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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-07-22 23:59:59 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-24 15:03:42 +0200 |
| commit | 935ace2fb5cc49ae88bd1f1735ddc51cdc2ebfb3 (patch) | |
| tree | e39e6c089dd493abfe99507e089d45eb8d61da6f /virt/kvm | |
| parent | entry: Provide generic interrupt entry/exit code (diff) | |
| download | linux-935ace2fb5cc49ae88bd1f1735ddc51cdc2ebfb3.tar.xz linux-935ace2fb5cc49ae88bd1f1735ddc51cdc2ebfb3.zip | |
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
Diffstat (limited to 'virt/kvm')
| -rw-r--r-- | virt/kvm/Kconfig | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index aad9284c043a..1c37ccd5d402 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -60,3 +60,6 @@ config HAVE_KVM_VCPU_RUN_PID_CHANGE config HAVE_KVM_NO_POLL bool + +config KVM_XFER_TO_GUEST_WORK + bool |