Christoffer Dall c726200dd1 KVM: arm/arm64: Allow reporting non-ISV data aborts to userspace ... For a long time, if a guest accessed memory outside of a memslot using any of the load/store instructions in the architecture which doesn't supply decoding information in the ESR_EL2 (the ISV bit is not set), the kernel would print the following message and terminate the VM as a result of returning -ENOSYS to userspace: load/store instruction decoding not implemented The reason behind this message is that KVM assumes that all accesses outside a memslot is an MMIO access which should be handled by userspace, and we originally expected to eventually implement some sort of decoding of load/store instructions where the ISV bit was not set. However, it turns out that many of the instructions which don't provide decoding information on abort are not safe to use for MMIO accesses, and the remaining few that would potentially make sense to use on MMIO accesses, such as those with register writeback, are not used in practice. It also turns out that fetching an instruction from guest memory can be a pretty horrible affair, involving stopping all CPUs on SMP systems, handling multiple corner cases of address translation in software, and more. It doesn't appear likely that we'll ever implement this in the kernel. What is much more common is that a user has misconfigured his/her guest and is actually not accessing an MMIO region, but just hitting some random hole in the IPA space. In this scenario, the error message above is almost misleading and has led to a great deal of confusion over the years. It is, nevertheless, ABI to userspace, and we therefore need to introduce a new capability that userspace explicitly enables to change behavior. This patch introduces KVM_CAP_ARM_NISV_TO_USER (NISV meaning Non-ISV) which does exactly that, and introduces a new exit reason to report the event to userspace. User space can then emulate an exception to the guest, restart the guest, suspend the guest, or take any other appropriate action as per the policy of the running system. Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Alexander Graf <graf@amazon.com> Signed-off-by: Marc Zyngier <maz@kernel.org>		2019-10-21 18:59:44 +01:00
..
ABI	Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity	2019-09-27 19:37:27 -07:00
accounting	docs: add some documentation dirs to the driver-api book	2019-07-15 11:03:02 -03:00
admin-guide	xen: fixes for 5.4-rc3	2019-10-12 14:11:21 -07:00
arm	Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title	2019-08-12 15:25:32 -06:00
arm64	docs: arm64: Fix indentation and doc formatting	2019-10-01 13:32:35 +01:00
block	docs: block: null_blk: enhance document style	2019-09-11 16:04:22 -06:00
bpf	bpf/flow_dissector: document flags	2019-07-25 18:00:41 -07:00
cdrom	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
core-api	Modules fixes for v5.4-rc3	2019-10-11 10:19:24 -07:00
cpu-freq	Documentation: cpufreq: Update policy notifier documentation	2019-09-02 22:44:05 +02:00
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2019-09-18 12:11:14 -07:00
dev-tools	kselftest: add capability to skip chosen TARGETS	2019-10-01 13:19:04 -06:00
devicetree	TTY/Serial driver fixes for 5.4-rc3	2019-10-12 15:42:19 -07:00
doc-guide	docs: remove extra conf.py files	2019-07-17 06:57:52 -03:00
driver-api	This is the bulk of pin control changes for the v5.4 kernel	2019-09-19 14:19:33 -07:00
EDID	docs: driver-api: add a series of orphaned documents	2019-07-15 11:03:02 -03:00
fault-injection	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
fb	docs conversion for v5.3-rc1	2019-07-16 12:21:41 -07:00
features	It's a somewhat calmer cycle for docs this time, as the churn of the mass	2019-09-17 16:22:26 -07:00
filesystems	add virtio-fs	2019-09-27 15:54:24 -07:00
firmware_class
firmware-guide	Documentation: ACPI: DSD: Convert LED documentation to ReST	2019-08-20 23:53:46 +02:00
fpga	Documentation: fpga: dfl: add descriptions for virtualization and new interfaces.	2019-09-03 19:35:42 -07:00
gpu	Merge drm/drm-next into drm-intel-next-queued	2019-08-22 00:10:36 -07:00
hid	docs: add some documentation dirs to the driver-api book	2019-07-15 11:03:02 -03:00
hwmon	hwmon: docs: Extend inspur-ipsps1 title underline	2019-10-07 05:56:57 -07:00
i2c	docs: i2c: convert to ReST and add to driver-api bookset	2019-07-31 13:25:27 -06:00
ia64	docs: add SPDX tags to new index files	2019-07-15 11:03:03 -03:00
ide	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
iio	docs: add some documentation dirs to the driver-api book	2019-07-15 11:03:02 -03:00
infiniband	Documentation/infiniband: update name of some functions	2019-09-13 16:55:55 -03:00
input	Input: docs: fix spelling mistake "potocol" -> "protocol"	2019-08-06 11:24:49 -06:00
ioctl	fs-verity: add UAPI header	2019-07-28 16:59:16 -07:00
isdn	docs: isdn: convert to ReST and add to kAPI bookset	2019-07-31 13:30:25 -06:00
kbuild	Modules fixes for v5.4-rc3	2019-10-11 10:19:24 -07:00
kernel-hacking	docs: Add documentation for Symbol Namespaces	2019-09-10 10:30:49 +02:00
leds	leds: core: Add support for composing LED class device names	2019-07-25 20:07:52 +02:00
livepatch	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
locking	doc🔒 remove reference to clever use of read-write lock	2019-09-14 01:53:27 -06:00
m68k	docs: README.buddha: convert to ReST and add to m68k book	2019-07-31 13:30:10 -06:00
maintainer	docs: Fix typo on pull requests guide	2019-08-12 15:14:14 -06:00
media	drm main pull for 5.4-rc1	2019-09-19 16:24:24 -07:00
mic	docs: driver-api: add remaining converted dirs to it	2019-07-15 11:03:03 -03:00
mips	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
misc-devices	Docs: misc: xilinx_sdfec: Add documentation	2019-08-15 17:54:38 +02:00
netlabel	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
networking	docs: networking: Add title caret and missing doc	2019-10-01 09:19:49 -07:00
nios2	docs: nios2: add it to the main Documentation body	2019-07-31 13:31:51 -06:00
openrisc	docs: openrisc: convert to ReST and add to documentation body	2019-07-31 13:30:20 -06:00
parisc	docs: parisc: convert to ReST and add to documentation body	2019-07-31 13:30:15 -06:00
PCI	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2019-08-27 14:23:31 -07:00
pcmcia	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
power	Merge branches 'pm-opp', 'pm-qos', 'acpi-pm', 'pm-domains' and 'pm-tools'	2019-09-17 09:49:19 +02:00
powerpc	docs: powerpc: Add missing documentation reference	2019-09-17 23:59:34 +10:00
process	Documentation/process: Add fallthrough pseudo-keyword	2019-10-11 09:26:05 -07:00
RCU	Merge branches 'consolidate.2019.08.01b', 'fixes.2019.08.12a', 'lists.2019.08.13a' and 'torture.2019.08.01b' into HEAD	2019-08-13 14:30:30 -07:00
riscv	It's a somewhat calmer cycle for docs this time, as the churn of the mass	2019-09-17 16:22:26 -07:00
s390	Documentation/s390: remove outdated debugging390 documentation	2019-08-21 12:41:43 +02:00
scheduler	sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices	2019-08-08 09:09:30 +02:00
scsi	scsi: ufs: Documentation: Announce ufs-tool v1.0	2019-06-26 22:47:51 -04:00
security	Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity	2019-09-27 19:37:27 -07:00
sh	docs: remove extra conf.py files	2019-07-17 06:57:52 -03:00
sound	sound updates for 5.4	2019-09-17 17:43:33 -07:00
sparc	docs: add arch doc directories to the index	2019-07-15 11:03:01 -03:00
sphinx	Documentation: sphinx: Don't parse socket() as identifier reference	2019-08-12 14:55:30 -06:00
sphinx-static
spi	spi: docs: convert to ReST and add it to the kABI bookset	2019-07-31 14:13:13 -06:00
target	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
timers	docs: add some directories to the main documentation index	2019-07-15 11:03:03 -03:00
trace	Tracing updates:	2019-09-20 11:19:48 -07:00
translations	doc: arm64: fix grammar dtb placed in no attributes region	2019-09-06 08:44:34 -06:00
usb	USB: rio500: Remove Rio 500 kernel driver	2019-10-04 10:53:36 +02:00
userspace-api	docs: remove extra conf.py files	2019-07-17 06:57:52 -03:00
virt	KVM: arm/arm64: Allow reporting non-ISV data aborts to userspace	2019-10-21 18:59:44 +01:00
virtual	cpuidle: add haltpoll governor	2019-07-30 17:27:37 +02:00
vm	mm: treewide: clarify pgtable_page_{ctor,dtor}() naming	2019-09-26 10:10:44 -07:00
w1	docs: w1: convert to ReST and add to the kAPI group of docs	2019-07-31 14:16:17 -06:00
watchdog	linux-watchdog 5.4-rc1 tag	2019-09-27 11:17:38 -07:00
x86	dma-mapping: fix filename references	2019-09-03 08:36:30 +02:00
xtensa	docs: add arch doc directories to the index	2019-07-15 11:03:01 -03:00
.gitignore
atomic_bitops.txt	docs: atomic_bitops.txt: add a title for this document	2019-04-11 12:37:02 -06:00
atomic_t.txt	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-07-08 16:12:03 -07:00
bus-virt-phys-mapping.txt
Changes
CodingStyle
conf.py	docs: conf.py: only use CJK if the font is available	2019-07-17 06:57:51 -03:00
COPYING-logo	docs: logo.txt: rename it to COPYING-logo	2019-07-15 09:20:27 -03:00
crc32.txt
debugging-modules.txt
debugging-via-ohci1394.txt
digsig.txt
DMA-API-HOWTO.txt	docs: DMA-API-HOWTO.txt: fix an unmarked code block	2019-07-15 09:20:24 -03:00
DMA-API.txt	dma-mapping: remove dma_release_declared_memory	2019-09-04 11:13:19 +02:00
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf	doc-rst: Add missing newline at end of file	2019-06-20 14:16:56 -06:00
dontdiff	kbuild: create *.mod with full directory path and remove MODVERDIR	2019-07-18 02:19:31 +09:00
futex-requeue-pi.txt
hwspinlock.txt	hwspinlock: add the 'in_atomic' API	2019-06-29 21:08:14 -07:00
index.rst	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
io_ordering.txt
io-mapping.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
Kconfig	docs: Kbuild/Makefile: allow check for missing docs at build time	2019-06-07 11:33:16 -06:00
kobject.txt
kprobes.txt	Merge branch 'parisc-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux	2019-05-07 19:34:17 -07:00
kref.txt
logo.gif
lzo.txt	lib/lzo: fix bugs for very short or empty input	2019-04-05 16:02:30 -10:00
mailbox.txt
Makefile	docs: Kbuild/Makefile: allow check for missing docs at build time	2019-06-07 11:33:16 -06:00
memory-barriers.txt	docs: fix broken doc references due to renames	2019-07-17 06:57:51 -03:00
nommu-mmap.txt
padata.txt	padata: allocate workqueue internally	2019-09-13 21:15:39 +10:00
percpu-rw-semaphore.txt
pi-futex.txt	docs: locking: convert docs to ReST and rename to *.rst	2019-07-15 08:53:27 -03:00
preempt-locking.txt	x86/fpu: Remove fpu__restore()	2019-04-09 19:27:42 +02:00
rbtree.txt	docs: rbtree.txt: fix Sphinx build warnings	2019-07-15 09:20:24 -03:00
remoteproc.txt	remoteproc: add vendor resources handling	2019-06-29 12:02:17 -07:00
robust-futex-ABI.txt
robust-futexes.txt	futex: Update comments and docs about return values of arch futex code	2019-04-26 13:57:55 +01:00
rpmsg.txt
speculation.txt	docs: speculation.txt: mark example blocks as such	2019-04-11 12:37:03 -06:00
static-keys.txt
SubmittingPatches
tee.txt	Documentation: tee: Grammar s/the its/its/	2019-06-07 11:23:38 -06:00
this_cpu_ops.txt
unaligned-memory-access.txt	docs: unaligned-memory-access.txt: use a lowercase title	2019-04-11 12:37:03 -06:00
xz.txt