Re: [Xen-devel] [PATCH v5 15/15] tools/xen-access: altp2m testcases

["Lengyel, Tamas" <tlengyel@xxxxxxxxxxx>]

On Tue, Jul 14, 2015 at 5:56 AM, Wei Liu <wei.liu2@xxxxxxxxxx> wrote:

On Mon, Jul 13, 2015 at 05:15:03PM -0700, Ed White wrote:
> From: Tamas K Lengyel <tlengyel@xxxxxxxxxxx>
>
> Working altp2m test-case. Extended the test tool to support singlestepping
> to better highlight the core feature of altp2m view switching.
>
> Signed-off-by: Tamas K Lengyel <tlengyel@xxxxxxxxxxx>
> Signed-off-by: Ed White <edmund.h.white@xxxxxxxxx>
>
> Reviewed-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>

Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>

Some nits below.

I do notice there is inconsistency in coding style, so I won't ask you
to resubmit just for fixing style. But a follow-up patch to fix up all
style problem is welcome.

> ---
>  tools/tests/xen-access/xen-access.c | 173 ++++++++++++++++++++++++++++++------
>  1 file changed, 148 insertions(+), 25 deletions(-)
>
> diff --git a/tools/tests/xen-access/xen-access.c b/tools/tests/xen-access/xen-access.c
> index 12ab921..6b69c26 100644
> --- a/tools/tests/xen-access/xen-access.c
> +++ b/tools/tests/xen-access/xen-access.c
> @@ -275,6 +275,19 @@ xenaccess_t *xenaccess_init(xc_interface **xch_r, domid_t domain_id)
>      return NULL;
>  }
>
> +static inline
> +int control_singlestep(
> +    xc_interface *xch,
> +    domid_t domain_id,
> +    unsigned long vcpu,
> +    bool enable)
> +{
> +    uint32_t op = enable ?
> +        XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_ON : XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_OFF;
> +
> +    return xc_domain_debug_control(xch, domain_id, op, vcpu);
> +}
> +
>  /*
>   * Note that this function is not thread safe.
>   */
> @@ -317,13 +330,15 @@ static void put_response(vm_event_t *vm_event, vm_event_response_t *rsp)
>
>  void usage(char* progname)
>  {
> -    fprintf(stderr,
> -            "Usage: %s [-m] <domain_id> write|exec|breakpoint\n"
> +    fprintf(stderr, "Usage: %s [-m] <domain_id> write|exec", progname);
> +#if defined(__i386__) || defined(__x86_64__)
> +            fprintf(stderr, "|breakpoint|altp2m_write|altp2m_exec");
> +#endif
> +            fprintf(stderr,
>              "\n"
>              "Logs first page writes, execs, or breakpoint traps that occur on the domain.\n"
>              "\n"
> -            "-m requires this program to run, or else the domain may pause\n",
> -            progname);
> +            "-m requires this program to run, or else the domain may pause\n");

Indentation looks wrong, but this is not your fault so don't worry
about this.

>  }
>
>  int main(int argc, char *argv[])
> @@ -341,6 +356,8 @@ int main(int argc, char *argv[])
>      int required = 0;
>      int breakpoint = 0;
>      int shutting_down = 0;
> +    int altp2m = 0;
> +    uint16_t altp2m_view_id = 0;
>
>      char* progname = argv[0];
>      argv++;
> @@ -379,10 +396,22 @@ int main(int argc, char *argv[])
>          default_access = XENMEM_access_rw;
>          after_first_access = XENMEM_access_rwx;
>      }
> +#if defined(__i386__) || defined(__x86_64__)
>      else if ( !strcmp(argv[0], "breakpoint") )
>      {
>          breakpoint = 1;
>      }
> +    else if ( !strcmp(argv[0], "altp2m_write") )
> +    {
> +        default_access = XENMEM_access_rx;
> +        altp2m = 1;
> +    }
> +    else if ( !strcmp(argv[0], "altp2m_exec") )
> +    {
> +        default_access = XENMEM_access_rw;
> +        altp2m = 1;
> +    }
> +#endif
>      else
>      {
>          usage(argv[0]);
> @@ -415,22 +444,73 @@ int main(int argc, char *argv[])
>          goto exit;
>      }
>
> -    /* Set the default access type and convert all pages to it */
> -    rc = xc_set_mem_access(xch, domain_id, default_access, ~0ull, 0);
> -    if ( rc < 0 )
> +    /* With altp2m we just create a new, restricted view of the memory */
> +    if ( altp2m )
>      {
> -        ERROR("Error %d setting default mem access type\n", rc);
> -        goto exit;
> -    }
> +        xen_pfn_t gfn = 0;
> +        unsigned long perm_set = 0;
> +
> +        rc = xc_altp2m_set_domain_state( xch, domain_id, 1 );

Extraneous spaces in brackets.

> +        if ( rc < 0 )
> +        {
> +            ERROR("Error %d enabling altp2m on domain!\n", rc);
> +            goto exit;
> +        }
> +
> +        rc = xc_altp2m_create_view( xch, domain_id, default_access, &altp2m_view_id );

Extraneous spaces and line too long.

> +        if ( rc < 0 )
> +        {
> +            ERROR("Error %d creating altp2m view!\n", rc);
> +            goto exit;
> +        }
>
> -    rc = xc_set_mem_access(xch, domain_id, default_access, START_PFN,
> -                           (xenaccess->max_gpfn - START_PFN) );
> +        DPRINTF("altp2m view created with id %u\n", altp2m_view_id);
> +        DPRINTF("Setting altp2m mem_access permissions.. ");
>
> -    if ( rc < 0 )
> +        for(; gfn < xenaccess->max_gpfn; ++gfn)
> +        {
> +            rc = xc_altp2m_set_mem_access( xch, domain_id, altp2m_view_id, gfn,
> +                                           default_access);

Space.

> +            if ( !rc )
> +                perm_set++;
> +        }
> +
> +        DPRINTF("done! Permissions set on %lu pages.\n", perm_set);
> +
> +        rc = xc_altp2m_switch_to_view( xch, domain_id, altp2m_view_id );

Ditto.

The rest of code has similar issues too. I won't point them out one by
one. Again, don't worry about this now.

Wei.

Thanks Wei! I'll submit a patch to fix the style issues after (and if) this gets merged!

Tamas

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