Upon receiving an LPI, we need to find the right VCPU and virtual IRQ
number to get this IRQ injected.
Iterate our two-level LPI table to find this information quickly when
the host takes an LPI. Call the existing injection function to let the
GIC emulation deal with this interrupt.
Signed-off-by: Andre Przywara <andre.przyw...@arm.com>
---
xen/arch/arm/gic-its.c | 35 +++++++++++++++++++++++++++++++++++
xen/arch/arm/gic.c | 6 ++++--
xen/include/asm-arm/irq.h | 8 ++++++++
3 files changed, 47 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/gic-its.c b/xen/arch/arm/gic-its.c
index e7ddd90..0d4ca1b 100644
--- a/xen/arch/arm/gic-its.c
+++ b/xen/arch/arm/gic-its.c
@@ -72,6 +72,41 @@ static union host_lpi *gic_get_host_lpi(uint32_t plpi)
return &lpi_data.host_lpis[plpi / HOST_LPIS_PER_PAGE][plpi %
HOST_LPIS_PER_PAGE];
}
+/* Handle incoming LPIs, which are a bit special, because they are potentially
+ * numerous and also only get injected into guests. Treat them specially here,
+ * by just looking up their target vCPU and virtual LPI number and hand it
+ * over to the injection function.
+ */
+void do_LPI(unsigned int lpi)
+{
+ struct domain *d;
+ union host_lpi *hlpip, hlpi;
+ struct vcpu *vcpu;
+
+ WRITE_SYSREG32(lpi, ICC_EOIR1_EL1);
+
+ hlpip = gic_get_host_lpi(lpi);
+ if ( !hlpip )
+ return;
+
+ hlpi.data = hlpip->data;
+
+ /* We may have mapped more host LPIs than the guest actually asked for. */
+ if ( !hlpi.virt_lpi )
+ return;
+
+ d = get_domain_by_id(hlpi.dom_id);
+ if ( !d )
+ return;
+
+ if ( hlpi.vcpu_id >= d->max_vcpus )
+ return;
+
+ vcpu = d->vcpu[hlpi.vcpu_id];
+
+ vgic_vcpu_inject_irq(vcpu, hlpi.virt_lpi);
+}
+
#define ITS_CMD_QUEUE_SZ SZ_64K
static int its_send_command(struct host_its *hw_its, void *its_cmd)
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 6f25501..7d428dc 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -700,8 +700,10 @@ void gic_interrupt(struct cpu_user_regs *regs, int is_fiq)
local_irq_enable();
do_IRQ(regs, irq, is_fiq);
local_irq_disable();
- }
- else if (unlikely(irq < 16))
+ } else if ( irq >= 8192 )
+ {
+ do_LPI(irq);
+ } else if ( unlikely(irq < 16) )
{
do_sgi(regs, irq);
}
diff --git a/xen/include/asm-arm/irq.h b/xen/include/asm-arm/irq.h
index 8f7a167..ee47de8 100644
--- a/xen/include/asm-arm/irq.h
+++ b/xen/include/asm-arm/irq.h
@@ -34,6 +34,14 @@ struct irq_desc *__irq_to_desc(int irq);
void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq);
+#ifdef CONFIG_HAS_ITS
+void do_LPI(unsigned int irq);
+#else
+static inline void do_LPI(unsigned int irq)
+{
+}
+#endif
+
#define domain_pirq_to_irq(d, pirq) (pirq)
bool_t is_assignable_irq(unsigned int irq);
--
2.9.0
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