The LPI pending status for a GICv3 redistributor is held in a table
in (guest) memory. To achieve reasonable performance, we cache this
data in our struct vgic_irq. The initial pending state must be read
from guest memory upon enabling LPIs for this redistributor.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
virt/kvm/arm/vgic/vgic-its.c | 43 +++++++++++++++++++++++++++++++++++++++++++
virt/kvm/arm/vgic/vgic.h | 6 ++++++
2 files changed, 49 insertions(+)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 9ef951f7..ba2af85 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -149,6 +149,43 @@ struct its_itte {
#define CBASER_ADDRESS(x) ((x) & GENMASK_ULL(51, 12))
#define BASER_ADDRESS(x) ((x) & GENMASK_ULL(47, 12))
+#define PENDBASER_ADDRESS(x) ((x) & GENMASK_ULL(51, 16))
+
+/*
+ * Scan the whole LPI pending table and sync the pending bit in there
+ * with our own data structures. This relies on the LPI being
+ * mapped before.
+ */
+static int its_sync_lpi_pending_table(struct kvm_vcpu *vcpu)
+{
+ gpa_t pendbase = PENDBASER_ADDRESS(vcpu->arch.vgic_cpu.pendbaser);
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+ struct vgic_irq *irq;
+ u8 pendmask;
+ int ret = 0;
+
+ mutex_lock(&dist->lpi_list_lock);
+ list_for_each_entry(irq, &dist->lpi_list_head, lpi_entry) {
+ int byte_offset, bit_nr;
+
+ byte_offset = irq->intid / BITS_PER_BYTE;
+ bit_nr = irq->intid % BITS_PER_BYTE;
+
+ ret = kvm_read_guest(vcpu->kvm, pendbase + byte_offset,
+ &pendmask, 1);
+ if (ret)
+ goto out_unlock;
+
+ spin_lock(&irq->irq_lock);
+ irq->pending = pendmask & (1U << bit_nr);
+ vgic_queue_irq_put(vcpu->kvm, irq);
+ }
+
+out_unlock:
+ mutex_unlock(&dist->lpi_list_lock);
+
+ return ret;
+}
#define ITS_FRAME(addr) ((addr) & ~(SZ_64K - 1))
@@ -454,6 +491,12 @@ struct vgic_register_region its_registers[] = {
VGIC_ACCESS_32bit),
};
+/* This is called on setting the LPI enable bit in the redistributor. */
+void vgic_enable_lpis(struct kvm_vcpu *vcpu)
+{
+ its_sync_lpi_pending_table(vcpu);
+}
+
static int vits_register(struct kvm *kvm, struct vgic_its *its)
{
struct vgic_io_device *iodev = &its->iodev;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 558252d..8c2105a 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -25,6 +25,7 @@
#define IS_VGIC_ADDR_UNDEF(_x) ((_x) == VGIC_ADDR_UNDEF)
#define INTERRUPT_ID_BITS_SPIS 10
+#define INTERRUPT_ID_BITS_ITS 16
#define VGIC_PRI_BITS 5
#define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
@@ -82,6 +83,7 @@ int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
bool vgic_has_its(struct kvm *kvm);
int kvm_vgic_register_its_device(void);
struct vgic_irq *vgic_its_get_lpi(struct kvm *kvm, u32 intid);
+void vgic_enable_lpis(struct kvm_vcpu *vcpu);
#else
static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
{
@@ -148,6 +150,10 @@ static inline struct vgic_irq *vgic_its_get_lpi(struct kvm *kvm, u32 intid)
{
return NULL;
}
+
+static inline void vgic_enable_lpis(struct kvm_vcpu *vcpu)
+{
+}
#endif
int kvm_register_vgic_device(unsigned long type);
--
2.8.2
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