[PATCH 01/14] x86/xstate: Update stale assertions in fpu_x{rstor,save}()

[Alejandro Vallejo <alejandro.vallejo@cloud.com>]

The asserts' intent was to establish whether the xsave instruction was
usable or not, which at the time was strictly given by the presence of
the xsave area. After edb48e76458b("x86/fpu: Combine fpu_ctxt and
xsave_area in arch_vcpu"), that area is always present a more relevant
assert is that the host supports XSAVE.

Fixes: edb48e76458b("x86/fpu: Combine fpu_ctxt and xsave_area in arch_vcpu")
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
---
I'd also be ok with removing the assertions altogether. They serve very
little purpose there after the merge of xsave and fpu_ctxt.
---
 xen/arch/x86/i387.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/i387.c b/xen/arch/x86/i387.c
index 83f9b2502bff..375a8274f632 100644
--- a/xen/arch/x86/i387.c
+++ b/xen/arch/x86/i387.c
@@ -24,7 +24,7 @@ static inline void fpu_xrstor(struct vcpu *v, uint64_t mask)
 {
     bool ok;
 
-    ASSERT(v->arch.xsave_area);
+    ASSERT(cpu_has_xsave);
     /*
      * XCR0 normally represents what guest OS set. In case of Xen itself,
      * we set the accumulated feature mask before doing save/restore.
@@ -136,7 +136,7 @@ static inline void fpu_xsave(struct vcpu *v)
     uint64_t mask = vcpu_xsave_mask(v);
 
     ASSERT(mask);
-    ASSERT(v->arch.xsave_area);
+    ASSERT(cpu_has_xsave);
     /*
      * XCR0 normally represents what guest OS set. In case of Xen itself,
      * we set the accumulated feature mask before doing save/restore.
-- 
2.47.0