arm: kvm: implement CPU PM notifier

Upon CPU shutdown and consequent warm-reboot, the hypervisor CPU state
must be re-initialized. This patch implements a CPU PM notifier that
upon warm-boot calls a KVM hook to reinitialize properly the hypervisor
state so that the CPU can be safely resumed.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
(cherry picked from commit 1fcf7ce0c60213994269fb59569ec161eb6e08d6)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Use cond_resched() directly and remove useless kvm_resched()

Since the commit 15ad7146 ("KVM: Use the scheduler preemption notifiers
to make kvm preemptible"), the remaining stuff in this function is a
simple cond_resched() call with an extra need_resched() check which was
there to avoid dropping VCPUs unnecessarily.  Now it is meaningless.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit c08ac06ab3f3cdb8d34376c3a8a5e46a31a62c8f)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Improve create VCPU parameter (CVE-2013-4587)

In multiple functions the vcpu_id is used as an offset into a bitfield.  Ag
malicious user could specify a vcpu_id greater than 255 in order to set or
clear bits in kernel memory.  This could be used to elevate priveges in the
kernel.  This patch verifies that the vcpu_id provided is less than 255.
The api documentation already specifies that the vcpu_id must be less than
max_vcpus, but this is currently not checked.

Reported-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 338c7dbadd2671189cec7faf64c84d01071b3f96)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm/arm64: kvm: Use virt_to_idmap instead of virt_to_phys for idmap mappings

KVM initialisation fails on architectures implementing virt_to_idmap()
because virt_to_phys() on such architectures won't fetch you the correct
idmap page.

So update the KVM ARM code to use the virt_to_idmap() to fix the issue.
Since the KVM code is shared between arm and arm64, we create
kvm_virt_to_phys() and handle the redirection in respective headers.

Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 4fda342cc7f577599c53fd27b99c953c7b1da18a)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: kvm_clear_guest_page(): fix empty_zero_page usage

Using the address of 'empty_zero_page' as source address in order to
clear a page is wrong. On some architectures empty_zero_page is only the
pointer to the struct page of the empty_zero_page.  Therefore the clear
page operation would copy the contents of a couple of struct pages instead
of clearing a page.  For kvm only arm/arm64 are affected by this bug.

To fix this use the ZERO_PAGE macro instead which will return the struct
page address of the empty_zero_page on all architectures.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 8a3caa6d74597c2a083f7c87f866891a0b12540b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm/arm64: KVM: Fix hyp mappings of vmalloc regions

Using virt_to_phys on percpu mappings is horribly wrong as it may be
backed by vmalloc.  Introduce kvm_kaddr_to_phys which translates both
types of valid kernel addresses to the corresponding physical address.

At the same time resolves a typing issue where we were storing the
physical address as a 32 bit unsigned long (on arm), truncating the
physical address for addresses above the 4GB limit.  This caused
breakage on Keystone.

Cc: <stable@vger.kernel.org> [3.10+]
Reported-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 40c2729bab48e2832b17c1fa8af9db60e776131b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm/arm64: KVM: PSCI: propagate caller endianness to the incoming vcpu

When booting a vcpu using PSCI, make sure we start it with the
endianness of the caller. Otherwise, secondaries can be pretty
unhappy to execute a BE kernel in LE mode...

This conforms to PSCI spec Rev B, 5.13.3.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit ce94fe93d566bf381c6ecbd45010d36c5f04d692)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm/arm64: KVM: MMIO support for BE guest

Do the necessary byteswap when host and guest have different
views of the universe. Actually, the only case we need to take
care of is when the guest is BE. All the other cases are naturally
handled.

Also be careful about endianness when the data is being memcopy-ed
from/to the run buffer.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6d89d2d9b5bac9dbe40ee106ceda9307b6265234)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: vgic: byteswap GICv2 access on world switch if BE

Ensure that accesses to the GICH_* registers are byteswapped
when the kernel is compiled as big-endian.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit c5b2c0f5203b3bc678a8967daedf7114029975ae)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: initialize HYP mode following the kernel endianness

Force SCTLR_EL2.EE to 1 if the kernel is compiled as BE.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 18ea3dbc9e5c8a53a361b17c4a5676ea6f4bcb72)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: remove vm mmap method

It was used in conjunction with KVM_SET_MEMORY_REGION ioctl which was
removed by b74a07beed0 in 2010, QEMU stopped using it in 2008, so
it is time to remove the code finally.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 80f5b5e700fa9c58480eafce0d47367bafb70006)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm_host: typo fix

fix up typo in comment.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 81e87e26796782e014fd1f2bb9cd8fb6ce4021a8)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: Add VFIO device

So far we've succeeded at making KVM and VFIO mostly unaware of each
other, but areas are cropping up where a connection beyond eventfds
and irqfds needs to be made.  This patch introduces a KVM-VFIO device
that is meant to be a gateway for such interaction.  The user creates
the device and can add and remove VFIO groups to it via file
descriptors.  When a group is added, KVM verifies the group is valid
and gets a reference to it via the VFIO external user interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit ec53500fae421e07c5d035918ca454a429732ef4)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: Add KVM_GET_EMULATED_CPUID

Add a kvm ioctl which states which system functionality kvm emulates.
The format used is that of CPUID and we return the corresponding CPUID
bits set for which we do emulate functionality.

Make sure ->padding is being passed on clean from userspace so that we
can use it for something in the future, after the ioctl gets cast in
stone.

s/kvm_dev_ioctl_get_supported_cpuid/kvm_dev_ioctl_get_cpuid/ while at
it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 9c15bb1d0a8411f9bb3395d21d5309bde7da0c1c)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: use a more sensible error number when debugfs directory creation fails

I don't know if this was due to cut and paste, or somebody was really
using a D20 to pick the error code for kvm_init_debugfs as suggested by
Linus (EFAULT is 14, so the possibility cannot be entirely ruled out).

In any case, this patch fixes it.

Reported-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 0c8eb04a6241da28deb108181213b791c378123b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: Yield CPU when vcpu executes a WFE

On an (even slightly) oversubscribed system, spinlocks are quickly
becoming a bottleneck, as some vcpus are spinning, waiting for a
lock to be released, while the vcpu holding the lock may not be
running at all.

The solution is to trap blocking WFEs and tell KVM that we're
now spinning. This ensures that other vpus will get a scheduling
boost, allowing the lock to be released more quickly. Also, using
CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance
when the VM is severely overcommited.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit d241aac798eb042e605f78c31a4122e583b2cd13)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Mapping IOMMU pages after updating memslot

In kvm_iommu_map_pages(), we need to know the page size via call
kvm_host_page_size(). And it will check whether the target slot
is valid before return the right page size.
Currently, we will map the iommu pages when creating a new slot.
But we call kvm_iommu_map_pages() during preparing the new slot.
At that time, the new slot is not visible by domain(still in preparing).
So we cannot get the right page size from kvm_host_page_size() and
this will break the IOMMU super page logic.
The solution is to map the iommu pages after we insert the new slot
into domain.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Tested-by: Patrick Lu <patrick.lu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit e0230e1327fb862c9b6cde24ae62d55f9db62c9b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm/arm64: KVM: PSCI: use MPIDR to identify a target CPU

The KVM PSCI code blindly assumes that vcpu_id and MPIDR are
the same thing. This is true when vcpus are organized as a flat
topology, but is wrong when trying to emulate any other topology
(such as A15 clusters).

Change the KVM PSCI CPU_ON code to look at the MPIDR instead
of the vcpu_id to pick a target CPU.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 79c648806f9034abf54332b78043bb242189d953)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: drop limitation to 4 CPU VMs

Now that the KVM/arm code knows about affinity, remove the hard
limit of 4 vcpus per VM.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 7999b4d18211bcfb40e3574cf75e94518e9fa2c6)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: fix L2CTLR to be per-cluster

The L2CTLR register contains the number of CPUs in this cluster.

Make sure the register content is actually relevant to the vcpu
that is being configured by computing the number of cores that are
part of its cluster.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 9cbb6d969cb6561de45d917b8bb9281cb374bb35)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Fix MPIDR computing to support virtual clusters

In order to be able to support more than 4 A7 or A15 CPUs,
we need to fix the MPIDR computing to reflect the fact that
both A15 and A7 can only exist in clusters of at most 4 CPUs.

Fix the MPIDR computing to allow virtual clusters to be exposed
to the guest.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 2d1d841bd44e24b58a3d3cc4fa793670aaa38fbf)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Transparent huge page (THP) support

Support transparent huge pages in KVM/ARM and KVM/ARM64.  The
transparent_hugepage_adjust is not very pretty, but this is also how
it's solved on x86 and seems to be simply an artifact on how THPs
behave.  This should eventually be shared across architectures if
possible, but that can always be changed down the road.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 9b5fdb9781f74fb15827e465bfb5aa63211953c8)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Support hugetlbfs backed huge pages

Support huge pages in KVM/ARM and KVM/ARM64.  The pud_huge checking on
the unmap path may feel a bit silly as the pud_huge check is always
defined to false, but the compiler should be smart about this.

Note: This deals only with VMAs marked as huge which are allocated by
users through hugetlbfs only.  Transparent huge pages can only be
detected by looking at the underlying pages (or the page tables
themselves) and this patch so far simply maps these on a page-by-page
level in the Stage-2 page tables.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit ad361f093c1e31d0b43946210a32ab4ff5c49850)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Update comments for kvm_handle_wfi

Update comments to reflect what is really going on and add the TWE bit
to the comments in kvm_arm.h.

Also renames the function to kvm_handle_wfx like is done on arm64 for
consistency and uber-correctness.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 86ed81aa2e1ce05a4e7f0819f0dfc34e8d8fb910)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Yield CPU when vcpu executes a WFE

On an (even slightly) oversubscribed system, spinlocks are quickly
becoming a bottleneck, as some vcpus are spinning, waiting for a
lock to be released, while the vcpu holding the lock may not be
running at all.

This creates contention, and the observed slowdown is 40x for
hackbench. No, this isn't a typo.

The solution is to trap blocking WFEs and tell KVM that we're
now spinning. This ensures that other vpus will get a scheduling
boost, allowing the lock to be released more quickly. Also, using
CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance
when the VM is severely overcommited.

Quick test to estimate the performance: hackbench 1 process 1000

2xA15 host (baseline): 1.843s

2xA15 guest w/o patch: 2.083s
4xA15 guest w/o patch: 80.212s
8xA15 guest w/o patch: Could not be bothered to find out

2xA15 guest w/ patch: 2.102s
4xA15 guest w/ patch: 3.205s
8xA15 guest w/ patch: 6.887s

So we go from a 40x degradation to 1.5x in the 2x overcommit case,
which is vaguely more acceptable.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 58d5ec8f8ee318b26b29207874fbaee626973952)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: Add struct kvm arg to memslot APIs

We will use that in the later patch to find the kvm ops handler

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
(cherry picked from commit 5587027ce9d59a57aecaa190be1c8e560aaff45d)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Drop FOLL_GET in GUP when doing async page fault

Page pinning is not mandatory in kvm async page fault processing since
after async page fault event is delivered to a guest it accesses page once
again and does its own GUP.  Drop the FOLL_GET flag in GUP in async_pf
code, and do some simplifying in check/clear processing.

Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Gu zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: chai wen <chaiw.fnst@cn.fujitsu.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit f2e106692d5189303997ad7b96de8d8123aa5613)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: arm64: Get rid of KVM_HPAGE defines

Now when the main kvm code relying on these defines has been moved to
the x86 specific part of the world, we can get rid of these.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit ef0cfe71c2b1710cd4ae747537e36c56f9a26ccf)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Get rid of KVM_HPAGE defines

The KVM_HPAGE_DEFINES are a little artificial on ARM, since the huge
page size is statically defined at compile time and there is only a
single huge page size.

Now when the main kvm code relying on these defines has been moved to
the x86 specific part of the world, we can get rid of these.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit dc6f6763dfeaf2dfec906bb78875dcea162accd9)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Move gfn_to_index to x86 specific code

The gfn_to_index function relies on huge page defines which either may
not make sense on systems that don't support huge pages or are defined
in an unconvenient way for other architectures.  Since this is
x86-specific, move the function to arch/x86/include/asm/kvm_host.h.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 6d9d41e57440e32a3400f37aa05ef7a1a09ced64)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Add support for Cortex-A7

This patch adds support for running Cortex-A7 guests on Cortex-A7 hosts.

As Cortex-A7 is architecturally compatible with A15, this patch is largely just
generalising existing code. Areas where 'implementation defined' behaviour
is identical for A7 and A15 is moved to allow it to be used by both cores.

The check to ensure that coprocessor register tables are sorted correctly is
also moved in to 'common' code to avoid each new cpu doing its own check
(and possibly forgetting to do so!)

Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit e8c2d99f8277d68d28a9f99d16289712bc2aee7f)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: fix the size of TTBCR_{T0SZ,T1SZ} masks

The T{0,1}SZ fields of TTBCR are 3 bits wide when using the long descriptor
format. Likewise, the T0SZ field of the HTCR is 3-bits. KVM currently
defines TTBCR_T{0,1}SZ as 3, not 7.

The T0SZ mask is used to calculate the value for the HTCR, both to pick out
TTBCR.T0SZ and mask off the equivalent field in the HTCR during
read-modify-write. The incorrect mask size causes the (UNKNOWN) reset value
of HTCR.T0SZ to leak in to the calculated HTCR value. Linux will hang when
initializing KVM if HTCR's reset value has bit 2 set (sometimes the case on
A7/TC2)

Fixing T0SZ allows A7 cores to boot and T1SZ is also fixed for completeness.

Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 5e497046f005528464f9600a4ee04f49df713596)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Fix calculation of virtual CPU ID

KVM does not have a notion of multiple clusters for CPUs, just a linear
array of CPUs. When using a system with cores in more than one cluster, the
current method for calculating the virtual MPIDR will leak the (physical)
cluster information into the virtual MPIDR. One effect of this is that
Linux under KVM fails to boot multiple CPUs that aren't in the 0th cluster.

This patch does away with exposing the real MPIDR fields in favour of simply
using the virtual CPU number (but preserving the U bit, as before).

Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 1158fca401e09665c440a9fe4fd4f131ee85c13b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

virt/kvm/iommu.c: Add leading zeros to device's BDF notation in debug messages

When KVM (de)assigns PCI(e) devices to VMs, a debug message is printed
including the BDF notation of the respective device. Currently, the BDF
notation does not have the commonly used leading zeros. This produces
messages like "assign device 0:1:8.0", which look strange at first sight.

The patch fixes this by exchanging the printk(KERN_DEBUG ...) with dev_info()
and also inserts "kvm" into the debug message, so that it is obvious where
the message comes from. Also reduces LoC.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Andre Richter <andre.o.richter@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 29242cb5c63b1f8e12e8055ba1a6c3e0004fa86d)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Fix NULL dereference in gfn_to_hva_prot()

gfn_to_memslot() can return NULL or invalid slot. We need to check slot
validity before accessing it.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit a2ac07fe292ea41296049dfdbfeed203e2467ee7)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM/ARM64: KVM: Implement KVM_ARM_PREFERRED_TARGET ioctl

For implementing CPU=host, we need a mechanism for querying
preferred VCPU target type on underlying Host.

This patch implements KVM_ARM_PREFERRED_TARGET vm ioctl which
returns struct kvm_vcpu_init instance containing information
about preferred VCPU target type and target specific features
available for it.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 42c4e0c77ac91505ab94284b14025e3a0865c0a5)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM64: KVM: Implement kvm_vcpu_preferred_target() function

This patch implements kvm_vcpu_preferred_target() function for
KVM ARM64 which will help us implement KVM_ARM_PREFERRED_TARGET
ioctl for user space.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 473bdc0e6565ebb22455657a40daa21b6b4ee16b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Implement kvm_vcpu_preferred_target() function

This patch implements kvm_vcpu_preferred_target() function for
KVM ARM which will help us implement KVM_ARM_PREFERRED_TARGET ioctl
for user space.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 4a6fee805d5e278e4733bf933cb5b184b7a8be1f)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Fix typo in comments of inject_abt()

Very minor typo in comments of inject_abt() when we update fault status
register for injecting prefetch abort.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit b373e492f3a3469c615c2ae218d2f723900bf981)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Convert kvm_lock back to non-raw spinlock

In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"),
the kvm_lock was made a raw lock.  However, the kvm mmu_shrink()
function tries to grab the (non-raw) mmu_lock within the scope of
the raw locked kvm_lock being held.  This leads to the following:

BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0
Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm]

Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt
Call Trace:
 [<ffffffff8106f2ad>] __might_sleep+0xfd/0x160
 [<ffffffff817d8d64>] rt_spin_lock+0x24/0x50
 [<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm]
 [<ffffffff8111455d>] shrink_slab+0x17d/0x3a0
 [<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260
 [<ffffffff8111824a>] balance_pgdat+0x54a/0x730
 [<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0
 [<ffffffff811185bf>] kswapd+0x18f/0x490
 [<ffffffff81070961>] ? get_parent_ip+0x11/0x50
 [<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50
 [<ffffffff81118430>] ? balance_pgdat+0x730/0x730
 [<ffffffff81060d2b>] kthread+0xdb/0xe0
 [<ffffffff8106e122>] ? finish_task_switch+0x52/0x100
 [<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10
 [<ffffffff81060c50>] ? __init_kthread_worker+0x

After the previous patch, kvm_lock need not be a raw spinlock anymore,
so change it back.

Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 2f303b74a62fb74983c0a66e2df353be963c527c)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: protect kvm_usage_count with its own spinlock

The VM list need not be protected by a raw spinlock.  Separate the
two so that kvm_lock can be made non-raw.

Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 4a937f96f3a29c58b7edd349d2e4dfac371efdf2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: cleanup (physical) CPU hotplug

Remove the useless argument, and do not do anything if there are no
VMs running at the time of the hotplug.

Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 4fa92fb25ae5a2d79d872ab54df511c831b1f363)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: kvm: rename cpu_reset to avoid name clash

cpu_reset is already #defined in <asm/proc-fns.h> as processor.reset,
so it expands here and causes problems.

Cc: <stable@vger.kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit ac570e0493815e0b41681c89cb50d66421429d27)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: remove .done from struct kvm_async_pf

'.done' is used to mark the completion of 'async_pf_execute()', but
'cancel_work_sync()' returns true when the work was canceled, so we
use it instead.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 98fda169290b3b28c0f2db2b8f02290c13da50ef)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: free resources after canceling async_pf

When we cancel 'async_pf_execute()', we should behave as if the work was
never scheduled in 'kvm_setup_async_pf()'.
Fixes a bug when we can't unload module because the vm wasn't destroyed.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 28b441e24088081c1e213139d1303b451a34a4f4)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: mmu: allow page tables to be in read-only slots

Page tables in a read-only memory slot will currently cause a triple
fault because the page walker uses gfn_to_hva and it fails on such a slot.

OVMF uses such a page table; however, real hardware seems to be fine with
that as long as the accessed/dirty bits are set.  Save whether the slot
is readonly, and later check it when updating the accessed and dirty bits.

Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit ba6a3541545542721ce821d1e7e5ce35752e6fdf)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Add newlines to panic strings

The panic strings are hard to read and on narrow terminals some
characters are simply truncated off the panic message.

Make is slightly prettier with a newline in the Hyp panic strings.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 1fe40f6d39d23f39e643607a3e1883bfc74f1244)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Work around older compiler bug

Compilers before 4.6 do not behave well with unnamed fields in structure
initializers and therefore produces build errors:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676

By refering to the unnamed union using braces, both older and newer
compilers produce the same result.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Russell King <linux@arm.linux.org.uk>
Tested-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 6833d83891140aedab7841589b7c7dbd7b600235)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Simplify tracepoint text

The tracepoint for kvm_guest_fault was extremely long, make it a
slightly bit shorter.

Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 6e72cc5700fe6b8776d537b736dab64b21ae0f1f)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Fix kvm_set_pte assignment

THe kvm_set_pte function was actually assigning the entire struct to the
structure member, which should work because the structure only has that
one member, but it is still not very nice.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 0963e5d0f22f9d197dbf206d8b5b2a150722cf5e)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: vgic: Bump VGIC_NR_IRQS to 256

The Versatile Express TC2 board, which we use as our main emulated
platform in QEMU, defines 160+32 == 192 interrupts, so limiting the
number of interrupts to 128 is not quite going to cut it for real board
emulation.

Note that this didn't use to be a problem because QEMU was buggy and
only defined 128 interrupts until recently.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 9b2d2e0df8a49414b1e5bc89148c9984dd87782a)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Bugfix: vgic_bytemap_get_reg per cpu regs

For bytemaps each IRQ field is 1 byte wide, so we pack 4 irq fields in
one word and since there are 32 private (per cpu) irqs, we have 8
private u32 fields on the vgic_bytemap struct.  We shift the offset from
the base of the register group right by 2, giving us the word index
instead of the field index.  But then there are 8 private words, not 4,
which is also why we subtract 8 words from the offset of the shared
words.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 8d98915b6bda499e47d19166101d0bbcfd409c80)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: vgic: fix GICD_ICFGRn access

All the code in handle_mmio_cfg_reg() assumes the offset has
been shifted right to accomodate for the 2:1 bit compression,
but this is only done when getting the register address.

Shift the offset early so the code works mostly unchanged.

Reported-by: Zhaobo (Bob, ERC) <zhaobo@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 6545eae3d7a1b6dc2edb8ede9107998aee1207ef)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: vgic: simplify vgic_get_target_reg

vgic_get_target_reg is quite complicated, for no good reason.
Actually, it is fairly easy to write it in a much more efficient
way by using the target CPU array instead of the bitmap.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 986af8e0789a41ac4844e6eefed4a33e86524918)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: optimize away THP checks in kvm_is_mmio_pfn()

The checks on PG_reserved in the page structure on head and tail pages
aren't necessary because split_huge_page wouldn't transfer the
PG_reserved bit from head to tail anyway.

This was a forward-thinking check done in the case PageReserved was
set by a driver-owned page mapped in userland with something like
remap_pfn_range in a VM_PFNMAP region, but using hugepmds (not
possible right now). It was meant to be very safe, but it's overkill
as it's unlikely split_huge_page could ever run without the driver
noticing and tearing down the hugepage itself.

And if a driver in the future will really want to map a reserved
hugepage in userland using an huge pmd it should simply take care of
marking all subpages reserved too to keep KVM safe. This of course
would require such a hypothetical driver to tear down the huge pmd
itself and splitting the hugepage itself, instead of relaying on
split_huge_page, but that sounds very reasonable, especially
considering split_huge_page wouldn't currently transfer the reserved
bit anyway.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 11feeb498086a3a5907b8148bdf1786a9b18fc55)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

kvm: use anon_inode_getfd() with O_CLOEXEC flag

KVM uses anon_inode_get() to allocate file descriptors as part
of some of its ioctls. But those ioctls are lacking a flag argument
allowing userspace to choose options for the newly opened file descriptor.

In such case it's advised to use O_CLOEXEC by default so that
userspace is allowed to choose, without race, if the file descriptor
is going to be inherited across exec().

This patch set O_CLOEXEC flag on all file descriptors created
with anon_inode_getfd() to not leak file descriptors across exec().

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 24009b0549de563006705b9af8694fc8fc9a5aa1)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: 7808/1: KVM: mm: Get rid of L_PTE_USER ref from PAGE_S2_DEVICE

THe L_PTE_USER actually has nothing to do with stage 2 mappings and the
L_PTE_S2_RDWR value sets the readable bit, which was what L_PTE_USER
was used for before proper handling of stage 2 memory defines.

Changelog:
  [v3]: Drop call to kvm_set_s2pte_writable in mmu.c
  [v2]: Change default mappings to be r/w instead of r/o, as per Marc
     Zyngier's suggestion.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
(cherry picked from commit 8947c09d05da9f0436f423518f449beaa5ea1bdc)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: kvm: use inner-shareable barriers after TLB flushing

When flushing the TLB at PL2 in response to remapping at stage-2 or VMID
rollover, we have a dsb instruction to ensure completion of the command
before continuing.

Since we only care about other processors for TLB invalidation, use the
inner-shareable variant of the dsb instruction instead.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit e3ab547f57bd626201d4b715b696c80ad1ef4ba2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: ARM: Squash len warning

The 'len' variable was declared an unsigned and then checked for less
than 0, which results in warnings on some compilers.  Since len is
assigned an int, make it an int.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 2184a60de26b94bc5a88de3e5a960ef9ff54ba5a)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: use 'int' instead of 'u32' for variable 'target' in kvm_host.h.

'target' will be set to '-1' in kvm_arch_vcpu_init(), and it need check
'target' whether less than zero or not in kvm_vcpu_initialized().

So need define target as 'int' instead of 'u32', just like ARM has done.

The related warning:

  arch/arm64/kvm/../../../arch/arm/kvm/arm.c:497:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]

Signed-off-by: Chen Gang <gang.chen@asianux.com>
[Marc: reformated the Subject line to fit the series]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6c8c0c4dc0e98ee2191211d66e9f876e95787073)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: add missing dsb before invalidating Stage-2 TLBs

When performing a Stage-2 TLB invalidation, it is necessary to
make sure the write to the page tables is observable by all CPUs.

For this purpose, add dsb instructions to __kvm_tlb_flush_vmid_ipa
and __kvm_flush_vm_context before doing the TLB invalidation itself.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit f142e5eeb724cfbedd203b32b3b542d78dbe2545)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: perform save/restore of PAR_EL1

Not saving PAR_EL1 is an unfortunate oversight. If the guest
performs an AT* operation and gets scheduled out before reading
the result of the translation from PAREL1, it could become
corrupted by another guest or the host.

Saving this register is made slightly more complicated as KVM also
uses it on the permission fault handling path, leading to an ugly
"stash and restore" sequence. Fortunately, this is already a slow
path so we don't really care. Also, Linux doesn't do any AT*
operation, so Linux guests are not impacted by this bug.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 1bbd80549810637b7381ab0649ba7c7d62f1342a)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: fix 2-level page tables unmapping

When using 64kB pages, we only have two levels of page tables,
meaning that PGD, PUD and PMD are fused. In this case, trying
to refcount PUDs and PMDs independently is a a complete disaster,
as they are the same.

We manage to get it right for the allocation (stage2_set_pte uses
{pmd,pud}_none), but the unmapping path clears both pud and pmd
refcounts, which fails spectacularly with 2-level page tables.

The fix is to avoid calling clear_pud_entry when both the pmd and
pud pages are empty. For this, and instead of introducing another
pud_empty function, consolidate both pte_empty and pmd_empty into
page_empty (the code is actually identical) and use that to also
test the validity of the pud.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 979acd5e18c3e5cb7e3308c699d79553af5af8c6)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Fix unaligned unmap_range leak

The unmap_range function did not properly cover the case when the start
address was not aligned to PMD_SIZE or PUD_SIZE and an entire pte table
or pmd table was cleared, causing us to leak memory when incrementing
the addr.

The fix is to always move onto the next page table entry boundary
instead of adding the full size of the VA range covered by the
corresponding table level entry.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit d3840b26614d8ce3db53c98061d9fcb1b9ccb0dd)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

KVM: Introduce kvm_arch_memslots_updated()

This is called right after the memslots is updated, i.e. when the result
of update_memslots() gets installed in install_new_memslots().  Since
the memslots needs to be updated twice when we delete or move a memslot,
kvm_arch_commit_memory_region() does not correspond to this exactly.

In the following patch, x86 will use this new API to check if the mmio
generation has reached its maximum value, in which case mmio sptes need
to be flushed out.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Acked-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit e59dbe09f8e6fb8f6ee19dc79d1a2f14299e4cd2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: Kconfig integration

Finally plug KVM/arm64 into the config system, making it possible
to enable KVM support on AArch64 CPUs.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit c3eb5b14449a0949e9764d39374a2ea63faae14f)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: kvm: don't include drivers/virtio/Kconfig

The virtio configuration has recently moved and is now visible everywhere.
Including the file again from KVM as we used to need earlier now causes
dependency problems:

warning: (CAIF_VIRTIO && VIRTIO_PCI && VIRTIO_MMIO && REMOTEPROC && RPMSG)
selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION)

Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit 8bd4ffd6b3a98f00267051dc095076ea2ff06ea8)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm/kvm: Cleanup KVM_ARM_MAX_VCPUS logic

Commit d21a1c83c7595e387545632e44cd7797b76e19cc (ARM: KVM: define KVM_ARM_MAX_VCPUS
unconditionally) changed the Kconfig logic for KVM_ARM_MAX_VCPUS to work around a
build error arising from the use of KVM_ARM_MAX_VCPUS when CONFIG_KVM=n.  The
resulting Kconfig logic is a bit awkward and leaves a KVM_ARM_MAX_VCPUS always
defined in the kernel config file.

This change reverts the Kconfig logic back and adds a simple preprocessor
conditional in kvm_host.h to handle when CONFIG_KVM_ARM_MAX_VCPUS is undefined.

Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
(cherry picked from commit f2dda9d829818b055510187059cdfa4ece10c82d)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: get rid of S2_PGD_SIZE

S2_PGD_SIZE defines the number of pages used by a stage-2 PGD
and is unused, except for a VM_BUG_ON check that missuses the
define.

As the check is very unlikely to ever triggered except in
circumstances where KVM is the least of our worries, just kill
both the define and the VM_BUG_ON check.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 4db845c3d8e2f8a219e8ac48834dd4fe085e5d63)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: don't special case PC when doing an MMIO

Admitedly, reading a MMIO register to load PC is very weird.
Writing PC to a MMIO register is probably even worse. But
the architecture doesn't forbid any of these, and injecting
a Prefetch Abort is the wrong thing to do anyway.

Remove this check altogether, and let the adventurous guest
wander into LaLaLand if they feel compelled to do so.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 8734f16fb2aa4ff0bb57ad6532661a38bc8ff957)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: use phys_addr_t instead of unsigned long long for HYP PGDs

HYP PGDs are passed around as phys_addr_t, except just before calling
into the hypervisor init code, where they are cast to a rather weird
unsigned long long.

Just keep them around as phys_addr_t, which is what makes the most
sense.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit dac288f7b38a7439502b77dabcdf8a9a5c4ae721)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: remove dead prototype for __kvm_tlb_flush_vmid

__kvm_tlb_flush_vmid has been renamed to __kvm_tlb_flush_vmid_ipa,
and the old prototype should have been removed when the code was
modified.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 368074d908b785588778f00b4384376cd636f4a1)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Don't handle PSCI calls via SMC

Currently, kvmtool unconditionally declares that HVC should be used
to call PSCI, so the function numbers in the DT tell the guest
nothing about the function ID namespace or calling convention for
SMC.

We already assume that the guest will examine and honour the DT,
since there is no way it could possibly guess the KVM-specific PSCI
function IDs otherwise.  So let's not encourage guests to violate
what's specified in the DT by using SMC to make the call.

[ Modified to apply to top of kvm/arm tree - Christoffer ]

Signed-off-by: Dave P Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 24a7f675752e06729589d40a5256970998a21502)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: Allow host virt timer irq to be different from guest timer virt irq

The arch_timer irq numbers (or PPI numbers) are implementation dependent,
so the host virtual timer irq number can be different from guest virtual
timer irq number.

This patch ensures that host virtual timer irq number is read from DTB and
guest virtual timer irq is determined based on vcpu target type.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit 5ae7f87a56fab10b8f9b135a8377c144397293ca)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: document kernel object mappings in HYP

HYP mode has access to some of the kernel pages. Document the
memory mapping and the offset between kernel VA and HYP VA.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit aa4a73a0a23a65a2f531d01f1865d1e61c6acb55)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: MAINTAINERS update

Elect myself as the KVM/arm64 maintainer.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6394a3ec02ab39147aab9ea56d0dabafd3dcae60)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: userspace API documentation

Unsurprisingly, the arm64 userspace API is extremely similar to
the 32bit one, the only significant difference being the ONE_REG
register mapping.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 379e04c79e8a9ded8a202f1e266f0c5830185bea)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: enable initialization of a 32bit vcpu

Wire the init of a 32bit vcpu by allowing 32bit modes in pstate,
and providing sensible defaults out of reset state.

This feature is of course conditioned by the presence of 32bit
capability on the physical CPU, and is checked by the KVM_CAP_ARM_EL1_32BIT
capability.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 0d854a60b1d7d39a37b25dd28f63cfa0df637b91)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: 32bit guest fault injection

Add fault injection capability for 32bit guests.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit e82e030556e42e823e174e0c3bd97988d1a09d1f)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: 32bit specific register world switch

Allow registers specific to 32bit guests to be saved/restored
during the world switch.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit b4afad06c19e3489767532f86ff453a1d1e28b8c)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: CPU specific 32bit coprocessor access

Enable handling of CPU specific 32bit coprocessor access. Not much
here either.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 06c7654d2fb8bac7b1af4340ad59434a5d89b86a)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: 32bit handling of coprocessor traps

Provide the necessary infrastructure to trap coprocessor accesses that
occur when running 32bit guests.

Also wire SMC and HVC trapped in 32bit mode while were at it.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 62a89c44954f09072bf07a714c8f68bda14ab87e)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: 32bit conditional execution emulation

As conditional instructions can trap on AArch32, add the thinest
possible emulation layer to keep 32bit guests happy.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 27b190bd9fbfee34536cb858f0b5924d294aac38)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: 32bit GP register access

Allow access to the 32bit register file through the usual API.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit b547631fc64e249a3c507e6ce854642507fa7c1c)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: define 32bit specific registers

Define the 32bit specific registers (SPSRs, cp15...).

Most CPU registers are directly mapped to a 64bit register
(r0->x0...). Only the SPSRs have separate registers.

cp15 registers are also mapped into their 64bit counterpart in most
cases.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 40033a614ea3db196d57c477ca328f44eb1e4df0)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: Build system integration

Only the Makefile is plugged in. The Kconfig stuff is in a separate
patch to allow for an easier merge process.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6211753fdfd05af9e08f54c8d0ba3ee516034878)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: PSCI implementation

Wire the PSCI backend into the exit handling code.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit dcd2e40c1e1cce302498d16d095b0f8a30326f74)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: Plug the arch timer

Add support for the in-kernel timer emulation.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 003300de6c3e51934fb52eb2677f6f4fb4996cbd)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

ARM: KVM: timer: allow DT matching for ARMv8 cores

ARMv8 cores have the exact same timer as ARMv7 cores. Make sure the
KVM timer code can match it in the device tree.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit f61701e0a24a09aa4a44baf24e57dcc5e706afa8)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: Plug the VGIC

Add support for the in-kernel GIC emulation.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 1f17f3b6044d8a81a74dc6c962b3b38a7336106b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: Exit handling

Handle the exit of a VM, decoding the exit reason from HYP mode
and calling the corresponding handler.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit c4b1afd022e93eada6ee4b209be37101cd4b3494)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: HYP mode world switch implementation

The HYP mode world switch in all its glory.

Implements save/restore of host/guest registers, EL2 trapping,
IPA resolution, and additional services (tlb invalidation).

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 55c7401d92e16360e0987afe39355f1eb6300f31)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: hypervisor initialization code

Provide EL2 with page tables and stack, and set the vectors
to point to the full blown world-switch code.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 092bd143cbb481b4ce1d55247a2987eaaf61f967)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: guest one-reg interface

Let userspace play with the guest registers.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 2f4a07c5f9fe4a5cdb9867e1e2fcab3165846ea7)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: MMIO access backend

Define the necessary structures to perform an MMIO access.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit d7246bf3571a82834984a42db52261525bc11159)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: kvm_arch and kvm_vcpu_arch definitions

Provide the architecture dependent structures for VM and
vcpu abstractions.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 4f8d6632ec71372a3b8dbb4775662c2c9025d173)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: virtual CPU reset

Provide the reset code for a virtual CPU booted in 64bit mode.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit f4672752c321ea36ce099cebdd7a082a8f327505)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: CPU specific system registers handling

Add the support code for CPU specific system registers. Not much
here yet.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit b990a9d3152bddca62cc1f8bf80518430b98737b)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: system register handling

Provide 64bit system register handling, modeled after the cp15
handling for ARM.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 7c8c5e6a9101ea57a1c2c9faff0917e79251a21e)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arm64: KVM: user space interface

Provide the kvm.h file that defines the user space visible
interface.

Reviewed-by: Christopher Covington <cov@codeaurora.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 54f81d0eb93896da73d1636bca84cf90f52cabdf)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>