[PATCH v3 3/3] tools/xen-ucode: print information about currently loaded ucode

[Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>]

Add an option to xen-ucode tool to print the currently loaded ucode
version and also print it during usage info.  Print CPU signature and
processor flags as well.  The raw data comes from XENPF_get_cpu_version
and XENPF_get_ucode_version platform ops.

Example output:
    Intel:
    Current CPU signature is: 06-55-04 (raw 0x50654)
    Current CPU microcode revision is: 0x2006e05
    Current CPU processor flags are: 0x1

    AMD:
    Current CPU signature is: fam19h (raw 0xa00f11)
    Current CPU microcode revision is: 0xa0011a8

Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
---
 tools/misc/xen-ucode.c | 66 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/tools/misc/xen-ucode.c b/tools/misc/xen-ucode.c
index ad32face2b..b9037ce6a1 100644
--- a/tools/misc/xen-ucode.c
+++ b/tools/misc/xen-ucode.c
@@ -12,6 +12,65 @@
 #include <fcntl.h>
 #include <xenctrl.h>
 
+static const char intel_id[] = "GenuineIntel";
+static const char   amd_id[] = "AuthenticAMD";
+
+static void show_curr_cpu(FILE *f)
+{
+    int ret;
+    xc_interface *xch;
+    struct xenpf_pcpu_version cpu_ver = { .xen_cpuid = 0 };
+    struct xenpf_ucode_version ucode_ver = { .xen_cpuid = 0 };
+    bool intel = false, amd = false;
+
+    xch = xc_interface_open(0, 0, 0);
+    if ( xch == NULL )
+        return;
+
+    ret = xc_get_cpu_version(xch, &cpu_ver);
+    if ( ret )
+        return;
+
+    ret = xc_get_ucode_version(xch, &ucode_ver);
+    if ( ret )
+        return;
+
+    if ( memcmp(cpu_ver.vendor_id, intel_id,
+                sizeof(cpu_ver.vendor_id)) == 0 )
+        intel = true;
+    else if ( memcmp(cpu_ver.vendor_id, amd_id,
+                     sizeof(cpu_ver.vendor_id)) == 0 )
+        amd = true;
+
+    /*
+     * Print signature in a form that allows to quickly identify which ucode
+     * blob to load, e.g.:
+     *
+     *      Intel:   /lib/firmware/intel-ucode/06-55-04
+     *      AMD:     /lib/firmware/amd-ucode/microcode_amd_fam19h.bin
+     */
+    if ( intel )
+    {
+        fprintf(f, "Current CPU signature is: %02x-%02x-%02x (raw %#x)\n",
+                   cpu_ver.family, cpu_ver.model, cpu_ver.stepping,
+                   ucode_ver.cpu_signature);
+    }
+    else if ( amd )
+    {
+        fprintf(f, "Current CPU signature is: fam%xh (raw %#x)\n",
+                   cpu_ver.family, ucode_ver.cpu_signature);
+    }
+
+    if ( intel || amd )
+        fprintf(f, "Current CPU microcode revision is: %#x\n",
+                   ucode_ver.ucode_revision);
+
+    if ( intel )
+        fprintf(f, "Current CPU processor flags are: %#x\n", ucode_ver.pf);
+
+    xc_interface_close(xch);
+}
+
 int main(int argc, char *argv[])
 {
     int fd, ret;
@@ -25,9 +84,16 @@ int main(int argc, char *argv[])
         fprintf(stderr,
                 "xen-ucode: Xen microcode updating tool\n"
                 "Usage: %s <microcode blob>\n", argv[0]);
+        show_curr_cpu(stderr);
         exit(2);
     }
 
+    if ( !strcmp(argv[1], "show-cpu-info") )
+    {
+        show_curr_cpu(stdout);
+        return 0;
+    }
+
     filename = argv[1];
     fd = open(filename, O_RDONLY);
     if ( fd < 0 )
-- 
2.17.1