diff options
Diffstat (limited to 'pkg/sentry/platform')
-rw-r--r-- | pkg/sentry/platform/kvm/BUILD | 1 | ||||
-rw-r--r-- | pkg/sentry/platform/kvm/kvm_amd64_test.go | 37 | ||||
-rw-r--r-- | pkg/sentry/platform/kvm/kvm_amd64_test.s | 21 |
3 files changed, 59 insertions, 0 deletions
diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD index f04898dc1..b307832fd 100644 --- a/pkg/sentry/platform/kvm/BUILD +++ b/pkg/sentry/platform/kvm/BUILD @@ -65,6 +65,7 @@ go_test( name = "kvm_test", srcs = [ "kvm_amd64_test.go", + "kvm_amd64_test.s", "kvm_arm64_test.go", "kvm_test.go", "virtual_map_test.go", diff --git a/pkg/sentry/platform/kvm/kvm_amd64_test.go b/pkg/sentry/platform/kvm/kvm_amd64_test.go index e44e995a0..b8dd1e4a5 100644 --- a/pkg/sentry/platform/kvm/kvm_amd64_test.go +++ b/pkg/sentry/platform/kvm/kvm_amd64_test.go @@ -49,3 +49,40 @@ func TestSegments(t *testing.T) { return false }) } + +// stmxcsr reads the MXCSR control and status register. +func stmxcsr(addr *uint32) + +func TestMXCSR(t *testing.T) { + applicationTest(t, true, testutil.SyscallLoop, func(c *vCPU, regs *arch.Registers, pt *pagetables.PageTables) bool { + var si arch.SignalInfo + switchOpts := ring0.SwitchOpts{ + Registers: regs, + FloatingPointState: &dummyFPState, + PageTables: pt, + FullRestore: true, + } + + const mxcsrControllMask = uint32(0x1f80) + mxcsrBefore := uint32(0) + mxcsrAfter := uint32(0) + stmxcsr(&mxcsrBefore) + if mxcsrBefore == 0 { + // goruntime sets mxcsr to 0x1f80 and it never changes + // the control configuration. + panic("mxcsr is zero") + } + switchOpts.FloatingPointState.SetMXCSR(0) + if _, err := c.SwitchToUser( + switchOpts, &si); err == platform.ErrContextInterrupt { + return true // Retry. + } else if err != nil { + t.Errorf("application syscall failed: %v", err) + } + stmxcsr(&mxcsrAfter) + if mxcsrAfter&mxcsrControllMask != mxcsrBefore&mxcsrControllMask { + t.Errorf("mxcsr = %x (expected %x)", mxcsrBefore, mxcsrAfter) + } + return false + }) +} diff --git a/pkg/sentry/platform/kvm/kvm_amd64_test.s b/pkg/sentry/platform/kvm/kvm_amd64_test.s new file mode 100644 index 000000000..8e9079867 --- /dev/null +++ b/pkg/sentry/platform/kvm/kvm_amd64_test.s @@ -0,0 +1,21 @@ +// Copyright 2021 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "textflag.h" + +// stmxcsr reads the MXCSR control and status register. +TEXT ·stmxcsr(SB),NOSPLIT,$0-8 + MOVQ addr+0(FP), SI + STMXCSR (SI) + RET |