On 18/04/2024 20:34, David Woodhouse wrote:
From: David Woodhouse dwmw@amazon.co.uk
KVM does make an attempt to cope with non-constant TSC, and has notifiers to handle host TSC frequency changes. However, it *only* adjusts the KVM clock, and doesn't adjust TSC frequency scaling when the host changes.
This is presumably because non-constant TSCs were fixed in hardware long before TSC scaling was implemented, so there should never be real CPUs which have TSC scaling but *not* CONSTANT_TSC.
Such a combination could potentially happen in some odd L1 nesting environment, but it isn't worth trying to support it. Just make the dependency explicit.
Signed-off-by: David Woodhouse dwmw@amazon.co.uk
arch/x86/kvm/svm/svm.c | 3 ++- arch/x86/kvm/vmx/vmx.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
Reviewed-by: Paul Durrant paul@xen.org