On Thu, Apr 09, 2020 at 11:28:04 +0100, Daniel P. Berrangé wrote:
On Thu, Apr 02, 2020 at 05:03:59PM +0800, Zhenyu Zheng wrote:
Introduce getHost support for ARM CPU driver, read CPU vendor_id, part_id and flags from registers directly.
Signed-off-by: Zhenyu Zheng <zhengzhenyulixi@gmail.com> --- src/cpu/cpu_arm.c | 194 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 193 insertions(+), 1 deletion(-)
diff --git a/src/cpu/cpu_arm.c b/src/cpu/cpu_arm.c index 88b4d91946..c8f5ce7e8a 100644 --- a/src/cpu/cpu_arm.c +++ b/src/cpu/cpu_arm.c @@ -21,6 +21,8 @@ */
#include <config.h> +#include <asm/hwcap.h> +#include <sys/auxv.h>
#include "viralloc.h" #include "cpu.h" @@ -31,6 +33,10 @@ #include "virxml.h"
#define VIR_FROM_THIS VIR_FROM_CPU +/* 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
VIR_LOG_INIT("cpu.cpu_arm");
@@ -498,14 +504,200 @@ virCPUarmValidateFeatures(virCPUDefPtr cpu) return 0; }
+/** + * armCpuDataFromRegs: + * + * @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 +armCpuDataFromRegs(virCPUarmData *data)
virCPUarmDataFromRegs()
+{ + /* 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; + char *cpu_feature_str = NULL;
g_autofree
+ 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; + }
Indent messed up here
+ + /* 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++; + } + }
Indent of } messed up again.
+ + if (cpu_feature_index > 1) { + cpu_feature_str = virStringListJoin((const char **)features, " "); + if (!cpu_feature_str) + goto cleanup; + } + data->features = g_strdup(cpu_feature_str); + + return 0; + + cleanup:
This should be called "error", since this label is only visited for fatal errors.
+ virStringListFree(features); + VIR_FREE(cpu_feature_str);
Can avoid the VIR_FREE with g_autofree.
virStringListFree can be avoided too if features is declared with VIR_AUTOSTRINGLIST. Jirka