Commit 6c3d63c9 authored by Marc Zyngier's avatar Marc Zyngier

KVM: arm/arm64: vgic: Allow dynamic mapping of physical/virtual interrupts

In order to be able to feed physical interrupts to a guest, we need
to be able to establish the virtual-physical mapping between the two
worlds.

The mappings are kept in a set of RCU lists, indexed by virtual interrupts.
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 7a67b4b7
......@@ -125,6 +125,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
if (ret)
goto out_free_stage2_pgd;
kvm_vgic_early_init(kvm);
kvm_timer_init(kvm);
/* Mark the initial VMID generation invalid */
......@@ -249,6 +250,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
kvm_vgic_vcpu_early_init(vcpu);
}
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
......
......@@ -159,6 +159,19 @@ struct vgic_io_device {
struct kvm_io_device dev;
};
struct irq_phys_map {
u32 virt_irq;
u32 phys_irq;
u32 irq;
bool active;
};
struct irq_phys_map_entry {
struct list_head entry;
struct rcu_head rcu;
struct irq_phys_map map;
};
struct vgic_dist {
spinlock_t lock;
bool in_kernel;
......@@ -256,6 +269,10 @@ struct vgic_dist {
struct vgic_vm_ops vm_ops;
struct vgic_io_device dist_iodev;
struct vgic_io_device *redist_iodevs;
/* Virtual irq to hwirq mapping */
spinlock_t irq_phys_map_lock;
struct list_head irq_phys_map_list;
};
struct vgic_v2_cpu_if {
......@@ -307,6 +324,9 @@ struct vgic_cpu {
struct vgic_v2_cpu_if vgic_v2;
struct vgic_v3_cpu_if vgic_v3;
};
/* Protected by the distributor's irq_phys_map_lock */
struct list_head irq_phys_map_list;
};
#define LR_EMPTY 0xff
......@@ -321,8 +341,10 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
int kvm_vgic_hyp_init(void);
int kvm_vgic_map_resources(struct kvm *kvm);
int kvm_vgic_get_max_vcpus(void);
void kvm_vgic_early_init(struct kvm *kvm);
int kvm_vgic_create(struct kvm *kvm, u32 type);
void kvm_vgic_destroy(struct kvm *kvm);
void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu);
void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
......@@ -331,6 +353,9 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
struct irq_phys_map *kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu,
int virt_irq, int irq);
int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
#define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel))
#define vgic_initialized(k) (!!((k)->arch.vgic.nr_cpus))
......
......@@ -24,6 +24,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/rculist.h>
#include <linux/uaccess.h>
#include <asm/kvm_emulate.h>
......@@ -74,6 +75,28 @@
* cause the interrupt to become inactive in such a situation.
* Conversely, writes to GICD_ICPENDRn do not cause the interrupt to become
* inactive as long as the external input line is held high.
*
*
* Initialization rules: there are multiple stages to the vgic
* initialization, both for the distributor and the CPU interfaces.
*
* Distributor:
*
* - kvm_vgic_early_init(): initialization of static data that doesn't
* depend on any sizing information or emulation type. No allocation
* is allowed there.
*
* - vgic_init(): allocation and initialization of the generic data
* structures that depend on sizing information (number of CPUs,
* number of interrupts). Also initializes the vcpu specific data
* structures. Can be executed lazily for GICv2.
* [to be renamed to kvm_vgic_init??]
*
* CPU Interface:
*
* - kvm_vgic_cpu_early_init(): initialization of static data that
* doesn't depend on any sizing information or emulation type. No
* allocation is allowed there.
*/
#include "vgic.h"
......@@ -82,6 +105,8 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu);
static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu);
static struct vgic_lr vgic_get_lr(const struct kvm_vcpu *vcpu, int lr);
static void vgic_set_lr(struct kvm_vcpu *vcpu, int lr, struct vgic_lr lr_desc);
static struct irq_phys_map *vgic_irq_map_search(struct kvm_vcpu *vcpu,
int virt_irq);
static const struct vgic_ops *vgic_ops;
static const struct vgic_params *vgic;
......@@ -1583,6 +1608,164 @@ static irqreturn_t vgic_maintenance_handler(int irq, void *data)
return IRQ_HANDLED;
}
static struct list_head *vgic_get_irq_phys_map_list(struct kvm_vcpu *vcpu,
int virt_irq)
{
if (virt_irq < VGIC_NR_PRIVATE_IRQS)
return &vcpu->arch.vgic_cpu.irq_phys_map_list;
else
return &vcpu->kvm->arch.vgic.irq_phys_map_list;
}
/**
* kvm_vgic_map_phys_irq - map a virtual IRQ to a physical IRQ
* @vcpu: The VCPU pointer
* @virt_irq: The virtual irq number
* @irq: The Linux IRQ number
*
* Establish a mapping between a guest visible irq (@virt_irq) and a
* Linux irq (@irq). On injection, @virt_irq will be associated with
* the physical interrupt represented by @irq. This mapping can be
* established multiple times as long as the parameters are the same.
*
* Returns a valid pointer on success, and an error pointer otherwise
*/
struct irq_phys_map *kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu,
int virt_irq, int irq)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
struct list_head *root = vgic_get_irq_phys_map_list(vcpu, virt_irq);
struct irq_phys_map *map;
struct irq_phys_map_entry *entry;
struct irq_desc *desc;
struct irq_data *data;
int phys_irq;
desc = irq_to_desc(irq);
if (!desc) {
kvm_err("%s: no interrupt descriptor\n", __func__);
return ERR_PTR(-EINVAL);
}
data = irq_desc_get_irq_data(desc);
while (data->parent_data)
data = data->parent_data;
phys_irq = data->hwirq;
/* Create a new mapping */
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return ERR_PTR(-ENOMEM);
spin_lock(&dist->irq_phys_map_lock);
/* Try to match an existing mapping */
map = vgic_irq_map_search(vcpu, virt_irq);
if (map) {
/* Make sure this mapping matches */
if (map->phys_irq != phys_irq ||
map->irq != irq)
map = ERR_PTR(-EINVAL);
/* Found an existing, valid mapping */
goto out;
}
map = &entry->map;
map->virt_irq = virt_irq;
map->phys_irq = phys_irq;
map->irq = irq;
list_add_tail_rcu(&entry->entry, root);
out:
spin_unlock(&dist->irq_phys_map_lock);
/* If we've found a hit in the existing list, free the useless
* entry */
if (IS_ERR(map) || map != &entry->map)
kfree(entry);
return map;
}
static struct irq_phys_map *vgic_irq_map_search(struct kvm_vcpu *vcpu,
int virt_irq)
{
struct list_head *root = vgic_get_irq_phys_map_list(vcpu, virt_irq);
struct irq_phys_map_entry *entry;
struct irq_phys_map *map;
rcu_read_lock();
list_for_each_entry_rcu(entry, root, entry) {
map = &entry->map;
if (map->virt_irq == virt_irq) {
rcu_read_unlock();
return map;
}
}
rcu_read_unlock();
return NULL;
}
static void vgic_free_phys_irq_map_rcu(struct rcu_head *rcu)
{
struct irq_phys_map_entry *entry;
entry = container_of(rcu, struct irq_phys_map_entry, rcu);
kfree(entry);
}
/**
* kvm_vgic_unmap_phys_irq - Remove a virtual to physical IRQ mapping
* @vcpu: The VCPU pointer
* @map: The pointer to a mapping obtained through kvm_vgic_map_phys_irq
*
* Remove an existing mapping between virtual and physical interrupts.
*/
int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
struct irq_phys_map_entry *entry;
struct list_head *root;
if (!map)
return -EINVAL;
root = vgic_get_irq_phys_map_list(vcpu, map->virt_irq);
spin_lock(&dist->irq_phys_map_lock);
list_for_each_entry(entry, root, entry) {
if (&entry->map == map) {
list_del_rcu(&entry->entry);
call_rcu(&entry->rcu, vgic_free_phys_irq_map_rcu);
break;
}
}
spin_unlock(&dist->irq_phys_map_lock);
return 0;
}
static void vgic_destroy_irq_phys_map(struct kvm *kvm, struct list_head *root)
{
struct vgic_dist *dist = &kvm->arch.vgic;
struct irq_phys_map_entry *entry;
spin_lock(&dist->irq_phys_map_lock);
list_for_each_entry(entry, root, entry) {
list_del_rcu(&entry->entry);
call_rcu(&entry->rcu, vgic_free_phys_irq_map_rcu);
}
spin_unlock(&dist->irq_phys_map_lock);
}
void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
......@@ -1591,6 +1774,7 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
kfree(vgic_cpu->active_shared);
kfree(vgic_cpu->pend_act_shared);
kfree(vgic_cpu->vgic_irq_lr_map);
vgic_destroy_irq_phys_map(vcpu->kvm, &vgic_cpu->irq_phys_map_list);
vgic_cpu->pending_shared = NULL;
vgic_cpu->active_shared = NULL;
vgic_cpu->pend_act_shared = NULL;
......@@ -1627,6 +1811,17 @@ static int vgic_vcpu_init_maps(struct kvm_vcpu *vcpu, int nr_irqs)
return 0;
}
/**
* kvm_vgic_vcpu_early_init - Earliest possible per-vcpu vgic init stage
*
* No memory allocation should be performed here, only static init.
*/
void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
INIT_LIST_HEAD(&vgic_cpu->irq_phys_map_list);
}
/**
* kvm_vgic_get_max_vcpus - Get the maximum number of VCPUs allowed by HW
*
......@@ -1664,6 +1859,7 @@ void kvm_vgic_destroy(struct kvm *kvm)
kfree(dist->irq_spi_target);
kfree(dist->irq_pending_on_cpu);
kfree(dist->irq_active_on_cpu);
vgic_destroy_irq_phys_map(kvm, &dist->irq_phys_map_list);
dist->irq_sgi_sources = NULL;
dist->irq_spi_cpu = NULL;
dist->irq_spi_target = NULL;
......@@ -1787,6 +1983,18 @@ static int init_vgic_model(struct kvm *kvm, int type)
return 0;
}
/**
* kvm_vgic_early_init - Earliest possible vgic initialization stage
*
* No memory allocation should be performed here, only static init.
*/
void kvm_vgic_early_init(struct kvm *kvm)
{
spin_lock_init(&kvm->arch.vgic.lock);
spin_lock_init(&kvm->arch.vgic.irq_phys_map_lock);
INIT_LIST_HEAD(&kvm->arch.vgic.irq_phys_map_list);
}
int kvm_vgic_create(struct kvm *kvm, u32 type)
{
int i, vcpu_lock_idx = -1, ret;
......@@ -1832,7 +2040,6 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
if (ret)
goto out_unlock;
spin_lock_init(&kvm->arch.vgic.lock);
kvm->arch.vgic.in_kernel = true;
kvm->arch.vgic.vgic_model = type;
kvm->arch.vgic.vctrl_base = vgic->vctrl_base;
......
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