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26baa1f1c4
Add the basic infrastructure to split the TIF_NEED_RESCHED bit in two. Either bit will cause a resched on return-to-user, but only TIF_NEED_RESCHED will drive IRQ preemption. No behavioural change intended. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lkml.kernel.org/r/20241007075055.219540785@infradead.org
49 lines
1.2 KiB
C
49 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/entry-kvm.h>
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#include <linux/kvm_host.h>
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static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
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{
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do {
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int ret;
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if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
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kvm_handle_signal_exit(vcpu);
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return -EINTR;
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}
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if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY))
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schedule();
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if (ti_work & _TIF_NOTIFY_RESUME)
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resume_user_mode_work(NULL);
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ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
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if (ret)
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return ret;
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ti_work = read_thread_flags();
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} while (ti_work & XFER_TO_GUEST_MODE_WORK);
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return 0;
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}
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int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
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{
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unsigned long ti_work;
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/*
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* This is invoked from the outer guest loop with interrupts and
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* preemption enabled.
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*
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* KVM invokes xfer_to_guest_mode_work_pending() with interrupts
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* disabled in the inner loop before going into guest mode. No need
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* to disable interrupts here.
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*/
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ti_work = read_thread_flags();
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if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
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return 0;
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return xfer_to_guest_mode_work(vcpu, ti_work);
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}
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EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
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