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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: epam.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: VI1PR03MB3758.eurprd03.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 422d6da5-4efd-4e6b-748e-08daa8650dbe X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Oct 2022 13:08:40.1470 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b41b72d0-4e9f-4c26-8a69-f949f367c91d X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: ynQqJEd9UUAis4QfPGVF6AtT+oD5Slskrzg0N0xc+yF0haYQA48j/pnJAppZyC6CNcBvTWVXyN6b2jmuUY297w== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS1PR03MB8150 X-Proofpoint-GUID: jBncKgJDaDydLMu5ka6Gw1AUXIsB3IX4 X-Proofpoint-ORIG-GUID: jBncKgJDaDydLMu5ka6Gw1AUXIsB3IX4 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-10-06_05,2022-10-07_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 clxscore=1015 mlxscore=0 priorityscore=1501 adultscore=0 mlxlogscore=999 impostorscore=0 lowpriorityscore=0 suspectscore=0 spamscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210070079 This is a series from Mirela Simonovic. Ported to 4.16 and with added changes suggested here=20 https://lore.kernel.org/all/CAKPH-NjmaZENb8gT=3D+FobrAycRF01_--6GuRA2ck9Di5= wiudhA@mail.gmail.com This series contains support for suspend to RAM (in the following text just 'suspend') for Xen on arm64. The implementation is aligned with the design specification that has been proposed on xen-devel list: https://lists.xenproject.org/archives/html/xen-devel/2017-12/msg01574.html At a high-level the series contains: 1) Support for suspending guests via virtual PSCI SYSTEM_SUSPEND call 2) Support for resuming a guest on an interrupt targeted to that guest 3) Support for suspending Xen after dom0 finalizes the suspend 4) Support for resuming Xen on an interrupt that is targeted to a guest ---------------------------------------------------------------------------= ----- In more details: *** About suspending/resuming guests The patches included in this series allow PSCI compliant guests that have support for suspend to RAM (e.g. echo mem > /sys/power/state in Linux) to suspend and resume on top of Xen without any EL1 code changes. During their suspend procedure guests will hot-unplug their secondary CPUs, triggering Xen's virtual CPU_OFF PSCI implementation, and then finalize the suspend from their boot CPU, triggering Xen's virtual SYSTEM_SUSPEND PSCI. Guests will save/restore their own EL1 context on suspend/resume. A guest is expected to leave enabled interrupts that are considered to be i= ts wake-up sources. Those interrupts will be able to wake up the guest. This h= olds regardless of the state of the underlying software layers, i.e. whether Xen= gets suspended or not doesn't affect the ability of the guest to wake up. First argument of SYSTEM_SUSPEND PSCI call is a resume entry point, from wh= ich the guest assumes to start on resume. On resume, guests assume to be runnin= g in an environment whose state matches the CPU state after reset, e.g. with res= et register values, MMU disabled, etc. To ensure this, Xen has to 'reset' the VCPU context and save the resume entry point into program counter before th= e guest's VCPU gets scheduled in on resume. This is done when the guest resum= es. Xen also needs to take care that the guest's view of GIC and timer gets sav= ed. Also, while a guest is suspended its watchdogs are paused, in order to avoi= d watchdog triggered shutdown of a guest that has been asleep for a period of= time that is longer than the watchdog period. After this point, from Xen's point of view a suspended guest has one VCPU blocked, waiting for an interrupt. When such an interrupt comes, Xen will unblock the VCPU of the suspended domain, which results in the guest resuming. *** About suspending/resuming Xen Xen starts its own suspend procedure once dom0 is suspended. Dom0 is considered to be the decision maker for EL1 and EL2. On suspend, Xen will first freeze all domains. Then, Xen disables physical secondary CPUs, which leads to physical CPU_OFF to be called by each second= ary CPU. After that Xen finalizes the suspend from the boot CPU. This consists of suspending the timer, i.e. suppressing its interrupts (we = don't want to be woken up by a timer, there is no VCPU ready to be scheduled). Th= en the state of GIC is saved, console is suspended, and CPU context is saved. = The saved context tells where Xen needs to continue execution on resume. Since Xen will resume with MMU disabled, the first thing to do in resume is= to resume memory management in order to be able to access the context that nee= ds to be restored (we know virtual address of the context data). Finally Xen call= s SYSTEM_SUSPEND PSCI to the EL3. When resuming, all the steps done in suspend need to be reverted. This is completed by unblocking dom0's VCPU, because we always want the dom0 to resume, regardless of the target domain whose interrupt woke up Xen. *** Handling of unprivileged guests during Xen suspend/resume Any domU that is not suspended when dom0 suspends will be frozen, domUs tha= t are already suspended remain suspended. On resume the suspended domUs still rem= ain suspended (unless their wake interrupt caused Xen to wake) while the others will be thawed. For more details please refer to patches or the design specification: https://lists.xenproject.org/archives/html/xen-devel/2017-12/msg01574.html Juergen Gross (1): xen: don't free percpu areas during suspend Mirela Simonovic (15): xen/arm: Implement PSCI system suspend xen/arm: While a domain is suspended put its watchdogs on pause xen/arm: Trigger Xen suspend when Dom0 completes suspend xen/x86: Move freeze/thaw_domains into common files xen/arm: Freeze domains on suspend and thaw them on resume xen/arm: Disable/enable non-boot physical CPUs on suspend/resume xen/arm: Add rcu_barrier() before enabling non-boot CPUs on resume xen/arm: Implement GIC suspend/resume functions (gicv2 only) xen/arm: Suspend/resume GIC on system suspend/resume xen/arm: Suspend/resume timer interrupt generation xen/arm: Implement PSCI SYSTEM_SUSPEND call (physical interface) xen/arm: Resume memory management on Xen resume xen/arm: Save/restore context on suspend/resume xen/arm: Resume Dom0 after Xen resumes xen/arm: Suspend/resume console on Xen suspend/resume Mykyta Poturai (2): watchdog: Introduce a separate struct for watchdog timers timers: Don't migrate timers during suspend Oleksandr Andrushchenko (1): Fix misleading indentation gcc warning xen/arch/arm/Makefile | 1 + xen/arch/arm/arm64/entry.S | 2 + xen/arch/arm/arm64/head.S | 121 +++++++++++++ xen/arch/arm/domain.c | 4 + xen/arch/arm/gic-v2.c | 138 ++++++++++++++- xen/arch/arm/gic.c | 25 +++ xen/arch/arm/mm.c | 1 + xen/arch/arm/percpu.c | 7 +- xen/arch/arm/psci.c | 16 ++ xen/arch/arm/suspend.c | 292 +++++++++++++++++++++++++++++++ xen/arch/arm/time.c | 22 +++ xen/arch/arm/vpsci.c | 28 +++ xen/common/domain.c | 29 +++ xen/common/keyhandler.c | 2 +- xen/common/sched/core.c | 55 +++++- xen/common/timer.c | 3 +- xen/include/asm-arm/domain.h | 3 + xen/include/asm-arm/gic.h | 8 + xen/include/asm-arm/perfc_defn.h | 1 + xen/include/asm-arm/processor.h | 22 +++ xen/include/asm-arm/psci.h | 3 + xen/include/asm-arm/suspend.h | 40 +++++ xen/include/asm-arm/time.h | 3 + xen/include/xen/sched.h | 16 +- xen/include/xen/watchdog.h | 6 + 25 files changed, 837 insertions(+), 11 deletions(-) create mode 100644 xen/arch/arm/suspend.c create mode 100644 xen/include/asm-arm/suspend.h --=20 2.37.1