diff options
| -rw-r--r-- | Documentation/virtual/kvm/devices/xive.txt | 29 | ||||
| -rw-r--r-- | arch/powerpc/include/uapi/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive_native.c | 85 |
3 files changed, 115 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt index 1e7f19d7594b..7ffd4c7be7b5 100644 --- a/Documentation/virtual/kvm/devices/xive.txt +++ b/Documentation/virtual/kvm/devices/xive.txt @@ -23,6 +23,12 @@ the legacy interrupt mode, referred as XICS (POWER7/8). queues. To be used by kexec and kdump. Errors: none + 1.2 KVM_DEV_XIVE_EQ_SYNC (write only) + Sync all the sources and queues and mark the EQ pages dirty. This + to make sure that a consistent memory state is captured when + migrating the VM. + Errors: none + 2. KVM_DEV_XIVE_GRP_SOURCE (write only) Initializes a new source in the XIVE device and mask it. Attributes: @@ -100,3 +106,26 @@ the legacy interrupt mode, referred as XICS (POWER7/8). Errors: -ENOENT: Unknown source number -EINVAL: Not initialized source number + +* Migration: + + Saving the state of a VM using the XIVE native exploitation mode + should follow a specific sequence. When the VM is stopped : + + 1. Mask all sources (PQ=01) to stop the flow of events. + + 2. Sync the XIVE device with the KVM control KVM_DEV_XIVE_EQ_SYNC to + flush any in-flight event notification and to stabilize the EQs. At + this stage, the EQ pages are marked dirty to make sure they are + transferred in the migration sequence. + + 3. Capture the state of the source targeting, the EQs configuration + and the state of thread interrupt context registers. + + Restore is similar : + + 1. Restore the EQ configuration. As targeting depends on it. + 2. Restore targeting + 3. Restore the thread interrupt contexts + 4. Restore the source states + 5. Let the vCPU run diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h index e4abe30f6fc6..12744608a61c 100644 --- a/arch/powerpc/include/uapi/asm/kvm.h +++ b/arch/powerpc/include/uapi/asm/kvm.h @@ -680,6 +680,7 @@ struct kvm_ppc_cpu_char { /* POWER9 XIVE Native Interrupt Controller */ #define KVM_DEV_XIVE_GRP_CTRL 1 #define KVM_DEV_XIVE_RESET 1 +#define KVM_DEV_XIVE_EQ_SYNC 2 #define KVM_DEV_XIVE_GRP_SOURCE 2 /* 64-bit source identifier */ #define KVM_DEV_XIVE_GRP_SOURCE_CONFIG 3 /* 64-bit source identifier */ #define KVM_DEV_XIVE_GRP_EQ_CONFIG 4 /* 64-bit EQ identifier */ diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c index 65380416d101..16d23ef3bd39 100644 --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -681,6 +681,88 @@ static int kvmppc_xive_reset(struct kvmppc_xive *xive) return 0; } +static void kvmppc_xive_native_sync_sources(struct kvmppc_xive_src_block *sb) +{ + int j; + + for (j = 0; j < KVMPPC_XICS_IRQ_PER_ICS; j++) { + struct kvmppc_xive_irq_state *state = &sb->irq_state[j]; + struct xive_irq_data *xd; + u32 hw_num; + + if (!state->valid) + continue; + + /* + * The struct kvmppc_xive_irq_state reflects the state + * of the EAS configuration and not the state of the + * source. The source is masked setting the PQ bits to + * '-Q', which is what is being done before calling + * the KVM_DEV_XIVE_EQ_SYNC control. + * + * If a source EAS is configured, OPAL syncs the XIVE + * IC of the source and the XIVE IC of the previous + * target if any. + * + * So it should be fine ignoring MASKED sources as + * they have been synced already. + */ + if (state->act_priority == MASKED) + continue; + + kvmppc_xive_select_irq(state, &hw_num, &xd); + xive_native_sync_source(hw_num); + xive_native_sync_queue(hw_num); + } +} + +static int kvmppc_xive_native_vcpu_eq_sync(struct kvm_vcpu *vcpu) +{ + struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu; + unsigned int prio; + + if (!xc) + return -ENOENT; + + for (prio = 0; prio < KVMPPC_XIVE_Q_COUNT; prio++) { + struct xive_q *q = &xc->queues[prio]; + + if (!q->qpage) + continue; + + /* Mark EQ page dirty for migration */ + mark_page_dirty(vcpu->kvm, gpa_to_gfn(q->guest_qaddr)); + } + return 0; +} + +static int kvmppc_xive_native_eq_sync(struct kvmppc_xive *xive) +{ + struct kvm *kvm = xive->kvm; + struct kvm_vcpu *vcpu; + unsigned int i; + + pr_devel("%s\n", __func__); + + mutex_lock(&kvm->lock); + for (i = 0; i <= xive->max_sbid; i++) { + struct kvmppc_xive_src_block *sb = xive->src_blocks[i]; + + if (sb) { + arch_spin_lock(&sb->lock); + kvmppc_xive_native_sync_sources(sb); + arch_spin_unlock(&sb->lock); + } + } + + kvm_for_each_vcpu(i, vcpu, kvm) { + kvmppc_xive_native_vcpu_eq_sync(vcpu); + } + mutex_unlock(&kvm->lock); + + return 0; +} + static int kvmppc_xive_native_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { @@ -691,6 +773,8 @@ static int kvmppc_xive_native_set_attr(struct kvm_device *dev, switch (attr->attr) { case KVM_DEV_XIVE_RESET: return kvmppc_xive_reset(xive); + case KVM_DEV_XIVE_EQ_SYNC: + return kvmppc_xive_native_eq_sync(xive); } break; case KVM_DEV_XIVE_GRP_SOURCE: @@ -729,6 +813,7 @@ static int kvmppc_xive_native_has_attr(struct kvm_device *dev, case KVM_DEV_XIVE_GRP_CTRL: switch (attr->attr) { case KVM_DEV_XIVE_RESET: + case KVM_DEV_XIVE_EQ_SYNC: return 0; } break; |