On 23.12.2020 17:34, Andrew Cooper wrote:
> --- /dev/null
> +++ b/tools/misc/xen-fault-ttl.c
> @@ -0,0 +1,56 @@
> +#include <stdio.h>
> +#include <err.h>
> +#include <string.h>
> +#include <errno.h>
> +
> +#include <xenctrl.h>
> +
> +int main(int argc, char **argv)
> +{
> + int rc;
> + xc_interface *xch = xc_interface_open(NULL, NULL, 0);
> +
> + if ( !xch )
> + err(1, "xc_interface_open");
> +
> + struct xen_domctl_createdomain create = {
> + .fault_ttl = 1,
> + .flags = (XEN_DOMCTL_CDF_hvm |
> + XEN_DOMCTL_CDF_hap),
> + .max_vcpus = 1,
> + .max_evtchn_port = -1,
> + .max_grant_frames = 64,
> + .max_maptrack_frames = 1024,
> + .arch = {
> + .emulation_flags = XEN_X86_EMU_LAPIC,
> + },
> + };
> + uint32_t domid = 0;
> +
> + for ( rc = 1; rc && errno == ENOMEM; create.fault_ttl++ )
> + rc = xc_domain_create(xch, &domid, &create);
The very first time you get here, how does errno end up being
set to ENOMEM? To me
do {
create.fault_ttl++;
rc = xc_domain_create(xch, &domid, &create);
} while ( rc && errno == ENOMEM );
would seem more natural (and also avoid the somewhat odd
"rc = 1").
Jan
