Marc Zyngier [Tue, 9 Feb 2016 17:36:09 +0000 (17:36 +0000)]
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>
Marc Zyngier [Tue, 9 Feb 2016 17:09:49 +0000 (17:09 +0000)]
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>
Marc Zyngier [Tue, 9 Feb 2016 18:53:04 +0000 (18:53 +0000)]
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>
Marc Zyngier [Wed, 17 Feb 2016 10:25:05 +0000 (10:25 +0000)]
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>
Marc Zyngier [Tue, 9 Feb 2016 17:37:39 +0000 (17:37 +0000)]
KVM: arm/arm64: vgic-v2: Make GICD_SGIR quicker to hit
The GICD_SGIR register lives a long way from the beginning of
the handler array, which is searched linearly. As this is hit
pretty often, let's move it up. This saves us some precious
cycles when the guest is generating IPIs.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Tue, 9 Feb 2016 17:36:09 +0000 (17:36 +0000)]
KVM: arm/arm64: vgic-v2: 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 lot 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>
Marc Zyngier [Tue, 9 Feb 2016 17:09:49 +0000 (17:09 +0000)]
KVM: arm/arm64: vgic-v2: Do not save an LR known to be empty
On exit, any empty LR will be signaled in GICH_ELRSR*. Which
means that we do not have to save it, and we can just clear
its state in the in-memory copy.
Take this opportunity to move the LR saving code into its
own function.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Tue, 9 Feb 2016 17:01:33 +0000 (17:01 +0000)]
KVM: arm/arm64: vgic-v2: Save maintenance interrupt state only if required
Next on our list of useless accesses is the maintenance interrupt
status registers (GICH_MISR, GICH_EISR{0,1}).
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: GICH_HCR_UIE will be set,
- EOI: GICH_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 GICH_MISR_EOI, and only when set read
GICH_EISR*.
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>
GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad.
But we're equaly bad, as we make a point in accessing them even if
we don't have any interrupt in flight.
A good solution is to first find out if we have anything useful to
write into the GIC, and if we don't, to simply not do it. This
involves tracking which LRs actually have something valid there.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Fri, 29 Jan 2016 19:04:48 +0000 (19:04 +0000)]
KVM: arm/arm64: timer: Add active state caching
Programming the active state in the (re)distributor can be an
expensive operation so it makes some sense to try and reduce
the number of accesses as much as possible. So far, we
program the active state on each VM entry, but there is some
opportunity to do less.
An obvious solution is to cache the active state in memory,
and only program it in the HW when conditions change. But
because the HW can also change things under our feet (the active
state can transition from 1 to 0 when the guest does an EOI),
some precautions have to be taken, which amount to only caching
an "inactive" state, and always programing it otherwise.
With this in place, we observe a reduction of around 700 cycles
on a 2GHz GICv2 platform for a NULL hypercall.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Thu, 21 Jan 2016 17:34:22 +0000 (17:34 +0000)]
ARM: KVM: Switch the CP reg search to be a binary search
Doing a linear search is a bit silly when we can do a binary search.
Not that we trap that so many things that it has become a burden yet,
but it makes sense to align it with the arm64 code.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Thu, 21 Jan 2016 15:34:35 +0000 (15:34 +0000)]
ARM: KVM: Enforce sorting of all CP tables
Since we're obviously terrible at sorting the CP tables, make sure
we're going to do it properly (or fail to boot). arm64 has had the
same mechanism for a while, and nobody ever broke it...
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Thu, 21 Jan 2016 18:27:04 +0000 (18:27 +0000)]
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>
Shannon Zhao [Mon, 11 Jan 2016 13:35:32 +0000 (21:35 +0800)]
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>
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>
Shannon Zhao [Mon, 11 Jan 2016 14:46:15 +0000 (22:46 +0800)]
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>
arm64: KVM: Free perf event of PMU when destroying vcpu
When KVM frees VCPU, it needs to free the perf_event of PMU.
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>
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>
Shannon Zhao [Fri, 26 Feb 2016 11:29:19 +0000 (19:29 +0800)]
arm64: KVM: Add PMU overflow interrupt routing
When calling perf_event_create_kernel_counter to create perf_event,
assign a overflow handler. Then when the perf event overflows, set the
corresponding bit of guest PMOVSSET register. If this counter is enabled
and its interrupt is enabled as well, kick the vcpu to sync the
interrupt.
On VM entry, if there is counter overflowed and interrupt level is
changed, inject the interrupt with corresponding level. On VM exit, sync
the interrupt level as well if it has been changed.
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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>
Shannon Zhao [Wed, 28 Oct 2015 04:10:30 +0000 (12:10 +0800)]
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>
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>
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>
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>
Shannon Zhao [Tue, 23 Feb 2016 03:11:27 +0000 (11:11 +0800)]
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>
arm64: KVM: PMU: Add perf event map and introduce perf event creating function
When we use tools like perf on host, perf passes the event type and the
id of this event type category to kernel, then kernel will map them to
hardware event number and write this number to PMU PMEVTYPER<n>_EL0
register. When getting the event number in KVM, directly use raw event
type to create a perf_event for it.
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>
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>
Shannon Zhao [Tue, 8 Dec 2015 07:29:06 +0000 (15:29 +0800)]
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>
Shannon Zhao [Mon, 31 Aug 2015 09:20:22 +0000 (17:20 +0800)]
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>
Shannon Zhao [Thu, 18 Jun 2015 08:01:53 +0000 (16:01 +0800)]
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>
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>
Marc Zyngier [Mon, 29 Feb 2016 11:25:04 +0000 (11:25 +0000)]
arm64: KVM: Add temporary kvm_perf_event.h
In order to merge the KVM/ARM PMU patches without creating a
conflict mess, let's have a temporary include file that won't
conflict with anything. Subsequent patches will clean that up.
Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Mon, 22 Feb 2016 10:57:30 +0000 (10:57 +0000)]
arm64: KVM: Move __cpu_init_stage2 after kvm_call_hyp
In order to ease the merge with the rest of the arm64 tree, move the
definition of __cpu_init_stage2() after what will be the new kvm_call_hyp.
Hopefully the resolution of the merge conflict will be obvious.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Thu, 28 Jan 2016 14:31:37 +0000 (14:31 +0000)]
ARM: KVM: Move kvm/hyp/hyp.h to include/asm/kvm_hyp.h
In order to be able to use the code located in virt/kvm/arm/hyp,
we need to make the global hyp.h file accessible from include/asm,
similar to what we did for arm64.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Wed, 28 Oct 2015 15:06:47 +0000 (15:06 +0000)]
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>
Marc Zyngier [Tue, 17 Nov 2015 14:07:45 +0000 (14:07 +0000)]
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>
Marc Zyngier [Wed, 28 Oct 2015 14:42:09 +0000 (14:42 +0000)]
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>
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>
Marc Zyngier [Wed, 28 Oct 2015 14:15:45 +0000 (14:15 +0000)]
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>
Marc Zyngier [Wed, 28 Oct 2015 12:39:38 +0000 (12:39 +0000)]
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>
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>
Marc Zyngier [Wed, 28 Oct 2015 12:00:00 +0000 (12:00 +0000)]
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>
Marc Zyngier [Thu, 20 Feb 2014 15:21:23 +0000 (15:21 +0000)]
arm64: Allow the arch timer to use the HYP timer
With the ARMv8.1 VHE, the kernel can run in HYP mode, and thus
use the HYP timer instead of the normal guest timer in a mostly
transparent way, except for the interrupt line.
This patch reworks the arch timer code to allow the selection of
the HYP PPI, possibly falling back to the guest timer if not
available.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Mon, 9 Jun 2014 18:47:09 +0000 (19:47 +0100)]
arm/arm64: Add new is_kernel_in_hyp_mode predicate
With ARMv8.1 VHE extension, it will be possible to run the kernel
at EL2 (aka HYP mode). In order for the kernel to easily find out
where it is running, add a new predicate that returns whether or
not the kernel is in HYP mode.
For completeness, the 32bit code also get such a predicate (always
returning false) so that code common to both architecture (timers,
KVM) can use it transparently.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Thu, 29 Jan 2015 13:19:45 +0000 (13:19 +0000)]
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>
Marc Zyngier [Fri, 29 Jan 2016 15:01:28 +0000 (15:01 +0000)]
arm/arm64: KVM: Handle out-of-RAM cache maintenance as a NOP
So far, our handling of cache maintenance by VA has been pretty
simple: Either the access is in the guest RAM and generates a S2
fault, which results in the page being mapped RW, or we go down
the io_mem_abort() path, and nuke the guest.
The first one is fine, but the second one is extremely weird.
Treating the CM as an I/O is wrong, and nothing in the ARM ARM
indicates that we should generate a fault for something that
cannot end-up in the cache anyway (even if the guest maps it,
it will keep on faulting at stage-2 for emulation).
So let's just skip this instruction, and let the guest get away
with it.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Tue, 5 Jan 2016 22:53:33 +0000 (22:53 +0000)]
ARM: KVM: Turn CP15 defines to an enum
Just like on arm64, having the CP15 registers expressed as a set
of #defines has been very conflict-prone. Let's turn it into an
enum, which should make it more manageable.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Wed, 6 Jan 2016 12:10:58 +0000 (12:10 +0000)]
ARM: KVM: Change kvm_call_hyp return type to unsigned long
Having u64 as the kvm_call_hyp return type is problematic, as
it forces all kind of tricks for the return values from HYP
to be promoted to 64bit (LE has the LSB in r0, and BE has them
in r1).
Since the only user of the return value is perfectly happy with
a 32bit value, let's make kvm_call_hyp return an unsigned long,
which is 32bit on ARM.
This solves yet another headache.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Tue, 5 Jan 2016 18:43:18 +0000 (18:43 +0000)]
ARM: KVM: Add HYP mode entry code
This part is almost entierely borrowed from the existing code, just
slightly simplifying the HYP function call (as we now save SPSR_hyp
in the world switch).
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Wed, 13 Jan 2016 19:02:51 +0000 (19:02 +0000)]
ARM: KVM: Add populating of fault data structure
On guest exit, we must take care of populating our fault data
structure so that the host code can handle it. This includes
resolving the IPA for permission faults, which can result in
restarting the guest.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Tue, 5 Jan 2016 18:42:49 +0000 (18:42 +0000)]
ARM: KVM: Add the new world switch implementation
The new world switch implementation is modeled after the arm64 one,
calling the various save/restore functions in turn, and having as
little state as possible.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Tue, 5 Jan 2016 18:40:51 +0000 (18:40 +0000)]
ARM: KVM: Add guest entry code
Add the very minimal piece of code that is now required to jump
into the guest (and return from it). This code is only concerned
with save/restoring the USR registers (r0-r12+lr for the guest,
r4-r12+lr for the host), as everything else is dealt with in C
(VFP is another matter though).
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Mon, 4 Jan 2016 15:41:51 +0000 (15:41 +0000)]
ARM: KVM: Add VFP save/restore
This is almost a copy/paste of the existing version, with a couple
of subtle differences:
- Only write to FPEXC once on the save path
- Add an isb when enabling VFP access
The patch also defines a few sysreg accessors and a __vfp_enabled
predicate that test the VFP trapping state.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Mon, 4 Jan 2016 09:06:11 +0000 (09:06 +0000)]
ARM: KVM: Add vgic v2 save/restore
This patch shouldn't exist, as we should be able to reuse the
arm64 version for free. I'll get there eventually, but in the
meantime I need an interrupt controller.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Mon, 4 Jan 2016 08:54:50 +0000 (08:54 +0000)]
ARM: KVM: Add timer save/restore
This patch shouldn't exist, as we should be able to reuse the
arm64 version for free. I'll get there eventually, but in the
meantime I need a timer ticking.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Sat, 2 Jan 2016 15:07:13 +0000 (15:07 +0000)]
ARM: KVM: Add system register accessor macros
In order to move system register (CP15, mostly) access to C code,
add a few macros to facilitate this, and minimize the difference
between 32 and 64bit CP15 registers.
This will get heavily used in the following patches.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Sun, 3 Jan 2016 11:26:01 +0000 (11:26 +0000)]
ARM: KVM: Move CP15 array into the CPU context structure
Continuing our rework of the CPU context, we now move the CP15
array into the CPU context structure. As this causes quite a bit
of churn, we introduce the vcpu_cp15() macro that abstract the
location of the actual array. This will probably help next time
we have to revisit that code.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Sun, 3 Jan 2016 11:01:49 +0000 (11:01 +0000)]
ARM: KVM: Move VFP registers to a CPU context structure
In order to turn the WS code into something that looks a bit
more like the arm64 version, move the VFP registers into a
CPU context container for both the host and the guest.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Now that we've unified the way we refer to the HYP text between
arm and arm64, drop __kvm_hyp_code_start/end, and just use the
__hyp_text_start/end symbols.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Marc Zyngier [Sat, 2 Jan 2016 13:57:18 +0000 (13:57 +0000)]
ARM: KVM: Move the HYP code to its own section
In order to be able to spread the HYP code into multiple compilation
units, adopt a layout similar to that of arm64:
- the HYP text is emited in its own section (.hyp.text)
- two linker generated symbols are use to identify the boundaries
of that section
No functionnal change.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Linus Torvalds [Sun, 28 Feb 2016 15:52:00 +0000 (07:52 -0800)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"A rather largish series of 12 patches addressing a maze of race
conditions in the perf core code from Peter Zijlstra"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Robustify task_function_call()
perf: Fix scaling vs. perf_install_in_context()
perf: Fix scaling vs. perf_event_enable()
perf: Fix scaling vs. perf_event_enable_on_exec()
perf: Fix ctx time tracking by introducing EVENT_TIME
perf: Cure event->pending_disable race
perf: Fix race between event install and jump_labels
perf: Fix cloning
perf: Only update context time when active
perf: Allow perf_release() with !event->ctx
perf: Do not double free
perf: Close install vs. exit race
Linus Torvalds [Sun, 28 Feb 2016 15:49:23 +0000 (07:49 -0800)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"This update contains:
- Hopefully the last ASM CLAC fixups
- A fix for the Quark family related to the IMR lock which makes
kexec work again
- A off-by-one fix in the MPX code. Ironic, isn't it?
- A fix for X86_PAE which addresses once more an unsigned long vs
phys_addr_t hickup"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mpx: Fix off-by-one comparison with nr_registers
x86/mm: Fix slow_virt_to_phys() for X86_PAE again
x86/entry/compat: Add missing CLAC to entry_INT80_32
x86/entry/32: Add an ASM_CLAC to entry_SYSENTER_32
x86/platform/intel/quark: Change the kernel's IMR lock bit to false