mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
synced 2026-10-16 22:39:48 +00:00
fdba608f15
Drop a check that guards triggering a posted interrupt on the currently
running vCPU, and more importantly guards waking the target vCPU if
triggering a posted interrupt fails because the vCPU isn't IN_GUEST_MODE.
If a vIRQ is delivered from asynchronous context, the target vCPU can be
the currently running vCPU and can also be blocking, in which case
skipping kvm_vcpu_wake_up() is effectively dropping what is supposed to
be a wake event for the vCPU.
The "do nothing" logic when "vcpu == running_vcpu" mostly works only
because the majority of calls to ->deliver_posted_interrupt(), especially
when using posted interrupts, come from synchronous KVM context. But if
a device is exposed to the guest using vfio-pci passthrough, the VFIO IRQ
and vCPU are bound to the same pCPU, and the IRQ is _not_ configured to
use posted interrupts, wake events from the device will be delivered to
KVM from IRQ context, e.g.
vfio_msihandler()
|
|-> eventfd_signal()
|
|-> ...
|
|-> irqfd_wakeup()
|
|->kvm_arch_set_irq_inatomic()
|
|-> kvm_irq_delivery_to_apic_fast()
|
|-> kvm_apic_set_irq()
This also aligns the non-nested and nested usage of triggering posted
interrupts, and will allow for additional cleanups.
Fixes:
|
History
|
|
|---|---|---|
| .. | ||
| mmu | ||
| svm | ||
| vmx | ||
| cpuid.c | ||
| cpuid.h | ||
| debugfs.c | ||
| emulate.c | ||
| fpu.h | ||
| hyperv.c | ||
| hyperv.h | ||
| i8254.c | ||
| i8254.h | ||
| i8259.c | ||
| ioapic.c | ||
| ioapic.h | ||
| irq.c | ||
| irq.h | ||
| irq_comm.c | ||
| Kconfig | ||
| kvm_cache_regs.h | ||
| kvm_emulate.h | ||
| kvm_onhyperv.c | ||
| kvm_onhyperv.h | ||
| lapic.c | ||
| lapic.h | ||
| Makefile | ||
| mmu.h | ||
| mtrr.c | ||
| pmu.c | ||
| pmu.h | ||
| reverse_cpuid.h | ||
| trace.h | ||
| tss.h | ||
| x86.c | ||
| x86.h | ||
| xen.c | ||
| xen.h | ||