linux-zen-server/arch/arm64/kvm/vgic/vgic-mmio-v2.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* VGICv2 MMIO handling functions
*/
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/nospec.h>
#include <kvm/iodev.h>
#include <kvm/arm_vgic.h>
#include "vgic.h"
#include "vgic-mmio.h"
/*
* The Revision field in the IIDR have the following meanings:
*
* Revision 1: Report GICv2 interrupts as group 0 instead of group 1
* Revision 2: Interrupt groups are guest-configurable and signaled using
* their configured groups.
*/
static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
struct vgic_dist *vgic = &vcpu->kvm->arch.vgic;
u32 value;
switch (addr & 0x0c) {
case GIC_DIST_CTRL:
value = vgic->enabled ? GICD_ENABLE : 0;
break;
case GIC_DIST_CTR:
value = 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 << GICD_IIDR_PRODUCT_ID_SHIFT) |
(vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) |
(IMPLEMENTER_ARM << GICD_IIDR_IMPLEMENTER_SHIFT);
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 int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
u32 reg;
switch (addr & 0x0c) {
case GIC_DIST_IIDR:
reg = vgic_mmio_read_v2_misc(vcpu, addr, len);
if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
return -EINVAL;
/*
* If we observe a write to GICD_IIDR we know that userspace
* has been updated and has had a chance to cope with older
* kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting
* interrupts as group 1, and therefore we now allow groups to
* be user writable. Doing this by default would break
* migration from old kernels to new kernels with legacy
* userspace.
*/
reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
switch (reg) {
case KVM_VGIC_IMP_REV_2:
case KVM_VGIC_IMP_REV_3:
vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
dist->implementation_rev = reg;
return 0;
default:
return -EINVAL;
}
}
vgic_mmio_write_v2_misc(vcpu, addr, len, val);
return 0;
}
static int vgic_mmio_uaccess_write_v2_group(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
if (vcpu->kvm->arch.vgic.v2_groups_user_writable)
vgic_mmio_write_group(vcpu, addr, len, val);
return 0;
}
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;
struct kvm_vcpu *vcpu;
unsigned long flags, c;
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);
raw_spin_lock_irqsave(&irq->irq_lock, flags);
irq->pending_latch = true;
irq->source |= 1U << source_vcpu->vcpu_id;
vgic_queue_irq_unlock(source_vcpu->kvm, irq, flags);
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;
unsigned long flags;
/* 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;
raw_spin_lock_irqsave(&irq->irq_lock, flags);
irq->targets = (val >> (i * 8)) & cpu_mask;
target = irq->targets ? __ffs(irq->targets) : 0;
irq->target_vcpu = kvm_get_vcpu(vcpu->kvm, target);
raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
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;
unsigned long flags;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
raw_spin_lock_irqsave(&irq->irq_lock, flags);
irq->source &= ~((val >> (i * 8)) & 0xff);
if (!irq->source)
irq->pending_latch = false;
raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
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;
unsigned long flags;
for (i = 0; i < len; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
raw_spin_lock_irqsave(&irq->irq_lock, flags);
irq->source |= (val >> (i * 8)) & 0xff;
if (irq->source) {
irq->pending_latch = true;
vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
} else {
raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
}
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
* 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
* 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;
n = array_index_nospec(n, 4);
/* 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;
n = array_index_nospec(n, 4);
/* 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_UACCESS(GIC_DIST_CTRL,
vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc,
NULL, vgic_mmio_uaccess_write_v2_misc,
12, VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
vgic_mmio_read_group, vgic_mmio_write_group,
NULL, vgic_mmio_uaccess_write_v2_group, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
vgic_mmio_read_enable, vgic_mmio_write_senable,
NULL, vgic_uaccess_write_senable, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
vgic_mmio_read_enable, vgic_mmio_write_cenable,
NULL, vgic_uaccess_write_cenable, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
vgic_mmio_read_pending, vgic_mmio_write_spending,
vgic_uaccess_read_pending, vgic_uaccess_write_spending, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
vgic_mmio_read_pending, vgic_mmio_write_cpending,
vgic_uaccess_read_pending, vgic_uaccess_write_cpending, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
vgic_mmio_read_active, vgic_mmio_write_sactive,
vgic_uaccess_read_active, 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,
vgic_uaccess_read_active, 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);
}