On Tue, Jun 08, 2021 at 02:08:11PM +0200, Vitaly Kuznetsov wrote: > Currently, the only eVMCS version, supported by KVM (and described in TLFS) > is '1'. When Enlightened VMCS feature is enabled, QEMU takes the supported > eVMCS version range (from KVM_CAP_HYPERV_ENLIGHTENED_VMCS enablement) and > puts it to guest visible CPUIDs. When (and if) eVMCS ver.2 appears a > problem on migration is expected: it doesn't seem to be possible to migrate > from a host supporting eVMCS ver.2 to a host, which only support eVMCS > ver.1.
Should we rewrite this as "it wouldn't be possible to migrate", as this patch fixes the problem and makes it possible? > > Hardcode eVMCS ver.1 as the result of 'hv-evmcs' enablement for now. Newer > eVMCS versions will have to have their own enablement options (e.g. > 'hv-evmcs=2'). > > Signed-off-by: Vitaly Kuznetsov <[email protected]> Reviewed-by: Eduardo Habkost <[email protected]> -- Eduardo
