Commit Graph

2 Commits

Author SHA1 Message Date
Vitaly Kuznetsov 561dbb41b1 i386: Make migration fail when Hyper-V reenlightenment was enabled but 'user_tsc_khz' is unset
KVM doesn't fully support Hyper-V reenlightenment notifications on
migration. In particular, it doesn't support emulating TSC frequency
of the source host by trapping all TSC accesses so unless TSC scaling
is supported on the destination host and KVM_SET_TSC_KHZ succeeds, it
is unsafe to proceed with migration.

KVM_SET_TSC_KHZ is called from two sites: kvm_arch_init_vcpu() and
kvm_arch_put_registers(). The later (intentionally) doesn't propagate
errors allowing migrations to succeed even when TSC scaling is not
supported on the destination. This doesn't suit 're-enlightenment'
use-case as we have to guarantee that TSC frequency stays constant.

Require 'tsc-frequency=' command line option to be specified for successful
migration when re-enlightenment was enabled by the guest.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210319123801.1111090-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-19 08:48:18 -04:00
Claudio Fontana a9dc68d9b2 i386: move kvm accel files into kvm/
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201212155530.23098-2-cfontana@suse.de>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-12-16 14:06:52 -05:00