[xen stable-4.13] x86/CPUID: correct error indicator for max extended leaf

[patchbot@xxxxxxx]

commit 70ed2d5f0d51d3bea012170bbf70553463862073
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu May 7 14:47:47 2020 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu May 7 14:47:47 2020 +0200

    x86/CPUID: correct error indicator for max extended leaf
    
    With the max base leaf using 0, this one should be using the extended
    leaf counterpart thereof, rather than some arbitrary extended leaf.
    
    Fixes: 588a966a572e ("libx86: Introduce x86_cpu_policies_are_compatible()")
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: 0135be8bd8cd60090298f02310691b688d95c3a8
    master date: 2020-04-30 10:45:09 +0200
---
 tools/tests/cpu-policy/test-cpu-policy.c | 2 +-
 xen/lib/x86/policy.c                     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/tests/cpu-policy/test-cpu-policy.c 
b/tools/tests/cpu-policy/test-cpu-policy.c
index 20ebed923b..fe8cdf6ea9 100644
--- a/tools/tests/cpu-policy/test-cpu-policy.c
+++ b/tools/tests/cpu-policy/test-cpu-policy.c
@@ -570,7 +570,7 @@ static void test_is_compatible_failure(void)
         {
             .name = "Host extd.max_leaf out of range",
             .guest_cpuid.extd.max_leaf = 1,
-            .e = { 0x80000008, -1, -1 },
+            .e = { 0x80000000, -1, -1 },
         },
         {
             .name = "Host no CPUID faulting, Guest wanted",
diff --git a/xen/lib/x86/policy.c b/xen/lib/x86/policy.c
index b156a304f4..4beca8767a 100644
--- a/xen/lib/x86/policy.c
+++ b/xen/lib/x86/policy.c
@@ -19,7 +19,7 @@ int x86_cpu_policies_are_compatible(const struct cpu_policy 
*host,
         FAIL_CPUID(0, NA);
 
     if ( guest->cpuid->extd.max_leaf > host->cpuid->extd.max_leaf )
-        FAIL_CPUID(0x80000008, NA);
+        FAIL_CPUID(0x80000000, NA);
 
     /* TODO: Audit more CPUID data. */
 
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.13