x86: add support for KVM_CAP_XSAVE2 and AMX state migration

When dynamic xfeatures (e.g. AMX) are used by the guest, the xsave
area would be larger than 4KB. KVM_GET_XSAVE2 and KVM_SET_XSAVE
under KVM_CAP_XSAVE2 works with a xsave buffer larger than 4KB.
Always use the new ioctls under KVM_CAP_XSAVE2 when KVM supports it.

Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20220217060434.52460-7-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/target/i386/xsave_helper.c b/target/i386/xsave_helper.c
index ac61a96..996e9f3 100644
--- a/target/i386/xsave_helper.c
+++ b/target/i386/xsave_helper.c
@@ -126,6 +126,20 @@ void x86_cpu_xsave_all_areas(X86CPU *cpu, void *buf, uint32_t buflen)
 
         memcpy(pkru, &env->pkru, sizeof(env->pkru));
     }
+
+    e = &x86_ext_save_areas[XSTATE_XTILE_CFG_BIT];
+    if (e->size && e->offset) {
+        XSaveXTILECFG *tilecfg = buf + e->offset;
+
+        memcpy(tilecfg, &env->xtilecfg, sizeof(env->xtilecfg));
+    }
+
+    e = &x86_ext_save_areas[XSTATE_XTILE_DATA_BIT];
+    if (e->size && e->offset && buflen >= e->size + e->offset) {
+        XSaveXTILEDATA *tiledata = buf + e->offset;
+
+        memcpy(tiledata, &env->xtiledata, sizeof(env->xtiledata));
+    }
 #endif
 }
 
@@ -247,5 +261,19 @@ void x86_cpu_xrstor_all_areas(X86CPU *cpu, const void *buf, uint32_t buflen)
         pkru = buf + e->offset;
         memcpy(&env->pkru, pkru, sizeof(env->pkru));
     }
+
+    e = &x86_ext_save_areas[XSTATE_XTILE_CFG_BIT];
+    if (e->size && e->offset) {
+        const XSaveXTILECFG *tilecfg = buf + e->offset;
+
+        memcpy(&env->xtilecfg, tilecfg, sizeof(env->xtilecfg));
+    }
+
+    e = &x86_ext_save_areas[XSTATE_XTILE_DATA_BIT];
+    if (e->size && e->offset && buflen >= e->size + e->offset) {
+        const XSaveXTILEDATA *tiledata = buf + e->offset;
+
+        memcpy(&env->xtiledata, tiledata, sizeof(env->xtiledata));
+    }
 #endif
 }