Hi,
This patch series adds virtual suspend time injection support to KVM.
Before this change, if the host goes into suspended state while the
guest is running, the guest will experience a time jump after the host's
resume. This can confuse some services in the guest since they can't
detect if the system went into suspend or not by comparing
CLOCK_BOOTTIME and CLOCK_MONOTONIC.
To solve this problem, we wanted to add a way to adjust the guest clocks
without actually suspending the guests. However, there was no way to
modify a gap between CLOCK_BOOTTIME and CLOCK_MONOTONIC without actually
suspending the guests. Therefore, this series introduce a new struct
called kvm_host_suspend_time to share the suspend time between host and
guest and a mechanism to inject a suspend time to the guest while
keeping
monotonicity of the clocks.
Could you take a look and let me know how we can improve the patches if
they are doing something wrong?
Thanks,
Hikaru Nishida
Hikaru Nishida (6):
x86/kvm: Reserve KVM_FEATURE_HOST_SUSPEND_TIME and
MSR_KVM_HOST_SUSPEND_TIME
x86/kvm: Add a struct and constants for virtual suspend time injection
x86/kvm: Add CONFIG_KVM_VIRT_SUSPEND_TIMING
x86/kvm: Add a host side support for virtual suspend time injection
x86/kvm: Add CONFIG_KVM_VIRT_SUSPEND_TIMING_GUEST
x86/kvm: Add a guest side support for virtual suspend time injection
Documentation/virt/kvm/cpuid.rst | 3 +
Documentation/virt/kvm/msr.rst | 29 +++++++++
arch/x86/Kconfig | 13 ++++
arch/x86/include/asm/kvm_host.h | 5 ++
arch/x86/include/asm/kvm_para.h | 9 +++
arch/x86/include/uapi/asm/kvm_para.h | 6 ++
arch/x86/kernel/kvmclock.c | 25 ++++++++
arch/x86/kvm/Kconfig | 13 ++++
arch/x86/kvm/cpuid.c | 4 ++
arch/x86/kvm/x86.c | 89 +++++++++++++++++++++++++++-
include/linux/kvm_host.h | 7 +++
include/linux/timekeeper_internal.h | 4 ++
kernel/time/timekeeping.c | 31 ++++++++++
13 files changed, 237 insertions(+), 1 deletion(-)
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2.31.1.498.g6c1eba8ee3d-goog
