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@xxxxxxxxx>
> > ---
> > 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
