- 09 Mar, 2016 12 commits
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Marc Zyngier authored
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>
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Marc Zyngier authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
In order to let make the GICv2 code 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. Reviewed-by:
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Marc Zyngier authored
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:
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Marc Zyngier authored
In order to make the saving path slightly more readable and prepare for some more optimizations, let's move the GICH_ELRSR saving to its own function. No functional change. Reviewed-by:
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Marc Zyngier authored
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: -
Marc Zyngier authored
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:
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- 29 Feb, 2016 28 commits
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Marc Zyngier authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
As we're going to play some tricks on the struct coproc_reg, make sure its 64bit indicator field matches that of coproc_params. Acked-by:
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Marc Zyngier authored
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:
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Marc Zyngier authored
Not having the invariant table properly sorted is an oddity, and may get in the way of future optimisations. Let's fix it. Reviewed-by:
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Marc Zyngier authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
When KVM frees VCPU, it needs to free the perf_event of PMU. Signed-off-by:
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Shannon Zhao authored
When resetting vcpu, it needs to reset the PMU state to initial status. Signed-off-by:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
Add access handler which emulates writing and reading PMSWINC register and add support for creating software increment event. Signed-off-by:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Shannon Zhao authored
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:
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Marc Zyngier authored
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:
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Marc Zyngier authored
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 authored
Using the common HYP timer code is a bit more tricky, since we use system register names. Nothing a set of macros cannot work around... Acked-by:
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