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Diffstat (limited to 'arch/powerpc/kvm/book3s_xive.c')
-rw-r--r--arch/powerpc/kvm/book3s_xive.c128
1 files changed, 101 insertions, 27 deletions
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index a3f9c665bb5b..66858b7d3c6b 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -1211,6 +1211,45 @@ void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu)
vcpu->arch.xive_vcpu = NULL;
}
+static bool kvmppc_xive_vcpu_id_valid(struct kvmppc_xive *xive, u32 cpu)
+{
+ /* We have a block of xive->nr_servers VPs. We just need to check
+ * raw vCPU ids are below the expected limit for this guest's
+ * core stride ; kvmppc_pack_vcpu_id() will pack them down to an
+ * index that can be safely used to compute a VP id that belongs
+ * to the VP block.
+ */
+ return cpu < xive->nr_servers * xive->kvm->arch.emul_smt_mode;
+}
+
+int kvmppc_xive_compute_vp_id(struct kvmppc_xive *xive, u32 cpu, u32 *vp)
+{
+ u32 vp_id;
+
+ if (!kvmppc_xive_vcpu_id_valid(xive, cpu)) {
+ pr_devel("Out of bounds !\n");
+ return -EINVAL;
+ }
+
+ if (xive->vp_base == XIVE_INVALID_VP) {
+ xive->vp_base = xive_native_alloc_vp_block(xive->nr_servers);
+ pr_devel("VP_Base=%x nr_servers=%d\n", xive->vp_base, xive->nr_servers);
+
+ if (xive->vp_base == XIVE_INVALID_VP)
+ return -ENOSPC;
+ }
+
+ vp_id = kvmppc_xive_vp(xive, cpu);
+ if (kvmppc_xive_vp_in_use(xive->kvm, vp_id)) {
+ pr_devel("Duplicate !\n");
+ return -EEXIST;
+ }
+
+ *vp = vp_id;
+
+ return 0;
+}
+
int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
struct kvm_vcpu *vcpu, u32 cpu)
{
@@ -1229,20 +1268,13 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
return -EPERM;
if (vcpu->arch.irq_type != KVMPPC_IRQ_DEFAULT)
return -EBUSY;
- if (cpu >= (KVM_MAX_VCPUS * vcpu->kvm->arch.emul_smt_mode)) {
- pr_devel("Out of bounds !\n");
- return -EINVAL;
- }
/* We need to synchronize with queue provisioning */
mutex_lock(&xive->lock);
- vp_id = kvmppc_xive_vp(xive, cpu);
- if (kvmppc_xive_vp_in_use(xive->kvm, vp_id)) {
- pr_devel("Duplicate !\n");
- r = -EEXIST;
+ r = kvmppc_xive_compute_vp_id(xive, cpu, &vp_id);
+ if (r)
goto bail;
- }
xc = kzalloc(sizeof(*xc), GFP_KERNEL);
if (!xc) {
@@ -1834,6 +1866,43 @@ int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
return 0;
}
+int kvmppc_xive_set_nr_servers(struct kvmppc_xive *xive, u64 addr)
+{
+ u32 __user *ubufp = (u32 __user *) addr;
+ u32 nr_servers;
+ int rc = 0;
+
+ if (get_user(nr_servers, ubufp))
+ return -EFAULT;
+
+ pr_devel("%s nr_servers=%u\n", __func__, nr_servers);
+
+ if (!nr_servers || nr_servers > KVM_MAX_VCPU_ID)
+ return -EINVAL;
+
+ mutex_lock(&xive->lock);
+ if (xive->vp_base != XIVE_INVALID_VP)
+ /* The VP block is allocated once and freed when the device
+ * is released. Better not allow to change its size since its
+ * used by connect_vcpu to validate vCPU ids are valid (eg,
+ * setting it back to a higher value could allow connect_vcpu
+ * to come up with a VP id that goes beyond the VP block, which
+ * is likely to cause a crash in OPAL).
+ */
+ rc = -EBUSY;
+ else if (nr_servers > KVM_MAX_VCPUS)
+ /* We don't need more servers. Higher vCPU ids get packed
+ * down below KVM_MAX_VCPUS by kvmppc_pack_vcpu_id().
+ */
+ xive->nr_servers = KVM_MAX_VCPUS;
+ else
+ xive->nr_servers = nr_servers;
+
+ mutex_unlock(&xive->lock);
+
+ return rc;
+}
+
static int xive_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xive *xive = dev->private;
@@ -1842,6 +1911,11 @@ static int xive_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xive_set_source(xive, attr->attr, attr->addr);
+ case KVM_DEV_XICS_GRP_CTRL:
+ switch (attr->attr) {
+ case KVM_DEV_XICS_NR_SERVERS:
+ return kvmppc_xive_set_nr_servers(xive, attr->addr);
+ }
}
return -ENXIO;
}
@@ -1867,6 +1941,11 @@ static int xive_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
attr->attr < KVMPPC_XICS_NR_IRQS)
return 0;
break;
+ case KVM_DEV_XICS_GRP_CTRL:
+ switch (attr->attr) {
+ case KVM_DEV_XICS_NR_SERVERS:
+ return 0;
+ }
}
return -ENXIO;
}
@@ -2001,10 +2080,13 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
{
struct kvmppc_xive *xive;
struct kvm *kvm = dev->kvm;
- int ret = 0;
pr_devel("Creating xive for partition\n");
+ /* Already there ? */
+ if (kvm->arch.xive)
+ return -EEXIST;
+
xive = kvmppc_xive_get_device(kvm, type);
if (!xive)
return -ENOMEM;
@@ -2014,12 +2096,6 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
xive->kvm = kvm;
mutex_init(&xive->lock);
- /* Already there ? */
- if (kvm->arch.xive)
- ret = -EEXIST;
- else
- kvm->arch.xive = xive;
-
/* We use the default queue size set by the host */
xive->q_order = xive_native_default_eq_shift();
if (xive->q_order < PAGE_SHIFT)
@@ -2027,18 +2103,16 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
else
xive->q_page_order = xive->q_order - PAGE_SHIFT;
- /* Allocate a bunch of VPs */
- xive->vp_base = xive_native_alloc_vp_block(KVM_MAX_VCPUS);
- pr_devel("VP_Base=%x\n", xive->vp_base);
-
- if (xive->vp_base == XIVE_INVALID_VP)
- ret = -ENOMEM;
+ /* VP allocation is delayed to the first call to connect_vcpu */
+ xive->vp_base = XIVE_INVALID_VP;
+ /* KVM_MAX_VCPUS limits the number of VMs to roughly 64 per sockets
+ * on a POWER9 system.
+ */
+ xive->nr_servers = KVM_MAX_VCPUS;
xive->single_escalation = xive_native_has_single_escalation();
- if (ret)
- return ret;
-
+ kvm->arch.xive = xive;
return 0;
}
@@ -2108,9 +2182,9 @@ static int xive_debug_show(struct seq_file *m, void *private)
if (!xc)
continue;
- seq_printf(m, "cpu server %#x CPPR:%#x HWCPPR:%#x"
+ seq_printf(m, "cpu server %#x VP:%#x CPPR:%#x HWCPPR:%#x"
" MFRR:%#x PEND:%#x h_xirr: R=%lld V=%lld\n",
- xc->server_num, xc->cppr, xc->hw_cppr,
+ xc->server_num, xc->vp_id, xc->cppr, xc->hw_cppr,
xc->mfrr, xc->pending,
xc->stat_rm_h_xirr, xc->stat_vm_h_xirr);