[PATCH 1/7] hyperv: Detect Nested virtualization support for SVM

[Vineeth Pillai]

Detect nested features exposed by Hyper-V if SVM is enabled.

Signed-off-by: Vineeth Pillai <virem...@linux.microsoft.com>
---
 arch/x86/kernel/cpu/mshyperv.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 3546d3e21787..4d364acfe95d 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -325,9 +325,17 @@ static void __init ms_hyperv_init_platform(void)
                        ms_hyperv.isolation_config_a, 
ms_hyperv.isolation_config_b);
        }
 
-       if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
+       /*
+        * AMD does not need enlightened VMCS as VMCB is already a
+        * datastructure in memory. We need to get the nested
+        * features if SVM is enabled.
+        */
+       if (boot_cpu_has(X86_FEATURE_SVM) ||
+           ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
                ms_hyperv.nested_features =
                        cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
+               pr_info("Hyper-V nested_features: 0x%x\n",
+                       ms_hyperv.nested_features);
        }
 
        /*
-- 
2.25.1