On Fri, Feb 22, 2019 at 12:28:31PM +0100, Cédric Le Goater wrote:
> This control is to be used by the H_INT_RESET hcall from QEMU. Its
> purpose is to clear all configuration of the sources and EQs. This is
> necessary in case of a kexec (for a kdump kernel for instance) to make
> sure that no remaining configuration is left from the previous boot
> setup so that the new kernel can start safely from a clean state.
>
> The queue 7 is ignored when the KVM device is configured to run in
> single escalation mode. Prio 7 is used by escalations.
>
> The XIVE VP is kept enabled as the vCPU is still active and connected
> to the XIVE device.
>
> Signed-off-by: Cédric Le Goater <c...@kaod.org>
> ---
> arch/powerpc/include/uapi/asm/kvm.h | 1 +
> arch/powerpc/kvm/book3s_xive_native.c | 82 ++++++++++++++++++++++
> Documentation/virtual/kvm/devices/xive.txt | 5 ++
> 3 files changed, 88 insertions(+)
>
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h
> b/arch/powerpc/include/uapi/asm/kvm.h
> index 177e43f3edaf..7ae8cb22af7d 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -677,6 +677,7 @@ 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_GRP_SOURCE 2 /* 64-bit source
> attributes */
> #define KVM_DEV_XIVE_GRP_SOURCE_CONFIG 3 /* 64-bit source
> attributes */
> #define KVM_DEV_XIVE_GRP_EQ_CONFIG 4 /* 64-bit eq attributes */
> diff --git a/arch/powerpc/kvm/book3s_xive_native.c
> b/arch/powerpc/kvm/book3s_xive_native.c
> index 34a35bcf550c..bb3e121c918a 100644
> --- a/arch/powerpc/kvm/book3s_xive_native.c
> +++ b/arch/powerpc/kvm/book3s_xive_native.c
> @@ -536,6 +536,80 @@ static int kvmppc_xive_native_get_queue_config(struct
> kvmppc_xive *xive,
> return 0;
> }
>
> +static void kvmppc_xive_reset_sources(struct kvmppc_xive_src_block *sb)
> +{
> + int i;
> +
> + for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
> + struct kvmppc_xive_irq_state *state = &sb->irq_state[i];
> +
> + if (!state->valid)
> + continue;
> +
> + if (state->act_priority == MASKED)
You're checking some things in state before you take the lock. Could
this race?
> + continue;
> +
> + arch_spin_lock(&sb->lock);
> + state->eisn = 0;
> + state->act_server = 0;
> + state->act_priority = MASKED;
> + xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01);
> + xive_native_configure_irq(state->ipi_number, 0, MASKED, 0);
> + if (state->pt_number) {
> + xive_vm_esb_load(state->pt_data, XIVE_ESB_SET_PQ_01);
> + xive_native_configure_irq(state->pt_number,
> + 0, MASKED, 0);
> + }
> + arch_spin_unlock(&sb->lock);
> + }
> +}
> +
> +static int kvmppc_xive_reset(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);
> +
> + kvm_for_each_vcpu(i, vcpu, kvm) {
> + struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
> + unsigned int prio;
> +
> + if (!xc)
> + continue;
> +
> + kvmppc_xive_disable_vcpu_interrupts(vcpu);
> +
> + for (prio = 0; prio < KVMPPC_XIVE_Q_COUNT; prio++) {
> +
> + /* Single escalation, no queue 7 */
> + if (prio == 7 && xive->single_escalation)
> + break;
> +
> + if (xc->esc_virq[prio]) {
> + free_irq(xc->esc_virq[prio], vcpu);
> + irq_dispose_mapping(xc->esc_virq[prio]);
> + kfree(xc->esc_virq_names[prio]);
> + xc->esc_virq[prio] = 0;
> + }
> +
> + kvmppc_xive_native_cleanup_queue(vcpu, prio);
> + }
> + }
> +
> + for (i = 0; i <= xive->max_sbid; i++) {
> + if (xive->src_blocks[i])
> + kvmppc_xive_reset_sources(xive->src_blocks[i]);
> + }
> +
> + mutex_unlock(&kvm->lock);
> +
> + return 0;
> +}
> +
> static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
> struct kvm_device_attr *attr)
> {
> @@ -543,6 +617,10 @@ static int kvmppc_xive_native_set_attr(struct kvm_device
> *dev,
>
> switch (attr->group) {
> case KVM_DEV_XIVE_GRP_CTRL:
> + switch (attr->attr) {
> + case KVM_DEV_XIVE_RESET:
> + return kvmppc_xive_reset(xive);
> + }
> break;
> case KVM_DEV_XIVE_GRP_SOURCE:
> return kvmppc_xive_native_set_source(xive, attr->attr,
> @@ -575,6 +653,10 @@ static int kvmppc_xive_native_has_attr(struct kvm_device
> *dev,
> {
> switch (attr->group) {
> case KVM_DEV_XIVE_GRP_CTRL:
> + switch (attr->attr) {
> + case KVM_DEV_XIVE_RESET:
> + return 0;
> + }
> break;
> case KVM_DEV_XIVE_GRP_SOURCE:
> case KVM_DEV_XIVE_GRP_SOURCE_CONFIG:
> diff --git a/Documentation/virtual/kvm/devices/xive.txt
> b/Documentation/virtual/kvm/devices/xive.txt
> index c0b5d9bd43fb..f1d007f485a9 100644
> --- a/Documentation/virtual/kvm/devices/xive.txt
> +++ b/Documentation/virtual/kvm/devices/xive.txt
> @@ -17,6 +17,11 @@ the legacy interrupt mode, referred as XICS (POWER7/8).
>
> 1. KVM_DEV_XIVE_GRP_CTRL
> Provides global controls on the device
> + Attributes:
> + 1.1 KVM_DEV_XIVE_RESET (write only)
> + Resets the interrupt controller configuration for sources and event
> + queues. To be used by kexec and kdump.
> + Errors: none
>
> 2. KVM_DEV_XIVE_GRP_SOURCE (write only)
> Initializes a new source in the XIVE device and mask it.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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