From 56a9a13976ad800a8a34b194d35f0169d0a0bb23 Mon Sep 17 00:00:00 2001
From: Andrei Vagin <avagin@google.com>
Date: Tue, 23 Mar 2021 18:44:38 -0700
Subject: Move the code that manages floating-point state to a separate package
This change is inspired by Adin's cl/355256448.
PiperOrigin-RevId: 364695931
---
pkg/sentry/platform/kvm/BUILD | 2 ++
pkg/sentry/platform/kvm/bluepill_amd64.go | 6 ++---
pkg/sentry/platform/kvm/bluepill_arm64.go | 10 ++++----
pkg/sentry/platform/kvm/context.go | 2 +-
pkg/sentry/platform/kvm/kvm_amd64_test.go | 2 +-
pkg/sentry/platform/kvm/kvm_test.go | 33 +++++++++++++------------
pkg/sentry/platform/kvm/machine_amd64.go | 5 ++--
pkg/sentry/platform/kvm/machine_arm64.go | 3 ++-
pkg/sentry/platform/kvm/machine_arm64_unsafe.go | 3 ++-
9 files changed, 36 insertions(+), 30 deletions(-)
(limited to 'pkg/sentry/platform/kvm')
diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD
index 4f9e781af..03a76eb9b 100644
--- a/pkg/sentry/platform/kvm/BUILD
+++ b/pkg/sentry/platform/kvm/BUILD
@@ -50,6 +50,7 @@ go_library(
"//pkg/safecopy",
"//pkg/seccomp",
"//pkg/sentry/arch",
+ "//pkg/sentry/arch/fpu",
"//pkg/sentry/memmap",
"//pkg/sentry/platform",
"//pkg/sentry/platform/interrupt",
@@ -78,6 +79,7 @@ go_test(
"//pkg/ring0",
"//pkg/ring0/pagetables",
"//pkg/sentry/arch",
+ "//pkg/sentry/arch/fpu",
"//pkg/sentry/platform",
"//pkg/sentry/platform/kvm/testutil",
"//pkg/sentry/time",
diff --git a/pkg/sentry/platform/kvm/bluepill_amd64.go b/pkg/sentry/platform/kvm/bluepill_amd64.go
index f4b9a5321..d761bbdee 100644
--- a/pkg/sentry/platform/kvm/bluepill_amd64.go
+++ b/pkg/sentry/platform/kvm/bluepill_amd64.go
@@ -73,7 +73,7 @@ func (c *vCPU) KernelSyscall() {
// We only trigger a bluepill entry in the bluepill function, and can
// therefore be guaranteed that there is no floating point state to be
// loaded on resuming from halt. We only worry about saving on exit.
- ring0.SaveFloatingPoint((*byte)(c.floatingPointState)) // escapes: no.
+ ring0.SaveFloatingPoint(c.floatingPointState.BytePointer()) // escapes: no.
ring0.Halt()
ring0.WriteFS(uintptr(regs.Fs_base)) // escapes: no, reload host segment.
}
@@ -92,7 +92,7 @@ func (c *vCPU) KernelException(vector ring0.Vector) {
regs.Rip = 0
}
// See above.
- ring0.SaveFloatingPoint((*byte)(c.floatingPointState)) // escapes: no.
+ ring0.SaveFloatingPoint(c.floatingPointState.BytePointer()) // escapes: no.
ring0.Halt()
ring0.WriteFS(uintptr(regs.Fs_base)) // escapes: no; reload host segment.
}
@@ -124,5 +124,5 @@ func bluepillArchExit(c *vCPU, context *arch.SignalContext64) {
// Set the context pointer to the saved floating point state. This is
// where the guest data has been serialized, the kernel will restore
// from this new pointer value.
- context.Fpstate = uint64(uintptrValue((*byte)(c.floatingPointState)))
+ context.Fpstate = uint64(uintptrValue(c.floatingPointState.BytePointer()))
}
diff --git a/pkg/sentry/platform/kvm/bluepill_arm64.go b/pkg/sentry/platform/kvm/bluepill_arm64.go
index e26b7da8d..578852c3f 100644
--- a/pkg/sentry/platform/kvm/bluepill_arm64.go
+++ b/pkg/sentry/platform/kvm/bluepill_arm64.go
@@ -92,7 +92,7 @@ func bluepillArchExit(c *vCPU, context *arch.SignalContext64) {
lazyVfp := c.GetLazyVFP()
if lazyVfp != 0 {
- fpsimd := fpsimdPtr((*byte)(c.floatingPointState))
+ fpsimd := fpsimdPtr(c.floatingPointState.BytePointer())
context.Fpsimd64.Fpsr = fpsimd.Fpsr
context.Fpsimd64.Fpcr = fpsimd.Fpcr
context.Fpsimd64.Vregs = fpsimd.Vregs
@@ -112,12 +112,12 @@ func (c *vCPU) KernelSyscall() {
fpDisableTrap := ring0.CPACREL1()
if fpDisableTrap != 0 {
- fpsimd := fpsimdPtr((*byte)(c.floatingPointState))
+ fpsimd := fpsimdPtr(c.floatingPointState.BytePointer())
fpcr := ring0.GetFPCR()
fpsr := ring0.GetFPSR()
fpsimd.Fpcr = uint32(fpcr)
fpsimd.Fpsr = uint32(fpsr)
- ring0.SaveVRegs((*byte)(c.floatingPointState))
+ ring0.SaveVRegs(c.floatingPointState.BytePointer())
}
ring0.Halt()
@@ -136,12 +136,12 @@ func (c *vCPU) KernelException(vector ring0.Vector) {
fpDisableTrap := ring0.CPACREL1()
if fpDisableTrap != 0 {
- fpsimd := fpsimdPtr((*byte)(c.floatingPointState))
+ fpsimd := fpsimdPtr(c.floatingPointState.BytePointer())
fpcr := ring0.GetFPCR()
fpsr := ring0.GetFPSR()
fpsimd.Fpcr = uint32(fpcr)
fpsimd.Fpsr = uint32(fpsr)
- ring0.SaveVRegs((*byte)(c.floatingPointState))
+ ring0.SaveVRegs(c.floatingPointState.BytePointer())
}
ring0.Halt()
diff --git a/pkg/sentry/platform/kvm/context.go b/pkg/sentry/platform/kvm/context.go
index aeae01dbd..706fa53dc 100644
--- a/pkg/sentry/platform/kvm/context.go
+++ b/pkg/sentry/platform/kvm/context.go
@@ -65,7 +65,7 @@ func (c *context) Switch(ctx pkgcontext.Context, mm platform.MemoryManager, ac a
// Prepare switch options.
switchOpts := ring0.SwitchOpts{
Registers: &ac.StateData().Regs,
- FloatingPointState: (*byte)(ac.FloatingPointData()),
+ FloatingPointState: ac.FloatingPointData(),
PageTables: localAS.pageTables,
Flush: localAS.Touch(cpu),
FullRestore: ac.FullRestore(),
diff --git a/pkg/sentry/platform/kvm/kvm_amd64_test.go b/pkg/sentry/platform/kvm/kvm_amd64_test.go
index 76fc594a0..e44e995a0 100644
--- a/pkg/sentry/platform/kvm/kvm_amd64_test.go
+++ b/pkg/sentry/platform/kvm/kvm_amd64_test.go
@@ -33,7 +33,7 @@ func TestSegments(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
FullRestore: true,
}, &si); err == platform.ErrContextInterrupt {
diff --git a/pkg/sentry/platform/kvm/kvm_test.go b/pkg/sentry/platform/kvm/kvm_test.go
index 6243b9a04..5bce16dde 100644
--- a/pkg/sentry/platform/kvm/kvm_test.go
+++ b/pkg/sentry/platform/kvm/kvm_test.go
@@ -25,13 +25,14 @@ import (
"gvisor.dev/gvisor/pkg/ring0"
"gvisor.dev/gvisor/pkg/ring0/pagetables"
"gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/arch/fpu"
"gvisor.dev/gvisor/pkg/sentry/platform"
"gvisor.dev/gvisor/pkg/sentry/platform/kvm/testutil"
ktime "gvisor.dev/gvisor/pkg/sentry/time"
"gvisor.dev/gvisor/pkg/usermem"
)
-var dummyFPState = (*byte)(arch.NewFloatingPointData())
+var dummyFPState = fpu.NewState()
type testHarness interface {
Errorf(format string, args ...interface{})
@@ -159,7 +160,7 @@ func TestApplicationSyscall(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
FullRestore: true,
}, &si); err == platform.ErrContextInterrupt {
@@ -173,7 +174,7 @@ func TestApplicationSyscall(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
return true // Retry.
@@ -190,7 +191,7 @@ func TestApplicationFault(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
FullRestore: true,
}, &si); err == platform.ErrContextInterrupt {
@@ -205,7 +206,7 @@ func TestApplicationFault(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
return true // Retry.
@@ -223,7 +224,7 @@ func TestRegistersSyscall(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
continue // Retry.
@@ -246,7 +247,7 @@ func TestRegistersFault(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
FullRestore: true,
}, &si); err == platform.ErrContextInterrupt {
@@ -272,7 +273,7 @@ func TestBounce(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err != platform.ErrContextInterrupt {
t.Errorf("application partial restore: got %v, wanted %v", err, platform.ErrContextInterrupt)
@@ -287,7 +288,7 @@ func TestBounce(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
FullRestore: true,
}, &si); err != platform.ErrContextInterrupt {
@@ -319,7 +320,7 @@ func TestBounceStress(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err != platform.ErrContextInterrupt {
t.Errorf("application partial restore: got %v, wanted %v", err, platform.ErrContextInterrupt)
@@ -340,7 +341,7 @@ func TestInvalidate(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
continue // Retry.
@@ -355,7 +356,7 @@ func TestInvalidate(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
Flush: true,
}, &si); err == platform.ErrContextInterrupt {
@@ -379,7 +380,7 @@ func TestEmptyAddressSpace(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
return true // Retry.
@@ -393,7 +394,7 @@ func TestEmptyAddressSpace(t *testing.T) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
FullRestore: true,
}, &si); err == platform.ErrContextInterrupt {
@@ -469,7 +470,7 @@ func BenchmarkApplicationSyscall(b *testing.B) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
a++
@@ -506,7 +507,7 @@ func BenchmarkWorldSwitchToUserRoundtrip(b *testing.B) {
var si arch.SignalInfo
if _, err := c.SwitchToUser(ring0.SwitchOpts{
Registers: regs,
- FloatingPointState: dummyFPState,
+ FloatingPointState: &dummyFPState,
PageTables: pt,
}, &si); err == platform.ErrContextInterrupt {
a++
diff --git a/pkg/sentry/platform/kvm/machine_amd64.go b/pkg/sentry/platform/kvm/machine_amd64.go
index 6e583baa3..8f2c82e73 100644
--- a/pkg/sentry/platform/kvm/machine_amd64.go
+++ b/pkg/sentry/platform/kvm/machine_amd64.go
@@ -27,6 +27,7 @@ import (
"gvisor.dev/gvisor/pkg/ring0"
"gvisor.dev/gvisor/pkg/ring0/pagetables"
"gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/arch/fpu"
"gvisor.dev/gvisor/pkg/sentry/platform"
ktime "gvisor.dev/gvisor/pkg/sentry/time"
"gvisor.dev/gvisor/pkg/usermem"
@@ -70,7 +71,7 @@ type vCPUArchState struct {
// floatingPointState is the floating point state buffer used in guest
// to host transitions. See usage in bluepill_amd64.go.
- floatingPointState *arch.FloatingPointData
+ floatingPointState fpu.State
}
const (
@@ -151,7 +152,7 @@ func (c *vCPU) initArchState() error {
// This will be saved prior to leaving the guest, and we restore from
// this always. We cannot use the pointer in the context alone because
// we don't know how large the area there is in reality.
- c.floatingPointState = arch.NewFloatingPointData()
+ c.floatingPointState = fpu.NewState()
// Set the time offset to the host native time.
return c.setSystemTime()
diff --git a/pkg/sentry/platform/kvm/machine_arm64.go b/pkg/sentry/platform/kvm/machine_arm64.go
index 7d7857067..2edc9d1b2 100644
--- a/pkg/sentry/platform/kvm/machine_arm64.go
+++ b/pkg/sentry/platform/kvm/machine_arm64.go
@@ -20,6 +20,7 @@ import (
"gvisor.dev/gvisor/pkg/ring0"
"gvisor.dev/gvisor/pkg/ring0/pagetables"
"gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/arch/fpu"
"gvisor.dev/gvisor/pkg/sentry/platform"
"gvisor.dev/gvisor/pkg/usermem"
)
@@ -32,7 +33,7 @@ type vCPUArchState struct {
// floatingPointState is the floating point state buffer used in guest
// to host transitions. See usage in bluepill_arm64.go.
- floatingPointState *arch.FloatingPointData
+ floatingPointState fpu.State
}
const (
diff --git a/pkg/sentry/platform/kvm/machine_arm64_unsafe.go b/pkg/sentry/platform/kvm/machine_arm64_unsafe.go
index 059aa43d0..e7d5f3193 100644
--- a/pkg/sentry/platform/kvm/machine_arm64_unsafe.go
+++ b/pkg/sentry/platform/kvm/machine_arm64_unsafe.go
@@ -26,6 +26,7 @@ import (
"gvisor.dev/gvisor/pkg/ring0"
"gvisor.dev/gvisor/pkg/ring0/pagetables"
"gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/arch/fpu"
"gvisor.dev/gvisor/pkg/sentry/platform"
"gvisor.dev/gvisor/pkg/usermem"
)
@@ -150,7 +151,7 @@ func (c *vCPU) initArchState() error {
c.PCIDs = pagetables.NewPCIDs(fixedKernelPCID+1, poolPCIDs)
}
- c.floatingPointState = arch.NewFloatingPointData()
+ c.floatingPointState = fpu.NewState()
return c.setSystemTime()
}
--
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