Implement pass through ioctl command VFIO_DEVICE_GET_IRQ_INFO.

PiperOrigin-RevId: 618034948

pkg/abi/linux/vfio.go

@@ -61,6 +61,14 @@ const (
 	VFIO_REGION_INFO_FLAG_CAPS
 )
 
+// VFIOIrqInfo flags.
+const (
+	VFIO_IRQ_INFO_EVENTFD = 1 << iota
+	VFIO_IRQ_INFO_MASKABLE
+	VFIO_IRQ_INFO_AUTOMASKED
+	VFIO_IRQ_INFO_NORESIZE
+)
+
 // IOCTLs for VFIO file descriptor from include/uapi/linux/vfio.h.
 var (
 	VFIO_CHECK_EXTENSION        = IO(VFIO_TYPE, VFIO_BASE+1)
@@ -69,6 +77,7 @@ var (
 	VFIO_GROUP_GET_DEVICE_FD    = IO(VFIO_TYPE, VFIO_BASE+6)
 	VFIO_DEVICE_GET_INFO        = IO(VFIO_TYPE, VFIO_BASE+7)
 	VFIO_DEVICE_GET_REGION_INFO = IO(VFIO_TYPE, VFIO_BASE+8)
+	VFIO_DEVICE_GET_IRQ_INFO    = IO(VFIO_TYPE, VFIO_BASE+9)
 )
 
 // VFIODeviceInfo is analogous to vfio_device_info
@@ -102,3 +111,14 @@ type VFIORegionInfo struct {
 	// Region offset from start of device fd.
 	Offset uint64
 }
+
+// VFIOIrqInfo is analogous to vfio_irq_info
+// from include/uapi/linux/vfio.h.
+//
+// +marshal
+type VFIOIrqInfo struct {
+	Argsz uint32
+	Flags uint32
+	Index uint32
+	Count uint32
+}

pkg/sentry/devices/tpuproxy/seccomp_filter.go

@@ -77,6 +77,10 @@ func Filters() seccomp.SyscallRules {
 				seccomp.NonNegativeFD{},
 				seccomp.EqualTo(linux.VFIO_DEVICE_GET_REGION_INFO),
 			},
+			seccomp.PerArg{
+				seccomp.NonNegativeFD{},
+				seccomp.EqualTo(linux.VFIO_DEVICE_GET_IRQ_INFO),
+			},
 		},
 	})
 }

pkg/sentry/devices/tpuproxy/tpu.go

@@ -229,6 +229,8 @@ func (fd *pciDeviceFD) Ioctl(ctx context.Context, uio usermem.IO, sysno uintptr,
 		return fd.vfioDeviceInfo(ctx, t, args[2].Pointer())
 	case linux.VFIO_DEVICE_GET_REGION_INFO:
 		return fd.vfioRegionInfo(ctx, t, args[2].Pointer())
+	case linux.VFIO_DEVICE_GET_IRQ_INFO:
+		return fd.vfioIrqInfo(ctx, t, args[2].Pointer())
 	}
 	return 0, linuxerr.ENOSYS
 }
@@ -278,3 +280,23 @@ func (fd *pciDeviceFD) vfioDeviceInfo(ctx context.Context, t *kernel.Task, arg h
 	}
 	return ret, nil
 }
+
+// Retrieve the device's interrupt information.
+func (fd *pciDeviceFD) vfioIrqInfo(ctx context.Context, t *kernel.Task, arg hostarch.Addr) (uintptr, error) {
+	var irqInfo linux.VFIOIrqInfo
+	if _, err := irqInfo.CopyIn(t, arg); err != nil {
+		return 0, err
+	}
+	// Callers must set the payload's size.
+	if irqInfo.Argsz == 0 {
+		return 0, linuxerr.EINVAL
+	}
+	ret, err := IOCTLInvokePtrArg[uint32](fd.hostFD, linux.VFIO_DEVICE_GET_IRQ_INFO, &irqInfo)
+	if err != nil {
+		return 0, err
+	}
+	if _, err := irqInfo.CopyOut(t, arg); err != nil {
+		return 0, err
+	}
+	return ret, nil
+}