linux/virt/kvm/arm/vgic/vgic-mmio-v2.c
Christoffer Dall 9b87e7a8bf KVM: arm/arm64: Support uaccess of GICC_APRn
When migrating guests around we need to know the active priorities to
ensure functional virtual interrupt prioritization by the GIC.

This commit clarifies the API and how active priorities of interrupts in
different groups are represented, and implements the accessor functions
for the uaccess register range.

We live with a slight layering violation in accessing GICv3 data
structures from vgic-mmio-v2.c, because anything else just adds too much
complexity for us to deal with (it's not like there's a benefit
elsewhere in the code of an intermediate representation as is the case
with the VMCR).  We accept this, because while doing v3 processing from
a file named something-v2.c can look strange at first, this really is
specific to dealing with the user space interface for something that
looks like a GICv2.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-09-05 17:33:39 +02:00

494 lines
13 KiB
C

/*
* VGICv2 MMIO handling functions
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <kvm/iodev.h>
#include <kvm/arm_vgic.h>
#include "vgic.h"
#include "vgic-mmio.h"
static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
u32 value;
switch (addr & 0x0c) {
case GIC_DIST_CTRL:
value = vcpu->kvm->arch.vgic.enabled ? GICD_ENABLE : 0;
break;
case GIC_DIST_CTR:
value = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
value = (value >> 5) - 1;
value |= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
break;
case GIC_DIST_IIDR:
value = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
break;
default:
return 0;
}
return value;
}
static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
bool was_enabled = dist->enabled;
switch (addr & 0x0c) {
case GIC_DIST_CTRL:
dist->enabled = val & GICD_ENABLE;
if (!was_enabled && dist->enabled)
vgic_kick_vcpus(vcpu->kvm);
break;
case GIC_DIST_CTR:
case GIC_DIST_IIDR:
/* Nothing to do */
return;
}
}
static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
int nr_vcpus = atomic_read(&source_vcpu->kvm->online_vcpus);
int intid = val & 0xf;
int targets = (val >> 16) & 0xff;
int mode = (val >> 24) & 0x03;
int c;
struct kvm_vcpu *vcpu;
switch (mode) {
case 0x0: /* as specified by targets */
break;
case 0x1:
targets = (1U << nr_vcpus) - 1; /* all, ... */
targets &= ~(1U << source_vcpu->vcpu_id); /* but self */
break;
case 0x2: /* this very vCPU only */
targets = (1U << source_vcpu->vcpu_id);
break;
case 0x3: /* reserved */
return;
}
kvm_for_each_vcpu(c, vcpu, source_vcpu->kvm) {
struct vgic_irq *irq;
if (!(targets & (1U << c)))
continue;
irq = vgic_get_irq(source_vcpu->kvm, vcpu, intid);
spin_lock(&irq->irq_lock);
irq->pending_latch = true;
irq->source |= 1U << source_vcpu->vcpu_id;
vgic_queue_irq_unlock(source_vcpu->kvm, irq);
vgic_put_irq(source_vcpu->kvm, irq);
}
}
static unsigned long vgic_mmio_read_target(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
int i;
u64 val = 0;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
val |= (u64)irq->targets << (i * 8);
vgic_put_irq(vcpu->kvm, irq);
}
return val;
}
static void vgic_mmio_write_target(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
u8 cpu_mask = GENMASK(atomic_read(&vcpu->kvm->online_vcpus) - 1, 0);
int i;
/* GICD_ITARGETSR[0-7] are read-only */
if (intid < VGIC_NR_PRIVATE_IRQS)
return;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid + i);
int target;
spin_lock(&irq->irq_lock);
irq->targets = (val >> (i * 8)) & cpu_mask;
target = irq->targets ? __ffs(irq->targets) : 0;
irq->target_vcpu = kvm_get_vcpu(vcpu->kvm, target);
spin_unlock(&irq->irq_lock);
vgic_put_irq(vcpu->kvm, irq);
}
}
static unsigned long vgic_mmio_read_sgipend(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
u32 intid = addr & 0x0f;
int i;
u64 val = 0;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
val |= (u64)irq->source << (i * 8);
vgic_put_irq(vcpu->kvm, irq);
}
return val;
}
static void vgic_mmio_write_sgipendc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
u32 intid = addr & 0x0f;
int i;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
spin_lock(&irq->irq_lock);
irq->source &= ~((val >> (i * 8)) & 0xff);
if (!irq->source)
irq->pending_latch = false;
spin_unlock(&irq->irq_lock);
vgic_put_irq(vcpu->kvm, irq);
}
}
static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
u32 intid = addr & 0x0f;
int i;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
spin_lock(&irq->irq_lock);
irq->source |= (val >> (i * 8)) & 0xff;
if (irq->source) {
irq->pending_latch = true;
vgic_queue_irq_unlock(vcpu->kvm, irq);
} else {
spin_unlock(&irq->irq_lock);
}
vgic_put_irq(vcpu->kvm, irq);
}
}
#define GICC_ARCH_VERSION_V2 0x2
/* These are for userland accesses only, there is no guest-facing emulation. */
static unsigned long vgic_mmio_read_vcpuif(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
struct vgic_vmcr vmcr;
u32 val;
vgic_get_vmcr(vcpu, &vmcr);
switch (addr & 0xff) {
case GIC_CPU_CTRL:
val = vmcr.grpen0 << GIC_CPU_CTRL_EnableGrp0_SHIFT;
val |= vmcr.grpen1 << GIC_CPU_CTRL_EnableGrp1_SHIFT;
val |= vmcr.ackctl << GIC_CPU_CTRL_AckCtl_SHIFT;
val |= vmcr.fiqen << GIC_CPU_CTRL_FIQEn_SHIFT;
val |= vmcr.cbpr << GIC_CPU_CTRL_CBPR_SHIFT;
val |= vmcr.eoim << GIC_CPU_CTRL_EOImodeNS_SHIFT;
break;
case GIC_CPU_PRIMASK:
/*
* Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
* the PMR field as GICH_VMCR.VMPriMask rather than
* GICC_PMR.Priority, so we expose the upper five bits of
* priority mask to userspace using the lower bits in the
* unsigned long.
*/
val = (vmcr.pmr & GICV_PMR_PRIORITY_MASK) >>
GICV_PMR_PRIORITY_SHIFT;
break;
case GIC_CPU_BINPOINT:
val = vmcr.bpr;
break;
case GIC_CPU_ALIAS_BINPOINT:
val = vmcr.abpr;
break;
case GIC_CPU_IDENT:
val = ((PRODUCT_ID_KVM << 20) |
(GICC_ARCH_VERSION_V2 << 16) |
IMPLEMENTER_ARM);
break;
default:
return 0;
}
return val;
}
static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
struct vgic_vmcr vmcr;
vgic_get_vmcr(vcpu, &vmcr);
switch (addr & 0xff) {
case GIC_CPU_CTRL:
vmcr.grpen0 = !!(val & GIC_CPU_CTRL_EnableGrp0);
vmcr.grpen1 = !!(val & GIC_CPU_CTRL_EnableGrp1);
vmcr.ackctl = !!(val & GIC_CPU_CTRL_AckCtl);
vmcr.fiqen = !!(val & GIC_CPU_CTRL_FIQEn);
vmcr.cbpr = !!(val & GIC_CPU_CTRL_CBPR);
vmcr.eoim = !!(val & GIC_CPU_CTRL_EOImodeNS);
break;
case GIC_CPU_PRIMASK:
/*
* Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
* the PMR field as GICH_VMCR.VMPriMask rather than
* GICC_PMR.Priority, so we expose the upper five bits of
* priority mask to userspace using the lower bits in the
* unsigned long.
*/
vmcr.pmr = (val << GICV_PMR_PRIORITY_SHIFT) &
GICV_PMR_PRIORITY_MASK;
break;
case GIC_CPU_BINPOINT:
vmcr.bpr = val;
break;
case GIC_CPU_ALIAS_BINPOINT:
vmcr.abpr = val;
break;
}
vgic_set_vmcr(vcpu, &vmcr);
}
static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
int n; /* which APRn is this */
n = (addr >> 2) & 0x3;
if (kvm_vgic_global_state.type == VGIC_V2) {
/* GICv2 hardware systems support max. 32 groups */
if (n != 0)
return 0;
return vcpu->arch.vgic_cpu.vgic_v2.vgic_apr;
} else {
struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
if (n > vgic_v3_max_apr_idx(vcpu))
return 0;
/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
return vgicv3->vgic_ap1r[n];
}
}
static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
int n; /* which APRn is this */
n = (addr >> 2) & 0x3;
if (kvm_vgic_global_state.type == VGIC_V2) {
/* GICv2 hardware systems support max. 32 groups */
if (n != 0)
return;
vcpu->arch.vgic_cpu.vgic_v2.vgic_apr = val;
} else {
struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
if (n > vgic_v3_max_apr_idx(vcpu))
return;
/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
vgicv3->vgic_ap1r[n] = val;
}
}
static const struct vgic_register_region vgic_v2_dist_registers[] = {
REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL,
vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
vgic_mmio_read_rao, vgic_mmio_write_wi, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
vgic_mmio_read_enable, vgic_mmio_write_senable, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
vgic_mmio_read_enable, vgic_mmio_write_cenable, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
vgic_mmio_read_pending, vgic_mmio_write_spending, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
vgic_mmio_read_pending, vgic_mmio_write_cpending, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
vgic_mmio_read_active, vgic_mmio_write_sactive,
NULL, vgic_mmio_uaccess_write_sactive, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR,
vgic_mmio_read_active, vgic_mmio_write_cactive,
NULL, vgic_mmio_uaccess_write_cactive, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
vgic_mmio_read_priority, vgic_mmio_write_priority, NULL, NULL,
8, VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
vgic_mmio_read_target, vgic_mmio_write_target, NULL, NULL, 8,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
vgic_mmio_read_raz, vgic_mmio_write_sgir, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
vgic_mmio_read_sgipend, vgic_mmio_write_sgipendc, 16,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_SET,
vgic_mmio_read_sgipend, vgic_mmio_write_sgipends, 16,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
};
static const struct vgic_register_region vgic_v2_cpu_registers[] = {
REGISTER_DESC_WITH_LENGTH(GIC_CPU_CTRL,
vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_CPU_PRIMASK,
vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_CPU_BINPOINT,
vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_CPU_ALIAS_BINPOINT,
vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
vgic_mmio_read_apr, vgic_mmio_write_apr, 16,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
VGIC_ACCESS_32bit),
};
unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev)
{
dev->regions = vgic_v2_dist_registers;
dev->nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
kvm_iodevice_init(&dev->dev, &kvm_io_gic_ops);
return SZ_4K;
}
int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
{
const struct vgic_register_region *region;
struct vgic_io_device iodev;
struct vgic_reg_attr reg_attr;
struct kvm_vcpu *vcpu;
gpa_t addr;
int ret;
ret = vgic_v2_parse_attr(dev, attr, &reg_attr);
if (ret)
return ret;
vcpu = reg_attr.vcpu;
addr = reg_attr.addr;
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
iodev.regions = vgic_v2_dist_registers;
iodev.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
iodev.base_addr = 0;
break;
case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
iodev.regions = vgic_v2_cpu_registers;
iodev.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers);
iodev.base_addr = 0;
break;
default:
return -ENXIO;
}
/* We only support aligned 32-bit accesses. */
if (addr & 3)
return -ENXIO;
region = vgic_get_mmio_region(vcpu, &iodev, addr, sizeof(u32));
if (!region)
return -ENXIO;
return 0;
}
int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
int offset, u32 *val)
{
struct vgic_io_device dev = {
.regions = vgic_v2_cpu_registers,
.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers),
.iodev_type = IODEV_CPUIF,
};
return vgic_uaccess(vcpu, &dev, is_write, offset, val);
}
int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
int offset, u32 *val)
{
struct vgic_io_device dev = {
.regions = vgic_v2_dist_registers,
.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers),
.iodev_type = IODEV_DIST,
};
return vgic_uaccess(vcpu, &dev, is_write, offset, val);
}