mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-25 12:04:46 +08:00
e4aa7f88af
Disable CPU hotplug when enabling/disabling hardware to prevent the
corner case where if the following sequence occurs:
1. A hotplugged CPU marks itself online in cpu_online_mask
2. The hotplugged CPU enables interrupt before invoking KVM's ONLINE
callback
3 hardware_{en,dis}able_all() is invoked on another CPU
the hotplugged CPU will be included in on_each_cpu() and thus get sent
through hardware_{en,dis}able_nolock() before kvm_online_cpu() is called.
start_secondary { ...
set_cpu_online(smp_processor_id(), true); <- 1
...
local_irq_enable(); <- 2
...
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); <- 3
}
KVM currently fudges around this race by keeping track of which CPUs have
done hardware enabling (see commit
|
||
|---|---|---|
| .. | ||
| async_pf.c | ||
| async_pf.h | ||
| binary_stats.c | ||
| coalesced_mmio.c | ||
| coalesced_mmio.h | ||
| dirty_ring.c | ||
| eventfd.c | ||
| irqchip.c | ||
| Kconfig | ||
| kvm_main.c | ||
| kvm_mm.h | ||
| Makefile.kvm | ||
| pfncache.c | ||
| vfio.c | ||
| vfio.h | ||