arm/arm64: KVM: vgic: switch to dynamic allocation
So far, all the VGIC data structures are statically defined by the
*maximum* number of vcpus and interrupts it supports. It means that
we always have to oversize it to cater for the worse case.
Start by changing the data structures to be dynamically sizeable,
and allocate them at runtime.
The sizes are still very static though.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 88c901c..c1a1149 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -161,6 +161,8 @@
kvm->vcpus[i] = NULL;
}
}
+
+ kvm_vgic_destroy(kvm);
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
@@ -243,6 +245,7 @@
{
kvm_mmu_free_memory_caches(vcpu);
kvm_timer_vcpu_terminate(vcpu);
+ kvm_vgic_vcpu_destroy(vcpu);
kmem_cache_free(kvm_vcpu_cache, vcpu);
}
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index f074539..fd1b8f2 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -54,19 +54,33 @@
* - a bunch of shared interrupts (SPI)
*/
struct vgic_bitmap {
- union {
- u32 reg[VGIC_NR_PRIVATE_IRQS / 32];
- DECLARE_BITMAP(reg_ul, VGIC_NR_PRIVATE_IRQS);
- } percpu[VGIC_MAX_CPUS];
- union {
- u32 reg[VGIC_NR_SHARED_IRQS / 32];
- DECLARE_BITMAP(reg_ul, VGIC_NR_SHARED_IRQS);
- } shared;
+ /*
+ * - One UL per VCPU for private interrupts (assumes UL is at
+ * least 32 bits)
+ * - As many UL as necessary for shared interrupts.
+ *
+ * The private interrupts are accessed via the "private"
+ * field, one UL per vcpu (the state for vcpu n is in
+ * private[n]). The shared interrupts are accessed via the
+ * "shared" pointer (IRQn state is at bit n-32 in the bitmap).
+ */
+ unsigned long *private;
+ unsigned long *shared;
};
struct vgic_bytemap {
- u32 percpu[VGIC_MAX_CPUS][VGIC_NR_PRIVATE_IRQS / 4];
- u32 shared[VGIC_NR_SHARED_IRQS / 4];
+ /*
+ * - 8 u32 per VCPU for private interrupts
+ * - As many u32 as necessary for shared interrupts.
+ *
+ * The private interrupts are accessed via the "private"
+ * field, (the state for vcpu n is in private[n*8] to
+ * private[n*8 + 7]). The shared interrupts are accessed via
+ * the "shared" pointer (IRQn state is at byte (n-32)%4 of the
+ * shared[(n-32)/4] word).
+ */
+ u32 *private;
+ u32 *shared;
};
struct kvm_vcpu;
@@ -127,6 +141,9 @@
bool in_kernel;
bool ready;
+ int nr_cpus;
+ int nr_irqs;
+
/* Virtual control interface mapping */
void __iomem *vctrl_base;
@@ -166,15 +183,36 @@
/* Level/edge triggered */
struct vgic_bitmap irq_cfg;
- /* Source CPU per SGI and target CPU */
- u8 irq_sgi_sources[VGIC_MAX_CPUS][VGIC_NR_SGIS];
+ /*
+ * Source CPU per SGI and target CPU:
+ *
+ * Each byte represent a SGI observable on a VCPU, each bit of
+ * this byte indicating if the corresponding VCPU has
+ * generated this interrupt. This is a GICv2 feature only.
+ *
+ * For VCPUn (n < 8), irq_sgi_sources[n*16] to [n*16 + 15] are
+ * the SGIs observable on VCPUn.
+ */
+ u8 *irq_sgi_sources;
- /* Target CPU for each IRQ */
- u8 irq_spi_cpu[VGIC_NR_SHARED_IRQS];
- struct vgic_bitmap irq_spi_target[VGIC_MAX_CPUS];
+ /*
+ * Target CPU for each SPI:
+ *
+ * Array of available SPI, each byte indicating the target
+ * VCPU for SPI. IRQn (n >=32) is at irq_spi_cpu[n-32].
+ */
+ u8 *irq_spi_cpu;
+
+ /*
+ * Reverse lookup of irq_spi_cpu for faster compute pending:
+ *
+ * Array of bitmaps, one per VCPU, describing if IRQn is
+ * routed to a particular VCPU.
+ */
+ struct vgic_bitmap *irq_spi_target;
/* Bitmap indicating which CPU has something pending */
- unsigned long irq_pending_on_cpu;
+ unsigned long *irq_pending_on_cpu;
#endif
};
@@ -204,11 +242,11 @@
struct vgic_cpu {
#ifdef CONFIG_KVM_ARM_VGIC
/* per IRQ to LR mapping */
- u8 vgic_irq_lr_map[VGIC_NR_IRQS];
+ u8 *vgic_irq_lr_map;
/* Pending interrupts on this VCPU */
DECLARE_BITMAP( pending_percpu, VGIC_NR_PRIVATE_IRQS);
- DECLARE_BITMAP( pending_shared, VGIC_NR_SHARED_IRQS);
+ unsigned long *pending_shared;
/* Bitmap of used/free list registers */
DECLARE_BITMAP( lr_used, VGIC_V2_MAX_LRS);
@@ -239,7 +277,9 @@
int kvm_vgic_hyp_init(void);
int kvm_vgic_init(struct kvm *kvm);
int kvm_vgic_create(struct kvm *kvm);
+void kvm_vgic_destroy(struct kvm *kvm);
int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
+void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 9bdf181..08db876 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -95,6 +95,7 @@
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 u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi);
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);
@@ -105,10 +106,8 @@
static const struct vgic_params *vgic;
/*
- * struct vgic_bitmap contains unions that provide two views of
- * the same data. In one case it is an array of registers of
- * u32's, and in the other case it is a bitmap of unsigned
- * longs.
+ * struct vgic_bitmap contains a bitmap made of unsigned longs, but
+ * extracts u32s out of them.
*
* This does not work on 64-bit BE systems, because the bitmap access
* will store two consecutive 32-bit words with the higher-addressed
@@ -124,23 +123,45 @@
#define REG_OFFSET_SWIZZLE 0
#endif
+static int vgic_init_bitmap(struct vgic_bitmap *b, int nr_cpus, int nr_irqs)
+{
+ int nr_longs;
+
+ nr_longs = nr_cpus + BITS_TO_LONGS(nr_irqs - VGIC_NR_PRIVATE_IRQS);
+
+ b->private = kzalloc(sizeof(unsigned long) * nr_longs, GFP_KERNEL);
+ if (!b->private)
+ return -ENOMEM;
+
+ b->shared = b->private + nr_cpus;
+
+ return 0;
+}
+
+static void vgic_free_bitmap(struct vgic_bitmap *b)
+{
+ kfree(b->private);
+ b->private = NULL;
+ b->shared = NULL;
+}
+
static u32 *vgic_bitmap_get_reg(struct vgic_bitmap *x,
int cpuid, u32 offset)
{
offset >>= 2;
if (!offset)
- return x->percpu[cpuid].reg + (offset ^ REG_OFFSET_SWIZZLE);
+ return (u32 *)(x->private + cpuid) + REG_OFFSET_SWIZZLE;
else
- return x->shared.reg + ((offset - 1) ^ REG_OFFSET_SWIZZLE);
+ return (u32 *)(x->shared) + ((offset - 1) ^ REG_OFFSET_SWIZZLE);
}
static int vgic_bitmap_get_irq_val(struct vgic_bitmap *x,
int cpuid, int irq)
{
if (irq < VGIC_NR_PRIVATE_IRQS)
- return test_bit(irq, x->percpu[cpuid].reg_ul);
+ return test_bit(irq, x->private + cpuid);
- return test_bit(irq - VGIC_NR_PRIVATE_IRQS, x->shared.reg_ul);
+ return test_bit(irq - VGIC_NR_PRIVATE_IRQS, x->shared);
}
static void vgic_bitmap_set_irq_val(struct vgic_bitmap *x, int cpuid,
@@ -149,9 +170,9 @@
unsigned long *reg;
if (irq < VGIC_NR_PRIVATE_IRQS) {
- reg = x->percpu[cpuid].reg_ul;
+ reg = x->private + cpuid;
} else {
- reg = x->shared.reg_ul;
+ reg = x->shared;
irq -= VGIC_NR_PRIVATE_IRQS;
}
@@ -163,24 +184,49 @@
static unsigned long *vgic_bitmap_get_cpu_map(struct vgic_bitmap *x, int cpuid)
{
- if (unlikely(cpuid >= VGIC_MAX_CPUS))
- return NULL;
- return x->percpu[cpuid].reg_ul;
+ return x->private + cpuid;
}
static unsigned long *vgic_bitmap_get_shared_map(struct vgic_bitmap *x)
{
- return x->shared.reg_ul;
+ return x->shared;
+}
+
+static int vgic_init_bytemap(struct vgic_bytemap *x, int nr_cpus, int nr_irqs)
+{
+ int size;
+
+ size = nr_cpus * VGIC_NR_PRIVATE_IRQS;
+ size += nr_irqs - VGIC_NR_PRIVATE_IRQS;
+
+ x->private = kzalloc(size, GFP_KERNEL);
+ if (!x->private)
+ return -ENOMEM;
+
+ x->shared = x->private + nr_cpus * VGIC_NR_PRIVATE_IRQS / sizeof(u32);
+ return 0;
+}
+
+static void vgic_free_bytemap(struct vgic_bytemap *b)
+{
+ kfree(b->private);
+ b->private = NULL;
+ b->shared = NULL;
}
static u32 *vgic_bytemap_get_reg(struct vgic_bytemap *x, int cpuid, u32 offset)
{
- offset >>= 2;
- BUG_ON(offset > (VGIC_NR_IRQS / 4));
- if (offset < 8)
- return x->percpu[cpuid] + offset;
- else
- return x->shared + offset - 8;
+ u32 *reg;
+
+ if (offset < VGIC_NR_PRIVATE_IRQS) {
+ reg = x->private;
+ offset += cpuid * VGIC_NR_PRIVATE_IRQS;
+ } else {
+ reg = x->shared;
+ offset -= VGIC_NR_PRIVATE_IRQS;
+ }
+
+ return reg + (offset / sizeof(u32));
}
#define VGIC_CFG_LEVEL 0
@@ -744,7 +790,7 @@
*/
vgic_dist_irq_set_pending(vcpu, lr.irq);
if (lr.irq < VGIC_NR_SGIS)
- dist->irq_sgi_sources[vcpu_id][lr.irq] |= 1 << lr.source;
+ *vgic_get_sgi_sources(dist, vcpu_id, lr.irq) |= 1 << lr.source;
lr.state &= ~LR_STATE_PENDING;
vgic_set_lr(vcpu, i, lr);
@@ -778,7 +824,7 @@
/* Copy source SGIs from distributor side */
for (sgi = min_sgi; sgi <= max_sgi; sgi++) {
int shift = 8 * (sgi - min_sgi);
- reg |= (u32)dist->irq_sgi_sources[vcpu_id][sgi] << shift;
+ reg |= ((u32)*vgic_get_sgi_sources(dist, vcpu_id, sgi)) << shift;
}
mmio_data_write(mmio, ~0, reg);
@@ -802,14 +848,15 @@
/* Clear pending SGIs on the distributor */
for (sgi = min_sgi; sgi <= max_sgi; sgi++) {
u8 mask = reg >> (8 * (sgi - min_sgi));
+ u8 *src = vgic_get_sgi_sources(dist, vcpu_id, sgi);
if (set) {
- if ((dist->irq_sgi_sources[vcpu_id][sgi] & mask) != mask)
+ if ((*src & mask) != mask)
updated = true;
- dist->irq_sgi_sources[vcpu_id][sgi] |= mask;
+ *src |= mask;
} else {
- if (dist->irq_sgi_sources[vcpu_id][sgi] & mask)
+ if (*src & mask)
updated = true;
- dist->irq_sgi_sources[vcpu_id][sgi] &= ~mask;
+ *src &= ~mask;
}
}
@@ -993,6 +1040,11 @@
return true;
}
+static u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi)
+{
+ return dist->irq_sgi_sources + vcpu_id * VGIC_NR_SGIS + sgi;
+}
+
static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg)
{
struct kvm *kvm = vcpu->kvm;
@@ -1026,7 +1078,7 @@
if (target_cpus & 1) {
/* Flag the SGI as pending */
vgic_dist_irq_set_pending(vcpu, sgi);
- dist->irq_sgi_sources[c][sgi] |= 1 << vcpu_id;
+ *vgic_get_sgi_sources(dist, c, sgi) |= 1 << vcpu_id;
kvm_debug("SGI%d from CPU%d to CPU%d\n", sgi, vcpu_id, c);
}
@@ -1073,14 +1125,14 @@
int c;
if (!dist->enabled) {
- set_bit(0, &dist->irq_pending_on_cpu);
+ set_bit(0, dist->irq_pending_on_cpu);
return;
}
kvm_for_each_vcpu(c, vcpu, kvm) {
if (compute_pending_for_cpu(vcpu)) {
pr_debug("CPU%d has pending interrupts\n", c);
- set_bit(c, &dist->irq_pending_on_cpu);
+ set_bit(c, dist->irq_pending_on_cpu);
}
}
}
@@ -1237,14 +1289,14 @@
int vcpu_id = vcpu->vcpu_id;
int c;
- sources = dist->irq_sgi_sources[vcpu_id][irq];
+ sources = *vgic_get_sgi_sources(dist, vcpu_id, irq);
for_each_set_bit(c, &sources, VGIC_MAX_CPUS) {
if (vgic_queue_irq(vcpu, c, irq))
clear_bit(c, &sources);
}
- dist->irq_sgi_sources[vcpu_id][irq] = sources;
+ *vgic_get_sgi_sources(dist, vcpu_id, irq) = sources;
/*
* If the sources bitmap has been cleared it means that we
@@ -1332,7 +1384,7 @@
* us. Claim we don't have anything pending. We'll
* adjust that if needed while exiting.
*/
- clear_bit(vcpu_id, &dist->irq_pending_on_cpu);
+ clear_bit(vcpu_id, dist->irq_pending_on_cpu);
}
}
@@ -1430,7 +1482,7 @@
/* Check if we still have something up our sleeve... */
pending = find_first_zero_bit(elrsr_ptr, vgic->nr_lr);
if (level_pending || pending < vgic->nr_lr)
- set_bit(vcpu->vcpu_id, &dist->irq_pending_on_cpu);
+ set_bit(vcpu->vcpu_id, dist->irq_pending_on_cpu);
}
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
@@ -1464,7 +1516,7 @@
if (!irqchip_in_kernel(vcpu->kvm))
return 0;
- return test_bit(vcpu->vcpu_id, &dist->irq_pending_on_cpu);
+ return test_bit(vcpu->vcpu_id, dist->irq_pending_on_cpu);
}
static void vgic_kick_vcpus(struct kvm *kvm)
@@ -1559,7 +1611,7 @@
if (level) {
vgic_cpu_irq_set(vcpu, irq_num);
- set_bit(cpuid, &dist->irq_pending_on_cpu);
+ set_bit(cpuid, dist->irq_pending_on_cpu);
}
out:
@@ -1603,6 +1655,32 @@
return IRQ_HANDLED;
}
+void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+ kfree(vgic_cpu->pending_shared);
+ kfree(vgic_cpu->vgic_irq_lr_map);
+ vgic_cpu->pending_shared = NULL;
+ vgic_cpu->vgic_irq_lr_map = NULL;
+}
+
+static int vgic_vcpu_init_maps(struct kvm_vcpu *vcpu, int nr_irqs)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+ int sz = (nr_irqs - VGIC_NR_PRIVATE_IRQS) / 8;
+ vgic_cpu->pending_shared = kzalloc(sz, GFP_KERNEL);
+ vgic_cpu->vgic_irq_lr_map = kzalloc(nr_irqs, GFP_KERNEL);
+
+ if (!vgic_cpu->pending_shared || !vgic_cpu->vgic_irq_lr_map) {
+ kvm_vgic_vcpu_destroy(vcpu);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
/**
* kvm_vgic_vcpu_init - Initialize per-vcpu VGIC state
* @vcpu: pointer to the vcpu struct
@@ -1642,6 +1720,97 @@
return 0;
}
+void kvm_vgic_destroy(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ kvm_vgic_vcpu_destroy(vcpu);
+
+ vgic_free_bitmap(&dist->irq_enabled);
+ vgic_free_bitmap(&dist->irq_level);
+ vgic_free_bitmap(&dist->irq_pending);
+ vgic_free_bitmap(&dist->irq_soft_pend);
+ vgic_free_bitmap(&dist->irq_queued);
+ vgic_free_bitmap(&dist->irq_cfg);
+ vgic_free_bytemap(&dist->irq_priority);
+ if (dist->irq_spi_target) {
+ for (i = 0; i < dist->nr_cpus; i++)
+ vgic_free_bitmap(&dist->irq_spi_target[i]);
+ }
+ kfree(dist->irq_sgi_sources);
+ kfree(dist->irq_spi_cpu);
+ kfree(dist->irq_spi_target);
+ kfree(dist->irq_pending_on_cpu);
+ dist->irq_sgi_sources = NULL;
+ dist->irq_spi_cpu = NULL;
+ dist->irq_spi_target = NULL;
+ dist->irq_pending_on_cpu = NULL;
+}
+
+/*
+ * Allocate and initialize the various data structures. Must be called
+ * with kvm->lock held!
+ */
+static int vgic_init_maps(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct kvm_vcpu *vcpu;
+ int nr_cpus, nr_irqs;
+ int ret, i;
+
+ nr_cpus = dist->nr_cpus = VGIC_MAX_CPUS;
+ nr_irqs = dist->nr_irqs = VGIC_NR_IRQS;
+
+ ret = vgic_init_bitmap(&dist->irq_enabled, nr_cpus, nr_irqs);
+ ret |= vgic_init_bitmap(&dist->irq_level, nr_cpus, nr_irqs);
+ ret |= vgic_init_bitmap(&dist->irq_pending, nr_cpus, nr_irqs);
+ ret |= vgic_init_bitmap(&dist->irq_soft_pend, nr_cpus, nr_irqs);
+ ret |= vgic_init_bitmap(&dist->irq_queued, nr_cpus, nr_irqs);
+ ret |= vgic_init_bitmap(&dist->irq_cfg, nr_cpus, nr_irqs);
+ ret |= vgic_init_bytemap(&dist->irq_priority, nr_cpus, nr_irqs);
+
+ if (ret)
+ goto out;
+
+ dist->irq_sgi_sources = kzalloc(nr_cpus * VGIC_NR_SGIS, GFP_KERNEL);
+ dist->irq_spi_cpu = kzalloc(nr_irqs - VGIC_NR_PRIVATE_IRQS, GFP_KERNEL);
+ dist->irq_spi_target = kzalloc(sizeof(*dist->irq_spi_target) * nr_cpus,
+ GFP_KERNEL);
+ dist->irq_pending_on_cpu = kzalloc(BITS_TO_LONGS(nr_cpus) * sizeof(long),
+ GFP_KERNEL);
+ if (!dist->irq_sgi_sources ||
+ !dist->irq_spi_cpu ||
+ !dist->irq_spi_target ||
+ !dist->irq_pending_on_cpu) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ for (i = 0; i < nr_cpus; i++)
+ ret |= vgic_init_bitmap(&dist->irq_spi_target[i],
+ nr_cpus, nr_irqs);
+
+ if (ret)
+ goto out;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ ret = vgic_vcpu_init_maps(vcpu, nr_irqs);
+ if (ret) {
+ kvm_err("VGIC: Failed to allocate vcpu memory\n");
+ break;
+ }
+ }
+
+out:
+ if (ret)
+ kvm_vgic_destroy(kvm);
+
+ return ret;
+}
+
/**
* kvm_vgic_init - Initialize global VGIC state before running any VCPUs
* @kvm: pointer to the kvm struct
@@ -1722,6 +1891,10 @@
kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+ ret = vgic_init_maps(kvm);
+ if (ret)
+ kvm_err("Unable to allocate maps\n");
+
out_unlock:
for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);