This series makes it so that the time that the host is suspended is included in guests' steal time. When the host resumes from a suspend, the guest thinks any task that was running during the suspend ran for a long time, even though the effective run time was much shorter, which can end up having negative effects with scheduling. To mitigate this issue, we include the time that the host was suspended in steal time, which lets the guest can subtract the duration from the tasks' runtime. In addition, we make the guest TSC behavior consistent whether the host TSC went backwards or not. v4: - Advance guest TSC on suspends where host TSC goes backwards. - Block vCPUs from running until resume notifier. - Move suspend duration accounting out of machine-independent kvm to x86. - Merge code and documentation patches. - Reworded documentation. v3: https://lore.kernel.org/kvm/Z5AB-6bLRNLle27G@xxxxxxxxxx/T/ - Use PM notifier instead of syscore ops (kvm_suspend()/kvm_resume()), because the latter doesn't get called on shallow suspend. - Don't call function under UACCESS. - Whitespace. v2: https://lore.kernel.org/lkml/20241118043745.1857272-1-suleiman@xxxxxxxxxx/ - Accumulate suspend time at machine-independent kvm layer and track per-VCPU instead of per-VM. - Document changes. v1: https://lore.kernel.org/kvm/20240710074410.770409-1-suleiman@xxxxxxxxxx/ Suleiman Souhlal (2): KVM: x86: Advance guest TSC after deep suspend. KVM: x86: Include host suspended time in steal time Documentation/virt/kvm/x86/msr.rst | 9 +++- arch/x86/include/asm/kvm_host.h | 7 +++ arch/x86/kvm/x86.c | 84 +++++++++++++++++++++++++++++- 3 files changed, 97 insertions(+), 3 deletions(-) -- 2.48.1.601.g30ceb7b040-goog
