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authorgVisor bot <gvisor-bot@google.com>2021-02-02 20:16:40 +0000
committergVisor bot <gvisor-bot@google.com>2021-02-02 20:16:40 +0000
commit5011c8943e1048c3b34b9dc11a888ee3c8d42302 (patch)
tree88cb34e1b1515c30ea029beb8b4fd575a66f779c /pkg/ring0/lib_amd64.go
parentc4bddc8deecbb4d6e3e9269e321610cdf085aab7 (diff)
parentf884ea13b713143ff9978092ddb352c159346167 (diff)
Merge release-20210125.0-61-gf884ea13b (automated)
Diffstat (limited to 'pkg/ring0/lib_amd64.go')
-rw-r--r--pkg/ring0/lib_amd64.go119
1 files changed, 119 insertions, 0 deletions
diff --git a/pkg/ring0/lib_amd64.go b/pkg/ring0/lib_amd64.go
new file mode 100644
index 000000000..0ec5c3bc5
--- /dev/null
+++ b/pkg/ring0/lib_amd64.go
@@ -0,0 +1,119 @@
+// Copyright 2018 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.
+
+// +build amd64
+
+package ring0
+
+import (
+ "gvisor.dev/gvisor/pkg/cpuid"
+)
+
+// LoadFloatingPoint loads floating point state by the most efficient mechanism
+// available (set by Init).
+var LoadFloatingPoint func(*byte)
+
+// SaveFloatingPoint saves floating point state by the most efficient mechanism
+// available (set by Init).
+var SaveFloatingPoint func(*byte)
+
+// fxrstor uses fxrstor64 to load floating point state.
+func fxrstor(*byte)
+
+// xrstor uses xrstor to load floating point state.
+func xrstor(*byte)
+
+// fxsave uses fxsave64 to save floating point state.
+func fxsave(*byte)
+
+// xsave uses xsave to save floating point state.
+func xsave(*byte)
+
+// xsaveopt uses xsaveopt to save floating point state.
+func xsaveopt(*byte)
+
+// WriteFS sets the GS address (set by init).
+var WriteFS func(addr uintptr)
+
+// wrfsbase writes to the GS base address.
+func wrfsbase(addr uintptr)
+
+// wrfsmsr writes to the GS_BASE MSR.
+func wrfsmsr(addr uintptr)
+
+// WriteGS sets the GS address (set by init).
+var WriteGS func(addr uintptr)
+
+// wrgsbase writes to the GS base address.
+func wrgsbase(addr uintptr)
+
+// wrgsmsr writes to the GS_BASE MSR.
+func wrgsmsr(addr uintptr)
+
+// readCR2 reads the current CR2 value.
+func readCR2() uintptr
+
+// fninit initializes the floating point unit.
+func fninit()
+
+// xsetbv writes to an extended control register.
+func xsetbv(reg, value uintptr)
+
+// xgetbv reads an extended control register.
+func xgetbv(reg uintptr) uintptr
+
+// wrmsr reads to the given MSR.
+func wrmsr(reg, value uintptr)
+
+// rdmsr reads the given MSR.
+func rdmsr(reg uintptr) uintptr
+
+// Mostly-constants set by Init.
+var (
+ hasSMEP bool
+ hasPCID bool
+ hasXSAVEOPT bool
+ hasXSAVE bool
+ hasFSGSBASE bool
+ validXCR0Mask uintptr
+)
+
+// Init sets function pointers based on architectural features.
+//
+// This must be called prior to using ring0.
+func Init(featureSet *cpuid.FeatureSet) {
+ hasSMEP = featureSet.HasFeature(cpuid.X86FeatureSMEP)
+ hasPCID = featureSet.HasFeature(cpuid.X86FeaturePCID)
+ hasXSAVEOPT = featureSet.UseXsaveopt()
+ hasXSAVE = featureSet.UseXsave()
+ hasFSGSBASE = featureSet.HasFeature(cpuid.X86FeatureFSGSBase)
+ validXCR0Mask = uintptr(featureSet.ValidXCR0Mask())
+ if hasXSAVEOPT {
+ SaveFloatingPoint = xsaveopt
+ LoadFloatingPoint = xrstor
+ } else if hasXSAVE {
+ SaveFloatingPoint = xsave
+ LoadFloatingPoint = xrstor
+ } else {
+ SaveFloatingPoint = fxsave
+ LoadFloatingPoint = fxrstor
+ }
+ if hasFSGSBASE {
+ WriteFS = wrfsbase
+ WriteGS = wrgsbase
+ } else {
+ WriteFS = wrfsmsr
+ WriteGS = wrgsmsr
+ }
+}