A failing usercopy of the slot uid will lead to a stale entry in the
file descriptor table as put_unused_fd() won't release it. This enables
userland to refer to a dangling 'file' object through that still valid
file descriptor, leading to all kinds of use-after-free exploitation
scenarios.
Exchanging put_unused_fd() for close_fd(), ksys_close() or alike won't
solve the underlying issue, as the file descriptor might have been
replaced in the meantime, e.g. via userland calling close() on it
(leading to a NULL pointer dereference in the error handling code as
'fget(enclave_fd)' will return a NULL pointer) or by dup2()'ing a
completely different file object to that very file descriptor, leading
to the same situation: a dangling file descriptor pointing to a freed
object -- just in this case to a file object of user's choosing.
Generally speaking, after the call to fd_install() the file descriptor
is live and userland is free to do whatever with it. We cannot rely on
it to still refer to our enclave object afterwards. In fact, by abusing
userfaultfd() userland can hit the condition without any racing and
abuse the error handling in the nitro code as it pleases.
To fix the above issues, defer the call to fd_install() until all
possible errors are handled. In this case it's just the usercopy, so do
it directly in ne_create_vm_ioctl() itself.
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210429165941.27020-2-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ioeventfd is a mechanism to register PIO/MMIO regions to trigger an
eventfd signal when written to by a User VM. ACRN userspace can register
any arbitrary I/O address with a corresponding eventfd and then pass the
eventfd to a specific end-point of interest for handling.
Vhost is a kernel-level virtio server which uses eventfd for signalling.
To support vhost on ACRN, ioeventfd is introduced in HSM.
A new I/O client dedicated to ioeventfd is associated with a User VM
during VM creation. HSM provides ioctls to associate an I/O region with
a eventfd. The I/O client signals a eventfd once its corresponding I/O
region is matched with an I/O request.
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: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-16-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACRN userspace need to inject virtual interrupts into a User VM in
devices emulation.
HSM needs provide interfaces to do so.
Introduce following interrupt injection interfaces:
ioctl ACRN_IOCTL_SET_IRQLINE:
Pass data from userspace to the hypervisor, and inform the hypervisor
to inject a virtual IOAPIC GSI interrupt to a User VM.
ioctl ACRN_IOCTL_INJECT_MSI:
Pass data struct acrn_msi_entry from userspace to the hypervisor, and
inform the hypervisor to inject a virtual MSI to a User VM.
ioctl ACRN_IOCTL_VM_INTR_MONITOR:
Set a 4-Kbyte aligned shared page for statistics information of
interrupts of a User VM.
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: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-13-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI device passthrough enables an OS in a virtual machine to directly
access a PCI device in the host. It promises almost the native
performance, which is required in performance-critical scenarios of
ACRN.
HSM provides the following ioctls:
- Assign - ACRN_IOCTL_ASSIGN_PCIDEV
Pass data struct acrn_pcidev from userspace to the hypervisor, and
inform the hypervisor to assign a PCI device to a User VM.
- De-assign - ACRN_IOCTL_DEASSIGN_PCIDEV
Pass data struct acrn_pcidev from userspace to the hypervisor, and
inform the hypervisor to de-assign a PCI device from a User VM.
- Set a interrupt of a passthrough device - ACRN_IOCTL_SET_PTDEV_INTR
Pass data struct acrn_ptdev_irq from userspace to the hypervisor,
and inform the hypervisor to map a INTx interrupt of passthrough
device of User VM.
- Reset passthrough device interrupt - ACRN_IOCTL_RESET_PTDEV_INTR
Pass data struct acrn_ptdev_irq from userspace to the hypervisor,
and inform the hypervisor to unmap a INTx interrupt of passthrough
device of User VM.
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: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-12-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A User VM can access its virtual PCI configuration spaces via port IO
approach, which has two following steps:
1) writes address into port 0xCF8
2) put/get data in/from port 0xCFC
To distribute a complete PCI configuration space access one time, HSM
need to combine such two accesses together.
Combine two paired PIO I/O requests into one PCI I/O request and
continue the I/O request distribution.
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/20210207031040.49576-11-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An I/O request of a User VM, which is constructed by the hypervisor, is
distributed by the ACRN Hypervisor Service Module to an I/O client
corresponding to the address range of the I/O request.
For each User VM, there is a shared 4-KByte memory region used for I/O
requests communication between the hypervisor and Service VM. An I/O
request is a 256-byte structure buffer, which is 'struct
acrn_io_request', that is filled by an I/O handler of the hypervisor
when a trapped I/O access happens in a User VM. ACRN userspace in the
Service VM first allocates a 4-KByte page and passes the GPA (Guest
Physical Address) of the buffer to the hypervisor. The buffer is used as
an array of 16 I/O request slots with each I/O request slot being 256
bytes. This array is indexed by vCPU ID.
An I/O client, which is 'struct acrn_ioreq_client', is responsible for
handling User VM I/O requests whose accessed GPA falls in a certain
range. Multiple I/O clients can be associated with each User VM. There
is a special client associated with each User VM, called the default
client, that handles all I/O requests that do not fit into the range of
any other I/O clients. The ACRN userspace acts as the default client for
each User VM.
The state transitions of a ACRN I/O request are as follows.
FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ...
FREE: this I/O request slot is empty
PENDING: a valid I/O request is pending in this slot
PROCESSING: the I/O request is being processed
COMPLETE: the I/O request has been processed
An I/O request in COMPLETE or FREE state is owned by the hypervisor. HSM
and ACRN userspace are in charge of processing the others.
The processing flow of I/O requests are listed as following:
a) The I/O handler of the hypervisor will fill an I/O request with
PENDING state when a trapped I/O access happens in a User VM.
b) The hypervisor makes an upcall, which is a notification interrupt, to
the Service VM.
c) The upcall handler schedules a worker to dispatch I/O requests.
d) The worker looks for the PENDING I/O requests, assigns them to
different registered clients based on the address of the I/O accesses,
updates their state to PROCESSING, and notifies the corresponding
client to handle.
e) The notified client handles the assigned I/O requests.
f) The HSM updates I/O requests states to COMPLETE and notifies the
hypervisor of the completion via hypercalls.
Cc: Davidlohr Bueso <dave@stgolabs.net>
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: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-10-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The HSM provides hypervisor services to the ACRN userspace. While
launching a User VM, ACRN userspace needs to allocate memory and request
the ACRN Hypervisor to set up the EPT mapping for the VM.
A mapping cache is introduced for accelerating the translation between
the Service VM kernel virtual address and User VM physical address.
>From the perspective of the hypervisor, the types of GPA of User VM can be
listed as following:
1) RAM region, which is used by User VM as system ram.
2) MMIO region, which is recognized by User VM as MMIO. MMIO region is
used to be utilized for devices emulation.
Generally, User VM RAM regions mapping is set up before VM started and
is released in the User VM destruction. MMIO regions mapping may be set
and unset dynamically during User VM running.
To achieve this, ioctls ACRN_IOCTL_SET_MEMSEG and ACRN_IOCTL_UNSET_MEMSEG
are introduced in HSM.
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: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-9-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Add kernel config entry for Nitro Enclaves, including dependencies.
Changelog
v9 -> v10
* Update commit message to include the changelog before the SoB tag(s).
v8 -> v9
* No changes.
v7 -> v8
* No changes.
v6 -> v7
* Remove, for now, the dependency on ARM64 arch. x86 is currently
supported, with Arm to come afterwards. The NE kernel driver can be
built for aarch64 arch.
v5 -> v6
* No changes.
v4 -> v5
* Add arch dependency for Arm / x86.
v3 -> v4
* Add PCI and SMP dependencies.
v2 -> v3
* Remove the GPL additional wording as SPDX-License-Identifier is
already in place.
v1 -> v2
* Update path to Kconfig to match the drivers/virt/nitro_enclaves
directory.
* Update help in Kconfig.
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-15-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Longpeng(Mike)
Mathias Krause
Shuo Liu
Yejune Deng
Hans de Goede
Andra Paraschiv
Qinglang Miao