Hi Leonid,
On 03/09/2025 15:29, Leonid Komarianskyi wrote:
---
xen/arch/arm/Kconfig | 8 +++++
xen/arch/arm/include/asm/irq.h | 37 ++++++++++++++++++++++++
xen/arch/arm/irq.c | 53 ++++++++++++++++++++++++++++++++--
3 files changed, 96 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 17df147b25..43b05533b1 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -135,6 +135,14 @@ config GICV3
Driver for the ARM Generic Interrupt Controller v3.
If unsure, use the default setting.
+config GICV3_ESPI
+ bool "Extended SPI range support"
+ depends on GICV3 && !NEW_VGIC
+ help
+ Allow Xen and domains to use interrupt numbers from the extended SPI
+ range, from 4096 to 5119. This feature is introduced in GICv3.1
+ architecture.
+
config HAS_ITS
bool "GICv3 ITS MSI controller support (UNSUPPORTED)" if UNSUPPORTED
depends on GICV3 && !NEW_VGIC && !ARM_32
diff --git a/xen/arch/arm/include/asm/irq.h b/xen/arch/arm/include/asm/irq.h
index 5bc6475eb4..f4d0997651 100644
--- a/xen/arch/arm/include/asm/irq.h
+++ b/xen/arch/arm/include/asm/irq.h
@@ -32,6 +32,10 @@ struct arch_irq_desc {
#define SPI_MAX_INTID 1019
#define LPI_OFFSET 8192
+#define ESPI_BASE_INTID 4096
+#define ESPI_MAX_INTID 5119
+#define NR_ESPI_IRQS 1024
+
/* LPIs are always numbered starting at 8192, so 0 is a good invalid case. */
#define INVALID_LPI 0
@@ -39,7 +43,12 @@ struct arch_irq_desc {
#define INVALID_IRQ 1023
extern const unsigned int nr_irqs;
+#ifdef CONFIG_GICV3_ESPI
+/* This will cover the eSPI range, to allow asignmant of eSPIs to domains. */
+#define nr_static_irqs (ESPI_MAX_INTID + 1)
+#else
#define nr_static_irqs NR_IRQS
+#endif
struct irq_desc;
struct irqaction;
@@ -55,6 +64,34 @@ static inline bool is_lpi(unsigned int irq)
return irq >= LPI_OFFSET;
}
+static inline unsigned int espi_intid_to_idx(unsigned int intid)
+{
+ ASSERT(intid >= ESPI_BASE_INTID && intid <= ESPI_MAX_INTID);
Can we use is_espi()?
+ return intid - ESPI_BASE_INTID;
+}
+
+static inline unsigned int espi_idx_to_intid(unsigned int idx)
+{
+ ASSERT(idx <= NR_ESPI_IRQS);
+ return idx + ESPI_BASE_INTID;
+}
+
+static inline bool is_espi(unsigned int irq)
+{
+#ifdef CONFIG_GICV3_ESPI
+ return irq >= ESPI_BASE_INTID && irq <= ESPI_MAX_INTID;
+#else
+ /*
+ * The function should not be called for eSPIs when CONFIG_GICV3_ESPI is
+ * disabled. Returning false allows the compiler to optimize the code
+ * when the config is disabled, while the assert ensures that out-of-range
+ * array resources are not accessed, e.g., in __irq_to_desc().
+ */
+ ASSERT(irq >= ESPI_BASE_INTID);
Regardless what Volodymyr mentioned about the assert!(), I am a bit
unsure where we guarantee is_espi() will not be called with an irq <=
ESPI_BASE_INTID. In fact, we could have the following code in Xen:
if (is_espi(irq))
{
}
else if (is_lpi(irq))
{
}
else
{
}
We could replace the check with "!(irq >= ESPI_BASE_INTID && irq <=
ESPI_MAX_INTID)". But I would actually prefer if there is no check
because I don't see the value.
+ return false;
+#endif
+}
+
Cheers,
--
Julien Grall
