If EL1 generates an asynchronous abort and then traps into EL2
before the abort has been delivered, we may end-up with the
abort firing at the worse possible place: on the host.

In order to avoid this, it is necessary to take the abort at EL2,
by clearing the PSTATE.A bit. In order to survive this abort,
we do it at a point where we're in a known state with respect
to the world switch, and handle the resulting exception,
overloading the exit code in the process.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

If we have caught an SError whilst exiting, we've tagged the
exit code with the pending information. In that case, let's
re-inject the error into the guest, after having adjusted
the PC if required.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Similarily to EL1, an asynchronous abort can be triggered whilst
running at EL2. But instead of making that a new error code,
we need to communicate it to the rest of KVM together with
the exit reason. So let's hijack a single bit that allows the
exception code to be tagged with a "pending SError" information.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

As we now have some basic handling to EL1-triggered aborts, we can
actually report them to KVM.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

If we've exited the guest because it has triggered an asynchronous
abort from EL1, a possible course of action is to let it know it
screwed up by giving it a Virtual Abort to chew on.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

So far, we don't have a code to indicate that we've taken an
asynchronous abort from EL1. Let's add one.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Now that we're able to context switch the HCR_EL2.VA bit, let's
introduce a helper that injects an Abort into a vcpu.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

The HCR_EL2.VSE bit is used to signal an SError to a guest, and has
the peculiar feature of getting cleared when the guest has taken
the abort (this is the only bit that behaves as such in this register).

This means that if we signal such an abort, we must leave it
in the guest context until it disappears from HCR_EL2, and at which
point it must be cleared from the context. This is achieved by
reading back from HCR_EL2 until the guest takes the fault.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

HCR_VA is a leftover from ARMv7, On ARMv8, this is HCR_VSE
(which stands for Virtual System Error), and has better
defined semantics.

Let's rename the constant.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

So far, we've been disabling KVM on systems where the GICV region couldn't
be safely given to a guest. Now that we're able to handle this access
safely by emulating it in HYP, we can enable this feature when we detect
an unsafe configuration.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Now that we have the necessary infrastructure to handle MMIO accesses
in HYP, perform the GICV access on behalf of the guest. This requires
checking that the access is strictly 32bit, properly aligned, and
falls within the expected range.

When all condition are satisfied, we perform the access and tell
the rest of the HYP code that the instruction has been correctly
emulated.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

In order to efficiently perform the GICV access on behalf of the
guest, we need to be able to avoid going back all the way to
the host kernel.

For this, we introduce a new hook in the world switch code,
conveniently placed just after populating the fault info.
At that point, we only have saved/restored the GP registers,
and we can quickly perform all the required checks (data abort,
translation fault, valid faulting syndrome, not an external
abort, not a PTW).

Coming back from the emulation code, we need to skip the emulated
instruction. This involves an additional bit of save/restore in
order to be able to access the guest's PC (and possibly CPSR if
this is a 32bit guest).

At this stage, no emulation code is provided.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

As we plan to do some emulation at HYP, let's make kvm_skip_instr32
as part of the hyp_text section. This doesn't preclude the kernel
from using it.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Add the bit of glue and const-ification that is required to use
the code inherited from the arm64 port, and move over to it.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

It would make some sense to share the conditional execution code
between 32 and 64bit. In order to achieve this, let's move that
code to virt/kvm/arm/aarch32.c. While we're at it, drop a
superfluous BUG_ON() that wasn't that useful.

Following patches will migrate the 32bit port to that code base.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

In order to make emulate.c more generic, move the arch-specific
manupulation bits out of emulate.c.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

SCTLR_EL2.SPAN bit controls what happens with the PSTATE.PAN bit on an
exception. However, this bit has no effect on the PSTATE.PAN when
HCR_EL2.E2H or HCR_EL2.TGE is unset. Thus when VHE is used and
exception taken from a guest PSTATE.PAN bit left unchanged and we
continue with a value guest has set.

To address that always reset PSTATE.PAN on entry from EL1.

Fixes: 1f364c8c ("arm64: VHE: Add support for running Linux in EL2 mode")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

When rewriting the assembly code to C code, it was useful to have
exported aliases or static functions so that we could keep the existing
common C code unmodified and at the same time rewrite arm64 from
assembly to C code, and later do the arm part.

Now when both are done, we really don't need this level of indirection
anymore, and it's time to save a few lines and brain cells.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Now that 32-bit KVM no longer performs cache maintenance for page table
updates, we no longer need empty stubs for arm64. Remove them.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

When modifying Stage-2 page tables, we perform cache maintenance to
account for non-coherent page table walks. However, this is unnecessary,
as page table walks are guaranteed to be coherent in the presence of the
virtualization extensions.

Per ARM DDI 0406C.c, section B1.7 ("The Virtualization Extensions"), the
virtualization extensions mandate the multiprocessing extensions.

Per ARM DDI 0406C.c, section B3.10.1 ("General TLB maintenance
requirements"), as described in the sub-section titled "TLB maintenance
operations and the memory order model", this maintenance is not required
in the presence of the multiprocessing extensions.

Hence, we need not perform this cache maintenance when modifying Stage-2
entries.

This patch removes the logic for performing the redundant maintenance.
To ensure visibility and ordering of updates, a dsb(ishst) that was
otherwise implicit in the maintenance is folded into kvm_set_pmd() and
kvm_set_pte().
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

As kvm_set_routing_entry() was changing prototype between 4.7 and 4.8,
an ugly hack was put in place in order to survive both building in
-next and the merge window.

Now that everything has been merged, let's dump the compatibility
hack for good.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

We are doing an unnecessary stack push/pop operation when restoring
the guest registers x0-x18 in __guest_enter(). This patch saves the
two instructions by using x18 as a base register. No need to store
the vcpu context pointer in stack because it is redundant, the same
information is available in tpidr_el2. The function __guest_exit()
calling convention is slightly modified, caller only pushes the regs
x0-x1 to stack instead of regs x0-x3.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Just a rename so we can implement a v3-specific function later.

We take the chance to get rid of the V2/V3 ops comments as well.

No functional change.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

As we are about to deal with multiple data types and situations where
the vgic should not be initialized when doing userspace accesses on the
register attributes, factor out the functionality of
vgic_attr_regs_access into smaller bits which can be reused by a new
function later.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Factor out the GICv3 and ITS-specific documentation into a separate
documentation file.  Add description for how to access distributor,
redistributor, and CPU interface registers for GICv3 in this new file,
and add a group for accessing level triggered IRQ information for GICv3
as well.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

Expose the feature to L1 hypervisor if host CPU supports it, since
certain hypervisors requires it for own purposes.

According to Intel SDM A.1, if CPU supports the feature,
VMX_INSTRUCTION_INFO field of VMCS will contain detailed information
about INS/OUTS instructions handling. This field is already copied to
VMCS12 for L1 hypervisor (see prepare_vmcs12 routine) independently
feature presence.
Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

setup_vmcs_config takes a pointer to the vmcs_config global.  The
indirection is somewhat pointless, but just keep things consistent
for now.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

handle_external_intr does not enable interrupts anymore, vcpu_enter_guest
does it after calling guest_exit_irqoff.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

These are mostly related to nested VMX.  They needn't have
a loglevel as high as KERN_WARN, and mustn't be allowed to
pollute the host logs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

If EPT support is exposed to L1 hypervisor, guest linear-address field
of VMCS should contain GVA of L2, the access to which caused EPT violation.
Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The workqueue "irqfd_cleanup_wq" queues a single work item
&irqfd->shutdown and hence doesn't require ordering. It is a host-wide
workqueue for issuing deferred shutdown requests aggregated from all
vm* instances. It is not being used on a memory reclaim path.
Hence, it has been converted to use system_wq.
The work item has been flushed in kvm_irqfd_release().

The workqueue "wqueue" queues a single work item &timer->expired
and hence doesn't require ordering. Also, it is not being used on
a memory reclaim path. Hence, it has been converted to use system_wq.

System workqueues have been able to handle high level of concurrency
for a long time now and hence it's not required to have a singlethreaded
workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
created with create_singlethread_workqueue(), system_wq allows multiple
work items to overlap executions even on the same CPU; however, a
per-cpu workqueue doesn't have any CPU locality or global ordering
guarantee unless the target CPU is explicitly specified and thus the
increase of local concurrency shouldn't make any difference.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Commit 61abdbe0 ("kvm: x86: make lapic hrtimer pinned") pins the emulated
lapic timer. This patch does the same for the emulated nested preemption
timer to avoid vmexit an unrelated vCPU and the latency of kicking IPI to
another vCPU.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The validity check for the guest line address is inefficient,
check the invalid value instead of enumerating the valid ones.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge IOMMU bits for virtualization of interrupt injection into
virtual machines.

Introduce struct iommu_dev_data.use_vapic flag, which IOMMU driver
uses to determine if it should enable vAPIC support, by setting
the ga_mode bit in the device's interrupt remapping table entry.

Currently, it is enabled for all pass-through device if vAPIC mode
is enabled.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

This patch implements irq_set_vcpu_affinity() function to set up interrupt
remapping table entry with vapic mode for pass-through devices.

In case requirements for vapic mode are not met, it falls back to set up
the IRTE in legacy mode.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Introduces a new IOMMU API, amd_iommu_update_ga(), which allows
KVM (SVM) to update existing posted interrupt IOMMU IRTE when
load/unload vcpu.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

This patch adds AMD IOMMU guest virtual APIC log (GALOG) handler.
When IOMMU hardware receives an interrupt targeting a blocking vcpu,
it creates an entry in the GALOG, and generates an interrupt to notify
the AMD IOMMU driver.

At this point, the driver processes the log entry, and notify the SVM
driver via the registered iommu_ga_log_notifier function.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

This patch adds support to detect and initialize IOMMU Guest vAPIC log
(GALOG). By default, it also enable GALog interrupt to notify IOMMU driver
when GA Log entry is created.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

This patch enables support for the new 128-bit IOMMU IRTE format,
which can be used for both legacy and vapic interrupt remapping modes.
It replaces the existing operations on IRTE, which can only support
the older 32-bit IRTE format, with calls to the new struct amd_irt_ops.

It also provides helper functions for setting up, accessing, and
updating interrupt remapping table entries in different mode.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>