From: Suresh Warrier <warr...@linux.vnet.ibm.com>
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.
[pau...@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: Suresh Warrier <warr...@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <pau...@ozlabs.org>
---
arch/powerpc/kvm/book3s_hv.c | 160 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 159 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 413b5c2f..aa11647 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -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 "book3s.h"
@@ -3247,6 +3250,8 @@ 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 */
@@ -3289,10 +3294,159 @@ 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,
@@ -3413,6 +3567,10 @@ 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)
--
2.8.1
