus, NULL) == 0 && ncpus > 0 && !virCapabilitiesAddGuestFeature(guest, "cpuselection", 1, 0)) - return -1; + goto error;
if (hvm) { if (virCapabilitiesAddGuestDomain(guest, @@ -888,7 +901,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error;
if (haskqemu && virCapabilitiesAddGuestDomain(guest, @@ -897,7 +910,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error;
if (haskvm) { virCapsGuestDomainPtr dom; @@ -911,9 +924,6 @@ qemudCapsInitGuest(virCapsPtr caps, binary_mtime = 0; }
- machines = NULL; - nmachines = 0; - if (!STREQ(binary, kvmbin)) { int probe = 1; if (old_caps && binary_mtime) @@ -922,7 +932,7 @@ qemudCapsInitGuest(virCapsPtr caps, old_caps, &machines, &nmachines); if (probe && qemudProbeMachineTypes(kvmbin, &machines, &nmachines) < 0) - return -1; + goto error; }
if ((dom = virCapabilitiesAddGuestDomain(guest, @@ -931,14 +941,12 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, nmachines, machines)) == NULL) { - for (i = 0; i < nmachines; i++) { - VIR_FREE(machines[i]->name); - VIR_FREE(machines[i]); - } - VIR_FREE(machines); - return -1; + goto error; }
+ machines = NULL; + nmachines = 0; + dom->info.emulator_mtime = binary_mtime; } } else { @@ -948,7 +956,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error; }
if (info->nflags) { @@ -957,11 +965,24 @@ qemudCapsInitGuest(virCapsPtr caps, info->flags[i].name, info->flags[i].default_on, info->flags[i].toggle) == NULL) - return -1; + goto error; } }
+ VIR_FREE(binary); + VIR_FREE(kvmbin); + return 0; + +no_memory: + virReportOOMError(NULL); + +error: + VIR_FREE(binary); + VIR_FREE(kvmbin); + virCapabilitiesFreeMachines(machines, nmachines); + + return -1; }
@@ -1011,6 +1032,7 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { struct utsname utsname; virCapsPtr caps; int i; + char *xenner = NULL;
/* Really, this never fails - look at the man-page. */ uname (&utsname); @@ -1051,7 +1073,9 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { goto no_memory;
/* Then possibly the Xen paravirt guests (ie Xenner */ - if (access("/usr/bin/xenner", X_OK) == 0 && + xenner = virFindFileInPath("xenner"); + + if (xenner != NULL && access(xenner, X_OK) == 0 && access("/dev/kvm", F_OK) == 0) { for (i = 0 ; i < ARRAY_CARDINALITY(arch_info_xen) ; i++) /* Allow Xen 32-on-32, 32-on-64 and 64-on-64 */ @@ -1065,12 +1089,15 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { } }
+ VIR_FREE(xenner); + /* QEMU Requires an emulator in the XML */ virCapabilitiesSetEmulatorRequired(caps);
return caps;
no_memory: + VIR_FREE(xenner); virCapabilitiesFree(caps); return NULL; }
Pro: it's more flexible Cons: it's less rigid :-) I think it's fine since in the majority of cases that code will be run by libvirtd, which as a daemon will have a relatively well defined and contained PATH . Like when a rogue shared library si available in some common place that lead to very painful debugging when an user has a problem, rather than the rather straighforward error about a missing binary the current version. It's a bit of a double edged sword, but in that case I think it's fine. But I could see how others could disagree ACK from my POV, Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ daniel@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/
2010/1/20 Daniel Veillard <veillard@redhat.com>:
On Wed, Jan 20, 2010 at 02:46:10AM +0100, Matthias Bolte wrote:
--- src/qemu/qemu_conf.c | 137 ++++++++++++++++++++++++++++++-------------------- 1 files changed, 82 insertions(+), 55 deletions(-)
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 92a9348..6141ec6 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -379,20 +379,20 @@ static const struct qemu_feature_flags const arch_info_x86_64_flags [] = {
/* The archicture tables for supported QEMU archs */ static const struct qemu_arch_info const arch_info_hvm[] = { - { "i686", 32, NULL, "/usr/bin/qemu", - "/usr/bin/qemu-system-x86_64", arch_info_i686_flags, 4 }, - { "x86_64", 64, NULL, "/usr/bin/qemu-system-x86_64", + { "i686", 32, NULL, "qemu", + "qemu-system-x86_64", arch_info_i686_flags, 4 }, + { "x86_64", 64, NULL, "qemu-system-x86_64", NULL, arch_info_x86_64_flags, 2 }, - { "arm", 32, NULL, "/usr/bin/qemu-system-arm", NULL, NULL, 0 }, - { "mips", 32, NULL, "/usr/bin/qemu-system-mips", NULL, NULL, 0 }, - { "mipsel", 32, NULL, "/usr/bin/qemu-system-mipsel", NULL, NULL, 0 }, - { "sparc", 32, NULL, "/usr/bin/qemu-system-sparc", NULL, NULL, 0 }, - { "ppc", 32, NULL, "/usr/bin/qemu-system-ppc", NULL, NULL, 0 }, + { "arm", 32, NULL, "qemu-system-arm", NULL, NULL, 0 }, + { "mips", 32, NULL, "qemu-system-mips", NULL, NULL, 0 }, + { "mipsel", 32, NULL, "qemu-system-mipsel", NULL, NULL, 0 }, + { "sparc", 32, NULL, "qemu-system-sparc", NULL, NULL, 0 }, + { "ppc", 32, NULL, "qemu-system-ppc", NULL, NULL, 0 }, };
static const struct qemu_arch_info const arch_info_xen[] = { - { "i686", 32, "xenner", "/usr/bin/xenner", NULL, arch_info_i686_flags, 4 }, - { "x86_64", 64, "xenner", "/usr/bin/xenner", NULL, arch_info_x86_64_flags, 2 }, + { "i686", 32, "xenner", "xenner", NULL, arch_info_i686_flags, 4 }, + { "x86_64", 64, "xenner", "xenner", NULL, arch_info_x86_64_flags, 2 }, };
@@ -768,8 +768,8 @@ qemudCapsInitGuest(virCapsPtr caps, int i; int haskvm = 0; int haskqemu = 0; - const char *kvmbin = NULL; - const char *binary = NULL; + char *kvmbin = NULL; + char *binary = NULL; time_t binary_mtime; virCapsGuestMachinePtr *machines = NULL; int nmachines = 0; @@ -779,10 +779,15 @@ qemudCapsInitGuest(virCapsPtr caps, /* Check for existance of base emulator, or alternate base * which can be used with magic cpu choice */ - if (access(info->binary, X_OK) == 0) - binary = info->binary; - else if (info->altbinary && access(info->altbinary, X_OK) == 0) - binary = info->altbinary; + binary = virFindFileInPath(info->binary); + + if (binary == NULL || access(binary, X_OK) != 0) { + VIR_FREE(binary); + binary = virFindFileInPath(info->altbinary); + + if (binary != NULL && access(binary, X_OK) != 0) + VIR_FREE(binary); + }
/* Can use acceleration for KVM/KQEMU if * - host & guest arches match @@ -792,16 +797,30 @@ qemudCapsInitGuest(virCapsPtr caps, */ if (STREQ(info->arch, hostmachine) || (STREQ(hostmachine, "x86_64") && STREQ(info->arch, "i686"))) { - const char *const kvmbins[] = { "/usr/bin/qemu-kvm", /* Fedora */ - "/usr/bin/kvm" }; /* Upstream .spec */ + if (access("/dev/kvm", F_OK) == 0) { + const char *const kvmbins[] = { "qemu-kvm", /* Fedora */ + "kvm" }; /* Upstream .spec */ + + for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { + kvmbin = virFindFileInPath(kvmbins[i]); + + if (kvmbin == NULL || access(kvmbin, X_OK) != 0) { + VIR_FREE(kvmbin); + continue; + }
- for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { - if (access(kvmbins[i], X_OK) == 0 && - access("/dev/kvm", F_OK) == 0) { haskvm = 1; - kvmbin = kvmbins[i]; - if (!binary) - binary = kvmbin; + + if (binary == NULL) { + binary = strdup(kvmbin); + + if (binary == NULL) { + virReportOOMError(NULL); + VIR_FREE(kvmbin); + return -1; + } + } + break; } } @@ -826,21 +845,18 @@ qemudCapsInitGuest(virCapsPtr caps, virCapsGuestMachinePtr machine;
if (VIR_ALLOC(machine) < 0) { - virReportOOMError(NULL); - return -1; + goto no_memory; }
if (!(machine->name = strdup(info->machine))) { - virReportOOMError(NULL); VIR_FREE(machine); - return -1; + goto no_memory; }
if (VIR_ALLOC_N(machines, 1) < 0) { - virReportOOMError(NULL); VIR_FREE(machine->name); VIR_FREE(machine); - return -1; + goto no_memory; }
machines[0] = machine; @@ -853,7 +869,7 @@ qemudCapsInitGuest(virCapsPtr caps, old_caps, &machines, &nmachines); if (probe && qemudProbeMachineTypes(binary, &machines, &nmachines) < 0) - return -1; + goto error; }
/* We register kvm as the base emulator too, since we can @@ -865,21 +881,18 @@ qemudCapsInitGuest(virCapsPtr caps, binary, NULL, nmachines, - machines)) == NULL) { - for (i = 0; i < nmachines; i++) { - VIR_FREE(machines[i]->name); - VIR_FREE(machines[i]); - } - VIR_FREE(machines); - return -1; - } + machines)) == NULL) + goto error; + + machines = NULL; + nmachines = 0;
guest->arch.defaultInfo.emulator_mtime = binary_mtime;
if (qemudProbeCPUModels(binary, info->arch, &ncpus, NULL) == 0 && ncpus > 0 && !virCapabilitiesAddGuestFeature(guest, "cpuselection", 1, 0)) - return -1; + goto error;
if (hvm) { if (virCapabilitiesAddGuestDomain(guest, @@ -888,7 +901,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error;
if (haskqemu && virCapabilitiesAddGuestDomain(guest, @@ -897,7 +910,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error;
if (haskvm) { virCapsGuestDomainPtr dom; @@ -911,9 +924,6 @@ qemudCapsInitGuest(virCapsPtr caps, binary_mtime = 0; }
- machines = NULL; - nmachines = 0; - if (!STREQ(binary, kvmbin)) { int probe = 1; if (old_caps && binary_mtime) @@ -922,7 +932,7 @@ qemudCapsInitGuest(virCapsPtr caps, old_caps, &machines, &nmachines); if (probe && qemudProbeMachineTypes(kvmbin, &machines, &nmachines) < 0) - return -1; + goto error; }
if ((dom = virCapabilitiesAddGuestDomain(guest, @@ -931,14 +941,12 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, nmachines, machines)) == NULL) { - for (i = 0; i < nmachines; i++) { - VIR_FREE(machines[i]->name); - VIR_FREE(machines[i]); - } - VIR_FREE(machines); - return -1; + goto error; }
+ machines = NULL; + nmachines = 0; + dom->info.emulator_mtime = binary_mtime; } } else { @@ -948,7 +956,7 @@ qemudCapsInitGuest(virCapsPtr caps, NULL, 0, NULL) == NULL) - return -1; + goto error; }
if (info->nflags) { @@ -957,11 +965,24 @@ qemudCapsInitGuest(virCapsPtr caps, info->flags[i].name, info->flags[i].default_on, info->flags[i].toggle) == NULL) - return -1; + goto error; } }
+ VIR_FREE(binary); + VIR_FREE(kvmbin); + return 0; + +no_memory: + virReportOOMError(NULL); + +error: + VIR_FREE(binary); + VIR_FREE(kvmbin); + virCapabilitiesFreeMachines(machines, nmachines); + + return -1; }
@@ -1011,6 +1032,7 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { struct utsname utsname; virCapsPtr caps; int i; + char *xenner = NULL;
/* Really, this never fails - look at the man-page. */ uname (&utsname); @@ -1051,7 +1073,9 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { goto no_memory;
/* Then possibly the Xen paravirt guests (ie Xenner */ - if (access("/usr/bin/xenner", X_OK) == 0 && + xenner = virFindFileInPath("xenner"); + + if (xenner != NULL && access(xenner, X_OK) == 0 && access("/dev/kvm", F_OK) == 0) { for (i = 0 ; i < ARRAY_CARDINALITY(arch_info_xen) ; i++) /* Allow Xen 32-on-32, 32-on-64 and 64-on-64 */ @@ -1065,12 +1089,15 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { } }
+ VIR_FREE(xenner); + /* QEMU Requires an emulator in the XML */ virCapabilitiesSetEmulatorRequired(caps);
return caps;
no_memory: + VIR_FREE(xenner); virCapabilitiesFree(caps); return NULL; }
Pro: it's more flexible Cons: it's less rigid
:-)
I think it's fine since in the majority of cases that code will be run by libvirtd, which as a daemon will have a relatively well defined and contained PATH . Like when a rogue shared library si available in some common place that lead to very painful debugging when an user has a problem, rather than the rather straighforward error about a missing binary the current version. It's a bit of a double edged sword, but in that case I think it's fine. But I could see how others could disagree
ACK from my POV,
Daniel
Actually this code will never be executed outside of libvirtd, because it's executed as part of the QEMU state driver startup only. Well, I wouldn't compare this to a "rogue shared library" or LD_PRELOAD stuff, because you can use virsh capabilities for example to see if it picks up unexpected QEMU binaries. So this shouldn't make debugging harder. You need to know where to look for information when debugging, that's right. Also this make libvirt behave more like the user expects it to. There were some people on the mailing list and on IRC lately that had problems with the hardcoding of /usr/bin. They expected libvirt to pick up their QEMU binaries in /usr/local/bin for example. Matthias
On Wed, Jan 20, 2010 at 10:32:03PM +0100, Matthias Bolte wrote:
2010/1/20 Daniel Veillard <veillard@redhat.com>:
Pro: it's more flexible Cons: it's less rigid
:-)
I think it's fine since in the majority of cases that code will be run by libvirtd, which as a daemon will have a relatively well defined and contained PATH . Like when a rogue shared library si available in some common place that lead to very painful debugging when an user has a problem, rather than the rather straighforward error about a missing binary the current version. It's a bit of a double edged sword, but in that case I think it's fine. But I could see how others could disagree
ACK from my POV,
Daniel
Actually this code will never be executed outside of libvirtd, because it's executed as part of the QEMU state driver startup only.
Well, I wouldn't compare this to a "rogue shared library" or LD_PRELOAD stuff, because you can use virsh capabilities for example to see if it picks up unexpected QEMU binaries. So this shouldn't make
hum, that's true.
debugging harder. You need to know where to look for information when debugging, that's right.
Also this make libvirt behave more like the user expects it to. There were some people on the mailing list and on IRC lately that had problems with the hardcoding of /usr/bin. They expected libvirt to pick up their QEMU binaries in /usr/local/bin for example.
Okay :-) Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ daniel@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/
On Wed, Jan 20, 2010 at 02:46:10AM +0100, Matthias Bolte wrote:
@@ -792,16 +797,30 @@ qemudCapsInitGuest(virCapsPtr caps, */ if (STREQ(info->arch, hostmachine) || (STREQ(hostmachine, "x86_64") && STREQ(info->arch, "i686"))) { - const char *const kvmbins[] = { "/usr/bin/qemu-kvm", /* Fedora */ - "/usr/bin/kvm" }; /* Upstream .spec */ + if (access("/dev/kvm", F_OK) == 0) { + const char *const kvmbins[] = { "qemu-kvm", /* Fedora */ + "kvm" }; /* Upstream .spec */ + + for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { + kvmbin = virFindFileInPath(kvmbins[i]); + + if (kvmbin == NULL || access(kvmbin, X_OK) != 0) { + VIR_FREE(kvmbin); + continue; + }
- for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { - if (access(kvmbins[i], X_OK) == 0 && - access("/dev/kvm", F_OK) == 0) { haskvm = 1; - kvmbin = kvmbins[i]; - if (!binary) - binary = kvmbin; + + if (binary == NULL) { + binary = strdup(kvmbin);
Why does this need to strdup(kvmbin), when virFindFileInPath() is already returning a newly allocated string ? Seems like we could just avoid that
+ + if (binary == NULL) { + virReportOOMError(NULL); + VIR_FREE(kvmbin); + return -1; + } + } + break; }
I think this loop is also leaking 'kvmbin', since it just overrwrites 'kvmbin' on each iteration, the final cleanup code will only free the last one that was allocated
- return -1; + goto error; } }
+ VIR_FREE(binary); + VIR_FREE(kvmbin); + return 0; + +no_memory: + virReportOOMError(NULL); + +error: + VIR_FREE(binary); + VIR_FREE(kvmbin); + virCapabilitiesFreeMachines(machines, nmachines); + + return -1; }
Generally the patch looks OK though Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|
2010/1/22 Daniel P. Berrange <berrange@redhat.com>:
On Wed, Jan 20, 2010 at 02:46:10AM +0100, Matthias Bolte wrote:
@@ -792,16 +797,30 @@ qemudCapsInitGuest(virCapsPtr caps, */ if (STREQ(info->arch, hostmachine) || (STREQ(hostmachine, "x86_64") && STREQ(info->arch, "i686"))) { - const char *const kvmbins[] = { "/usr/bin/qemu-kvm", /* Fedora */ - "/usr/bin/kvm" }; /* Upstream .spec */ + if (access("/dev/kvm", F_OK) == 0) { + const char *const kvmbins[] = { "qemu-kvm", /* Fedora */ + "kvm" }; /* Upstream .spec */ + + for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { + kvmbin = virFindFileInPath(kvmbins[i]); + + if (kvmbin == NULL || access(kvmbin, X_OK) != 0) { + VIR_FREE(kvmbin); + continue; + }
- for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { - if (access(kvmbins[i], X_OK) == 0 && - access("/dev/kvm", F_OK) == 0) { haskvm = 1; - kvmbin = kvmbins[i]; - if (!binary) - binary = kvmbin; + + if (binary == NULL) { + binary = strdup(kvmbin);
Why does this need to strdup(kvmbin), when virFindFileInPath() is already returning a newly allocated string ? Seems like we could just avoid that
The common case is binary pointing to a QEMU binary and if KVM could be used and is available kvmbin points to a KVM enabled QEMU binary. So the paths a different in the common case. In the cleanup section both strings need to be freed. The special case is if binary is NULL but we find a KVM binary, then binary is strdup'ed from kvmbin. Before this patch binary and kvmbin were stack allocated and binary = kvmbin was okay. Now binary = kvmbin would result in a double free with VIR_FREE(binary); VIR_FREE(kvmbin); But you're right, I just thought about it and binary = strdup(kvmbin); could be changed back to binary = kvmbin; and the cleanup code could be changed to if (binary == kvmbin) { /* don't double free */ VIR_FREE(binary); } else { VIR_FREE(binary); VIR_FREE(kvmbin); } to avoid a double free.
+ + if (binary == NULL) { + virReportOOMError(NULL); + VIR_FREE(kvmbin); + return -1; + } + } + break; }
I think this loop is also leaking 'kvmbin', since it just overrwrites 'kvmbin' on each iteration, the final cleanup code will only free the last one that was allocated
No leak here. The for loop can be left at 3 points: - continue; if binary not found or not executable - return -1; on OOM error - break; on success In both negative cases kvmbin is freed.
- return -1; + goto error; } }
+ VIR_FREE(binary); + VIR_FREE(kvmbin); + return 0; + +no_memory: + virReportOOMError(NULL); + +error: + VIR_FREE(binary); + VIR_FREE(kvmbin); + virCapabilitiesFreeMachines(machines, nmachines); + + return -1; }
Generally the patch looks OK though
Daniel
Version 2 of the patch is attached. Matthias
2010/1/22 Matthias Bolte <matthias.bolte@googlemail.com>:
2010/1/22 Daniel P. Berrange <berrange@redhat.com>:
On Wed, Jan 20, 2010 at 02:46:10AM +0100, Matthias Bolte wrote:
@@ -792,16 +797,30 @@ qemudCapsInitGuest(virCapsPtr caps, */ if (STREQ(info->arch, hostmachine) || (STREQ(hostmachine, "x86_64") && STREQ(info->arch, "i686"))) { - const char *const kvmbins[] = { "/usr/bin/qemu-kvm", /* Fedora */ - "/usr/bin/kvm" }; /* Upstream .spec */ + if (access("/dev/kvm", F_OK) == 0) { + const char *const kvmbins[] = { "qemu-kvm", /* Fedora */ + "kvm" }; /* Upstream .spec */ + + for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { + kvmbin = virFindFileInPath(kvmbins[i]); + + if (kvmbin == NULL || access(kvmbin, X_OK) != 0) { + VIR_FREE(kvmbin); + continue; + }
- for (i = 0; i < ARRAY_CARDINALITY(kvmbins); ++i) { - if (access(kvmbins[i], X_OK) == 0 && - access("/dev/kvm", F_OK) == 0) { haskvm = 1; - kvmbin = kvmbins[i]; - if (!binary) - binary = kvmbin; + + if (binary == NULL) { + binary = strdup(kvmbin);
Why does this need to strdup(kvmbin), when virFindFileInPath() is already returning a newly allocated string ? Seems like we could just avoid that
The common case is binary pointing to a QEMU binary and if KVM could be used and is available kvmbin points to a KVM enabled QEMU binary. So the paths a different in the common case. In the cleanup section both strings need to be freed.
The special case is if binary is NULL but we find a KVM binary, then binary is strdup'ed from kvmbin. Before this patch binary and kvmbin were stack allocated and binary = kvmbin was okay. Now binary = kvmbin would result in a double free with
VIR_FREE(binary); VIR_FREE(kvmbin);
But you're right, I just thought about it and
binary = strdup(kvmbin);
could be changed back to
binary = kvmbin;
and the cleanup code could be changed to
if (binary == kvmbin) { /* don't double free */ VIR_FREE(binary); } else { VIR_FREE(binary); VIR_FREE(kvmbin); }
to avoid a double free.
+ + if (binary == NULL) { + virReportOOMError(NULL); + VIR_FREE(kvmbin); + return -1; + } + } + break; }
I think this loop is also leaking 'kvmbin', since it just overrwrites 'kvmbin' on each iteration, the final cleanup code will only free the last one that was allocated
No leak here. The for loop can be left at 3 points:
- continue; if binary not found or not executable - return -1; on OOM error - break; on success
In both negative cases kvmbin is freed.
- return -1; + goto error; } }
+ VIR_FREE(binary); + VIR_FREE(kvmbin); + return 0; + +no_memory: + virReportOOMError(NULL); + +error: + VIR_FREE(binary); + VIR_FREE(kvmbin); + virCapabilitiesFreeMachines(machines, nmachines); + + return -1; }
Generally the patch looks OK though
Daniel
Version 2 of the patch is attached.
Matthias
Okay, pushed version 2. Matthias
participants (3)
-
Daniel P. Berrange -
Daniel Veillard -
Matthias Bolte