| Message ID | 20240319130957.1050637-1-dwmw2@infradead.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add PSCI v1.3 SYSTEM_OFF2 support for hibernation | expand |
On Tue, Mar 19, 2024 at 12:59:01PM +0000, David Woodhouse wrote: > David Woodhouse (5): > firmware/psci: Add definitions for PSCI v1.3 specification (ALPHA) > KVM: arm64: Add support for PSCI v1.2 and v1.3 > KVM: arm64: Add PSCI v1.3 SYSTEM_OFF2 function for hibernation > KVM: arm64: nvhe: Pass through PSCI v1.3 SYSTEM_OFF2 call > arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate If we're going down the route of having this PSCI call live in KVM, it really deserves a test. I think you can just pile on the existing psci_test selftest.
On Tue, 2024-03-19 at 08:27 -0700, Oliver Upton wrote: > If we're going down the route of having this PSCI call live in KVM, it > really deserves a test. I think you can just pile on the existing > psci_test selftest. Added to https://git.infradead.org/users/dwmw2/linux.git/shortlog/refs/heads/psci-hibernate for next time. From 8c72a78e6179bc8970edc66a85ab6bee26f581fb Mon Sep 17 00:00:00 2001 From: David Woodhouse <dwmw@amazon.co.uk> Date: Tue, 19 Mar 2024 17:07:46 +0000 Subject: [PATCH 4/8] KVM: selftests: Add test for PSCI SYSTEM_OFF2 Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> --- .../testing/selftests/kvm/aarch64/psci_test.c | 61 +++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/tools/testing/selftests/kvm/aarch64/psci_test.c b/tools/testing/selftests/kvm/aarch64/psci_test.c index 9b004905d1d3..1c1cf1580d70 100644 --- a/tools/testing/selftests/kvm/aarch64/psci_test.c +++ b/tools/testing/selftests/kvm/aarch64/psci_test.c @@ -54,6 +54,15 @@ static uint64_t psci_system_suspend(uint64_t entry_addr, uint64_t context_id) return res.a0; } +static uint64_t psci_system_off2(uint64_t type) +{ + struct arm_smccc_res res; + + smccc_hvc(PSCI_1_3_FN64_SYSTEM_OFF2, type, 0, 0, 0, 0, 0, 0, &res); + + return res.a0; +} + static uint64_t psci_features(uint32_t func_id) { struct arm_smccc_res res; @@ -188,11 +197,63 @@ static void host_test_system_suspend(void) kvm_vm_free(vm); } +static void guest_test_system_off2(void) +{ + uint64_t ret; + + /* assert that SYSTEM_OFF2 is discoverable */ + GUEST_ASSERT(psci_features(PSCI_1_3_FN_SYSTEM_OFF2) & + (1UL << PSCI_1_3_HIBERNATE_TYPE_OFF)); + GUEST_ASSERT(psci_features(PSCI_1_3_FN64_SYSTEM_OFF2) & + (1UL << PSCI_1_3_HIBERNATE_TYPE_OFF)); + + ret = psci_system_off2(PSCI_1_3_HIBERNATE_TYPE_OFF); + GUEST_SYNC(ret); +} + +static void host_test_system_off2(void) +{ + struct kvm_vcpu *source, *target; + uint64_t psci_version = 0; + struct kvm_run *run; + struct kvm_vm *vm; + + vm = setup_vm(guest_test_system_off2, &source, &target); + vcpu_get_reg(target, KVM_REG_ARM_PSCI_VERSION, &psci_version); + TEST_ASSERT(psci_version >= PSCI_VERSION(0, 2), + "Unexpected PSCI version %lu.%lu", + PSCI_VERSION_MAJOR(psci_version), + PSCI_VERSION_MINOR(psci_version)); + + if (psci_version < PSCI_VERSION(1,3)) + goto skip; + + vcpu_power_off(target); + run = source->run; + + enter_guest(source); + + TEST_ASSERT_KVM_EXIT_REASON(source, KVM_EXIT_SYSTEM_EVENT); + TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SHUTDOWN, + "Unhandled system event: %u (expected: %u)", + run->system_event.type, KVM_SYSTEM_EVENT_SHUTDOWN); + TEST_ASSERT(run->system_event.ndata >= 1, + "Unexpected amount of system event data: %u (expected, >= 1)", + run->system_event.ndata); + TEST_ASSERT(run->system_event.data[0] & KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2, + "PSCI_OFF2 flag not set. Flags %llu (expected %llu)", + run->system_event.data[0], KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2); + + skip: + kvm_vm_free(vm); +} + int main(void) { TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SYSTEM_SUSPEND)); host_test_cpu_on(); host_test_system_suspend(); + host_test_system_off2(); return 0; }
On Tue, Mar 19, 2024 at 05:14:42PM +0000, David Woodhouse wrote: > On Tue, 2024-03-19 at 08:27 -0700, Oliver Upton wrote: > > If we're going down the route of having this PSCI call live in KVM, it > > really deserves a test. I think you can just pile on the existing > > psci_test selftest. > > Added to > https://git.infradead.org/users/dwmw2/linux.git/shortlog/refs/heads/psci-hibernate > for next time. > > From 8c72a78e6179bc8970edc66a85ab6bee26f581fb Mon Sep 17 00:00:00 2001 > From: David Woodhouse <dwmw@amazon.co.uk> > Date: Tue, 19 Mar 2024 17:07:46 +0000 > Subject: [PATCH 4/8] KVM: selftests: Add test for PSCI SYSTEM_OFF2 > > Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Looks good, thanks!
On Tue, 2024-03-19 at 12:41 -0700, Oliver Upton wrote: > On Tue, Mar 19, 2024 at 05:14:42PM +0000, David Woodhouse wrote: > > On Tue, 2024-03-19 at 08:27 -0700, Oliver Upton wrote: > > > If we're going down the route of having this PSCI call live in KVM, it > > > really deserves a test. I think you can just pile on the existing > > > psci_test selftest. > > > > Added to > > https://git.infradead.org/users/dwmw2/linux.git/shortlog/refs/heads/psci-hibernate > > for next time. > > > > From 8c72a78e6179bc8970edc66a85ab6bee26f581fb Mon Sep 17 00:00:00 2001 > > From: David Woodhouse <dwmw@amazon.co.uk> > > Date: Tue, 19 Mar 2024 17:07:46 +0000 > > Subject: [PATCH 4/8] KVM: selftests: Add test for PSCI SYSTEM_OFF2 > > > > Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> > > Looks good, thanks! Thanks. Marc, I think I've also addressed your feedback? Is there anything else to do other than wait for the spec to be published? Shall I post a v4 with PSCI v1.3 as default and the self-test? Would you apply that into a branch ready for merging when the spec is ready, or should I just wait and repost it all then?
On Fri, 22 Mar 2024 10:17:58 +0000, David Woodhouse <dwmw2@infradead.org> wrote: > > [1 <text/plain; UTF-8 (quoted-printable)>] > On Tue, 2024-03-19 at 12:41 -0700, Oliver Upton wrote: > > On Tue, Mar 19, 2024 at 05:14:42PM +0000, David Woodhouse wrote: > > > On Tue, 2024-03-19 at 08:27 -0700, Oliver Upton wrote: > > > > If we're going down the route of having this PSCI call live in KVM, it > > > > really deserves a test. I think you can just pile on the existing > > > > psci_test selftest. > > > > > > Added to > > > https://git.infradead.org/users/dwmw2/linux.git/shortlog/refs/heads/psci-hibernate > > > for next time. > > > > > > From 8c72a78e6179bc8970edc66a85ab6bee26f581fb Mon Sep 17 00:00:00 2001 > > > From: David Woodhouse <dwmw@amazon.co.uk> > > > Date: Tue, 19 Mar 2024 17:07:46 +0000 > > > Subject: [PATCH 4/8] KVM: selftests: Add test for PSCI SYSTEM_OFF2 > > > > > > Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> > > > > Looks good, thanks! > > Thanks. > > Marc, I think I've also addressed your feedback? Is there anything else > to do other than wait for the spec to be published? Other than the couple of minor nits I mentioned in replies to the individual patches, this looks good to me. > Shall I post a v4 with PSCI v1.3 as default and the self-test? Would > you apply that into a branch ready for merging when the spec is ready, > or should I just wait and repost it all then? I think this can wait for the final spec. I assume that you are directly tracking this anyway, so we don't need to poll for the spec update. Thanks, M.
On Fri, 2024-03-22 at 16:09 +0000, Marc Zyngier wrote: > > > Marc, I think I've also addressed your feedback? Is there anything else > > to do other than wait for the spec to be published? > > Other than the couple of minor nits I mentioned in replies to the > individual patches, this looks good to me. I believe I've handled all that. And also Sudeep's implicit nudge to use BIT() instead of manually shifting (1<<PSCI_1_3_HIBERNATE_TYPE_OFF). Rebased onto 6.8 and pushed to https://git.infradead.org/users/dwmw2/linux.git/shortlog/refs/heads/psci-hibernate-6.8 > > Shall I post a v4 with PSCI v1.3 as default and the self-test? Would > > you apply that into a branch ready for merging when the spec is ready, > > or should I just wait and repost it all then? > > I think this can wait for the final spec. I assume that you are > directly tracking this anyway, so we don't need to poll for the spec > update. Indeed, will post again when the spec is published. Thanks.
The PSCI v1.3 spec (https://developer.arm.com/documentation/den0022, currently in Alpha state, hence 'RFC') adds support for a SYSTEM_OFF2 function enabling a HIBERNATE_OFF state which is analogous to ACPI S4. This will allow hosting environments to determine that a guest is hibernated rather than just powered off, and ensure that they preserve the virtual environment appropriately to allow the guest to resume safely (or bump the hardware_signature in the FACS to trigger a clean reboot instead). This updates KVM to support advertising PSCI v1.3, and unconditionally enables the SYSTEM_OFF2 support when PSCI v1.3 is enabled. For now, KVM defaults to PSCI v1.2 unless explicitly requested. For the guest side, add a new SYS_OFF_MODE_POWER_OFF handler with higher priority than the EFI one, but which *only* triggers when there's a hibernation in progress. There are other ways to do this (see the commit message for more details) but this seemed like the simplest. Version 2 of the patch series splits out the psci.h definitions into a separate commit (a dependency for both the guest and KVM side), and adds definitions for the other new functions added in v1.3. It also moves the pKVM psci-relay support to a separate commit; although in arch/arm64/kvm that's actually about the *guest* side of SYSTEM_OFF2 (i.e. using it from the host kernel, relayed through nVHE). Version 3 dropped the KVM_CAP which allowed userspace to explicitly opt in to the new feature like with SYSTEM_SUSPEND, and makes it depend only on PSCI v1.3 being exposed to the guest. David Woodhouse (5): firmware/psci: Add definitions for PSCI v1.3 specification (ALPHA) KVM: arm64: Add support for PSCI v1.2 and v1.3 KVM: arm64: Add PSCI v1.3 SYSTEM_OFF2 function for hibernation KVM: arm64: nvhe: Pass through PSCI v1.3 SYSTEM_OFF2 call arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate Documentation/virt/kvm/api.rst | 11 +++++++++ arch/arm64/include/uapi/asm/kvm.h | 6 +++++ arch/arm64/kvm/hyp/nvhe/psci-relay.c | 2 ++ arch/arm64/kvm/hypercalls.c | 2 ++ arch/arm64/kvm/psci.c | 43 +++++++++++++++++++++++++++++++++++- drivers/firmware/psci/psci.c | 35 +++++++++++++++++++++++++++++ include/kvm/arm_psci.h | 4 +++- include/uapi/linux/psci.h | 20 +++++++++++++++++ kernel/power/hibernate.c | 5 ++++- 9 files changed, 125 insertions(+), 3 deletions(-)