Merge release-20190806.1-348-gca93332 (automated)

1 files changed, 24 insertions, 0 deletions

diff --git a/pkg/sentry/platform/kvm/machine_unsafe.go b/pkg/sentry/platform/kvm/machine_unsafe.go
index e00c7ae40..ed9433311 100644
--- a/pkg/sentry/platform/kvm/machine_unsafe.go
+++ b/pkg/sentry/platform/kvm/machine_unsafe.go
@@ -35,6 +35,30 @@ func entersyscall()
 //go:linkname exitsyscall runtime.exitsyscall
 func exitsyscall()
 
+// setMemoryRegion initializes a region.
+//
+// This may be called from bluepillHandler, and therefore returns an errno
+// directly (instead of wrapping in an error) to avoid allocations.
+//
+//go:nosplit
+func (m *machine) setMemoryRegion(slot int, physical, length, virtual uintptr, flags uint32) syscall.Errno {
+	userRegion := userMemoryRegion{
+		slot:          uint32(slot),
+		flags:         uint32(flags),
+		guestPhysAddr: uint64(physical),
+		memorySize:    uint64(length),
+		userspaceAddr: uint64(virtual),
+	}
+
+	// Set the region.
+	_, _, errno := syscall.RawSyscall(
+		syscall.SYS_IOCTL,
+		uintptr(m.fd),
+		_KVM_SET_USER_MEMORY_REGION,
+		uintptr(unsafe.Pointer(&userRegion)))
+	return errno
+}
+
 // mapRunData maps the vCPU run data.
 func mapRunData(fd int) (*runData, error) {
 	r, _, errno := syscall.RawSyscall6(