[PATCH v2 17/54] KVM: arm/arm64: vgic-new: Add GICv2 world switch backend
Andre Przywara
andre.przywara at arm.com
Thu Apr 28 09:45:36 PDT 2016
From: Marc Zyngier <marc.zyngier at arm.com>
Processing maintenance interrupts and accessing the list registers
are dependent on the host's GIC version.
Introduce vgic-v2.c to contain GICv2 specific functions.
Implement the GICv2 specific code for syncing the emulation state
into the VGIC registers.
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
Signed-off-by: Eric Auger <eric.auger at linaro.org>
Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
Changelog RFC..v1:
- remove explicit LR_STATE clearing on maintenance interrupt handling
- improve documentation for vgic_v2_populate_lr()
- remove WARN_ON on non-edge IRQs in maintenance interrupts
- simplify multi-CPU source SGI handling
Changelog v1 .. v2:
- inject the IRQ priority into the list register
include/linux/irqchip/arm-gic.h | 1 +
virt/kvm/arm/vgic/vgic-v2.c | 178 ++++++++++++++++++++++++++++++++++++++++
virt/kvm/arm/vgic/vgic.c | 19 ++---
virt/kvm/arm/vgic/vgic.h | 6 ++
4 files changed, 194 insertions(+), 10 deletions(-)
create mode 100644 virt/kvm/arm/vgic/vgic-v2.c
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index 9c94026..be0d26f 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -76,6 +76,7 @@
#define GICH_LR_VIRTUALID (0x3ff << 0)
#define GICH_LR_PHYSID_CPUID_SHIFT (10)
#define GICH_LR_PHYSID_CPUID (0x3ff << GICH_LR_PHYSID_CPUID_SHIFT)
+#define GICH_LR_PRIORITY_SHIFT 23
#define GICH_LR_STATE (3 << 28)
#define GICH_LR_PENDING_BIT (1 << 28)
#define GICH_LR_ACTIVE_BIT (1 << 29)
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
new file mode 100644
index 0000000..4cee616
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -0,0 +1,178 @@
+/*
+ * 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);
+
+ cpuif->vgic_elrsr |= 1ULL << lr;
+ }
+ }
+
+ /* 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;
+}
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index a656a12e5..9f75685 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -397,10 +397,12 @@ retry:
static inline void vgic_process_maintenance_interrupt(struct kvm_vcpu *vcpu)
{
+ vgic_v2_process_maintenance(vcpu);
}
static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)
{
+ vgic_v2_fold_lr_state(vcpu);
}
/* Requires the ap_list_lock and the irq_lock to be held. */
@@ -409,14 +411,18 @@ static inline void vgic_populate_lr(struct kvm_vcpu *vcpu,
{
DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vcpu->arch.vgic_cpu.ap_list_lock));
DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
+
+ vgic_v2_populate_lr(vcpu, irq, lr);
}
static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr)
{
+ vgic_v2_clear_lr(vcpu, lr);
}
static inline void vgic_set_underflow(struct kvm_vcpu *vcpu)
{
+ vgic_v2_set_underflow(vcpu);
}
static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
@@ -441,14 +447,12 @@ static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
- struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
- u32 model = dist->vgic_model;
struct vgic_irq *irq;
int count = 0;
DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(vgic_cpu->ap_list_lock));
- if (unlikely(!dist->enabled))
+ if (unlikely(!vcpu->kvm->arch.vgic.enabled))
goto out_clean;
if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) {
@@ -466,14 +470,9 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
* If we get an SGI with multiple sources, try to get
* them in all at once.
*/
- if (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
- vgic_irq_is_sgi(irq->intid)) {
- while (irq->source &&
- count < kvm_vgic_global_state.nr_lr)
- vgic_populate_lr(vcpu, irq, count++);
- } else {
+ do {
vgic_populate_lr(vcpu, irq, count++);
- }
+ } while (irq->source && count < kvm_vgic_global_state.nr_lr);
next:
spin_unlock(&irq->irq_lock);
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 29b96b9..0db490e 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -22,4 +22,10 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
u32 intid);
bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq);
+void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu);
+void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu);
+void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr);
+void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr);
+void vgic_v2_set_underflow(struct kvm_vcpu *vcpu);
+
#endif
--
2.7.3
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