Commit c57875f5 authored by Suresh Warrier's avatar Suresh Warrier Committed by Paul Mackerras

KVM: PPC: Book3S HV: Enable IRQ bypass

Add the irq_bypass_add_producer and irq_bypass_del_producer
functions. These functions get called whenever a GSI is being
defined for a guest. They create/remove the mapping between
host real IRQ numbers and the guest GSI.

Add the following helper functions to manage the
passthrough IRQ map.

kvmppc_set_passthru_irq()
  Creates a mapping in the passthrough IRQ map that maps a host
  IRQ to a guest GSI. It allocates the structure (one per guest VM)
  the first time it is called.

kvmppc_clr_passthru_irq()
  Removes the passthrough IRQ map entry given a guest GSI.
  The passthrough IRQ map structure is not freed even when the
  number of mapped entries goes to zero. It is only freed when
  the VM is destroyed.

[paulus@ozlabs.org - modified to use is_pnv_opal_msi() rather than
 requiring all passed-through interrupts to use the same irq_chip;
 changed deletion so it zeroes out the r_hwirq field rather than
 copying the last entry down and decrementing the number of entries.]
Signed-off-by: default avatarSuresh Warrier <warrier@linux.vnet.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 8daaafc8
......@@ -53,10 +53,13 @@
#include <asm/smp.h>
#include <asm/dbell.h>
#include <asm/hmi.h>
#include <asm/pnv-pci.h>
#include <linux/gfp.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/hugetlb.h>
#include <linux/kvm_irqfd.h>
#include <linux/irqbypass.h>
#include <linux/module.h>
#include <linux/compiler.h>
......@@ -3377,6 +3380,8 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
kvmppc_free_vcores(kvm);
kvmppc_free_hpt(kvm);
kvmppc_free_pimap(kvm);
}
/* We don't need to emulate any privileged instructions or dcbz */
......@@ -3419,10 +3424,159 @@ void kvmppc_free_pimap(struct kvm *kvm)
kfree(kvm->arch.pimap);
}
struct kvmppc_passthru_irqmap *kvmppc_alloc_pimap(void)
static struct kvmppc_passthru_irqmap *kvmppc_alloc_pimap(void)
{
return kzalloc(sizeof(struct kvmppc_passthru_irqmap), GFP_KERNEL);
}
static int kvmppc_set_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
{
struct irq_desc *desc;
struct kvmppc_irq_map *irq_map;
struct kvmppc_passthru_irqmap *pimap;
struct irq_chip *chip;
int i;
desc = irq_to_desc(host_irq);
if (!desc)
return -EIO;
mutex_lock(&kvm->lock);
pimap = kvm->arch.pimap;
if (pimap == NULL) {
/* First call, allocate structure to hold IRQ map */
pimap = kvmppc_alloc_pimap();
if (pimap == NULL) {
mutex_unlock(&kvm->lock);
return -ENOMEM;
}
kvm->arch.pimap = pimap;
}
/*
* For now, we only support interrupts for which the EOI operation
* is an OPAL call followed by a write to XIRR, since that's
* what our real-mode EOI code does.
*/
chip = irq_data_get_irq_chip(&desc->irq_data);
if (!chip || !is_pnv_opal_msi(chip)) {
pr_warn("kvmppc_set_passthru_irq_hv: Could not assign IRQ map for (%d,%d)\n",
host_irq, guest_gsi);
mutex_unlock(&kvm->lock);
return -ENOENT;
}
/*
* See if we already have an entry for this guest IRQ number.
* If it's mapped to a hardware IRQ number, that's an error,
* otherwise re-use this entry.
*/
for (i = 0; i < pimap->n_mapped; i++) {
if (guest_gsi == pimap->mapped[i].v_hwirq) {
if (pimap->mapped[i].r_hwirq) {
mutex_unlock(&kvm->lock);
return -EINVAL;
}
break;
}
}
if (i == KVMPPC_PIRQ_MAPPED) {
mutex_unlock(&kvm->lock);
return -EAGAIN; /* table is full */
}
irq_map = &pimap->mapped[i];
irq_map->v_hwirq = guest_gsi;
irq_map->r_hwirq = desc->irq_data.hwirq;
irq_map->desc = desc;
if (i == pimap->n_mapped)
pimap->n_mapped++;
mutex_unlock(&kvm->lock);
return 0;
}
static int kvmppc_clr_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
{
struct irq_desc *desc;
struct kvmppc_passthru_irqmap *pimap;
int i;
desc = irq_to_desc(host_irq);
if (!desc)
return -EIO;
mutex_lock(&kvm->lock);
if (kvm->arch.pimap == NULL) {
mutex_unlock(&kvm->lock);
return 0;
}
pimap = kvm->arch.pimap;
for (i = 0; i < pimap->n_mapped; i++) {
if (guest_gsi == pimap->mapped[i].v_hwirq)
break;
}
if (i == pimap->n_mapped) {
mutex_unlock(&kvm->lock);
return -ENODEV;
}
/* invalidate the entry */
pimap->mapped[i].r_hwirq = 0;
/*
* We don't free this structure even when the count goes to
* zero. The structure is freed when we destroy the VM.
*/
mutex_unlock(&kvm->lock);
return 0;
}
static int kvmppc_irq_bypass_add_producer_hv(struct irq_bypass_consumer *cons,
struct irq_bypass_producer *prod)
{
int ret = 0;
struct kvm_kernel_irqfd *irqfd =
container_of(cons, struct kvm_kernel_irqfd, consumer);
irqfd->producer = prod;
ret = kvmppc_set_passthru_irq(irqfd->kvm, prod->irq, irqfd->gsi);
if (ret)
pr_info("kvmppc_set_passthru_irq (irq %d, gsi %d) fails: %d\n",
prod->irq, irqfd->gsi, ret);
return ret;
}
static void kvmppc_irq_bypass_del_producer_hv(struct irq_bypass_consumer *cons,
struct irq_bypass_producer *prod)
{
int ret;
struct kvm_kernel_irqfd *irqfd =
container_of(cons, struct kvm_kernel_irqfd, consumer);
irqfd->producer = NULL;
/*
* When producer of consumer is unregistered, we change back to
* default external interrupt handling mode - KVM real mode
* will switch back to host.
*/
ret = kvmppc_clr_passthru_irq(irqfd->kvm, prod->irq, irqfd->gsi);
if (ret)
pr_warn("kvmppc_clr_passthru_irq (irq %d, gsi %d) fails: %d\n",
prod->irq, irqfd->gsi, ret);
}
#endif
static long kvm_arch_vm_ioctl_hv(struct file *filp,
......@@ -3543,6 +3697,10 @@ static struct kvmppc_ops kvm_ops_hv = {
.fast_vcpu_kick = kvmppc_fast_vcpu_kick_hv,
.arch_vm_ioctl = kvm_arch_vm_ioctl_hv,
.hcall_implemented = kvmppc_hcall_impl_hv,
#ifdef CONFIG_KVM_XICS
.irq_bypass_add_producer = kvmppc_irq_bypass_add_producer_hv,
.irq_bypass_del_producer = kvmppc_irq_bypass_del_producer_hv,
#endif
};
static int kvm_init_subcore_bitmap(void)
......
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