Re: [libvirt] [PATCHv3 2/6] qemu: Add monitor APIs to fetch CPUID data from QEMU

From: Jiri Denemark <jdenemar(a)redhat.com&gt; The qemu monitor supports retrieval of actual CPUID bits presented to the guest using QMP monitor. Add APIs to extract these information and tests for them. Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- Notes: Version 3: - removed unneeded error state - fixed typo in error message Version 2: - unified global and JSON monitor func signatures - changed return values so that errors can be differenitated from lack of support - code is conditionally run only when architecture matches src/qemu/qemu_monitor.c | 31 +++++ src/qemu/qemu_monitor.h | 4 + src/qemu/qemu_monitor_json.c | 133 +++++++++++++++++++++ src/qemu/qemu_monitor_json.h | 2 + tests/Makefile.am | 1 + .../qemumonitorjson-getcpu-full.data | 5 + .../qemumonitorjson-getcpu-full.json | 46 +++++++ .../qemumonitorjson-getcpu-host.data | 6 + .../qemumonitorjson-getcpu-host.json | 45 +++++++ tests/qemumonitorjsontest.c | 75 ++++++++++++ 10 files changed, 348 insertions(+) create mode 100644 tests/qemumonitorjsondata/qemumonitorjson-getcpu-full.data create mode 100644 tests/qemumonitorjsondata/qemumonitorjson-getcpu-full.json create mode 100644 tests/qemumonitorjsondata/qemumonitorjson-getcpu-host.data create mode 100644 tests/qemumonitorjsondata/qemumonitorjson-getcpu-host.json diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 2bafe28..e865808 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -3926,3 +3926,34 @@ qemuMonitorSetDomainLog(qemuMonitorPtr mon, int logfd) return 0; } + + +/** + * qemuMonitorJSONGetGuestCPU: + * @mon: Pointer to the monitor + * @arch: arch of the guest + * + * Retrieve the definition of the guest CPU from a running qemu instance. + * + * Returns the cpu definition object. On error returns NULL. + */ +virCPUDataPtr +qemuMonitorGetGuestCPU(qemuMonitorPtr mon, + virArch arch) +{ + VIR_DEBUG("mon=%p, arch='%s'", mon, virArchToString(arch)); + + if (!mon) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("monitor must not be NULL")); + return NULL; + } + + if (!mon->json) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", + _("JSON monitor is required")); + return NULL; + } + + return qemuMonitorJSONGetGuestCPU(mon, arch); +} diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 06ba7e8..ecc6d7b 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -32,6 +32,7 @@ # include "virhash.h" # include "virjson.h" # include "device_conf.h" +# include "cpu/cpu.h" typedef struct _qemuMonitor qemuMonitor; typedef qemuMonitor *qemuMonitorPtr; @@ -763,6 +764,9 @@ int qemuMonitorGetDeviceAliases(qemuMonitorPtr mon, int qemuMonitorSetDomainLog(qemuMonitorPtr mon, int logfd); +virCPUDataPtr qemuMonitorGetGuestCPU(qemuMonitorPtr mon, + virArch arch); + /** * When running two dd process and using <> redirection, we need a * shell that will not truncate files. These two strings serve that diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 05f8aa6..e738fe3 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -42,6 +42,7 @@ #include "virerror.h" #include "virjson.h" #include "virstring.h" +#include "cpu/cpu_x86.h" #ifdef WITH_DTRACE_PROBES # include "libvirt_qemu_probes.h" @@ -49,6 +50,7 @@ #define VIR_FROM_THIS VIR_FROM_QEMU +#define QOM_CPU_PATH "/machine/unattached/device[0]" #define LINE_ENDING "\r\n" @@ -5454,3 +5456,134 @@ cleanup: VIR_FREE(paths); return ret; } + + +static int +qemuMonitorJSONParseCPUx86FeatureWord(virJSONValuePtr data, + virCPUx86CPUID *cpuid) +{ + const char *reg; + unsigned long long fun; + unsigned long long features; + + memset(cpuid, 0, sizeof(*cpuid)); + + if (!(reg = virJSONValueObjectGetString(data, "cpuid-register"))) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("missing cpuid-register in CPU data")); + return -1; + } + if (virJSONValueObjectGetNumberUlong(data, "cpuid-input-eax", &fun)) {

+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("missing or invalid cpuid-input-eax in CPU data")); + return -1; + } + if (virJSONValueObjectGetNumberUlong(data, "features", &features) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("missing or invalid features in CPU data")); + return -1; + }