Linux-5.8 introduced interrupt based mechanism for 'page ready' events
delivery and disabled the old, #PF based one (see commit 2635b5c4a0e4
"KVM: x86: interrupt based APF 'page ready' event delivery"). Linux
guest switches to using in in 5.9 (see commit b1d405751cd5 "KVM: x86:
Switch KVM guest to using interrupts for page ready APF delivery").
The feature has a new KVM_FEATURE_ASYNC_PF_INT bit assigned and
the interrupt vector is set in MSR_KVM_ASYNC_PF_INT MSR. Support this
in QEMU.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200908141206.357450-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
db5daafab2