Re: [PATCH v2 3/4] virhostcpu: Introduce virHostCPUGetIsolated()

This is a helper that parses /sys/devices/system/cpu/isolated into a virBitmap. It's going to be needed soon. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/libvirt_private.syms | 1 + src/util/virhostcpu.c | 31 +++++++++++++++++++++++++++++++ src/util/virhostcpu.h | 1 + 3 files changed, 33 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 2c7e4b45d3..0f2d5db883 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -2504,6 +2504,7 @@ virHostCPUGetCount; virHostCPUGetCPUID; virHostCPUGetHaltPollTime; virHostCPUGetInfo; +virHostCPUGetIsolated; virHostCPUGetKVMMaxVCPUs; virHostCPUGetMap; virHostCPUGetMicrocodeVersion; diff --git a/src/util/virhostcpu.c b/src/util/virhostcpu.c index 01de69c0d1..b6d1db2302 100644 --- a/src/util/virhostcpu.c +++ b/src/util/virhostcpu.c @@ -1152,6 +1152,37 @@ virHostCPUGetAvailableCPUsBitmap(void) } +/** + * virHostCPUGetIsolated: + * @isolated: returned bitmap of isolated CPUs + * + * Sets @isolated to point to a bitmap of isolated CPUs (e.g. those passed to + * isolcpus= kernel cmdline). If the file doesn't exist, @isolated is set to + * NULL and success is returned. If the file does exist but it's empty, + * @isolated is set to an empty bitmap an success is returned.

+ * + * Returns: 0 on success, + * -1 otherwise (with error reported). + */ +int +virHostCPUGetIsolated(virBitmap **isolated) +{ + g_autoptr(virBitmap) bitmap = NULL; + int rc; + + rc = virFileReadValueBitmapAllowEmpty(&bitmap, "%s/cpu/isolated", SYSFS_SYSTEM_PATH); + if (rc == -2) { + *isolated = NULL; + return 0; + } else if (rc < 0) { + return -1; + } + + *isolated = g_steal_pointer(&bitmap); + return 0; +}