linux_dsm_epyc7002/virt/kvm/arm/vgic/vgic-mmio-v3.c
Andre Przywara 621ecd8d21 KVM: arm/arm64: vgic-new: Add GICv3 SGI system register trap handler
In contrast to GICv2 SGIs in a GICv3 implementation are not triggered
by a MMIO write, but with a system register write. KVM knows about
that register already, we just need to implement the handler and wire
it up to the core KVM/ARM code.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20 15:39:59 +02:00

456 lines
14 KiB
C

/*
* VGICv3 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-v3.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <kvm/iodev.h>
#include <kvm/arm_vgic.h>
#include <asm/kvm_emulate.h>
#include "vgic.h"
#include "vgic-mmio.h"
/* extract @num bytes at @offset bytes offset in data */
static unsigned long extract_bytes(unsigned long data, unsigned int offset,
unsigned int num)
{
return (data >> (offset * 8)) & GENMASK_ULL(num * 8 - 1, 0);
}
static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
u32 value = 0;
switch (addr & 0x0c) {
case GICD_CTLR:
if (vcpu->kvm->arch.vgic.enabled)
value |= GICD_CTLR_ENABLE_SS_G1;
value |= GICD_CTLR_ARE_NS | GICD_CTLR_DS;
break;
case GICD_TYPER:
value = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
value = (value >> 5) - 1;
value |= (INTERRUPT_ID_BITS_SPIS - 1) << 19;
break;
case GICD_IIDR:
value = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
break;
default:
return 0;
}
return value;
}
static void vgic_mmio_write_v3_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 GICD_CTLR:
dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;
if (!was_enabled && dist->enabled)
vgic_kick_vcpus(vcpu->kvm);
break;
case GICD_TYPER:
case GICD_IIDR:
return;
}
}
static unsigned long vgic_mmio_read_irouter(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
int intid = VGIC_ADDR_TO_INTID(addr, 64);
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid);
if (!irq)
return 0;
/* The upper word is RAZ for us. */
if (addr & 4)
return 0;
return extract_bytes(READ_ONCE(irq->mpidr), addr & 7, len);
}
static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
int intid = VGIC_ADDR_TO_INTID(addr, 64);
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid);
if (!irq)
return;
/* The upper word is WI for us since we don't implement Aff3. */
if (addr & 4)
return;
spin_lock(&irq->irq_lock);
/* We only care about and preserve Aff0, Aff1 and Aff2. */
irq->mpidr = val & GENMASK(23, 0);
irq->target_vcpu = kvm_mpidr_to_vcpu(vcpu->kvm, irq->mpidr);
spin_unlock(&irq->irq_lock);
}
static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
int target_vcpu_id = vcpu->vcpu_id;
u64 value;
value = (mpidr & GENMASK(23, 0)) << 32;
value |= ((target_vcpu_id & 0xffff) << 8);
if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
value |= GICR_TYPER_LAST;
return extract_bytes(value, addr & 7, len);
}
static unsigned long vgic_mmio_read_v3r_iidr(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
return (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0);
}
static unsigned long vgic_mmio_read_v3_idregs(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
switch (addr & 0xffff) {
case GICD_PIDR2:
/* report a GICv3 compliant implementation */
return 0x3b;
}
return 0;
}
/*
* The GICv3 per-IRQ registers are split to control PPIs and SGIs in the
* redistributors, while SPIs are covered by registers in the distributor
* block. Trying to set private IRQs in this block gets ignored.
* We take some special care here to fix the calculation of the register
* offset.
*/
#define REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(off, rd, wr, bpi, acc) \
{ \
.reg_offset = off, \
.bits_per_irq = bpi, \
.len = (bpi * VGIC_NR_PRIVATE_IRQS) / 8, \
.access_flags = acc, \
.read = vgic_mmio_read_raz, \
.write = vgic_mmio_write_wi, \
}, { \
.reg_offset = off + (bpi * VGIC_NR_PRIVATE_IRQS) / 8, \
.bits_per_irq = bpi, \
.len = (bpi * (1024 - VGIC_NR_PRIVATE_IRQS)) / 8, \
.access_flags = acc, \
.read = rd, \
.write = wr, \
}
static const struct vgic_register_region vgic_v3_dist_registers[] = {
REGISTER_DESC_WITH_LENGTH(GICD_CTLR,
vgic_mmio_read_v3_misc, vgic_mmio_write_v3_misc, 16,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGROUPR,
vgic_mmio_read_rao, vgic_mmio_write_wi, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISENABLER,
vgic_mmio_read_enable, vgic_mmio_write_senable, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICENABLER,
vgic_mmio_read_enable, vgic_mmio_write_cenable, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISPENDR,
vgic_mmio_read_pending, vgic_mmio_write_spending, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICPENDR,
vgic_mmio_read_pending, vgic_mmio_write_cpending, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISACTIVER,
vgic_mmio_read_active, vgic_mmio_write_sactive, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICACTIVER,
vgic_mmio_read_active, vgic_mmio_write_cactive, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IPRIORITYR,
vgic_mmio_read_priority, vgic_mmio_write_priority, 8,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ITARGETSR,
vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICFGR,
vgic_mmio_read_config, vgic_mmio_write_config, 2,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGRPMODR,
vgic_mmio_read_raz, vgic_mmio_write_wi, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IROUTER,
vgic_mmio_read_irouter, vgic_mmio_write_irouter, 64,
VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICD_IDREGS,
vgic_mmio_read_v3_idregs, vgic_mmio_write_wi, 48,
VGIC_ACCESS_32bit),
};
static const struct vgic_register_region vgic_v3_rdbase_registers[] = {
REGISTER_DESC_WITH_LENGTH(GICR_CTLR,
vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_IIDR,
vgic_mmio_read_v3r_iidr, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_TYPER,
vgic_mmio_read_v3r_typer, vgic_mmio_write_wi, 8,
VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_PROPBASER,
vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_PENDBASER,
vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_IDREGS,
vgic_mmio_read_v3_idregs, vgic_mmio_write_wi, 48,
VGIC_ACCESS_32bit),
};
static const struct vgic_register_region vgic_v3_sgibase_registers[] = {
REGISTER_DESC_WITH_LENGTH(GICR_IGROUPR0,
vgic_mmio_read_rao, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ISENABLER0,
vgic_mmio_read_enable, vgic_mmio_write_senable, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ICENABLER0,
vgic_mmio_read_enable, vgic_mmio_write_cenable, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ISPENDR0,
vgic_mmio_read_pending, vgic_mmio_write_spending, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ICPENDR0,
vgic_mmio_read_pending, vgic_mmio_write_cpending, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ISACTIVER0,
vgic_mmio_read_active, vgic_mmio_write_sactive, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ICACTIVER0,
vgic_mmio_read_active, vgic_mmio_write_cactive, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_IPRIORITYR0,
vgic_mmio_read_priority, vgic_mmio_write_priority, 32,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_LENGTH(GICR_ICFGR0,
vgic_mmio_read_config, vgic_mmio_write_config, 8,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_IGRPMODR0,
vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_NSACR,
vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),
};
unsigned int vgic_v3_init_dist_iodev(struct vgic_io_device *dev)
{
dev->regions = vgic_v3_dist_registers;
dev->nr_regions = ARRAY_SIZE(vgic_v3_dist_registers);
kvm_iodevice_init(&dev->dev, &kvm_io_gic_ops);
return SZ_64K;
}
int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t redist_base_address)
{
int nr_vcpus = atomic_read(&kvm->online_vcpus);
struct kvm_vcpu *vcpu;
struct vgic_io_device *devices;
int c, ret = 0;
devices = kmalloc(sizeof(struct vgic_io_device) * nr_vcpus * 2,
GFP_KERNEL);
if (!devices)
return -ENOMEM;
kvm_for_each_vcpu(c, vcpu, kvm) {
gpa_t rd_base = redist_base_address + c * SZ_64K * 2;
gpa_t sgi_base = rd_base + SZ_64K;
struct vgic_io_device *rd_dev = &devices[c * 2];
struct vgic_io_device *sgi_dev = &devices[c * 2 + 1];
kvm_iodevice_init(&rd_dev->dev, &kvm_io_gic_ops);
rd_dev->base_addr = rd_base;
rd_dev->regions = vgic_v3_rdbase_registers;
rd_dev->nr_regions = ARRAY_SIZE(vgic_v3_rdbase_registers);
rd_dev->redist_vcpu = vcpu;
mutex_lock(&kvm->slots_lock);
ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, rd_base,
SZ_64K, &rd_dev->dev);
mutex_unlock(&kvm->slots_lock);
if (ret)
break;
kvm_iodevice_init(&sgi_dev->dev, &kvm_io_gic_ops);
sgi_dev->base_addr = sgi_base;
sgi_dev->regions = vgic_v3_sgibase_registers;
sgi_dev->nr_regions = ARRAY_SIZE(vgic_v3_sgibase_registers);
sgi_dev->redist_vcpu = vcpu;
mutex_lock(&kvm->slots_lock);
ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, sgi_base,
SZ_64K, &sgi_dev->dev);
mutex_unlock(&kvm->slots_lock);
if (ret) {
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
&rd_dev->dev);
break;
}
}
if (ret) {
/* The current c failed, so we start with the previous one. */
for (c--; c >= 0; c--) {
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
&devices[c * 2].dev);
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
&devices[c * 2 + 1].dev);
}
kfree(devices);
} else {
kvm->arch.vgic.redist_iodevs = devices;
}
return ret;
}
/*
* Compare a given affinity (level 1-3 and a level 0 mask, from the SGI
* generation register ICC_SGI1R_EL1) with a given VCPU.
* If the VCPU's MPIDR matches, return the level0 affinity, otherwise
* return -1.
*/
static int match_mpidr(u64 sgi_aff, u16 sgi_cpu_mask, struct kvm_vcpu *vcpu)
{
unsigned long affinity;
int level0;
/*
* Split the current VCPU's MPIDR into affinity level 0 and the
* rest as this is what we have to compare against.
*/
affinity = kvm_vcpu_get_mpidr_aff(vcpu);
level0 = MPIDR_AFFINITY_LEVEL(affinity, 0);
affinity &= ~MPIDR_LEVEL_MASK;
/* bail out if the upper three levels don't match */
if (sgi_aff != affinity)
return -1;
/* Is this VCPU's bit set in the mask ? */
if (!(sgi_cpu_mask & BIT(level0)))
return -1;
return level0;
}
/*
* The ICC_SGI* registers encode the affinity differently from the MPIDR,
* so provide a wrapper to use the existing defines to isolate a certain
* affinity level.
*/
#define SGI_AFFINITY_LEVEL(reg, level) \
((((reg) & ICC_SGI1R_AFFINITY_## level ##_MASK) \
>> ICC_SGI1R_AFFINITY_## level ##_SHIFT) << MPIDR_LEVEL_SHIFT(level))
/**
* vgic_v3_dispatch_sgi - handle SGI requests from VCPUs
* @vcpu: The VCPU requesting a SGI
* @reg: The value written into the ICC_SGI1R_EL1 register by that VCPU
*
* With GICv3 (and ARE=1) CPUs trigger SGIs by writing to a system register.
* This will trap in sys_regs.c and call this function.
* This ICC_SGI1R_EL1 register contains the upper three affinity levels of the
* target processors as well as a bitmask of 16 Aff0 CPUs.
* If the interrupt routing mode bit is not set, we iterate over all VCPUs to
* check for matching ones. If this bit is set, we signal all, but not the
* calling VCPU.
*/
void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_vcpu *c_vcpu;
u16 target_cpus;
u64 mpidr;
int sgi, c;
int vcpu_id = vcpu->vcpu_id;
bool broadcast;
sgi = (reg & ICC_SGI1R_SGI_ID_MASK) >> ICC_SGI1R_SGI_ID_SHIFT;
broadcast = reg & BIT(ICC_SGI1R_IRQ_ROUTING_MODE_BIT);
target_cpus = (reg & ICC_SGI1R_TARGET_LIST_MASK) >> ICC_SGI1R_TARGET_LIST_SHIFT;
mpidr = SGI_AFFINITY_LEVEL(reg, 3);
mpidr |= SGI_AFFINITY_LEVEL(reg, 2);
mpidr |= SGI_AFFINITY_LEVEL(reg, 1);
/*
* We iterate over all VCPUs to find the MPIDRs matching the request.
* If we have handled one CPU, we clear its bit to detect early
* if we are already finished. This avoids iterating through all
* VCPUs when most of the times we just signal a single VCPU.
*/
kvm_for_each_vcpu(c, c_vcpu, kvm) {
struct vgic_irq *irq;
/* Exit early if we have dealt with all requested CPUs */
if (!broadcast && target_cpus == 0)
break;
/* Don't signal the calling VCPU */
if (broadcast && c == vcpu_id)
continue;
if (!broadcast) {
int level0;
level0 = match_mpidr(mpidr, target_cpus, c_vcpu);
if (level0 == -1)
continue;
/* remove this matching VCPU from the mask */
target_cpus &= ~BIT(level0);
}
irq = vgic_get_irq(vcpu->kvm, c_vcpu, sgi);
spin_lock(&irq->irq_lock);
irq->pending = true;
vgic_queue_irq_unlock(vcpu->kvm, irq);
}
}