Marc,
On Thu, Aug 19, 2021 at 3:36 PM Oliver Upton <oupton@xxxxxxxxxx> wrote:
>
> Certain VMMs/operators may wish to give their guests the ability to
> initiate a system suspend that could result in the VM being saved to
> persistent storage to be resumed at a later time. The PSCI v1.0
> specification describes an SMC, SYSTEM_SUSPEND, that allows a kernel to
> request a system suspend. This call is optional for v1.0, and KVM
> elected to not support the call in its v1.0 implementation.
>
> This series adds support for the SYSTEM_SUSPEND PSCI call to KVM/arm64.
> Since this is a system-scoped event, KVM cannot quiesce the VM on its
> own. We add a new system exit type in this series to clue in userspace
> that a suspend was requested. Per the KVM_EXIT_SYSTEM_EVENT ABI, a VMM
> that doesn't care about this event can simply resume the guest without
> issue (we set up the calling vCPU to come out of reset correctly on next
> KVM_RUN).
>
> Patch 1 is unrelated, and is a fix for "KVM: arm64: Enforce reserved
> bits for PSCI target affinities" on the kvmarm/next branch. Nothing
> particularly hairy, just an unused param.
Title line may not have been clear on this series, Patch 1 is a fix
for the PSCI CPU_ON series that's in kvmarm/next to suppress a
compiler warning.
> Patch 2 simplifies the function to check if KVM allows a particular PSCI
> function. We can generally disallow any PSCI function that sets the
> SMC64 bit in the PSCI function ID.
>
> Patch 3 wraps up the PSCI reset logic used for CPU_ON, which will be
> needed later to queue up a reset on the vCPU that requested the system
> suspend.
>
> Patch 4 brings in the new UAPI and PSCI call, guarded behind a VM
> capability for backwards compatibility.
>
> Patch 5 is indirectly related to this series, and avoids compiler
> reordering on PSCI calls in the selftest introduced by "selftests: KVM:
> Introduce psci_cpu_on_test".
This too is a fix for the PSCI CPU_ON series. Just wanted to raise it
to your attention beyond the new feature I'm working on here.
--
Thanks,
Oliver
> Finally, patch 6 extends the PSCI selftest to verify the
> SYSTEM_SUSPEND PSCI call behaves as intended.
>
> These patches apply cleanly to kvmarm/next at the following commit:
>
> f2267b87ecd5 ("Merge branch kvm-arm64/misc-5.15 into kvmarm-master/next")
>
> The series is intentionally based on kvmarm/next for the sake of fixing
> patches only present there in [1/6] and [5/6]. Tested on QEMU (ick)
> since my Mt. Jade box is out to lunch at the moment and for some unknown
> reason the toolchain on my work computer doesn't play nice with the FVP.
>
> Oliver Upton (6):
> KVM: arm64: Drop unused vcpu param to kvm_psci_valid_affinity()
> KVM: arm64: Clean up SMC64 PSCI filtering for AArch32 guests
> KVM: arm64: Encapsulate reset request logic in a helper function
> KVM: arm64: Add support for SYSTEM_SUSPEND PSCI call
> selftests: KVM: Promote PSCI hypercalls to asm volatile
> selftests: KVM: Test SYSTEM_SUSPEND PSCI call
>
> arch/arm64/include/asm/kvm_host.h | 3 +
> arch/arm64/kvm/arm.c | 5 +
> arch/arm64/kvm/psci.c | 134 +++++++++++++-----
> include/uapi/linux/kvm.h | 2 +
> .../selftests/kvm/aarch64/psci_cpu_on_test.c | 126 +++++++++++-----
> 5 files changed, 202 insertions(+), 68 deletions(-)
>
> --
> 2.33.0.rc2.250.ged5fa647cd-goog
>
