| Message ID | 20210923191610.3814698-1-oupton@google.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: arm64: Implement PSCI SYSTEM_SUSPEND support | expand |
On Thu, Sep 23, 2021 at 07:15:59PM +0000, Oliver Upton 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). If a VMM would like to have KVM emulate the suspend, it can do > so by setting the vCPU's MP state to KVM_MP_STATE_HALTED. Support for > this state has been added in this series. > > Patch 1 is an unrelated cleanup, dropping an unused parameter > > Patch 2 simplifies how KVM filters SMC64 functions for AArch32 guests. > > Patch 3 wraps up the vCPU reset logic used by the PSCI CPU_ON > implementation in KVM for subsequent use, as we must queue up a reset > for the vCPU that requested a system suspend. > > Patch 4 is another unrelated cleanup, fixing the naming for the > KVM_REQ_SLEEP handler to avoid confusion and remain consistent with the > handler introduced in this series. > > Patch 5 changes how WFI-like events are handled in KVM (WFI instruction, > PSCI CPU_SUSPEND). Instead of directly blocking the vCPU in the > respective handlers, set a request bit and block before resuming the > guest. WFI and PSCI CPU_SUSPEND do not require deferral of > kvm_vcpu_block(), but SYSTEM_SUSPEND does. Rather than adding a deferral > mechanism just for SYSTEM_SUSPEND, it is a bit cleaner to have all > blocking events just request the event. > > Patch 6 actually adds PSCI SYSTEM_SUSPEND support to KVM, and adds the > necessary UAPI to pair with the call. > > Patch 7 renames the PSCI selftest to something more generic, as we will > test more than just CPU_ON. > > Patch 8 creates a common helper for making SMC64 calls in KVM selftests, > rather than having tests open-code their own approach. > > Patch 9 makes the PSCI test use KVM_SET_MP_STATE for powering off a vCPU > rather than the vCPU init flag. This change is necessary to separate > generic VM setup from the setup for a particular PSCI test. > > Patch 10 reworks psci_test into a bunch of helpers, making it easier to > build additional test cases with the common parts. > > Finally, patch 11 adds 2 test cases for the SYSTEM_SUSPEND PSCI call. > Verify that the call succeeds if all other vCPUs have been powered off > and that it fails if more than the calling vCPU is powered on. > > This series applies cleanly to v5.15-rc2. Testing was performed on an > Ampere Mt. Jade system. Gah, forgot to summarize updates: v1 -> v2: - Rebase to 5.15-rc2 - Allow userspace to request in-kernel suspend emulation (Marc) - Add another test case for SYSTEM_SUSPEND, cleaning up the PSCI selftest - Create a common SMCCC function for KVM selftests v1: http://lore.kernel.org/r/20210819223640.3564975-1-oupton@google.com > Oliver Upton (11): > 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: Rename the KVM_REQ_SLEEP handler > KVM: arm64: Defer WFI emulation as a requested event > KVM: arm64: Add support for SYSTEM_SUSPEND PSCI call > selftests: KVM: Rename psci_cpu_on_test to psci_test > selftests: KVM: Create helper for making SMCCC calls > selftests: KVM: Use KVM_SET_MP_STATE to power off vCPU in psci_test > selftests: KVM: Refactor psci_test to make it amenable to new tests > selftests: KVM: Test SYSTEM_SUSPEND PSCI call > > Documentation/virt/kvm/api.rst | 6 + > arch/arm64/include/asm/kvm_host.h | 4 + > arch/arm64/kvm/arm.c | 21 +- > arch/arm64/kvm/handle_exit.c | 3 +- > arch/arm64/kvm/psci.c | 138 ++++++++--- > include/uapi/linux/kvm.h | 2 + > tools/testing/selftests/kvm/.gitignore | 2 +- > tools/testing/selftests/kvm/Makefile | 2 +- > .../selftests/kvm/aarch64/psci_cpu_on_test.c | 121 ---------- > .../testing/selftests/kvm/aarch64/psci_test.c | 218 ++++++++++++++++++ > .../selftests/kvm/include/aarch64/processor.h | 22 ++ > .../selftests/kvm/lib/aarch64/processor.c | 25 ++ > tools/testing/selftests/kvm/steal_time.c | 13 +- > 13 files changed, 403 insertions(+), 174 deletions(-) > delete mode 100644 tools/testing/selftests/kvm/aarch64/psci_cpu_on_test.c > create mode 100644 tools/testing/selftests/kvm/aarch64/psci_test.c > > -- > 2.33.0.685.g46640cef36-goog >