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2014-01-08KVM: ARM: Remove duplicate includeSachin Kamat
trace.h was included twice. Remove duplicate inclusion. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-17KVM: ARM: Update comments for kvm_handle_wfiChristoffer Dall
Update comments to reflect what is really going on and add the TWE bit to the comments in kvm_arm.h. Also renames the function to kvm_handle_wfx like is done on arm64 for consistency and uber-correctness. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-17ARM: KVM: Yield CPU when vcpu executes a WFEMarc Zyngier
On an (even slightly) oversubscribed system, spinlocks are quickly becoming a bottleneck, as some vcpus are spinning, waiting for a lock to be released, while the vcpu holding the lock may not be running at all. This creates contention, and the observed slowdown is 40x for hackbench. No, this isn't a typo. The solution is to trap blocking WFEs and tell KVM that we're now spinning. This ensures that other vpus will get a scheduling boost, allowing the lock to be released more quickly. Also, using CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance when the VM is severely overcommited. Quick test to estimate the performance: hackbench 1 process 1000 2xA15 host (baseline): 1.843s 2xA15 guest w/o patch: 2.083s 4xA15 guest w/o patch: 80.212s 8xA15 guest w/o patch: Could not be bothered to find out 2xA15 guest w/ patch: 2.102s 4xA15 guest w/ patch: 3.205s 8xA15 guest w/ patch: 6.887s So we go from a 40x degradation to 1.5x in the 2x overcommit case, which is vaguely more acceptable. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-26ARM: KVM: Don't handle PSCI calls via SMCDave P Martin
Currently, kvmtool unconditionally declares that HVC should be used to call PSCI, so the function numbers in the DT tell the guest nothing about the function ID namespace or calling convention for SMC. We already assume that the guest will examine and honour the DT, since there is no way it could possibly guess the KVM-specific PSCI function IDs otherwise. So let's not encourage guests to violate what's specified in the DT by using SMC to make the call. [ Modified to apply to top of kvm/arm tree - Christoffer ] Signed-off-by: Dave P Martin <Dave.Martin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-05-03Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds
Pull ARM updates from Russell King: "The major items included in here are: - MCPM, multi-cluster power management, part of the infrastructure required for ARMs big.LITTLE support. - A rework of the ARM KVM code to allow re-use by ARM64. - Error handling cleanups of the IS_ERR_OR_NULL() madness and fixes of that stuff for arch/arm - Preparatory patches for Cortex-M3 support from Uwe Kleine-König. There is also a set of three patches in here from Hugh/Catalin to address freeing of inappropriate page tables on LPAE. You already have these from akpm, but they were already part of my tree at the time he sent them, so unfortunately they'll end up with duplicate commits" * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits) ARM: EXYNOS: remove unnecessary use of IS_ERR_VALUE() ARM: IMX: remove unnecessary use of IS_ERR_VALUE() ARM: OMAP: use consistent error checking ARM: cleanup: OMAP hwmod error checking ARM: 7709/1: mcpm: Add explicit AFLAGS to support v6/v7 multiplatform kernels ARM: 7700/2: Make cpu_init() notrace ARM: 7702/1: Set the page table freeing ceiling to TASK_SIZE ARM: 7701/1: mm: Allow arch code to control the user page table ceiling ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum() ARM: mcpm: provide an interface to set the SMP ops at run time ARM: mcpm: generic SMP secondary bringup and hotplug support ARM: mcpm_head.S: vlock-based first man election ARM: mcpm: Add baremetal voting mutexes ARM: mcpm: introduce helpers for platform coherency exit/setup ARM: mcpm: introduce the CPU/cluster power API ARM: multi-cluster PM: secondary kernel entry code ARM: cacheflush: add synchronization helpers for mixed cache state accesses ARM: cpu hotplug: remove majority of cache flushing from platforms ARM: smp: flush L1 cache in cpu_die() ARM: tegra: remove tegra specific cpu_disable() ...
2013-03-06ARM: KVM: move kvm_handle_wfi to handle_exit.cMarc Zyngier
It has little to do in emulate.c these days... Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06KVM: ARM: Reintroduce trace_kvm_hvcChristoffer Dall
This one got lost in the move to handle_exit, so let's reintroduce it using an accessor to the immediate value field like the other ones. Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06ARM: KVM: move exit handler selection to a separate fileMarc Zyngier
The exit handler selection code cannot be shared with arm64 (two different modes, more exception classes...). Move it to a separate file (handle_exit.c). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>