Commit Graph

6 Commits

Author SHA1 Message Date
Jason A. Donenfeld af6b54e2b5 virt: vmgenid: notify RNG of VM fork and supply generation ID
VM Generation ID is a feature from Microsoft, described at
<https://go.microsoft.com/fwlink/?LinkId=260709>, and supported by
Hyper-V and QEMU. Its usage is described in Microsoft's RNG whitepaper,
<https://aka.ms/win10rng>, as:

    If the OS is running in a VM, there is a problem that most
    hypervisors can snapshot the state of the machine and later rewind
    the VM state to the saved state. This results in the machine running
    a second time with the exact same RNG state, which leads to serious
    security problems.  To reduce the window of vulnerability, Windows
    10 on a Hyper-V VM will detect when the VM state is reset, retrieve
    a unique (not random) value from the hypervisor, and reseed the root
    RNG with that unique value.  This does not eliminate the
    vulnerability, but it greatly reduces the time during which the RNG
    system will produce the same outputs as it did during a previous
    instantiation of the same VM state.

Linux has the same issue, and given that vmgenid is supported already by
multiple hypervisors, we can implement more or less the same solution.
So this commit wires up the vmgenid ACPI notification to the RNG's newly
added add_vmfork_randomness() function.

It can be used from qemu via the `-device vmgenid,guid=auto` parameter.
After setting that, use `savevm` in the monitor to save the VM state,
then quit QEMU, start it again, and use `loadvm`. That will trigger this
driver's notify function, which hands the new UUID to the RNG. This is
described in <https://git.qemu.org/?p=qemu.git;a=blob;f=docs/specs/vmgenid.txt>.
And there are hooks for this in libvirt as well, described in
<https://libvirt.org/formatdomain.html#general-metadata>.

Note, however, that the treatment of this as a UUID is considered to be
an accidental QEMU nuance, per
<https://github.com/libguestfs/virt-v2v/blob/master/docs/vm-generation-id-across-hypervisors.txt>,
so this driver simply treats these bytes as an opaque 128-bit binary
blob, as per the spec. This doesn't really make a difference anyway,
considering that's how it ends up when handed to the RNG in the end.

Cc: Alexander Graf <graf@amazon.com>
Cc: Adrian Catangiu <adrian@parity.io>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Tested-by: Souradeep Chakrabarti <souradch.linux@gmail.com> # With Hyper-V's virtual hardware
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-12 18:00:56 -07:00
Shuo Liu 666834c47d virt: acrn: Introduce ACRN HSM basic driver
ACRN Hypervisor Service Module (HSM) is a kernel module in Service VM
which communicates with ACRN userspace through ioctls and talks to ACRN
Hypervisor through hypercalls.

Add a basic HSM driver which allows Service VM userspace to communicate
with ACRN. The following patches will add more ioctls, guest VM memory
mapping caching, I/O request processing, ioeventfd and irqfd into this
module. HSM exports a char device interface (/dev/acrn_hsm) to userspace.

Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Yu Wang <yu1.wang@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-6-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-09 10:58:18 +01:00
Andra Paraschiv 0f5c7b7484 nitro_enclaves: Add Makefile for the Nitro Enclaves driver
Add Makefile for the Nitro Enclaves driver, considering the option set
in the kernel config.

Changelog

v9 -> v10

* Update commit message to include the changelog before the SoB tag(s).

v8 -> v9

* Remove -Wall flags, could use W=1 as an option for this.

v7 -> v8

* No changes.

v6 -> v7

* No changes.

v5 -> v6

* No changes.

v4 -> v5

* No changes.

v3 -> v4

* No changes.

v2 -> v3

* Remove the GPL additional wording as SPDX-License-Identifier is
  already in place.

v1 -> v2

* Update path to Makefile to match the drivers/virt/nitro_enclaves
  directory.

Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-16-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-22 13:58:41 +02:00
Thomas Gleixner ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Hans de Goede 0ba002bc43 virt: Add vboxguest driver for Virtual Box Guest integration
This commit adds a driver for the Virtual Box Guest PCI device used in
Virtual Box virtual machines. Enabling this driver will add support for
Virtual Box Guest integration features such as copy-and-paste, seamless
mode and OpenGL pass-through.

This driver also offers vboxguest IPC functionality which is needed
for the vboxfs driver which offers folder sharing support.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18 16:12:22 +01:00
Timur Tabi 6db7199407 drivers/virt: introduce Freescale hypervisor management driver
Add the drivers/virt directory, which houses drivers that support
virtualization environments, and add the Freescale hypervisor management
driver.

The Freescale hypervisor management driver provides several services to
drivers and applications related to the Freescale hypervisor:

1. An ioctl interface for querying and managing partitions

2. A file interface to reading incoming doorbells

3. An interrupt handler for shutting down the partition upon receiving the
   shutdown doorbell from a manager partition

4. A kernel interface for receiving callbacks when a managed partition
   shuts down.

Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-07-08 00:21:27 -05:00