aboutsummaryrefslogtreecommitdiff
path: root/virt/kvm/arm/vgic/vgic-v2.c
blob: fb5e65ceffd0d298ae62917d02e65ed90fa6a9f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/*
 * Copyright (C) 2015, 2016 ARM Ltd.
 *
 * 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/irqchip/arm-gic.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>

#include "vgic.h"

/*
 * Call this function to convert a u64 value to an unsigned long * bitmask
 * in a way that works on both 32-bit and 64-bit LE and BE platforms.
 *
 * Warning: Calling this function may modify *val.
 */
static unsigned long *u64_to_bitmask(u64 *val)
{
#if defined(CONFIG_CPU_BIG_ENDIAN) && BITS_PER_LONG == 32
	*val = (*val >> 32) | (*val << 32);
#endif
	return (unsigned long *)val;
}

void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu)
{
	struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2;

	if (cpuif->vgic_misr & GICH_MISR_EOI) {
		u64 eisr = cpuif->vgic_eisr;
		unsigned long *eisr_bmap = u64_to_bitmask(&eisr);
		int lr;

		for_each_set_bit(lr, eisr_bmap, kvm_vgic_global_state.nr_lr) {
			u32 intid = cpuif->vgic_lr[lr] & GICH_LR_VIRTUALID;

			WARN_ON(cpuif->vgic_lr[lr] & GICH_LR_STATE);

			kvm_notify_acked_irq(vcpu->kvm, 0,
					     intid - VGIC_NR_PRIVATE_IRQS);
		}
	}

	/* check and disable underflow maintenance IRQ */
	cpuif->vgic_hcr &= ~GICH_HCR_UIE;

	/*
	 * In the next iterations of the vcpu loop, if we sync the
	 * vgic state after flushing it, but before entering the guest
	 * (this happens for pending signals and vmid rollovers), then
	 * make sure we don't pick up any old maintenance interrupts
	 * here.
	 */
	cpuif->vgic_eisr = 0;
}

void vgic_v2_set_underflow(struct kvm_vcpu *vcpu)
{
	struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2;

	cpuif->vgic_hcr |= GICH_HCR_UIE;
}

/*
 * transfer the content of the LRs back into the corresponding ap_list:
 * - active bit is transferred as is
 * - pending bit is
 *   - transferred as is in case of edge sensitive IRQs
 *   - set to the line-level (resample time) for level sensitive IRQs
 */
void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
{
	struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2;
	int lr;

	for (lr = 0; lr < vcpu->arch.vgic_cpu.used_lrs; lr++) {
		u32 val = cpuif->vgic_lr[lr];
		u32 intid = val & GICH_LR_VIRTUALID;
		struct vgic_irq *irq;

		irq = vgic_get_irq(vcpu->kvm, vcpu, intid);

		spin_lock(&irq->irq_lock);

		/* Always preserve the active bit */
		irq->active = !!(val & GICH_LR_ACTIVE_BIT);

		/* Edge is the only case where we preserve the pending bit */
		if (irq->config == VGIC_CONFIG_EDGE &&
		    (val & GICH_LR_PENDING_BIT)) {
			irq->pending = true;

			if (vgic_irq_is_sgi(intid)) {
				u32 cpuid = val & GICH_LR_PHYSID_CPUID;

				cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT;
				irq->source |= (1 << cpuid);
			}
		}

		/* Clear soft pending state when level IRQs have been acked */
		if (irq->config == VGIC_CONFIG_LEVEL &&
		    !(val & GICH_LR_PENDING_BIT)) {
			irq->soft_pending = false;
			irq->pending = irq->line_level;
		}

		spin_unlock(&irq->irq_lock);
	}
}

/*
 * Populates the particular LR with the state of a given IRQ:
 * - for an edge sensitive IRQ the pending state is cleared in struct vgic_irq
 * - for a level sensitive IRQ the pending state value is unchanged;
 *   it is dictated directly by the input level
 *
 * If @irq describes an SGI with multiple sources, we choose the
 * lowest-numbered source VCPU and clear that bit in the source bitmap.
 *
 * The irq_lock must be held by the caller.
 */
void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr)
{
	u32 val = irq->intid;

	if (irq->pending) {
		val |= GICH_LR_PENDING_BIT;

		if (irq->config == VGIC_CONFIG_EDGE)
			irq->pending = false;

		if (vgic_irq_is_sgi(irq->intid)) {
			u32 src = ffs(irq->source);

			BUG_ON(!src);
			val |= (src - 1) << GICH_LR_PHYSID_CPUID_SHIFT;
			irq->source &= ~(1 << (src - 1));
			if (irq->source)
				irq->pending = true;
		}
	}

	if (irq->active)
		val |= GICH_LR_ACTIVE_BIT;

	if (irq->hw) {
		val |= GICH_LR_HW;
		val |= irq->hwintid << GICH_LR_PHYSID_CPUID_SHIFT;
	} else {
		if (irq->config == VGIC_CONFIG_LEVEL)
			val |= GICH_LR_EOI;
	}

	/* The GICv2 LR only holds five bits of priority. */
	val |= (irq->priority >> 3) << GICH_LR_PRIORITY_SHIFT;

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

void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr)
{
	vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = 0;
}