[PATCH 5/5] cpu: Introduce getHost supoort for ARM
Zhenyu Zheng
zhengzhenyulixi at gmail.com
Mon Mar 30 11:32:36 UTC 2020
Hi Daniel,
Thanks for thre review and reply, my first implementation was going to
gather data from /proc/cpuinfo, but unlike X86, we can only get this kind
of info:
processor : 0
BogoMIPS : 200.00
Features : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x43
CPU architecture: 8
CPU variant : 0x1
CPU part : 0x0a1
CPU revision : 1
so we have to perform some translation to perform human readable
information, and I mentioned that 'lscpu' has done that too. So Andrea
Bolognani
suggested that maybe we can use it directly, to avoid re-implement the
translation. Here is the discussion:
https://www.redhat.com/archives/libvir-list/2020-March/msg00812.html
BR,
Zhenyu
On Mon, Mar 30, 2020 at 7:27 PM Daniel P. Berrangé <berrange at redhat.com>
wrote:
> On Fri, Mar 27, 2020 at 04:52:25PM +0800, Zhenyu Zheng wrote:
> > Introduce getHost support for ARM, use data from 'lscpu' cmd
> > result. 'util-linux/lscpu' provided a very good translation of
> > ARM cpu data start from release v2.32, use it directly to avoid
> > re-implement the translation.
>
> I'm a bit wary of this approach, because parsing the output of
> command line tools is generally fragile / liable to break in
> future releases, since few tools guarantee that their output
> format is stable for machine parsing.
>
> How hard would it be to probe this directly in libvirt, as we
> do on x86 arch.
>
> >
> > Signed-of-by: Zhenyu Zheng <zhengzhenyulixi at gmail.com>
> > ---
> > src/cpu/cpu_arm.c | 198 +++++++++++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 197 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/cpu/cpu_arm.c b/src/cpu/cpu_arm.c
> > index 969025b5cf..30d9c0ae2e 100644
> > --- a/src/cpu/cpu_arm.c
> > +++ b/src/cpu/cpu_arm.c
> > @@ -22,8 +22,11 @@
> > #include <config.h>
> >
> > #include "viralloc.h"
> > +#include "virlog.h"
> > #include "cpu.h"
> > #include "cpu_map.h"
> > +#include "vircommand.h"
> > +#include "virfile.h"
> > #include "virstring.h"
> > #include "virxml.h"
> > #include "cpu_map.h"
> > @@ -31,6 +34,14 @@
> >
> > #define VIR_FROM_THIS VIR_FROM_CPU
> >
> > +VIR_LOG_INIT("cpu.cpu_arm");
> > +
> > +static const char *lsCpuPath = "/usr/bin/lscpu";
> > +
> > +#define LSCPU lsCpuPath
> > +#define MAX_LSCPU_SIZE = (1024*1024) /* 1MB limit for lscpu output */
> > +
> > +
> > static const virArch archs[] = {
> > VIR_ARCH_ARMV6L,
> > VIR_ARCH_ARMV7B,
> > @@ -464,13 +475,198 @@ virCPUarmValidateFeatures(virCPUDefPtr cpu)
> > return 0;
> > }
> >
> > +static int
> > +armCpuDataFromLsCpu(virCPUarmData *data)
> > +{
> > + int ret = -1;
> > + char *outbuf = NULL;
> > + char *eol = NULL;
> > + const char *cur;
> > + virCommandPtr cmd = NULL;
> > + g_autofree char *lscpu = NULL;
> > +
> > + if (!data)
> > + return ret;
> > +
> > + lscpu = virFindFileInPath("lscpu");
> > + cmd = virCommandNew(lscpu);
> > + virCommandSetOutputBuffer(cmd, &outbuf);
> > +
> > + if (virCommandRun(cmd, NULL) < 0)
> > + goto cleanup;
> > +
> > + if ((cur = strstr(outbuf, "Vendor ID")) == NULL) {
> > + virReportError(VIR_ERR_INTERNAL_ERROR,
> > + _("there is no \"Vendor ID\" info in %s command
> result"), LSCPU);
> > + goto cleanup;
> > + }
> > + cur = strchr(cur, ':') + 1;
> > + eol = strchr(cur, '\n');
> > + virSkipSpaces(&cur);
> > + if (!eol)
> > + goto cleanup;
> > +
> > + data->vendor_id = g_strndup(cur, eol - cur);
> > +
> > + if ((cur = strstr(outbuf, "Model name")) == NULL) {
> > + virReportError(VIR_ERR_INTERNAL_ERROR,
> > + _("there is no \"Model name\" info in %s command
> result"), LSCPU);
> > + goto cleanup;
> > + }
> > + cur = strchr(cur, ':') + 1;
> > + eol = strchr(cur, '\n');
> > + virSkipSpaces(&cur);
> > + if (!eol)
> > + goto cleanup;
> > +
> > + data->model_name = g_strndup(cur, eol - cur);
> > +
> > + if ((cur = strstr(outbuf, "Flags")) == NULL) {
> > + virReportError(VIR_ERR_INTERNAL_ERROR,
> > + _("there is no \"Flags\" info in %s command
> result"), LSCPU);
> > + goto cleanup;
> > + }
> > + cur = strchr(cur, ':') + 1;
> > + eol = strchr(cur, '\n');
> > + virSkipSpaces(&cur);
> > + if (!eol)
> > + goto cleanup;
> > +
> > + data->features = g_strndup(cur, eol - cur);
> > +
> > + ret = 0;
> > +
> > + cleanup:
> > + virCommandFree(cmd);
> > + VIR_FREE(outbuf);
> > + return ret;
> > +}
> > +
> > +static int
> > +armCpuDataParseFeatures(virCPUDefPtr cpu,
> > + const virCPUarmData *cpuData)
> > +{
> > + int ret = -1;
> > + size_t i;
> > + char **features;
> > +
> > + if (!cpu || !cpuData)
> > + return ret;
> > +
> > + if (!(features = virStringSplitCount(cpuData->features, " ",
> > + 0, &cpu->nfeatures)))
> > + return ret;
> > + if (cpu->nfeatures) {
> > + if (VIR_ALLOC_N(cpu->features, cpu->nfeatures) < 0)
> > + goto error;
> > +
> > + for (i = 0; i < cpu->nfeatures; i++) {
> > + cpu->features[i].policy = VIR_CPU_FEATURE_REQUIRE;
> > + cpu->features[i].name = g_strdup(features[i]);
> > + }
> > + }
> > +
> > + ret = 0;
> > +
> > + cleanup:
> > + virStringListFree(features);
> > + return ret;
> > +
> > + error:
> > + for (i = 0; i < cpu->nfeatures; i++)
> > + VIR_FREE(cpu->features[i].name);
> > + VIR_FREE(cpu->features);
> > + cpu->nfeatures = 0;
> > + goto cleanup;
> > +}
> > +
> > +static int
> > +armDecode(virCPUDefPtr cpu,
> > + const virCPUarmData *cpuData,
> > + virDomainCapsCPUModelsPtr models)
> > +{
> > + virCPUarmMapPtr map;
> > + virCPUarmModelPtr model;
> > + virCPUarmVendorPtr vendor = NULL;
> > +
> > + if (!cpuData || !(map = virCPUarmGetMap()))
> > + return -1;
> > +
> > + if (!(model = armModelFind(map, cpuData->model_name))) {
> > + virReportError(VIR_ERR_OPERATION_FAILED,
> > + _("Cannot find CPU model with name %s"),
> > + cpuData->model_name);
> > + return -1;
> > + }
> > +
> > + if (!virCPUModelIsAllowed(model->name, models)) {
> > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> > + _("CPU model %s is not supported by hypervisor"),
> > + model->name);
> > + return -1;
> > + }
> > +
> > + cpu->model = g_strdup(model->name);
> > +
> > + if (cpuData->vendor_id &&
> > + !(vendor = armVendorFindByName(map, cpuData->vendor_id))) {
> > + virReportError(VIR_ERR_OPERATION_FAILED,
> > + _("Cannot find CPU vendor with vendor id %s"),
> > + cpuData->vendor_id);
> > + return -1;
> > + }
> > +
> > +
> > + if (vendor)
> > + cpu->vendor = g_strdup(vendor->name);
> > +
> > + if (cpuData->features &&
> > + armCpuDataParseFeatures(cpu, cpuData) < 0)
> > + return -1;
> > +
> > + return 0;
> > +}
> > +
> > +static int
> > +armDecodeCPUData(virCPUDefPtr cpu,
> > + const virCPUData *data,
> > + virDomainCapsCPUModelsPtr models)
> > +{
> > + return armDecode(cpu, &data->data.arm, models);
> > +}
> > +
> > +static int
> > +virCPUarmGetHost(virCPUDefPtr cpu,
> > + virDomainCapsCPUModelsPtr models)
> > +{
> > + virCPUDataPtr cpuData = NULL;
> > + int ret = -1;
> > +
> > + if (virCPUarmDriverInitialize() < 0)
> > + goto cleanup;
> > +
> > + if (!(cpuData = virCPUDataNew(archs[0])))
> > + goto cleanup;
> > +
> > + if (armCpuDataFromLsCpu(&cpuData->data.arm) < 0)
> > + goto cleanup;
> > +
> > + ret = armDecodeCPUData(cpu, cpuData, models);
> > +
> > + cleanup:
> > + virCPUarmDataFree(cpuData);
> > + return ret;
> > +}
> > +
> > struct cpuArchDriver cpuDriverArm = {
> > .name = "arm",
> > .arch = archs,
> > .narch = G_N_ELEMENTS(archs),
> > .compare = virCPUarmCompare,
> > - .decode = NULL,
> > + .decode = armDecodeCPUData,
> > .encode = NULL,
> > + .dataFree = virCPUarmDataFree,
> > + .getHost = virCPUarmGetHost,
> > .baseline = virCPUarmBaseline,
> > .update = virCPUarmUpdate,
> > .validateFeatures = virCPUarmValidateFeatures,
> > --
> > 2.26.0.windows.1
> >
> >
>
> Regards,
> Daniel
> --
> |: https://berrange.com -o-
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> |: https://libvirt.org -o-
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>
>
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