Commit Graph

213 Commits

Author SHA1 Message Date
Linus Torvalds
10dc374766 One of the largest releases for KVM... Hardly any generic improvement,
but lots of architecture-specific changes.
 
 * ARM:
 - VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
 - PMU support for guests
 - 32bit world switch rewritten in C
 - various optimizations to the vgic save/restore code.
 
 * PPC:
 - enabled KVM-VFIO integration ("VFIO device")
 - optimizations to speed up IPIs between vcpus
 - in-kernel handling of IOMMU hypercalls
 - support for dynamic DMA windows (DDW).
 
 * s390:
 - provide the floating point registers via sync regs;
 - separated instruction vs. data accesses
 - dirty log improvements for huge guests
 - bugfixes and documentation improvements.
 
 * x86:
 - Hyper-V VMBus hypercall userspace exit
 - alternative implementation of lowest-priority interrupts using vector
 hashing (for better VT-d posted interrupt support)
 - fixed guest debugging with nested virtualizations
 - improved interrupt tracking in the in-kernel IOAPIC
 - generic infrastructure for tracking writes to guest memory---currently
 its only use is to speedup the legacy shadow paging (pre-EPT) case, but
 in the future it will be used for virtual GPUs as well
 - much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "One of the largest releases for KVM...  Hardly any generic
  changes, but lots of architecture-specific updates.

  ARM:
   - VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
   - PMU support for guests
   - 32bit world switch rewritten in C
   - various optimizations to the vgic save/restore code.

  PPC:
   - enabled KVM-VFIO integration ("VFIO device")
   - optimizations to speed up IPIs between vcpus
   - in-kernel handling of IOMMU hypercalls
   - support for dynamic DMA windows (DDW).

  s390:
   - provide the floating point registers via sync regs;
   - separated instruction vs.  data accesses
   - dirty log improvements for huge guests
   - bugfixes and documentation improvements.

  x86:
   - Hyper-V VMBus hypercall userspace exit
   - alternative implementation of lowest-priority interrupts using
     vector hashing (for better VT-d posted interrupt support)
   - fixed guest debugging with nested virtualizations
   - improved interrupt tracking in the in-kernel IOAPIC
   - generic infrastructure for tracking writes to guest
     memory - currently its only use is to speedup the legacy shadow
     paging (pre-EPT) case, but in the future it will be used for
     virtual GPUs as well
   - much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (217 commits)
  KVM: x86: remove eager_fpu field of struct kvm_vcpu_arch
  KVM: x86: disable MPX if host did not enable MPX XSAVE features
  arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit
  arm64: KVM: vgic-v3: Reset LRs at boot time
  arm64: KVM: vgic-v3: Do not save an LR known to be empty
  arm64: KVM: vgic-v3: Save maintenance interrupt state only if required
  arm64: KVM: vgic-v3: Avoid accessing ICH registers
  KVM: arm/arm64: vgic-v2: Make GICD_SGIR quicker to hit
  KVM: arm/arm64: vgic-v2: Only wipe LRs on vcpu exit
  KVM: arm/arm64: vgic-v2: Reset LRs at boot time
  KVM: arm/arm64: vgic-v2: Do not save an LR known to be empty
  KVM: arm/arm64: vgic-v2: Move GICH_ELRSR saving to its own function
  KVM: arm/arm64: vgic-v2: Save maintenance interrupt state only if required
  KVM: arm/arm64: vgic-v2: Avoid accessing GICH registers
  KVM: s390: allocate only one DMA page per VM
  KVM: s390: enable STFLE interpretation only if enabled for the guest
  KVM: s390: wake up when the VCPU cpu timer expires
  KVM: s390: step the VCPU timer while in enabled wait
  KVM: s390: protect VCPU cpu timer with a seqcount
  KVM: s390: step VCPU cpu timer during kvm_run ioctl
  ...
2016-03-16 09:55:35 -07:00
Marc Zyngier
b40c4892d1 arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit
So far, we're always writing all possible LRs, setting the empty
ones with a zero value. This is obvious doing a low of work for
nothing, and we're better off clearing those we've actually
dirtied on the exit path (it is very rare to inject more than one
interrupt at a time anyway).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:16 +00:00
Marc Zyngier
0d98d00b8d arm64: KVM: vgic-v3: Reset LRs at boot time
In order to let the GICv3 code be more lazy in the way it
accesses the LRs, it is necessary to start with a clean slate.

Let's reset the LRs on each CPU when the vgic is probed (which
includes a round trip to EL2...).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:09 +00:00
Marc Zyngier
84e8b9c88d arm64: KVM: vgic-v3: Do not save an LR known to be empty
On exit, any empty LR will be signaled in ICH_ELRSR_EL2. Which
means that we do not have to save it, and we can just clear
its state in the in-memory copy.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:07 +00:00
Marc Zyngier
b4344545cf arm64: KVM: vgic-v3: Save maintenance interrupt state only if required
Next on our list of useless accesses is the maintenance interrupt
status registers (ICH_MISR_EL2, ICH_EISR_EL2).

It is pointless to save them if we haven't asked for a maintenance
interrupt the first place, which can only happen for two reasons:
- Underflow: ICH_HCR_UIE will be set,
- EOI: ICH_LR_EOI will be set.

These conditions can be checked on the in-memory copies of the regs.
Should any of these two condition be valid, we must read GICH_MISR.
We can then check for ICH_MISR_EOI, and only when set read
ICH_EISR_EL2.

This means that in most case, we don't have to save them at all.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:06 +00:00
Marc Zyngier
1b8e83c04e arm64: KVM: vgic-v3: Avoid accessing ICH registers
Just like on GICv2, we're a bit hammer-happy with GICv3, and access
them more often than we should.

Adopt a policy similar to what we do for GICv2, only save/restoring
the minimal set of registers. As we don't access the registers
linearly anymore (we may skip some), the convoluted accessors become
slightly simpler, and we can drop the ugly indexing macro that
tended to confuse the reviewers.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:04 +00:00
Marc Zyngier
623eefa8d0 arm64: KVM: Switch the sys_reg search to be a binary search
Our 64bit sys_reg table is about 90 entries long (so far, and the
PMU support is likely to increase this). This means that on average,
it takes 45 comparaisons to find the right entry (and actually the
full 90 if we have to search the invariant table).

Not the most efficient thing. Specially when you think that this
table is already sorted. Switching to a binary search effectively
reduces the search to about 7 comparaisons. Slightly better!

As an added bonus, the comparison is done by comparing all the
fields at once, instead of one at a time.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:22 +00:00
Shannon Zhao
bb0c70bcca arm64: KVM: Add a new vcpu device control group for PMUv3
To configure the virtual PMUv3 overflow interrupt number, we use the
vcpu kvm_device ioctl, encapsulating the KVM_ARM_VCPU_PMU_V3_IRQ
attribute within the KVM_ARM_VCPU_PMU_V3_CTRL group.

After configuring the PMUv3, call the vcpu ioctl with attribute
KVM_ARM_VCPU_PMU_V3_INIT to initialize the PMUv3.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao
f577f6c2a6 arm64: KVM: Introduce per-vcpu kvm device controls
In some cases it needs to get/set attributes specific to a vcpu and so
needs something else than ONE_REG.

Let's copy the KVM_DEVICE approach, and define the respective ioctls
for the vcpu file descriptor.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao
808e738142 arm64: KVM: Add a new feature bit for PMUv3
To support guest PMUv3, use one bit of the VCPU INIT feature array.
Initialize the PMU when initialzing the vcpu with that bit and PMU
overflow interrupt set.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao
2aa36e9840 arm64: KVM: Reset PMU state when resetting vcpu
When resetting vcpu, it needs to reset the PMU state to initial status.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao
d692b8ad6e arm64: KVM: Add access handler for PMUSERENR register
This register resets as unknown in 64bit mode while it resets as zero
in 32bit mode. Here we choose to reset it as zero for consistency.

PMUSERENR_EL0 holds some bits which decide whether PMU registers can be
accessed from EL0. Add some check helpers to handle the access from EL0.

When these bits are zero, only reading PMUSERENR will trap to EL2 and
writing PMUSERENR or reading/writing other PMU registers will trap to
EL1 other than EL2 when HCR.TGE==0. To current KVM configuration
(HCR.TGE==0) there is no way to get these traps. Here we write 0xf to
physical PMUSERENR register on VM entry, so that it will trap PMU access
from EL0 to EL2. Within the register access handler we check the real
value of guest PMUSERENR register to decide whether this access is
allowed. If not allowed, return false to inject UND to guest.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao
76993739cd arm64: KVM: Add helper to handle PMCR register bits
According to ARMv8 spec, when writing 1 to PMCR.E, all counters are
enabled by PMCNTENSET, while writing 0 to PMCR.E, all counters are
disabled. When writing 1 to PMCR.P, reset all event counters, not
including PMCCNTR, to zero. When writing 1 to PMCR.C, reset PMCCNTR to
zero.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao
7a0adc7064 arm64: KVM: Add access handler for PMSWINC register
Add access handler which emulates writing and reading PMSWINC
register and add support for creating software increment event.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao
76d883c4e6 arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register
Since the reset value of PMOVSSET and PMOVSCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMOVSSET or PMOVSCLR register.

When writing non-zero value to PMOVSSET, the counter and its interrupt
is enabled, kick this vcpu to sync PMU interrupt.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao
9db52c78cd arm64: KVM: Add access handler for PMINTENSET and PMINTENCLR register
Since the reset value of PMINTENSET and PMINTENCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMINTENSET or PMINTENCLR register.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao
9feb21ac57 arm64: KVM: Add access handler for event type register
These kind of registers include PMEVTYPERn, PMCCFILTR and PMXEVTYPER
which is mapped to PMEVTYPERn or PMCCFILTR.

The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.

When writing to these registers, create a perf_event for the selected
event type.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao
96b0eebcc6 arm64: KVM: Add access handler for PMCNTENSET and PMCNTENCLR register
Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMCNTENSET or PMCNTENCLR register.

When writing to PMCNTENSET, call perf_event_enable to enable the perf
event. When writing to PMCNTENCLR, call perf_event_disable to disable
the perf event.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao
051ff581ce arm64: KVM: Add access handler for event counter register
These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which
is mapped to PMEVCNTRn.

The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.

When reading these registers, return the sum of register value and the
value perf event counts.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao
a86b550530 arm64: KVM: Add access handler for PMCEID0 and PMCEID1 register
Add access handler which gets host value of PMCEID0 or PMCEID1 when
guest access these registers. Writing action to PMCEID0 or PMCEID1 is
UNDEFINED.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Shannon Zhao
3965c3ce75 arm64: KVM: Add access handler for PMSELR register
Since the reset value of PMSELR_EL0 is UNKNOWN, use reset_unknown for
its reset handler. When reading PMSELR, return the PMSELR.SEL field to
guest.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Shannon Zhao
ab9468340d arm64: KVM: Add access handler for PMCR register
Add reset handler which gets host value of PMCR_EL0 and make writable
bits architecturally UNKNOWN except PMCR.E which is zero. Add an access
handler for PMCR.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Shannon Zhao
04fe472615 arm64: KVM: Define PMU data structure for each vcpu
Here we plan to support virtual PMU for guest by full software
emulation, so define some basic structs and functions preparing for
futher steps. Define struct kvm_pmc for performance monitor counter and
struct kvm_pmu for performance monitor unit for each vcpu. According to
ARMv8 spec, the PMU contains at most 32(ARMV8_PMU_MAX_COUNTERS)
counters.

Since this only supports ARM64 (or PMUv3), add a separate config symbol
for it.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Marc Zyngier
6d50d54cd8 arm64: KVM: Move vgic-v2 and timer save/restore to virt/kvm/arm/hyp
We already have virt/kvm/arm/ containing timer and vgic stuff.
Add yet another subdirectory to contain the hyp-specific files
(timer and vgic again).

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier
13720a56ed arm64: KVM: Move kvm/hyp/hyp.h to include/asm/kvm_hyp.h
In order to be able to move code outside of kvm/hyp, we need to make
the global hyp.h file accessible from a standard location.

include/asm/kvm_hyp.h seems good enough.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier
5f05a72aed arm64: KVM: Move most of the fault decoding to C
The fault decoding process (including computing the IPA in the case
of a permission fault) would be much better done in C code, as we
have a reasonable infrastructure to deal with the VHE/non-VHE
differences.

Let's move the whole thing to C, including the workaround for
erratum 834220, and just patch the odd ESR_EL2 access remaining
in hyp-entry.S.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier
253dcbd39a arm64: KVM: VHE: Add alternative panic handling
As the kernel fully runs in HYP when VHE is enabled, we can
directly branch to the kernel's panic() implementation, and
not perform an exception return.

Add the alternative code to deal with this.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier
77cb2d9133 arm64: KVM: VHE: Add fpsimd enabling on guest access
Despite the fact that a VHE enabled kernel runs at EL2, it uses
CPACR_EL1 to trap FPSIMD access. Add the required alternative
code to re-enable guest FPSIMD access when it has trapped to
EL2.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
5efe6de138 arm64: KVM: VHE: Use unified sysreg accessors for timer
Switch the timer code to the unified sysreg accessors.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
68908bf789 arm64: KVM: VHE: Implement VHE activate/deactivate_traps
Running the kernel in HYP mode requires the HCR_E2H bit to be set
at all times, and the HCR_TGE bit to be set when running as a host
(and cleared when running as a guest). At the same time, the vector
 must be set to the current role of the kernel (either host or
hypervisor), and a couple of system registers differ between VHE
and non-VHE.

We implement these by using another set of alternate functions
that get dynamically patched.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
328762247c arm64: KVM: VHE: Make __fpsimd_enabled VHE aware
As non-VHE and VHE have different ways to express the trapping of
FPSIMD registers to EL2, make __fpsimd_enabled a patchable predicate
and provide a VHE implementation.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
d1526e5efc arm64: KVM: VHE: Enable minimal sysreg save/restore
We're now in a position where we can introduce VHE's minimal
save/restore, which is limited to the handful of shared sysregs.

Add the required alternative function calls that result in a
"do nothing" call on VHE, and the normal save/restore for non-VHE.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
094f8233c0 arm64: KVM: VHE: Use unified system register accessors
Use the recently introduced unified system register accessors for
those sysregs that behave differently depending on VHE being in
use or not.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
9c6c356832 arm64: KVM: VHE: Split save/restore of registers shared between guest and host
A handful of system registers are still shared between host and guest,
even while using VHE (tpidr*_el[01] and actlr_el1).

Also, some of the vcpu state (sp_el0, PC and PSTATE) must be
save/restored on entry/exit, as they are used on the host as well.

In order to facilitate the introduction of a VHE-specific sysreg
save/restore, make move the access to these registers to their
own save/restore functions.

No functional change.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier
edef528dc4 arm64: KVM: VHE: Differenciate host/guest sysreg save/restore
With ARMv8, host and guest share the same system register file,
making the save/restore procedure completely symetrical.
With VHE, host and guest now have different requirements, as they
use different sysregs.

In order to prepare for this, add split sysreg save/restore functions
for both host and guest. No functional changes yet.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier
915ccd1dbf arm64: KVM: VHE: Introduce unified system register accessors
VHE brings its own bag of new system registers, or rather system
register accessors, as it define new ways to access both guest
and host system registers. For example, from the host:

- The host TCR_EL2 register is accessed using the TCR_EL1 accessor
- The guest TCR_EL1 register is accessed using the TCR_EL12 accessor

Obviously, this is confusing. A way to somehow reduce the complexity
of writing code for both ARMv8 and ARMv8.1 is to use a set of unified
accessors that will generate the right sysreg, depending on the mode
the CPU is running in. For example:

- read_sysreg_el1(tcr) will use TCR_EL1 on ARMv8, and TCR_EL12 on
  ARMv8.1 with VHE.
- read_sysreg_el2(tcr) will use TCR_EL2 on ARMv8, and TCR_EL1 on
  ARMv8.1 with VHE.

We end up with three sets of accessors ({read,write}_sysreg_el[012])
that can be directly used from C code. We take this opportunity to
also add the definition for the new VHE sysregs.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier
cedbb8b78c arm64: KVM: VHE: Patch out kern_hyp_va
The kern_hyp_va macro is pretty meaninless with VHE, as there is
only one mapping - the kernel one.

In order to keep the code readable and efficient, use runtime
patching to replace the 'and' instruction used to compute the VA
with a 'nop'.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier
b81125c791 arm64: KVM: VHE: Patch out use of HVC
With VHE, the host never issues an HVC instruction to get into the
KVM code, as we can simply branch there.

Use runtime code patching to simplify things a bit.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier
3a3604bc5e arm64: KVM: Switch to C-based stage2 init
There is no real need to leave the stage2 initialization as part
of the early HYP bootstrap, and we can easily postpone it to
the point where we can safely run C code.

This will help VHE, which doesn't need any of this bootstrap.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:15 +00:00
Michael S. Tsirkin
4cad67fca3 arm/arm64: KVM: Fix ioctl error handling
Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.

Fix up kvm to do
	return copy_to_user(...)) ?  -EFAULT : 0;

everywhere.

Cc: stable@vger.kernel.org
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 09:56:40 +00:00
Marc Zyngier
fd451b90e7 arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR1Rn_EL2
The GICv3 architecture spec says:

Writing to the active priority registers in any order other than
the following order will result in UNPREDICTABLE behavior:
- ICH_AP0R<n>_EL2.
- ICH_AP1R<n>_EL2.

So let's not pointlessly go against the rule...

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-24 17:25:58 +00:00
Tirumalesh Chalamarla
3c5b1d92b3 arm64: KVM: Configure TCR_EL2.PS at runtime
Setting TCR_EL2.PS to 40 bits is wrong on systems with less that
less than 40 bits of physical addresses. and breaks KVM on systems
where the RAM is above 40 bits.

This patch uses ID_AA64MMFR0_EL1.PARange to set TCR_EL2.PS dynamically,
just like we already do for VTCR_EL2.PS.

[Marc: rewrote commit message, patch tidy up]

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-11 13:16:47 +00:00
Shannon Zhao
6327f35a20 arm64: KVM: Fix guest dead loop when register accessor returns false
Currently emulate_cp will return 0 (Handled) no matter what the accessor
returns. If register accessor returns false, it will not skip current PC
while emulate_cp return handled. Then guest will stuck in a dead loop.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:56:01 +00:00
Shannon Zhao
7769db905b arm64: KVM: Fix comments of the CP handler
Make sure the documentation reflects the actual name of the functions.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:56:00 +00:00
Dave Martin
a7e0ac295d arm64: KVM: Obey RES0/1 reserved bits when setting CPTR_EL2
Some bits in CPTR are defined as RES1 in the architecture.  Setting
these bits to zero may unintentionally enable future architecture
extensions, allowing guests to use them without supervision by the host.

This would be bad: for forwards compatibility, this patch makes
sure the affected bits are always written with 1, not 0.

This patch only addresses CPTR_EL2.  Initialisation of other system
registers may still need review.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:55:58 +00:00
Marc Zyngier
8fc153cda9 arm64: KVM: Fix AArch64 guest userspace exception injection
At the moment, our fault injection is pretty limited. We always
generate a SYNC exception into EL1, as if the fault was actually
from EL1h, no matter how it was generated.

This is obviously wrong, as EL0 can generate faults of its own
(not to mention the pretty-much unused EL1t mode).

This patch fixes it by implementing section D1.10.2 of the ARMv8 ARM,
and in particular table D1-7 ("Vector offsets from vector table base
address"), which describes which vector to use depending on the source
exception level and type (synchronous, IRQ, FIQ or SError).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:55:57 +00:00
Vladimir Murzin
20475f784d arm64: KVM: Add support for 16-bit VMID
The ARMv8.1 architecture extension allows to choose between 8-bit and
16-bit of VMID, so use this capability for KVM.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-18 10:15:12 +00:00
Marc Zyngier
281243cbe0 arm64: KVM: debug: Remove spurious inline attributes
The debug trapping code is pretty heavy on the "inline" attribute,
but most functions are actually referenced in the sysreg tables,
making the inlining imposible.

Removing the useless inline qualifier seems the right thing to do,
having verified that the output code is similar.

Cc: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-18 10:15:11 +00:00
Marc Zyngier
3ffa75cd18 arm64: KVM: Remove weak attributes
As we've now switched to the new world switch implementation,
remove the weak attributes, as nobody is supposed to override
it anymore.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:44 +00:00
Marc Zyngier
9d8415d6c1 arm64: KVM: Turn system register numbers to an enum
Having the system register numbers as #defines has been a pain
since day one, as the ordering is pretty fragile, and moving
things around leads to renumbering and epic conflict resolutions.

Now that we're mostly acessing the sysreg file in C, an enum is
a much better type to use, and we can clean things up a bit.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:43 +00:00