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linux/virt/kvm/arm/vgic-v3.c
Ming Lei ef748917b5 arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS' 
This patch removes config option of KVM_ARM_MAX_VCPUS,
and like other ARCHs, just choose the maximum allowed
value from hardware, and follows the reasons:

1) from distribution view, the option has to be
defined as the max allowed value because it need to
meet all kinds of virtulization applications and
need to support most of SoCs;

2) using a bigger value doesn't introduce extra memory
consumption, and the help text in Kconfig isn't accurate
because kvm_vpu structure isn't allocated until request
of creating VCPU is sent from QEMU;

3) the main effect is that the field of vcpus[] in 'struct kvm'
becomes a bit bigger(sizeof(void *) per vcpu) and need more cache
lines to hold the structure, but 'struct kvm' is one generic struct,
and it has worked well on other ARCHs already in this way. Also,
the world switch frequecy is often low, for example, it is ~2000
when running kernel building load in VM from APM xgene KVM host,
so the effect is very small, and the difference can't be observed
in my test at all.

Cc: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-09-17 13:13:27 +01:00

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/*
* Copyright (C) 2013 ARM Limited, All Rights Reserved.
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/cpu.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
/* These are for GICv2 emulation only */
#define GICH_LR_VIRTUALID (0x3ffUL << 0)
#define GICH_LR_PHYSID_CPUID_SHIFT (10)
#define GICH_LR_PHYSID_CPUID (7UL << GICH_LR_PHYSID_CPUID_SHIFT)
#define ICH_LR_VIRTUALID_MASK (BIT_ULL(32) - 1)
/*
* LRs are stored in reverse order in memory. make sure we index them
* correctly.
*/
#define LR_INDEX(lr) (VGIC_V3_MAX_LRS - 1 - lr)
static u32 ich_vtr_el2;
static struct vgic_lr vgic_v3_get_lr(const struct kvm_vcpu *vcpu, int lr)
{
struct vgic_lr lr_desc;
u64 val = vcpu->arch.vgic_cpu.vgic_v3.vgic_lr[LR_INDEX(lr)];
if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
lr_desc.irq = val & ICH_LR_VIRTUALID_MASK;
else
lr_desc.irq = val & GICH_LR_VIRTUALID;
lr_desc.source = 0;
if (lr_desc.irq <= 15 &&
vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
lr_desc.source = (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
lr_desc.state = 0;
if (val & ICH_LR_PENDING_BIT)
lr_desc.state |= LR_STATE_PENDING;
if (val & ICH_LR_ACTIVE_BIT)
lr_desc.state |= LR_STATE_ACTIVE;
if (val & ICH_LR_EOI)
lr_desc.state |= LR_EOI_INT;
if (val & ICH_LR_HW) {
lr_desc.state |= LR_HW;
lr_desc.hwirq = (val >> ICH_LR_PHYS_ID_SHIFT) & GENMASK(9, 0);
}
return lr_desc;
}
static void vgic_v3_set_lr(struct kvm_vcpu *vcpu, int lr,
struct vgic_lr lr_desc)
{
u64 lr_val;
lr_val = lr_desc.irq;
/*
* Currently all guest IRQs are Group1, as Group0 would result
* in a FIQ in the guest, which it wouldn't expect.
* Eventually we want to make this configurable, so we may revisit
* this in the future.
*/
switch (vcpu->kvm->arch.vgic.vgic_model) {
case KVM_DEV_TYPE_ARM_VGIC_V3:
lr_val |= ICH_LR_GROUP;
break;
case KVM_DEV_TYPE_ARM_VGIC_V2:
if (lr_desc.irq < VGIC_NR_SGIS)
lr_val |= (u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT;
break;
default:
BUG();
}
if (lr_desc.state & LR_STATE_PENDING)
lr_val |= ICH_LR_PENDING_BIT;
if (lr_desc.state & LR_STATE_ACTIVE)
lr_val |= ICH_LR_ACTIVE_BIT;
if (lr_desc.state & LR_EOI_INT)
lr_val |= ICH_LR_EOI;
if (lr_desc.state & LR_HW) {
lr_val |= ICH_LR_HW;
lr_val |= ((u64)lr_desc.hwirq) << ICH_LR_PHYS_ID_SHIFT;
}
vcpu->arch.vgic_cpu.vgic_v3.vgic_lr[LR_INDEX(lr)] = lr_val;
}
static void vgic_v3_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
struct vgic_lr lr_desc)
{
if (!(lr_desc.state & LR_STATE_MASK))
vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr |= (1U << lr);
else
vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr &= ~(1U << lr);
}
static u64 vgic_v3_get_elrsr(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr;
}
static u64 vgic_v3_get_eisr(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr;
}
static void vgic_v3_clear_eisr(struct kvm_vcpu *vcpu)
{
vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr = 0;
}
static u32 vgic_v3_get_interrupt_status(const struct kvm_vcpu *vcpu)
{
u32 misr = vcpu->arch.vgic_cpu.vgic_v3.vgic_misr;
u32 ret = 0;
if (misr & ICH_MISR_EOI)
ret |= INT_STATUS_EOI;
if (misr & ICH_MISR_U)
ret |= INT_STATUS_UNDERFLOW;
return ret;
}
static void vgic_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
{
u32 vmcr = vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr;
vmcrp->ctlr = (vmcr & ICH_VMCR_CTLR_MASK) >> ICH_VMCR_CTLR_SHIFT;
vmcrp->abpr = (vmcr & ICH_VMCR_BPR1_MASK) >> ICH_VMCR_BPR1_SHIFT;
vmcrp->bpr = (vmcr & ICH_VMCR_BPR0_MASK) >> ICH_VMCR_BPR0_SHIFT;
vmcrp->pmr = (vmcr & ICH_VMCR_PMR_MASK) >> ICH_VMCR_PMR_SHIFT;
}
static void vgic_v3_enable_underflow(struct kvm_vcpu *vcpu)
{
vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr |= ICH_HCR_UIE;
}
static void vgic_v3_disable_underflow(struct kvm_vcpu *vcpu)
{
vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr &= ~ICH_HCR_UIE;
}
static void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
{
u32 vmcr;
vmcr = (vmcrp->ctlr << ICH_VMCR_CTLR_SHIFT) & ICH_VMCR_CTLR_MASK;
vmcr |= (vmcrp->abpr << ICH_VMCR_BPR1_SHIFT) & ICH_VMCR_BPR1_MASK;
vmcr |= (vmcrp->bpr << ICH_VMCR_BPR0_SHIFT) & ICH_VMCR_BPR0_MASK;
vmcr |= (vmcrp->pmr << ICH_VMCR_PMR_SHIFT) & ICH_VMCR_PMR_MASK;
vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr = vmcr;
}
static void vgic_v3_enable(struct kvm_vcpu *vcpu)
{
struct vgic_v3_cpu_if *vgic_v3 = &vcpu->arch.vgic_cpu.vgic_v3;
/*
* By forcing VMCR to zero, the GIC will restore the binary
* points to their reset values. Anything else resets to zero
* anyway.
*/
vgic_v3->vgic_vmcr = 0;
/*
* If we are emulating a GICv3, we do it in an non-GICv2-compatible
* way, so we force SRE to 1 to demonstrate this to the guest.
* This goes with the spec allowing the value to be RAO/WI.
*/
if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
vgic_v3->vgic_sre = ICC_SRE_EL1_SRE;
else
vgic_v3->vgic_sre = 0;
/* Get the show on the road... */
vgic_v3->vgic_hcr = ICH_HCR_EN;
}
static const struct vgic_ops vgic_v3_ops = {
.get_lr = vgic_v3_get_lr,
.set_lr = vgic_v3_set_lr,
.sync_lr_elrsr = vgic_v3_sync_lr_elrsr,
.get_elrsr = vgic_v3_get_elrsr,
.get_eisr = vgic_v3_get_eisr,
.clear_eisr = vgic_v3_clear_eisr,
.get_interrupt_status = vgic_v3_get_interrupt_status,
.enable_underflow = vgic_v3_enable_underflow,
.disable_underflow = vgic_v3_disable_underflow,
.get_vmcr = vgic_v3_get_vmcr,
.set_vmcr = vgic_v3_set_vmcr,
.enable = vgic_v3_enable,
};
static struct vgic_params vgic_v3_params;
/**
* vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
* @node: pointer to the DT node
* @ops: address of a pointer to the GICv3 operations
* @params: address of a pointer to HW-specific parameters
*
* Returns 0 if a GICv3 has been found, with the low level operations
* in *ops and the HW parameters in *params. Returns an error code
* otherwise.
*/
int vgic_v3_probe(struct device_node *vgic_node,
const struct vgic_ops **ops,
const struct vgic_params **params)
{
int ret = 0;
u32 gicv_idx;
struct resource vcpu_res;
struct vgic_params *vgic = &vgic_v3_params;
vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
if (!vgic->maint_irq) {
kvm_err("error getting vgic maintenance irq from DT\n");
ret = -ENXIO;
goto out;
}
ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
/*
* The ListRegs field is 5 bits, but there is a architectural
* maximum of 16 list registers. Just ignore bit 4...
*/
vgic->nr_lr = (ich_vtr_el2 & 0xf) + 1;
vgic->can_emulate_gicv2 = false;
if (of_property_read_u32(vgic_node, "#redistributor-regions", &gicv_idx))
gicv_idx = 1;
gicv_idx += 3; /* Also skip GICD, GICC, GICH */
if (of_address_to_resource(vgic_node, gicv_idx, &vcpu_res)) {
kvm_info("GICv3: no GICV resource entry\n");
vgic->vcpu_base = 0;
} else if (!PAGE_ALIGNED(vcpu_res.start)) {
pr_warn("GICV physical address 0x%llx not page aligned\n",
(unsigned long long)vcpu_res.start);
vgic->vcpu_base = 0;
} else if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
(unsigned long long)resource_size(&vcpu_res),
PAGE_SIZE);
vgic->vcpu_base = 0;
} else {
vgic->vcpu_base = vcpu_res.start;
vgic->can_emulate_gicv2 = true;
kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
KVM_DEV_TYPE_ARM_VGIC_V2);
}
if (vgic->vcpu_base == 0)
kvm_info("disabling GICv2 emulation\n");
kvm_register_device_ops(&kvm_arm_vgic_v3_ops, KVM_DEV_TYPE_ARM_VGIC_V3);
vgic->vctrl_base = NULL;
vgic->type = VGIC_V3;
vgic->max_gic_vcpus = VGIC_V3_MAX_CPUS;
kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
vcpu_res.start, vgic->maint_irq);
*ops = &vgic_v3_ops;
*params = vgic;
out:
of_node_put(vgic_node);
return ret;
}
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