1 files changed, 1 insertions, 53 deletions
diff --git a/pkg/sentry/arch/arch_state_x86.go b/pkg/sentry/arch/arch_state_x86.go
index 840e53d33..b2b94c304 100644
--- a/pkg/sentry/arch/arch_state_x86.go
+++ b/pkg/sentry/arch/arch_state_x86.go
@@ -16,59 +16,7 @@
 
 package arch
 
-import (
-	"gvisor.dev/gvisor/pkg/cpuid"
-	"gvisor.dev/gvisor/pkg/usermem"
-)
-
-// XSTATE_BV does not exist if FXSAVE is used, but FXSAVE implicitly saves x87
-// and SSE state, so this is the equivalent XSTATE_BV value.
-const fxsaveBV uint64 = cpuid.XSAVEFeatureX87 | cpuid.XSAVEFeatureSSE
-
 // afterLoadFPState is invoked by afterLoad.
 func (s *State) afterLoadFPState() {
-	old := s.x86FPState
-
-	// Recreate the slice. This is done to ensure that it is aligned
-	// appropriately in memory, and large enough to accommodate any new
-	// state that may be saved by the new CPU. Even if extraneous new state
-	// is saved, the state we care about is guaranteed to be a subset of
-	// new state. Later optimizations can use less space when using a
-	// smaller state component bitmap. Intel SDM Volume 1 Chapter 13 has
-	// more info.
-	s.x86FPState = newX86FPState()
-
-	// x86FPState always contains all the FP state supported by the host.
-	// We may have come from a newer machine that supports additional state
-	// which we cannot restore.
-	//
-	// The x86 FP state areas are backwards compatible, so we can simply
-	// truncate the additional floating point state.
-	//
-	// Applications should not depend on the truncated state because it
-	// should relate only to features that were not exposed in the app
-	// FeatureSet. However, because we do not *prevent* them from using
-	// this state, we must verify here that there is no in-use state
-	// (according to XSTATE_BV) which we do not support.
-	if len(s.x86FPState) < len(old) {
-		// What do we support?
-		supportedBV := fxsaveBV
-		if fs := cpuid.HostFeatureSet(); fs.UseXsave() {
-			supportedBV = fs.ValidXCR0Mask()
-		}
-
-		// What was in use?
-		savedBV := fxsaveBV
-		if len(old) >= xstateBVOffset+8 {
-			savedBV = usermem.ByteOrder.Uint64(old[xstateBVOffset:])
-		}
-
-		// Supported features must be a superset of saved features.
-		if savedBV&^supportedBV != 0 {
-			panic(ErrFloatingPoint{supported: supportedBV, saved: savedBV})
-		}
-	}
-
-	// Copy to the new, aligned location.
-	copy(s.x86FPState, old)
+	s.fpState.AfterLoad()
 }