-----BEGIN PGP SIGNATURE-----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=NfL4
-----END PGP SIGNATURE-----
Merge tag 'random-5.18-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator fixes from Jason Donenfeld:
- If a hardware random number generator passes a sufficiently large
chunk of entropy to random.c during early boot, we now skip the
"fast_init" business and let it initialize the RNG.
This makes CONFIG_RANDOM_TRUST_BOOTLOADER=y actually useful.
- We already have the command line `random.trust_cpu=0/1` option for
RDRAND, which let distros enable CONFIG_RANDOM_TRUST_CPU=y while
placating concerns of more paranoid users.
Now we add `random.trust_bootloader=0/1` so that distros can
similarly enable CONFIG_RANDOM_TRUST_BOOTLOADER=y.
- Re-add a comment that got removed by accident in the recent revert.
- Add the spec-compliant ACPI CID for vmgenid, which Microsoft added to
the vmgenid spec at Ard's request during earlier review.
- Restore build-time randomness via the latent entropy plugin, which
was lost when we transitioned to using a hash function.
* tag 'random-5.18-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
random: mix build-time latent entropy into pool at init
virt: vmgenid: recognize new CID added by Hyper-V
random: re-add removed comment about get_random_{u32,u64} reseeding
random: treat bootloader trust toggle the same way as cpu trust toggle
random: skip fast_init if hwrng provides large chunk of entropy
Here is the big set of char/misc and other small driver subsystem
updates for 5.18-rc1.
Included in here are merges from driver subsystems which contain:
- iio driver updates and new drivers
- fsi driver updates
- fpga driver updates
- habanalabs driver updates and support for new hardware
- soundwire driver updates and new drivers
- phy driver updates and new drivers
- coresight driver updates
- icc driver updates
Individual changes include:
- mei driver updates
- interconnect driver updates
- new PECI driver subsystem added
- vmci driver updates
- lots of tiny misc/char driver updates
There will be two merge conflicts with your tree, one in MAINTAINERS
which is obvious to fix up, and one in drivers/phy/freescale/Kconfig
which also should be easy to resolve.
All of these have been in linux-next for a while with no reported
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCYkG3fQ8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykNEgCfaRG8CRxewDXOO4+GSeA3NGK+AIoAnR89donC
R4bgCjfg8BWIBcVVXg3/
=WWXC
-----END PGP SIGNATURE-----
Merge tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc and other driver updates from Greg KH:
"Here is the big set of char/misc and other small driver subsystem
updates for 5.18-rc1.
Included in here are merges from driver subsystems which contain:
- iio driver updates and new drivers
- fsi driver updates
- fpga driver updates
- habanalabs driver updates and support for new hardware
- soundwire driver updates and new drivers
- phy driver updates and new drivers
- coresight driver updates
- icc driver updates
Individual changes include:
- mei driver updates
- interconnect driver updates
- new PECI driver subsystem added
- vmci driver updates
- lots of tiny misc/char driver updates
All of these have been in linux-next for a while with no reported
problems"
* tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (556 commits)
firmware: google: Properly state IOMEM dependency
kgdbts: fix return value of __setup handler
firmware: sysfb: fix platform-device leak in error path
firmware: stratix10-svc: add missing callback parameter on RSU
arm64: dts: qcom: add non-secure domain property to fastrpc nodes
misc: fastrpc: Add dma handle implementation
misc: fastrpc: Add fdlist implementation
misc: fastrpc: Add helper function to get list and page
misc: fastrpc: Add support to secure memory map
dt-bindings: misc: add fastrpc domain vmid property
misc: fastrpc: check before loading process to the DSP
misc: fastrpc: add secure domain support
dt-bindings: misc: add property to support non-secure DSP
misc: fastrpc: Add support to get DSP capabilities
misc: fastrpc: add support for FASTRPC_IOCTL_MEM_MAP/UNMAP
misc: fastrpc: separate fastrpc device from channel context
dt-bindings: nvmem: brcm,nvram: add basic NVMEM cells
dt-bindings: nvmem: make "reg" property optional
nvmem: brcm_nvram: parse NVRAM content into NVMEM cells
nvmem: dt-bindings: Fix the error of dt-bindings check
...
In the Windows spec for VM Generation ID, the originally specified CID
is longer than allowed by the ACPI spec. Hyper-V has added "VMGENCTR" as
a second valid CID that is conformant, while retaining the original CID
for compatibility with Windows guests.
Add this new CID to the list recognized by the driver.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The vm_param and cpu_regs need to be freed via kfree()
before return -EINVAL error.
Fixes: 9c5137aedd ("virt: acrn: Introduce VM management interfaces")
Fixes: 2ad2aaee1b ("virt: acrn: Introduce an ioctl to set vCPU registers state")
Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20220308092047.1008409-1-butterflyhuangxx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
acrn_vm_ram_map can't pin the user pages with VM_PFNMAP flag
by calling get_user_pages_fast(), the PA(physical pages)
may be mapped by kernel driver and set PFNMAP flag.
This patch fixes logic to setup EPT mapping for PFN mapped RAM region
by checking the memory attribute before adding EPT mapping for them.
Fixes: 88f537d5e8 ("virt: acrn: Introduce EPT mapping management")
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20220228022212.419406-1-yonghua.huang@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
acrn_irqfds_mutex is not used, never was.
Remove acrn_irqfds_mutex.
Fixes: aa3b483ff1 ("virt: acrn: Introduce irqfd")
Cc: Fei Li <fei1.li@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/YidLo57Kw/u/cpA5@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
-----BEGIN PGP SIGNATURE-----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=RKW4
-----END PGP SIGNATURE-----
Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linux
Pull bitmap updates from Yury Norov:
- introduce for_each_set_bitrange()
- use find_first_*_bit() instead of find_next_*_bit() where possible
- unify for_each_bit() macros
* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
vsprintf: rework bitmap_list_string
lib: bitmap: add performance test for bitmap_print_to_pagebuf
bitmap: unify find_bit operations
mm/percpu: micro-optimize pcpu_is_populated()
Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
find: micro-optimize for_each_{set,clear}_bit()
include/linux: move for_each_bit() macros from bitops.h to find.h
cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
tools: sync tools/bitmap with mother linux
all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
cpumask: use find_first_and_bit()
lib: add find_first_and_bit()
arch: remove GENERIC_FIND_FIRST_BIT entirely
include: move find.h from asm_generic to linux
bitops: move find_bit_*_le functions from le.h to find.h
bitops: protect find_first_{,zero}_bit properly
find_first{,_zero}_bit is a more effective analogue of 'next' version if
start == 0. This patch replaces 'next' with 'first' where things look
trivial.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Add KUnit tests for the contiguous physical memory regions merging
functionality from the Nitro Enclaves misc device logic.
We can build the test binary with the following configuration:
CONFIG_KUNIT=y
CONFIG_NITRO_ENCLAVES=m
CONFIG_NITRO_ENCLAVES_MISC_DEV_TEST=y
and install the nitro_enclaves module to run the testcases.
We'll see the following message using dmesg if everything goes well:
[...] # Subtest: ne_misc_dev_test
[...] 1..1
[...] (NULL device *): Physical mem region address is not 2 MiB aligned
[...] (NULL device *): Physical mem region size is not multiple of 2 MiB
[...] (NULL device *): Physical mem region address is not 2 MiB aligned
[...] ok 1 - ne_misc_dev_test_merge_phys_contig_memory_regions
[...] ok 1 - ne_misc_dev_test
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20211107140918.2106-5-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the initial setup for the KUnit tests that will target the Nitro
Enclaves misc device functionality.
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20211107140918.2106-4-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sanity check the physical memory regions during the merge of contiguous
regions. Thus we can test the physical memory regions setup logic
individually, including the error cases coming from the sanity checks.
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20211107140918.2106-3-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There can be cases when there are more memory regions that need to be
set for an enclave than the maximum supported number of memory regions
per enclave. One example can be when the memory regions are backed by 2
MiB hugepages (the minimum supported hugepage size).
Let's merge the adjacent regions if they are physically contiguous. This
way the final number of memory regions is less than before merging and
could potentially avoid reaching maximum.
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20211107140918.2106-2-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'destroy_workqueue()' already drains the queue before destroying it, so
there is no need to flush it explicitly.
Remove the redundant 'flush_workqueue()' calls.
This was generated with coccinelle:
@@
expression E;
@@
- flush_workqueue(E);
destroy_workqueue(E);
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/d57f5c7e362837a8dfcde0d726a76b56f114e619.1636736947.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ACRN hypervisor can emulate a virtual device within hypervisor for a
Guest VM. The emulated virtual device can work without the ACRN
userspace after creation. The hypervisor do the emulation of that device.
To support the virtual device creating/destroying, HSM provides the
following ioctls:
- ACRN_IOCTL_CREATE_VDEV
Pass data struct acrn_vdev from userspace to the hypervisor, and inform
the hypervisor to create a virtual device for a User VM.
- ACRN_IOCTL_DESTROY_VDEV
Pass data struct acrn_vdev from userspace to the hypervisor, and inform
the hypervisor to destroy a virtual device of a User VM.
These new APIs will be used by user space code vm_add_hv_vdev and
vm_remove_hv_vdev in
https://github.com/projectacrn/acrn-hypervisor/blob/master/devicemodel/core/vmmapi.c
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20210923084128.18902-3-fei1.li@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MMIO device passthrough enables an OS in a virtual machine to directly
access a MMIO 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_MMIODEV
Pass data struct acrn_mmiodev from userspace to the hypervisor, and
inform the hypervisor to assign a MMIO device to a User VM.
- De-assign - ACRN_IOCTL_DEASSIGN_PCIDEV
Pass data struct acrn_mmiodev from userspace to the hypervisor, and
inform the hypervisor to de-assign a MMIO device from a User VM.
These new APIs will be used by user space code vm_assign_mmiodev and
vm_deassign_mmiodev in
https://github.com/projectacrn/acrn-hypervisor/blob/master/devicemodel/core/vmmapi.c
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20210923084128.18902-2-fei1.li@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Update the codebase formatting to fix the reports from the checkpatch
script, to match the open parenthesis.
Reviewed-by: George-Aurelian Popescu <popegeo@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20210827154930.40608-6-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Update the copyright statement to include 2021, as a change has been
made over this year.
Check commit d874742f6a ("nitro_enclaves: Set Bus Master for the NE
PCI device") for the codebase update from this file (ne_pci_dev.c).
Reviewed-by: George-Aurelian Popescu <popegeo@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20210827154930.40608-5-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the reported issue from the kernel-doc script, to have a comment per
identifier.
Reviewed-by: George-Aurelian Popescu <popegeo@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20210827154930.40608-4-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ACRN hypervisor has scenarios which could run a real-time guest VM.
The real-time guest VM occupies dedicated CPU cores, be assigned with
dedicated PCI devices. It can run without the Service VM after boot up.
hcall_destroy_vm() returns failure when a real-time guest VM refuses.
The clearing of flag ACRN_VM_FLAG_DESTROYED causes some kernel resource
double-freed in a later acrn_vm_destroy().
Do hcall_destroy_vm() before resource release to drop this chance to
destroy the VM if hypercall fails.
Fixes: 9c5137aedd ("virt: acrn: Introduce VM management interfaces")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20210722062736.15050-1-fei1.li@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable Bus Master for the NE PCI device, according to the PCI spec
for submitting memory or I/O requests:
Master Enable – Controls the ability of a PCI Express
Endpoint to issue Memory and I/O Read/Write Requests, and
the ability of a Root or Switch Port to forward Memory and
I/O Read/Write Requests in the Upstream direction
Cc: Andra Paraschiv <andraprs@amazon.com>
Cc: Alexandru Vasile <lexnv@amazon.com>
Cc: Alexandru Ciobotaru <alcioa@amazon.com>
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20210621004046.1419-1-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
This fixes the following sparse warning:
"sparse warnings: (new ones prefixed by >>)"
>> drivers/virt/acrn/irqfd.c:163:13: sparse: sparse: restricted __poll_t
degrades to integer
Fixes: dcf9625f2a ("virt: acrn: Use vfs_poll() instead of f_op->poll()")
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Shuo Liu <shuo.a.liu@intel.com>
Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Link: https://lore.kernel.org/r/20210310074901.7486-1-yejune.deng@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use a more advanced function vfs_poll() in acrn_irqfd_assign().
At the same time, modify the definition of events.
Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210221133306.33530-1-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without cpu hotplug support, vCPU cannot be removed from a Service VM.
Don't expose remove_cpu sysfs when CONFIG_HOTPLUG_CPU disabled.
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Qais Yousef <qais.yousef@arm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210221134339.57851-2-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACRN supports partition mode to achieve real-time requirements. In
partition mode, a CPU core can be dedicated to a vCPU of User VM. The
local APIC of the dedicated CPU core can be passthrough to the User VM.
The Service VM controls the assignment of the CPU cores.
Introduce an interface for the Service VM to remove the control of CPU
core from hypervisor perspective so that the CPU core can be a dedicated
CPU core 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/20210207031040.49576-18-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
irqfd is a mechanism to inject a specific interrupt to a User VM using a
decoupled eventfd mechanism.
Vhost is a kernel-level virtio server which uses eventfd for interrupt
injection. To support vhost on ACRN, irqfd is introduced in HSM.
HSM provides ioctls to associate a virtual Message Signaled Interrupt
(MSI) with an eventfd. The corresponding virtual MSI will be injected
into a User VM once the eventfd got signal.
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/20210207031040.49576-17-shuo.a.liu@intel.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>
An I/O request of a User VM, which is constructed by hypervisor, is
distributed by the ACRN Hypervisor Service Module to an I/O client
corresponding to the address range of the I/O request.
I/O client maintains a list of address ranges. Introduce
acrn_ioreq_range_{add,del}() to manage these address ranges.
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/20210207031040.49576-15-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The C-states and P-states data are used to support CPU power management.
The hypervisor controls C-states and P-states for a User VM.
ACRN userspace need to query the data from the hypervisor to build ACPI
tables for a User VM.
HSM provides ioctls for ACRN userspace to query C-states and P-states
data obtained from the hypervisor.
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/20210207031040.49576-14-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>
A virtual CPU of User VM has different context due to the different
registers state. ACRN userspace needs to set the virtual CPU
registers state (e.g. giving a initial registers state to a virtual
BSP of a User VM).
HSM provides an ioctl ACRN_IOCTL_SET_VCPU_REGS to do the virtual CPU
registers state setting. The ioctl passes the registers state from ACRN
userspace to the hypervisor directly.
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/20210207031040.49576-8-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The VM management interfaces expose several VM operations to ACRN
userspace via ioctls. For example, creating VM, starting VM, destroying
VM and so on.
The ACRN Hypervisor needs to exchange data with the ACRN userspace
during the VM operations. HSM provides VM operation ioctls to the ACRN
userspace and communicates with the ACRN Hypervisor for VM operations
via hypercalls.
HSM maintains a list of User VM. Each User VM will be bound to an
existing file descriptor of /dev/acrn_hsm. The User VM will be
destroyed when the file descriptor is closed.
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/20210207031040.49576-7-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Do not use wait_event_interruptible when vbg_hgcm_call() gets called from
kernel-context, such as it being called by the vboxsf filesystem code.
This fixes some filesystem related system calls on shared folders
unexpectedly failing with -EINTR.
Fixes: 0532a1b0d0 ("virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x")
Reported-by: Ludovic Pouzenc <bugreports@pouzenc.fr>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210121150754.147598-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Update the assigned value of the poll result to be EPOLLHUP instead of
POLLHUP to match the __poll_t type.
While at it, simplify the logic of setting the mask result of the poll
function.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20201102173622.32169-1-andraprs@amazon.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>
An enclave is associated with an fd that is returned after the enclave
creation logic is completed. This enclave fd is further used to setup
enclave resources. Once the enclave needs to be terminated, the enclave
fd is closed.
Add logic for enclave termination, that is mapped to the enclave fd
release callback. Free the internal enclave info used for bookkeeping.
Changelog
v9 -> v10
* Update commit message to include the changelog before the SoB tag(s).
v8 -> v9
* Use the ne_devs data structure to get the refs for the NE PCI device.
v7 -> v8
* No changes.
v6 -> v7
* Remove the pci_dev_put() call as the NE misc device parent field is
used now to get the NE PCI device.
* Update the naming and add more comments to make more clear the logic
of handling full CPU cores and dedicating them to the enclave.
v5 -> v6
* Update documentation to kernel-doc format.
* Use directly put_page() instead of unpin_user_pages(), to match the
get_user_pages() calls.
v4 -> v5
* Release the reference to the NE PCI device on enclave fd release.
* Adapt the logic to cpumask enclave vCPU ids and CPU cores.
* Remove sanity checks for situations that shouldn't happen, only if
buggy system or broken logic at all.
v3 -> v4
* Use dev_err instead of custom NE log pattern.
v2 -> v3
* Remove the WARN_ON calls.
* Update static calls sanity checks.
* Update kzfree() calls to kfree().
v1 -> v2
* Add log pattern for NE.
* Remove the BUG_ON calls.
* Update goto labels to match their purpose.
* Add early exit in release() if there was a slot alloc error in the fd
creation path.
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Alexandru Vasile <lexnv@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-14-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linus Torvalds