libxc: introduce xc_domain_get_guest_width()

As a wrapper to XEN_DOMCTL_get_address_size, and use it
wherever the call was being issued directly via do_domctl(),
saving quite some line of code.

Actually, the function returns the guest width in bytes,
rather than directly what XEN_DOMCTL_get_address_size provides
(which is a number of bits), since that is what it is useful
almost everywhere.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
index fa47787d3e..bbbf9b80eb 100644
--- a/tools/libxc/xc_cpuid_x86.c
+++ b/tools/libxc/xc_cpuid_x86.c
@@ -436,17 +436,15 @@ static void xc_cpuid_pv_policy(
     const unsigned int *input, unsigned int *regs)
 {
     DECLARE_DOMCTL;
+    unsigned int guest_width;
     int guest_64bit, xen_64bit = hypervisor_is_64bit(xch);
     char brand[13];
     uint64_t xfeature_mask;
 
     xc_cpuid_brand_get(brand);
 
-    memset(&domctl, 0, sizeof(domctl));
-    domctl.domain = domid;
-    domctl.cmd = XEN_DOMCTL_get_address_size;
-    do_domctl(xch, &domctl);
-    guest_64bit = (domctl.u.address_size.size == 64);
+    xc_domain_get_guest_width(xch, domid, &guest_width);
+    guest_64bit = (guest_width == 8);
 
     /* Detecting Xen's atitude towards XSAVE */
     memset(&domctl, 0, sizeof(domctl));