i386/cpu: Fix supervisor xstate initialization

Arch lbr is a supervisor xstate, but its area is not covered in
x86_cpu_init_xsave().

Fix it by checking supported xss bitmap.

In addition, drop the (uint64_t) type casts for supported_xcr0 since
x86_cpu_get_supported_feature_word() returns uint64_t so that the cast
is not needed. Then ensure line length is within 90 characters.

Tested-by: Farrah Chen <farrah.chen@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Co-developed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20251211060801.3600039-10-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 5ba4d49dc35d64c7e8717f644d31869023bbe50c..e9ef8b992fda90850aaea09163c144dd8b72500a 100644 (file)
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -9711,20 +9711,23 @@ static void x86_cpu_post_initfn(Object *obj)
 static void x86_cpu_init_xsave(void)
 {
     static bool first = true;
-    uint64_t supported_xcr0;
+    uint64_t supported_xcr0, supported_xss;
     int i;
 
     if (first) {
         first = false;
 
         supported_xcr0 =
-            ((uint64_t) x86_cpu_get_supported_feature_word(NULL, FEAT_XSAVE_XCR0_HI) << 32) |
+            x86_cpu_get_supported_feature_word(NULL, FEAT_XSAVE_XCR0_HI) << 32 |
             x86_cpu_get_supported_feature_word(NULL, FEAT_XSAVE_XCR0_LO);
+        supported_xss =
+            x86_cpu_get_supported_feature_word(NULL, FEAT_XSAVE_XSS_HI) << 32 |
+            x86_cpu_get_supported_feature_word(NULL, FEAT_XSAVE_XSS_LO);
 
         for (i = XSTATE_SSE_BIT + 1; i < XSAVE_STATE_AREA_COUNT; i++) {
             ExtSaveArea *esa = &x86_ext_save_areas[i];
 
-            if (!(supported_xcr0 & (1 << i))) {
+            if (!((supported_xcr0 | supported_xss) & (1 << i))) {
                 esa->size = 0;
             }
         }