2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-27 14:43:58 +08:00
linux-next/include/uapi
Roman Kagan efc479e690 kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2
There is a flaw in the Hyper-V SynIC implementation in KVM: when message
page or event flags page is enabled by setting the corresponding msr,
KVM zeroes it out.  This is problematic because on migration the
corresponding MSRs are loaded on the destination, so the content of
those pages is lost.

This went unnoticed so far because the only user of those pages was
in-KVM hyperv synic timers, which could continue working despite that
zeroing.

Newer QEMU uses those pages for Hyper-V VMBus implementation, and
zeroing them breaks the migration.

Besides, in newer QEMU the content of those pages is fully managed by
QEMU, so zeroing them is undesirable even when writing the MSRs from the
guest side.

To support this new scheme, introduce a new capability,
KVM_CAP_HYPERV_SYNIC2, which, when enabled, makes sure that the synic
pages aren't zeroed out in KVM.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-07-13 17:41:04 +02:00
..
asm-generic Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
drm drm/amdgpu: Fix the exported always on CU bitmap 2017-06-29 12:43:49 -04:00
linux kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2 2017-07-13 17:41:04 +02:00
misc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
mtd uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
rdma uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
scsi scsi: cxlflash: Support AFU debug 2017-06-26 15:01:12 -04:00
sound ASoC: Updates for v4.13 2017-07-03 19:51:42 +02:00
video uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
xen uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00