Commit 72c3c0fe authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/kvm: Use generic xfer to guest work function 



Use the generic infrastructure to check for and handle pending work before
transitioning into guest mode.

This now handles TIF_NOTIFY_RESUME as well which was ignored so
far. Handling it is important as this covers task work and task work will
be used to offload the heavy lifting of POSIX CPU timers to thread context.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200722220520.979724969@linutronix.de
parent a27a0a55

arch/x86/kvm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ config KVM 
	select HAVE_KVM_MSI

	select HAVE_KVM_CPU_RELAX_INTERCEPT

	select HAVE_KVM_NO_POLL

	select KVM_XFER_TO_GUEST_WORK

	select KVM_GENERIC_DIRTYLOG_READ_PROTECT

	select KVM_VFIO

	select SRCU

arch/x86/kvm/vmx/vmx.c

+5 −6
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/slab.h>

#include <linux/tboot.h>

#include <linux/trace_events.h>

#include <linux/entry-kvm.h>



#include <asm/apic.h>

#include <asm/asm.h>
@@ -5373,14 +5374,12 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) 
		}



		/*

		 * Note, return 1 and not 0, vcpu_run() is responsible for

		 * morphing the pending signal into the proper return code.

		 * Note, return 1 and not 0, vcpu_run() will invoke

		 * xfer_to_guest_mode() which will create a proper return

		 * code.

		 */

		if (signal_pending(current))

		if (__xfer_to_guest_mode_work_pending())

			return 1;



		if (need_resched())

			schedule();

	}



	return 1;

arch/x86/kvm/x86.c

+6 −9
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ 
#include <linux/sched/stat.h>

#include <linux/sched/isolation.h>

#include <linux/mem_encrypt.h>

#include <linux/entry-kvm.h>



#include <trace/events/kvm.h>
@@ -1587,7 +1588,7 @@ EXPORT_SYMBOL_GPL(kvm_emulate_wrmsr); 
bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu)

{

	return vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) ||

		need_resched() || signal_pending(current);

		xfer_to_guest_mode_work_pending();

}

EXPORT_SYMBOL_GPL(kvm_vcpu_exit_request);
@@ -8681,15 +8682,11 @@ static int vcpu_run(struct kvm_vcpu *vcpu) 
			break;

		}



		if (signal_pending(current)) {

			r = -EINTR;

			vcpu->run->exit_reason = KVM_EXIT_INTR;

			++vcpu->stat.signal_exits;

			break;

		}

		if (need_resched()) {

		if (xfer_to_guest_mode_work_pending()) {

			srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);

			cond_resched();

			r = xfer_to_guest_mode_handle_work(vcpu);

			if (r)

				return r;

			vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);

		}

	}

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