From 1e5794295c5dbfcc31cf5de840c9e095ae50efb7 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 4 May 2022 03:24:36 +0000 Subject: KVM: arm64: Dedupe vCPU power off helpers vcpu_power_off() and kvm_psci_vcpu_off() are equivalent; rename the former and replace all callsites to the latter. No functional change intended. Signed-off-by: Oliver Upton Reviewed-by: Reiji Watanabe Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220504032446.4133305-3-oupton@google.com --- arch/arm64/include/asm/kvm_host.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm64/include/asm/kvm_host.h') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 94a27a7520f4..490cd7f3a905 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -841,4 +841,6 @@ void __init kvm_hyp_reserve(void); static inline void kvm_hyp_reserve(void) { } #endif +void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu); + #endif /* __ARM64_KVM_HOST_H__ */ -- cgit v1.2.3 From b171f9bbb130cb323f2101edd32da2a25d43ebfa Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 4 May 2022 03:24:37 +0000 Subject: KVM: arm64: Track vCPU power state using MP state values A subsequent change to KVM will add support for additional power states. Store the MP state by value rather than keeping track of it as a boolean. No functional change intended. Signed-off-by: Oliver Upton Reviewed-by: Reiji Watanabe Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220504032446.4133305-4-oupton@google.com --- arch/arm64/include/asm/kvm_host.h | 5 +++-- arch/arm64/kvm/arm.c | 22 ++++++++++++---------- arch/arm64/kvm/psci.c | 12 ++++++------ 3 files changed, 21 insertions(+), 18 deletions(-) (limited to 'arch/arm64/include/asm/kvm_host.h') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 490cd7f3a905..f3f93d48e21a 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -365,8 +365,8 @@ struct kvm_vcpu_arch { u32 mdscr_el1; } guest_debug_preserved; - /* vcpu power-off state */ - bool power_off; + /* vcpu power state */ + struct kvm_mp_state mp_state; /* Don't run the guest (internal implementation need) */ bool pause; @@ -842,5 +842,6 @@ static inline void kvm_hyp_reserve(void) { } #endif void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu); +bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu); #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 28c83c6ddbae..29e107457c4d 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -434,18 +434,20 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) { - vcpu->arch.power_off = true; + vcpu->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED; kvm_make_request(KVM_REQ_SLEEP, vcpu); kvm_vcpu_kick(vcpu); } +bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_STOPPED; +} + int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { - if (vcpu->arch.power_off) - mp_state->mp_state = KVM_MP_STATE_STOPPED; - else - mp_state->mp_state = KVM_MP_STATE_RUNNABLE; + *mp_state = vcpu->arch.mp_state; return 0; } @@ -457,7 +459,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, switch (mp_state->mp_state) { case KVM_MP_STATE_RUNNABLE: - vcpu->arch.power_off = false; + vcpu->arch.mp_state = *mp_state; break; case KVM_MP_STATE_STOPPED: kvm_arm_vcpu_power_off(vcpu); @@ -480,7 +482,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF); return ((irq_lines || kvm_vgic_vcpu_pending_irq(v)) - && !v->arch.power_off && !v->arch.pause); + && !kvm_arm_vcpu_stopped(v) && !v->arch.pause); } bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) @@ -597,10 +599,10 @@ static void vcpu_req_sleep(struct kvm_vcpu *vcpu) struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); rcuwait_wait_event(wait, - (!vcpu->arch.power_off) &&(!vcpu->arch.pause), + (!kvm_arm_vcpu_stopped(vcpu)) && (!vcpu->arch.pause), TASK_INTERRUPTIBLE); - if (vcpu->arch.power_off || vcpu->arch.pause) { + if (kvm_arm_vcpu_stopped(vcpu) || vcpu->arch.pause) { /* Awaken to handle a signal, request we sleep again later. */ kvm_make_request(KVM_REQ_SLEEP, vcpu); } @@ -1126,7 +1128,7 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) kvm_arm_vcpu_power_off(vcpu); else - vcpu->arch.power_off = false; + vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE; return 0; } diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 9b1f3acae155..2e6f060214a7 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -76,7 +76,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) */ if (!vcpu) return PSCI_RET_INVALID_PARAMS; - if (!vcpu->arch.power_off) { + if (!kvm_arm_vcpu_stopped(vcpu)) { if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) return PSCI_RET_ALREADY_ON; else @@ -100,12 +100,12 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); /* - * Make sure the reset request is observed if the change to - * power_off is observed. + * Make sure the reset request is observed if the RUNNABLE mp_state is + * observed. */ smp_wmb(); - vcpu->arch.power_off = false; + vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE; kvm_vcpu_wake_up(vcpu); return PSCI_RET_SUCCESS; @@ -143,7 +143,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) mpidr = kvm_vcpu_get_mpidr_aff(tmp); if ((mpidr & target_affinity_mask) == target_affinity) { matching_cpus++; - if (!tmp->arch.power_off) + if (!kvm_arm_vcpu_stopped(tmp)) return PSCI_0_2_AFFINITY_LEVEL_ON; } } @@ -169,7 +169,7 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags) * re-initialized. */ kvm_for_each_vcpu(i, tmp, vcpu->kvm) - tmp->arch.power_off = true; + tmp->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED; kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP); memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); -- cgit v1.2.3 From 7b33a09d036ffd9a04506122840629c7e870cf08 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 4 May 2022 03:24:40 +0000 Subject: KVM: arm64: Add support for userspace to suspend a vCPU Introduce a new MP state, KVM_MP_STATE_SUSPENDED, which indicates a vCPU is in a suspended state. In the suspended state the vCPU will block until a wakeup event (pending interrupt) is recognized. Add a new system event type, KVM_SYSTEM_EVENT_WAKEUP, to indicate to userspace that KVM has recognized one such wakeup event. It is the responsibility of userspace to then make the vCPU runnable, or leave it suspended until the next wakeup event. Signed-off-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220504032446.4133305-7-oupton@google.com --- Documentation/virt/kvm/api.rst | 37 ++++++++++++++++++++++++++-- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 51 +++++++++++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 2 ++ 4 files changed, 89 insertions(+), 2 deletions(-) (limited to 'arch/arm64/include/asm/kvm_host.h') diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 4a900cdbc62e..46ca84600dca 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -1476,14 +1476,43 @@ Possible values are: [s390] KVM_MP_STATE_LOAD the vcpu is in a special load/startup state [s390] + KVM_MP_STATE_SUSPENDED the vcpu is in a suspend state and is waiting + for a wakeup event [arm64] ========================== =============================================== On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an in-kernel irqchip, the multiprocessing state must be maintained by userspace on these architectures. -For arm64/riscv: -^^^^^^^^^^^^^^^^ +For arm64: +^^^^^^^^^^ + +If a vCPU is in the KVM_MP_STATE_SUSPENDED state, KVM will emulate the +architectural execution of a WFI instruction. + +If a wakeup event is recognized, KVM will exit to userspace with a +KVM_SYSTEM_EVENT exit, where the event type is KVM_SYSTEM_EVENT_WAKEUP. If +userspace wants to honor the wakeup, it must set the vCPU's MP state to +KVM_MP_STATE_RUNNABLE. If it does not, KVM will continue to await a wakeup +event in subsequent calls to KVM_RUN. + +.. warning:: + + If userspace intends to keep the vCPU in a SUSPENDED state, it is + strongly recommended that userspace take action to suppress the + wakeup event (such as masking an interrupt). Otherwise, subsequent + calls to KVM_RUN will immediately exit with a KVM_SYSTEM_EVENT_WAKEUP + event and inadvertently waste CPU cycles. + + Additionally, if userspace takes action to suppress a wakeup event, + it is strongly recommended that it also restores the vCPU to its + original state when the vCPU is made RUNNABLE again. For example, + if userspace masked a pending interrupt to suppress the wakeup, + the interrupt should be unmasked before returning control to the + guest. + +For riscv: +^^^^^^^^^^ The only states that are valid are KVM_MP_STATE_STOPPED and KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. @@ -5985,6 +6014,7 @@ should put the acknowledged interrupt vector into the 'epr' field. #define KVM_SYSTEM_EVENT_SHUTDOWN 1 #define KVM_SYSTEM_EVENT_RESET 2 #define KVM_SYSTEM_EVENT_CRASH 3 + #define KVM_SYSTEM_EVENT_WAKEUP 4 __u32 type; __u32 ndata; __u64 data[16]; @@ -6009,6 +6039,9 @@ Valid values for 'type' are: has requested a crash condition maintenance. Userspace can choose to ignore the request, or to gather VM memory core dump and/or reset/shutdown of the VM. + - KVM_SYSTEM_EVENT_WAKEUP -- the exiting vCPU is in a suspended state and + KVM has recognized a wakeup event. Userspace may honor this event by + marking the exiting vCPU as runnable, or deny it and call KVM_RUN again. If KVM_CAP_SYSTEM_EVENT_DATA is present, the 'data' field can contain architecture specific information for the system-level event. Only diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f3f93d48e21a..46027b9b80ca 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -46,6 +46,7 @@ #define KVM_REQ_RECORD_STEAL KVM_ARCH_REQ(3) #define KVM_REQ_RELOAD_GICv4 KVM_ARCH_REQ(4) #define KVM_REQ_RELOAD_PMU KVM_ARCH_REQ(5) +#define KVM_REQ_SUSPEND KVM_ARCH_REQ(6) #define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \ KVM_DIRTY_LOG_INITIALLY_SET) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index efe54aba5cce..abd32a84ed7a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -444,6 +444,18 @@ bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu) return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_STOPPED; } +static void kvm_arm_vcpu_suspend(struct kvm_vcpu *vcpu) +{ + vcpu->arch.mp_state.mp_state = KVM_MP_STATE_SUSPENDED; + kvm_make_request(KVM_REQ_SUSPEND, vcpu); + kvm_vcpu_kick(vcpu); +} + +static bool kvm_arm_vcpu_suspended(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_SUSPENDED; +} + int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { @@ -464,6 +476,9 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, case KVM_MP_STATE_STOPPED: kvm_arm_vcpu_power_off(vcpu); break; + case KVM_MP_STATE_SUSPENDED: + kvm_arm_vcpu_suspend(vcpu); + break; default: ret = -EINVAL; } @@ -648,6 +663,39 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu) preempt_enable(); } +static int kvm_vcpu_suspend(struct kvm_vcpu *vcpu) +{ + if (!kvm_arm_vcpu_suspended(vcpu)) + return 1; + + kvm_vcpu_wfi(vcpu); + + /* + * The suspend state is sticky; we do not leave it until userspace + * explicitly marks the vCPU as runnable. Request that we suspend again + * later. + */ + kvm_make_request(KVM_REQ_SUSPEND, vcpu); + + /* + * Check to make sure the vCPU is actually runnable. If so, exit to + * userspace informing it of the wakeup condition. + */ + if (kvm_arch_vcpu_runnable(vcpu)) { + memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); + vcpu->run->system_event.type = KVM_SYSTEM_EVENT_WAKEUP; + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; + return 0; + } + + /* + * Otherwise, we were unblocked to process a different event, such as a + * pending signal. Return 1 and allow kvm_arch_vcpu_ioctl_run() to + * process the event. + */ + return 1; +} + /** * check_vcpu_requests - check and handle pending vCPU requests * @vcpu: the VCPU pointer @@ -686,6 +734,9 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu)) kvm_pmu_handle_pmcr(vcpu, __vcpu_sys_reg(vcpu, PMCR_EL0)); + + if (kvm_check_request(KVM_REQ_SUSPEND, vcpu)) + return kvm_vcpu_suspend(vcpu); } return 1; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 6a184d260c7f..7f72fb7b05f2 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -444,6 +444,7 @@ struct kvm_run { #define KVM_SYSTEM_EVENT_SHUTDOWN 1 #define KVM_SYSTEM_EVENT_RESET 2 #define KVM_SYSTEM_EVENT_CRASH 3 +#define KVM_SYSTEM_EVENT_WAKEUP 4 __u32 type; __u32 ndata; union { @@ -646,6 +647,7 @@ struct kvm_vapic_addr { #define KVM_MP_STATE_OPERATING 7 #define KVM_MP_STATE_LOAD 8 #define KVM_MP_STATE_AP_RESET_HOLD 9 +#define KVM_MP_STATE_SUSPENDED 10 struct kvm_mp_state { __u32 mp_state; -- cgit v1.2.3 From bfbab44568779e1682bc6f63688bb9c965f0e74a Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 4 May 2022 03:24:41 +0000 Subject: KVM: arm64: Implement PSCI SYSTEM_SUSPEND ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND" describes a PSCI call that allows software to request that a system be placed in the deepest possible low-power state. Effectively, software can use this to suspend itself to RAM. Unfortunately, there really is no good way to implement a system-wide PSCI call in KVM. Any precondition checks done in the kernel will need to be repeated by userspace since there is no good way to protect a critical section that spans an exit to userspace. SYSTEM_RESET and SYSTEM_OFF are equally plagued by this issue, although no users have seemingly cared for the relatively long time these calls have been supported. The solution is to just make the whole implementation userspace's problem. Introduce a new system event, KVM_SYSTEM_EVENT_SUSPEND, that indicates to userspace a calling vCPU has invoked PSCI SYSTEM_SUSPEND. Additionally, add a CAP to get buy-in from userspace for this new exit type. Only advertise the SYSTEM_SUSPEND PSCI call if userspace has opted in. If a vCPU calls SYSTEM_SUSPEND, punt straight to userspace. Provide explicit documentation of userspace's responsibilites for the exit and point to the PSCI specification to describe the actual PSCI call. Reviewed-by: Reiji Watanabe Signed-off-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220504032446.4133305-8-oupton@google.com --- Documentation/virt/kvm/api.rst | 39 +++++++++++++++++++++++++++++++++++++++ arch/arm64/include/asm/kvm_host.h | 2 ++ arch/arm64/kvm/arm.c | 5 +++++ arch/arm64/kvm/psci.c | 29 +++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 2 ++ 5 files changed, 77 insertions(+) (limited to 'arch/arm64/include/asm/kvm_host.h') diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 46ca84600dca..d8d7859fc556 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6015,6 +6015,7 @@ should put the acknowledged interrupt vector into the 'epr' field. #define KVM_SYSTEM_EVENT_RESET 2 #define KVM_SYSTEM_EVENT_CRASH 3 #define KVM_SYSTEM_EVENT_WAKEUP 4 + #define KVM_SYSTEM_EVENT_SUSPEND 5 __u32 type; __u32 ndata; __u64 data[16]; @@ -6042,6 +6043,34 @@ Valid values for 'type' are: - KVM_SYSTEM_EVENT_WAKEUP -- the exiting vCPU is in a suspended state and KVM has recognized a wakeup event. Userspace may honor this event by marking the exiting vCPU as runnable, or deny it and call KVM_RUN again. + - KVM_SYSTEM_EVENT_SUSPEND -- the guest has requested a suspension of + the VM. + +For arm/arm64: +^^^^^^^^^^^^^^ + + KVM_SYSTEM_EVENT_SUSPEND exits are enabled with the + KVM_CAP_ARM_SYSTEM_SUSPEND VM capability. If a guest invokes the PSCI + SYSTEM_SUSPEND function, KVM will exit to userspace with this event + type. + + It is the sole responsibility of userspace to implement the PSCI + SYSTEM_SUSPEND call according to ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND". + KVM does not change the vCPU's state before exiting to userspace, so + the call parameters are left in-place in the vCPU registers. + + Userspace is _required_ to take action for such an exit. It must + either: + + - Honor the guest request to suspend the VM. Userspace can request + in-kernel emulation of suspension by setting the calling vCPU's + state to KVM_MP_STATE_SUSPENDED. Userspace must configure the vCPU's + state according to the parameters passed to the PSCI function when + the calling vCPU is resumed. See ARM DEN0022D.b 5.19.1 "Intended use" + for details on the function parameters. + + - Deny the guest request to suspend the VM. See ARM DEN0022D.b 5.19.2 + "Caller responsibilities" for possible return values. If KVM_CAP_SYSTEM_EVENT_DATA is present, the 'data' field can contain architecture specific information for the system-level event. Only @@ -7767,6 +7796,16 @@ At this time, KVM_PMU_CAP_DISABLE is the only capability. Setting this capability will disable PMU virtualization for that VM. Usermode should adjust CPUID leaf 0xA to reflect that the PMU is disabled. +8.36 KVM_CAP_ARM_SYSTEM_SUSPEND +------------------------------- + +:Capability: KVM_CAP_ARM_SYSTEM_SUSPEND +:Architectures: arm64 +:Type: vm + +When enabled, KVM will exit to userspace with KVM_EXIT_SYSTEM_EVENT of +type KVM_SYSTEM_EVENT_SUSPEND to process the guest suspend request. + 9. Known KVM API problems ========================= diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 46027b9b80ca..d9df81949f76 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -137,6 +137,8 @@ struct kvm_arch { */ #define KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED 3 #define KVM_ARCH_FLAG_EL1_32BIT 4 + /* PSCI SYSTEM_SUSPEND enabled for the guest */ +#define KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED 5 unsigned long flags; diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index abd32a84ed7a..f8a89ae52710 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -97,6 +97,10 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, } mutex_unlock(&kvm->lock); break; + case KVM_CAP_ARM_SYSTEM_SUSPEND: + r = 0; + set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags); + break; default: r = -EINVAL; break; @@ -210,6 +214,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_SET_GUEST_DEBUG: case KVM_CAP_VCPU_ATTRIBUTES: case KVM_CAP_PTP_KVM: + case KVM_CAP_ARM_SYSTEM_SUSPEND: r = 1; break; case KVM_CAP_SET_GUEST_DEBUG2: diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 2e6f060214a7..5de30e72ad40 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -195,6 +195,15 @@ static void kvm_psci_system_reset2(struct kvm_vcpu *vcpu) KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2); } +static void kvm_psci_system_suspend(struct kvm_vcpu *vcpu) +{ + struct kvm_run *run = vcpu->run; + + memset(&run->system_event, 0, sizeof(vcpu->run->system_event)); + run->system_event.type = KVM_SYSTEM_EVENT_SUSPEND; + run->exit_reason = KVM_EXIT_SYSTEM_EVENT; +} + static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu) { int i; @@ -300,6 +309,7 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) { unsigned long val = PSCI_RET_NOT_SUPPORTED; u32 psci_fn = smccc_get_function(vcpu); + struct kvm *kvm = vcpu->kvm; u32 arg; int ret = 1; @@ -331,6 +341,11 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) case ARM_SMCCC_VERSION_FUNC_ID: val = 0; break; + case PSCI_1_0_FN_SYSTEM_SUSPEND: + case PSCI_1_0_FN64_SYSTEM_SUSPEND: + if (test_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags)) + val = 0; + break; case PSCI_1_1_FN_SYSTEM_RESET2: case PSCI_1_1_FN64_SYSTEM_RESET2: if (minor >= 1) @@ -338,6 +353,20 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) break; } break; + case PSCI_1_0_FN_SYSTEM_SUSPEND: + kvm_psci_narrow_to_32bit(vcpu); + fallthrough; + case PSCI_1_0_FN64_SYSTEM_SUSPEND: + /* + * Return directly to userspace without changing the vCPU's + * registers. Userspace depends on reading the SMCCC parameters + * to implement SYSTEM_SUSPEND. + */ + if (test_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags)) { + kvm_psci_system_suspend(vcpu); + return 0; + } + break; case PSCI_1_1_FN_SYSTEM_RESET2: kvm_psci_narrow_to_32bit(vcpu); fallthrough; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 7f72fb7b05f2..32c56384fd08 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -445,6 +445,7 @@ struct kvm_run { #define KVM_SYSTEM_EVENT_RESET 2 #define KVM_SYSTEM_EVENT_CRASH 3 #define KVM_SYSTEM_EVENT_WAKEUP 4 +#define KVM_SYSTEM_EVENT_SUSPEND 5 __u32 type; __u32 ndata; union { @@ -1154,6 +1155,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_DISABLE_QUIRKS2 213 /* #define KVM_CAP_VM_TSC_CONTROL 214 */ #define KVM_CAP_SYSTEM_EVENT_DATA 215 +#define KVM_CAP_ARM_SYSTEM_SUSPEND 216 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3