pkg: expose kvm device

This greatly improves vm test performance.

Signed-off-by: Ophestra <cat@gensokyo.uk>

4 files changed, 14 insertions, 1 deletions

diff --git a/fhs/abs.go b/fhs/abs.go
index 7adde1db..5d061567 100644
--- a/fhs/abs.go
+++ b/fhs/abs.go
@@ -40,6 +40,8 @@ var (
 	AbsDev = unsafeAbs(Dev)
 	// AbsDevShm is [DevShm] as [check.Absolute].
 	AbsDevShm = unsafeAbs(DevShm)
+	// AbsDevKvm is [DevKvm] as [check.Absolute].
+	AbsDevKvm = unsafeAbs(DevKvm)
 	// AbsProc is [Proc] as [check.Absolute].
 	AbsProc = unsafeAbs(Proc)
 	// AbsProcSys is [ProcSys] as [check.Absolute].
diff --git a/fhs/fhs.go b/fhs/fhs.go
index 6d098d0c..b526dc6f 100644
--- a/fhs/fhs.go
+++ b/fhs/fhs.go
@@ -35,6 +35,8 @@ const (
 	// DevShm is the place for POSIX shared memory segments, as created via
 	// shm_open(3).
 	DevShm = "/dev/shm/"
+	// DevKvm is the KVM system device.
+	DevKvm = "/dev/kvm"
 	// Proc points to a virtual kernel file system exposing the process list and
 	// other functionality.
 	Proc = "/proc/"
diff --git a/pkg/exec.go b/pkg/exec.go
index b40ae84b..fe099ac9 100644
--- a/pkg/exec.go
+++ b/pkg/exec.go
@@ -601,7 +601,12 @@ func (a *execArtifact) makeContainer(
 		fhs.AbsTmp,
 		std.BindWritable|std.BindEnsure,
 	)
-	z.Proc(fhs.AbsProc).Dev(fhs.AbsDev, true)
+	z.
+		Proc(fhs.AbsProc).
+		DevWritable(fhs.AbsDev, true).
+		Tmpfs(fhs.AbsDevShm, 0, 01777).
+		Bind(fhs.AbsDevKvm, fhs.AbsDevKvm, std.BindOptional|std.BindDevice).
+		Remount(fhs.AbsDev, syscall.MS_RDONLY)
 	return
 }
 
diff --git a/pkg/internal/testtool/main.go b/pkg/internal/testtool/main.go
index edffab7e..80f87435 100644
--- a/pkg/internal/testtool/main.go
+++ b/pkg/internal/testtool/main.go
@@ -259,6 +259,10 @@ func main() {
 		next()
 	}
 
+	if m.Next != nil && m.Next.Root == "/kvm" {
+		next()
+	}
+
 	if m.Next != nil {
 		log.Println("unexpected extra mount entries")
 		for m.Next != nil {