This is a note to let you know that I've just added the patch titled

KVM: PPC: Book3S: fix XIVE migration of pending interrupts

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kvm-ppc-book3s-fix-xive-migration-of-pending-interrupts.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From dc1c4165d189350cb51bdd3057deb6ecd164beda Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= clg@kaod.org Date: Tue, 12 Dec 2017 12:02:04 +0000 Subject: KVM: PPC: Book3S: fix XIVE migration of pending interrupts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

From: Cédric Le Goater clg@kaod.org

commit dc1c4165d189350cb51bdd3057deb6ecd164beda upstream.

When restoring a pending interrupt, we are setting the Q bit to force a retrigger in xive_finish_unmask(). But we also need to force an EOI in this case to reach the same initial state : P=1, Q=0.

This can be done by not setting 'old_p' for pending interrupts which will inform xive_finish_unmask() that an EOI needs to be sent.

Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Suggested-by: Benjamin Herrenschmidt benh@kernel.crashing.org Signed-off-by: Cédric Le Goater clg@kaod.org Reviewed-by: Laurent Vivier lvivier@redhat.com Tested-by: Laurent Vivier lvivier@redhat.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/powerpc/kvm/book3s_xive.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -1558,7 +1558,7 @@ static int xive_set_source(struct kvmppc

/* * Restore P and Q. If the interrupt was pending, we - * force both P and Q, which will trigger a resend. + * force Q and !P, which will trigger a resend. * * That means that a guest that had both an interrupt * pending (queued) and Q set will restore with only @@ -1566,7 +1566,7 @@ static int xive_set_source(struct kvmppc * is perfectly fine as coalescing interrupts that haven't * been presented yet is always allowed. */ - if (val & KVM_XICS_PRESENTED || val & KVM_XICS_PENDING) + if (val & KVM_XICS_PRESENTED && !(val & KVM_XICS_PENDING)) state->old_p = true; if (val & KVM_XICS_QUEUED || val & KVM_XICS_PENDING) state->old_q = true;

Patches currently in stable-queue which might be from clg@kaod.org are

queue-4.14/kvm-ppc-book3s-fix-xive-migration-of-pending-interrupts.patch