[PATCH v3 7/9] target/i386/mshv: populate xsave area offsets

[Magnus Kulke <magnuskulke@linux.microsoft.com>]

This function is copied verbatim from kvm_cpu_xsave_init(), for MSHV we
need to populate the offsets similarly.

Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
---
 target/i386/mshv/mshv-cpu.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/target/i386/mshv/mshv-cpu.c b/target/i386/mshv/mshv-cpu.c
index 3b392533b4..ee25eb5f6f 100644
--- a/target/i386/mshv/mshv-cpu.c
+++ b/target/i386/mshv/mshv-cpu.c
@@ -1706,11 +1706,42 @@ int mshv_arch_post_init_vm(int vm_fd)
     return ret;
 }
 
+static void mshv_cpu_xsave_init(void)
+{
+    static bool first = true;
+    uint32_t eax, ebx, ecx, edx;
+    int i;
+
+    if (!first) {
+        return;
+    }
+    first = false;
+
+    /* x87 and SSE states are in the legacy region of the XSAVE area. */
+    x86_ext_save_areas[XSTATE_FP_BIT].offset = 0;
+    x86_ext_save_areas[XSTATE_SSE_BIT].offset = 0;
+
+    for (i = XSTATE_SSE_BIT + 1; i < XSAVE_STATE_AREA_COUNT; i++) {
+        ExtSaveArea *esa = &x86_ext_save_areas[i];
+
+        if (!esa->size) {
+            continue;
+        }
+        host_cpuid(0xd, i, &eax, &ebx, &ecx, &edx);
+        if (eax != 0) {
+            assert(esa->size == eax);
+            esa->offset = ebx;
+            esa->ecx = ecx;
+        }
+    }
+}
+
 static void mshv_cpu_instance_init(CPUState *cs)
 {
     X86CPU *cpu = X86_CPU(cs);
 
     host_cpu_instance_init(cpu);
+    mshv_cpu_xsave_init();
 }
 
 static void mshv_cpu_accel_class_init(ObjectClass *oc, const void *data)
-- 
2.34.1