[Qemu-devel] [PATCH 14/14] target-i386: Enable XCR0 features for user-mode

[Richard Henderson <rth@twiddle.net>]

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-i386/cpu.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index c19ff8a..2402c2a 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2654,7 +2654,17 @@ static void x86_cpu_reset(CPUState *s)
     cpu_set_fpuc(env, 0x37f);
 
     env->mxcsr = 0x1f80;
-    env->xstate_bv = XSTATE_FP | XSTATE_SSE;
+
+    /* ??? This variable is somewhat silly.  Methinks KVM should be
+       using XCR0 to store into the XSTATE_BV field.  Either that or
+       there's more missing information, e.g. the AVX bits.  */
+    env->xstate_bv = XSTATE_FP;
+    if (env->features[FEAT_1_EDX] & CPUID_SSE) {
+        env->xstate_bv |= XSTATE_SSE;
+    }
+    if (env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_MPX) {
+        env->xstate_bv |= XSTATE_BNDREGS | XSTATE_BNDCSR;
+    }
 
     env->pat = 0x0007040600070406ULL;
     env->msr_ia32_misc_enable = MSR_IA32_MISC_ENABLE_DEFAULT;
@@ -2665,7 +2675,15 @@ static void x86_cpu_reset(CPUState *s)
     cpu_breakpoint_remove_all(s, BP_CPU);
     cpu_watchpoint_remove_all(s, BP_CPU);
 
-    env->xcr0 = 1;
+    env->xcr0 = XSTATE_FP;
+
+#ifdef CONFIG_USER_ONLY
+    /* Enable all the features for user-mode.  */
+    env->xcr0 = env->xstate_bv;
+    if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
+        cpu_x86_update_cr4(env, CR4_OSFXSR_MASK | CR4_OSXSAVE_MASK);
+    }
+#endif
 
     /*
      * SDM 11.11.5 requires:
-- 
2.4.3