linux/virt/kvm/Kconfig
Thomas Gleixner 935ace2fb5 entry: Provide infrastructure for work before transitioning to guest mode
Entering a guest is similar to exiting to user space. Pending work like
handling signals, rescheduling, task work etc. needs to be handled before
that.

Provide generic infrastructure to avoid duplication of the same handling
code all over the place.

The transfer to guest mode handling is different from the exit to usermode
handling, e.g. vs. rseq and live patching, so a separate function is used.

The initial list of work items handled is:

    TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME

Architecture specific TIF flags can be added via defines in the
architecture specific include files.

The calling convention is also different from the syscall/interrupt entry
functions as KVM invokes this from the outer vcpu_run() loop with
interrupts and preemption enabled. To prevent missing a pending work item
it invokes a check for pending TIF work from interrupt disabled code right
before transitioning to guest mode. The lockdep, RCU and tracing state
handling is also done directly around the switch to and from guest mode.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200722220519.833296398@linutronix.de
2020-07-24 15:03:42 +02:00

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# SPDX-License-Identifier: GPL-2.0
# KVM common configuration items and defaults
config HAVE_KVM
bool
config HAVE_KVM_IRQCHIP
bool
config HAVE_KVM_IRQFD
bool
config HAVE_KVM_IRQ_ROUTING
bool
config HAVE_KVM_EVENTFD
bool
select EVENTFD
config KVM_MMIO
bool
config KVM_ASYNC_PF
bool
# Toggle to switch between direct notification and batch job
config KVM_ASYNC_PF_SYNC
bool
config HAVE_KVM_MSI
bool
config HAVE_KVM_CPU_RELAX_INTERCEPT
bool
config KVM_VFIO
bool
config HAVE_KVM_ARCH_TLB_FLUSH_ALL
bool
config HAVE_KVM_INVALID_WAKEUPS
bool
config KVM_GENERIC_DIRTYLOG_READ_PROTECT
bool
config KVM_COMPAT
def_bool y
depends on KVM && COMPAT && !(S390 || ARM64)
config HAVE_KVM_IRQ_BYPASS
bool
config HAVE_KVM_VCPU_ASYNC_IOCTL
bool
config HAVE_KVM_VCPU_RUN_PID_CHANGE
bool
config HAVE_KVM_NO_POLL
bool
config KVM_XFER_TO_GUEST_WORK
bool