Re: [PATCH V4 4/5] cpu: Introduce getHost support for ARM CPU driver

Introduce getHost support for ARM CPU driver, read CPU vendor_id, part_id and flags from registers directly. These codes will only be compiled on aarch64 hardwares. Signed-off-by: Zhenyu Zheng <zhengzhenyulixi(a)gmail.com&gt; --- src/cpu/cpu_arm.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) diff --git a/src/cpu/cpu_arm.c b/src/cpu/cpu_arm.c index 24404eac2c..887932cc5a 100644 --- a/src/cpu/cpu_arm.c +++ b/src/cpu/cpu_arm.c @@ -21,6 +21,10 @@ */ #include <config.h> +#if defined(__aarch64__) +# include <asm/hwcap.h> +# include <sys/auxv.h> +#endif #include "viralloc.h" #include "cpu.h" @@ -31,6 +35,12 @@ #include "virxml.h" #define VIR_FROM_THIS VIR_FROM_CPU +#if defined(__aarch64__) +/* Shift bit mask for parsing cpu flags */ +# define BIT_SHIFTS(n) (1UL << (n)) +/* The current max number of cpu flags on ARM is 32 */ +# define MAX_CPU_FLAGS 32 +#endif VIR_LOG_INIT("cpu.cpu_arm"); @@ -495,12 +505,203 @@ virCPUarmValidateFeatures(virCPUDefPtr cpu) return 0; } +#if defined(__aarch64__) +/** + * virCPUarmCpuDataFromRegs: + * + * @data: 64-bit arm CPU specific data + * + * Fetches CPU vendor_id and part_id from MIDR_EL1 register, parse CPU + * flags from AT_HWCAP. There are currently 32 valid flags on ARM arch + * represented by each bit. + */ +static int +virCPUarmCpuDataFromRegs(virCPUarmData *data) +{ + /* Generate human readable flag list according to the order of */ + /* AT_HWCAP bit map */ + const char *flag_list[MAX_CPU_FLAGS] = { + "fp", "asimd", "evtstrm", "aes", "pmull", "sha1", "sha2", + "crc32", "atomics", "fphp", "asimdhp", "cpuid", "asimdrdm", + "jscvt", "fcma", "lrcpc", "dcpop", "sha3", "sm3", "sm4", + "asimddp", "sha512", "sve", "asimdfhm", "dit", "uscat", + "ilrcpc", "flagm", "ssbs", "sb", "paca", "pacg"}; + unsigned long cpuid, hwcaps; + char **features = NULL; + g_autofree char *cpu_feature_str = NULL; + int cpu_feature_index = 0; + size_t i; + + if (!(getauxval(AT_HWCAP) & HWCAP_CPUID)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("CPUID registers unavailable")); + return -1; + } + + /* read the cpuid data from MIDR_EL1 register */ + asm("mrs %0, MIDR_EL1" : "=r" (cpuid)); + VIR_DEBUG("CPUID read from register: 0x%016lx", cpuid); + + /* parse the coresponding part_id bits */ + data->pvr = cpuid>>4&0xFFF; + /* parse the coresponding vendor_id bits */ + data->vendor_id = cpuid>>24&0xFF; + + hwcaps = getauxval(AT_HWCAP); + VIR_DEBUG("CPU flags read from register: 0x%016lx", hwcaps); + + if (VIR_ALLOC_N(features, MAX_CPU_FLAGS) < 0) + return -1; + + /* shift bit map mask to parse for CPU flags */ + for (i = 0; i< MAX_CPU_FLAGS; i++) { + if (hwcaps & BIT_SHIFTS(i)) { + features[cpu_feature_index] = g_strdup(flag_list[i]); + cpu_feature_index++; + } + } + + if (cpu_feature_index > 1) { + cpu_feature_str = virStringListJoin((const char **)features, " "); + if (!cpu_feature_str) + goto error; + } + data->features = g_strdup(cpu_feature_str); + + return 0; + + error: + virStringListFree(features); + return -1; +} + +static int +virCPUarmDataParseFeatures(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 +virCPUarmDecode(virCPUDefPtr cpu, + const virCPUarmData *cpuData, + virDomainCapsCPUModelsPtr models) +{ + virCPUarmMapPtr map; + virCPUarmModelPtr model; + virCPUarmVendorPtr vendor = NULL; + + if (!cpuData || !(map = virCPUarmGetMap())) + return -1; + + if (!(model = virCPUarmModelFindByPVR(map, cpuData->pvr))) { + virReportError(VIR_ERR_OPERATION_FAILED, + _("Cannot find CPU model with PVR 0x%03lx"), + cpuData->pvr); + 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 = virCPUarmVendorFindByID(map, cpuData->vendor_id))) { + virReportError(VIR_ERR_OPERATION_FAILED, + _("Cannot find CPU vendor with vendor id 0x%02lx"), + cpuData->vendor_id); + return -1; + } + + if (vendor) + cpu->vendor = g_strdup(vendor->name); + + if (cpuData->features && + virCPUarmDataParseFeatures(cpu, cpuData) < 0) + return -1; + + return 0; +} + +static int +virCPUarmDecodeCPUData(virCPUDefPtr cpu, + const virCPUData *data, + virDomainCapsCPUModelsPtr models) +{ + return virCPUarmDecode(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 (virCPUarmCpuDataFromRegs(&cpuData->data.arm) < 0) + goto cleanup; + + ret = virCPUarmDecodeCPUData(cpu, cpuData, models); + + cleanup: + virCPUarmDataFree(cpuData); + return ret; +} +#endif + struct cpuArchDriver cpuDriverArm = { .name = "arm", .arch = archs, .narch = G_N_ELEMENTS(archs), .compare = virCPUarmCompare, +#if defined(__aarch64__) + .getHost = virCPUarmGetHost, + .decode = virCPUarmDecodeCPUData, +#else .decode = NULL, +#endif .encode = NULL, .dataFree = virCPUarmDataFree, .baseline = virCPUarmBaseline, -- 2.26.2