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KVM: ARM: vgic: introduce vgic_ops and LR manipulation primitives
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In order to split the various register manipulation from the main vgic
code, introduce a vgic_ops structure, and start by abstracting the
LR manipulation code with a couple of accessors.

Reviewed-by: Christoffer Dall <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
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@chazy
Marc Zyngier authored and chazy committed Jul 11, 2014
1 parent eede821 commit 8d5c6b0
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Showing 2 changed files with 128 additions and 52 deletions.
18 changes: 18 additions & 0 deletions include/kvm/arm_vgic.h
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Original file line number Diff line number Diff line change
Expand Up @@ -68,6 +68,24 @@ struct vgic_bytemap {
u32 shared[VGIC_NR_SHARED_IRQS / 4];
};

struct kvm_vcpu;

#define LR_STATE_PENDING (1 << 0)
#define LR_STATE_ACTIVE (1 << 1)
#define LR_STATE_MASK (3 << 0)
#define LR_EOI_INT (1 << 2)

struct vgic_lr {
u16 irq;
u8 source;
u8 state;
};

struct vgic_ops {
struct vgic_lr (*get_lr)(const struct kvm_vcpu *, int);
void (*set_lr)(struct kvm_vcpu *, int, struct vgic_lr);
};

struct vgic_dist {
#ifdef CONFIG_KVM_ARM_VGIC
spinlock_t lock;
Expand Down
162 changes: 110 additions & 52 deletions virt/kvm/arm/vgic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -94,9 +94,12 @@ static struct device_node *vgic_node;
#define ACCESS_WRITE_MASK(x) ((x) & (3 << 1))

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 void vgic_update_state(struct kvm *kvm);
static void vgic_kick_vcpus(struct kvm *kvm);
static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
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 u32 vgic_nr_lr;

static unsigned int vgic_maint_irq;
Expand Down Expand Up @@ -593,18 +596,6 @@ static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu,
return false;
}

#define LR_CPUID(lr) \
(((lr) & GICH_LR_PHYSID_CPUID) >> GICH_LR_PHYSID_CPUID_SHIFT)
#define LR_IRQID(lr) \
((lr) & GICH_LR_VIRTUALID)

static void vgic_retire_lr(int lr_nr, int irq, struct vgic_cpu *vgic_cpu)
{
clear_bit(lr_nr, vgic_cpu->lr_used);
vgic_cpu->vgic_v2.vgic_lr[lr_nr] &= ~GICH_LR_STATE;
vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY;
}

/**
* vgic_unqueue_irqs - move pending IRQs from LRs to the distributor
* @vgic_cpu: Pointer to the vgic_cpu struct holding the LRs
Expand All @@ -622,13 +613,10 @@ static void vgic_unqueue_irqs(struct kvm_vcpu *vcpu)
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
int vcpu_id = vcpu->vcpu_id;
int i, irq, source_cpu;
u32 *lr;
int i;

for_each_set_bit(i, vgic_cpu->lr_used, vgic_cpu->nr_lr) {
lr = &vgic_cpu->vgic_v2.vgic_lr[i];
irq = LR_IRQID(*lr);
source_cpu = LR_CPUID(*lr);
struct vgic_lr lr = vgic_get_lr(vcpu, i);

/*
* There are three options for the state bits:
Expand All @@ -640,7 +628,7 @@ static void vgic_unqueue_irqs(struct kvm_vcpu *vcpu)
* If the LR holds only an active interrupt (not pending) then
* just leave it alone.
*/
if ((*lr & GICH_LR_STATE) == GICH_LR_ACTIVE_BIT)
if ((lr.state & LR_STATE_MASK) == LR_STATE_ACTIVE)
continue;

/*
Expand All @@ -649,18 +637,19 @@ static void vgic_unqueue_irqs(struct kvm_vcpu *vcpu)
* is fine, then we are only setting a few bits that were
* already set.
*/
vgic_dist_irq_set(vcpu, irq);
if (irq < VGIC_NR_SGIS)
dist->irq_sgi_sources[vcpu_id][irq] |= 1 << source_cpu;
*lr &= ~GICH_LR_PENDING_BIT;
vgic_dist_irq_set(vcpu, lr.irq);
if (lr.irq < VGIC_NR_SGIS)
dist->irq_sgi_sources[vcpu_id][lr.irq] |= 1 << lr.source;
lr.state &= ~LR_STATE_PENDING;
vgic_set_lr(vcpu, i, lr);

/*
* If there's no state left on the LR (it could still be
* active), then the LR does not hold any useful info and can
* be marked as free for other use.
*/
if (!(*lr & GICH_LR_STATE))
vgic_retire_lr(i, irq, vgic_cpu);
if (!(lr.state & LR_STATE_MASK))
vgic_retire_lr(i, lr.irq, vcpu);

/* Finally update the VGIC state. */
vgic_update_state(vcpu->kvm);
Expand Down Expand Up @@ -989,8 +978,69 @@ static void vgic_update_state(struct kvm *kvm)
}
}

#define MK_LR_PEND(src, irq) \
(GICH_LR_PENDING_BIT | ((src) << GICH_LR_PHYSID_CPUID_SHIFT) | (irq))
static struct vgic_lr vgic_v2_get_lr(const struct kvm_vcpu *vcpu, int lr)
{
struct vgic_lr lr_desc;
u32 val = vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr];

lr_desc.irq = val & GICH_LR_VIRTUALID;
if (lr_desc.irq <= 15)
lr_desc.source = (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
else
lr_desc.source = 0;
lr_desc.state = 0;

if (val & GICH_LR_PENDING_BIT)
lr_desc.state |= LR_STATE_PENDING;
if (val & GICH_LR_ACTIVE_BIT)
lr_desc.state |= LR_STATE_ACTIVE;
if (val & GICH_LR_EOI)
lr_desc.state |= LR_EOI_INT;

return lr_desc;
}

static void vgic_v2_set_lr(struct kvm_vcpu *vcpu, int lr,
struct vgic_lr lr_desc)
{
u32 lr_val = (lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT) | lr_desc.irq;

if (lr_desc.state & LR_STATE_PENDING)
lr_val |= GICH_LR_PENDING_BIT;
if (lr_desc.state & LR_STATE_ACTIVE)
lr_val |= GICH_LR_ACTIVE_BIT;
if (lr_desc.state & LR_EOI_INT)
lr_val |= GICH_LR_EOI;

vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = lr_val;
}

static const struct vgic_ops vgic_ops = {
.get_lr = vgic_v2_get_lr,
.set_lr = vgic_v2_set_lr,
};

static struct vgic_lr vgic_get_lr(const struct kvm_vcpu *vcpu, int lr)
{
return vgic_ops.get_lr(vcpu, lr);
}

static void vgic_set_lr(struct kvm_vcpu *vcpu, int lr,
struct vgic_lr vlr)
{
vgic_ops.set_lr(vcpu, lr, vlr);
}

static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
struct vgic_lr vlr = vgic_get_lr(vcpu, lr_nr);

vlr.state = 0;
vgic_set_lr(vcpu, lr_nr, vlr);
clear_bit(lr_nr, vgic_cpu->lr_used);
vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY;
}

/*
* An interrupt may have been disabled after being made pending on the
Expand All @@ -1007,12 +1057,12 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu)
int lr;

for_each_set_bit(lr, vgic_cpu->lr_used, vgic_cpu->nr_lr) {
int irq = vgic_cpu->vgic_v2.vgic_lr[lr] & GICH_LR_VIRTUALID;
struct vgic_lr vlr = vgic_get_lr(vcpu, lr);

if (!vgic_irq_is_enabled(vcpu, irq)) {
vgic_retire_lr(lr, irq, vgic_cpu);
if (vgic_irq_is_active(vcpu, irq))
vgic_irq_clear_active(vcpu, irq);
if (!vgic_irq_is_enabled(vcpu, vlr.irq)) {
vgic_retire_lr(lr, vlr.irq, vcpu);
if (vgic_irq_is_active(vcpu, vlr.irq))
vgic_irq_clear_active(vcpu, vlr.irq);
}
}
}
Expand All @@ -1024,6 +1074,7 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu)
static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
struct vgic_lr vlr;
int lr;

/* Sanitize the input... */
Expand All @@ -1036,13 +1087,15 @@ static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq)
lr = vgic_cpu->vgic_irq_lr_map[irq];

/* Do we have an active interrupt for the same CPUID? */
if (lr != LR_EMPTY &&
(LR_CPUID(vgic_cpu->vgic_v2.vgic_lr[lr]) == sgi_source_id)) {
kvm_debug("LR%d piggyback for IRQ%d %x\n",
lr, irq, vgic_cpu->vgic_v2.vgic_lr[lr]);
BUG_ON(!test_bit(lr, vgic_cpu->lr_used));
vgic_cpu->vgic_v2.vgic_lr[lr] |= GICH_LR_PENDING_BIT;
return true;
if (lr != LR_EMPTY) {
vlr = vgic_get_lr(vcpu, lr);
if (vlr.source == sgi_source_id) {
kvm_debug("LR%d piggyback for IRQ%d\n", lr, vlr.irq);
BUG_ON(!test_bit(lr, vgic_cpu->lr_used));
vlr.state |= LR_STATE_PENDING;
vgic_set_lr(vcpu, lr, vlr);
return true;
}
}

/* Try to use another LR for this interrupt */
Expand All @@ -1052,12 +1105,16 @@ static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq)
return false;

kvm_debug("LR%d allocated for IRQ%d %x\n", lr, irq, sgi_source_id);
vgic_cpu->vgic_v2.vgic_lr[lr] = MK_LR_PEND(sgi_source_id, irq);
vgic_cpu->vgic_irq_lr_map[irq] = lr;
set_bit(lr, vgic_cpu->lr_used);

vlr.irq = irq;
vlr.source = sgi_source_id;
vlr.state = LR_STATE_PENDING;
if (!vgic_irq_is_edge(vcpu, irq))
vgic_cpu->vgic_v2.vgic_lr[lr] |= GICH_LR_EOI;
vlr.state |= LR_EOI_INT;

vgic_set_lr(vcpu, lr, vlr);

return true;
}
Expand Down Expand Up @@ -1180,29 +1237,30 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
* Some level interrupts have been EOIed. Clear their
* active bit.
*/
int lr, irq;
int lr;

for_each_set_bit(lr, (unsigned long *)vgic_cpu->vgic_v2.vgic_eisr,
vgic_cpu->nr_lr) {
irq = vgic_cpu->vgic_v2.vgic_lr[lr] & GICH_LR_VIRTUALID;
struct vgic_lr vlr = vgic_get_lr(vcpu, lr);

vgic_irq_clear_active(vcpu, irq);
vgic_cpu->vgic_v2.vgic_lr[lr] &= ~GICH_LR_EOI;
vgic_irq_clear_active(vcpu, vlr.irq);
WARN_ON(vlr.state & LR_STATE_MASK);
vlr.state = 0;
vgic_set_lr(vcpu, lr, vlr);

/* Any additional pending interrupt? */
if (vgic_dist_irq_is_pending(vcpu, irq)) {
vgic_cpu_irq_set(vcpu, irq);
if (vgic_dist_irq_is_pending(vcpu, vlr.irq)) {
vgic_cpu_irq_set(vcpu, vlr.irq);
level_pending = true;
} else {
vgic_cpu_irq_clear(vcpu, irq);
vgic_cpu_irq_clear(vcpu, vlr.irq);
}

/*
* Despite being EOIed, the LR may not have
* been marked as empty.
*/
set_bit(lr, (unsigned long *)vgic_cpu->vgic_v2.vgic_elrsr);
vgic_cpu->vgic_v2.vgic_lr[lr] &= ~GICH_LR_ACTIVE_BIT;
}
}

Expand All @@ -1228,15 +1286,15 @@ static void __kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
/* Clear mappings for empty LRs */
for_each_set_bit(lr, (unsigned long *)vgic_cpu->vgic_v2.vgic_elrsr,
vgic_cpu->nr_lr) {
int irq;
struct vgic_lr vlr;

if (!test_and_clear_bit(lr, vgic_cpu->lr_used))
continue;

irq = vgic_cpu->vgic_v2.vgic_lr[lr] & GICH_LR_VIRTUALID;
vlr = vgic_get_lr(vcpu, lr);

BUG_ON(irq >= VGIC_NR_IRQS);
vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY;
BUG_ON(vlr.irq >= VGIC_NR_IRQS);
vgic_cpu->vgic_irq_lr_map[vlr.irq] = LR_EMPTY;
}

/* Check if we still have something up our sleeve... */
Expand Down

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