xive/kvm: Trigger interrupts from userspace
commit58246041d372f5b1cd7ec5242b44dbd5c3a556c4
authorGreg Kurz <groug@kaod.org>
Mon, 18 Nov 2019 15:12:07 +0000 (18 16:12 +0100)
committerDavid Gibson <david@gibson.dropbear.id.au>
Mon, 16 Dec 2019 23:39:47 +0000 (17 10:39 +1100)
tree987e129de5ff50740458393edc1565f5ce2b7eea
parent7aa22e18092e8eef2bcc77f247576fa44980c7cb
xive/kvm: Trigger interrupts from userspace

When using the XIVE KVM device, the trigger page is directly accessible
in QEMU. Unlike with XICS, no need to ask KVM to fire the interrupt. A
simple store on the trigger page does the job.

Just call xive_esb_trigger().

This may improve performance of emulated devices that go through
qemu_set_irq(), eg. virtio devices created with ioeventfd=off or
configured by the guest to use LSI interrupts, which aren't really
recommended setups.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <157408992731.494439.3405812941731584740.stgit@bahia.lan>
Reviewed-by: C├ędric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
hw/intc/spapr_xive_kvm.c