[Qemu-devel][PATCH v5 3/4] x86/cpuid: Add support for XSAVES dependent feature enumeration

[Yang Weijiang <weijiang.yang@intel.com>]

Currently XSAVES dependent features are not supported in CPUID enumeration,
update CPUID(0xD,n>=1) to enable it.

CET XSAVES related enumeration includes:
CPUID(0xD,1):ECX[bit 11]: user mode CET state, controls bit 11 in XSS.
CPUID(0xD,1):ECX[bit 12]: supervisor mode CET state, controls bit 12 in XSS.
CPUID(0xD,11): user mode CET state sub-leaf, reports the state size.
CPUID(0xD,12): supervisor mode CE state sub-leaf, reports the state size.

Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 target/i386/cpu.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 3174e05482..881c84a3b3 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1513,6 +1513,12 @@ static inline uint64_t x86_cpu_xsave_components(X86CPU *cpu)
            cpu->env.features[FEAT_XSAVE_COMP_LO];
 }
 
+static inline uint64_t x86_cpu_xsave_sv_components(X86CPU *cpu)
+{
+    return ((uint64_t)cpu->env.features[FEAT_XSAVES_HI]) << 32 |
+           cpu->env.features[FEAT_XSAVES_LO];
+}
+
 const char *get_register_name_32(unsigned int reg)
 {
     if (reg >= CPU_NB_REGS32) {
@@ -5722,13 +5728,22 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
              */
             *ebx = kvm_enabled() ? *ecx : xsave_area_size(env->xcr0);
         } else if (count == 1) {
+            /* ebx is updated in kvm.*/
             *eax = env->features[FEAT_XSAVE];
+            *ecx = env->features[FEAT_XSAVES_LO];
+            *edx = env->features[FEAT_XSAVES_HI];
         } else if (count < ARRAY_SIZE(x86_ext_save_areas)) {
             if ((x86_cpu_xsave_components(cpu) >> count) & 1) {
                 const ExtSaveArea *esa = &x86_ext_save_areas[count];
                 *eax = esa->size;
                 *ebx = esa->offset;
             }
+            if ((x86_cpu_xsave_sv_components(cpu) >> count) & 1) {
+                const ExtSaveArea *esa_sv = &x86_ext_save_areas[count];
+                *eax = esa_sv->size;
+                *ebx = 0;
+                *ecx = 1;
+            }
         }
         break;
     }
@@ -6280,8 +6295,10 @@ static void x86_cpu_enable_xsave_components(X86CPU *cpu)
         }
     }
 
-    env->features[FEAT_XSAVE_COMP_LO] = mask;
+    env->features[FEAT_XSAVE_COMP_LO] = mask & CPUID_XSTATE_USER_MASK;
     env->features[FEAT_XSAVE_COMP_HI] = mask >> 32;
+    env->features[FEAT_XSAVES_LO] = mask & CPUID_XSTATE_KERNEL_MASK;
+    env->features[FEAT_XSAVES_HI] = mask >> 32;
 }
 
 /***** Steps involved on loading and filtering CPUID data
-- 
2.17.2