Marc Zyngier 8c3252c065 KVM: arm64: pmu: Reset sample period on overflow handling ... The PMU emulation code uses the perf event sample period to trigger the overflow detection. This works fine for the *first* overflow handling, but results in a huge number of interrupts on the host, unrelated to the number of interrupts handled in the guest (a x20 factor is pretty common for the cycle counter). On a slow system (such as a SW model), this can result in the guest only making forward progress at a glacial pace. It turns out that the clue is in the name. The sample period is exactly that: a period. And once the an overflow has occured, the following period should be the full width of the associated counter, instead of whatever the guest had initially programed. Reset the sample period to the architected value in the overflow handler, which now results in a number of host interrupts that is much closer to the number of interrupts in the guest. Fixes: b02386eb7d ("arm64: KVM: Add PMU overflow interrupt routing") Reviewed-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>		2019-10-20 10:47:07 +01:00
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hyp
vgic	KVM/arm fixes for 5.4, take #1	2019-10-03 12:08:50 +02:00
aarch32.c
arch_timer.c
arm.c	KVM: arm/arm64: vgic: Allow more than 256 vcpus for KVM_IRQ_LINE	2019-09-09 12:29:09 +01:00
mmio.c	KVM: arm/arm64: Only skip MMIO insn once	2019-08-22 13:19:56 +01:00
mmu.c
perf.c
pmu.c	KVM: arm64: pmu: Reset sample period on overflow handling	2019-10-20 10:47:07 +01:00
psci.c
trace.h