diff mbox series

arm64: gic: increase the number of IRQ descriptors

Message ID 20230104012215.1222263-1-sdonthineni@nvidia.com
State New
Headers
Series arm64: gic: increase the number of IRQ descriptors |

Commit Message

Shanker Donthineni Jan. 4, 2023, 1:22 a.m. UTC 
  The default value of NR_IRQS is not sufficient to support GICv4.1
features and ~64K LPIs. This parameter would be too small for certain
server platforms where it has many IO devices and is capable of
direct injection of vSGI and vLPI features.

Currently, maximum of 64 + 8192 (IRQ_BITMAP_BITS) IRQ descriptors
are allowed. The vCPU creation fails after reaching count ~400 with
kvm-arm.vgic_v4_enable=1.

This patch increases NR_IRQS to 1^19 to cover 64K LPIs and 262144
vSGIs (16K vPEs x 16).

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
---
 arch/arm64/include/asm/irq.h | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Shanker Donthineni Jan. 4, 2023, 2:35 a.m. UTC | #1 
Hi,

On 1/3/23 19:22, Shanker Donthineni wrote:
> The default value of NR_IRQS is not sufficient to support GICv4.1
> features and ~64K LPIs. This parameter would be too small for certain
> server platforms where it has many IO devices and is capable of
> direct injection of vSGI and vLPI features.
> 
> Currently, maximum of 64 + 8192 (IRQ_BITMAP_BITS) IRQ descriptors
> are allowed. The vCPU creation fails after reaching count ~400 with
> kvm-arm.vgic_v4_enable=1.
> 
> This patch increases NR_IRQS to 1^19  to cover 64K LPIs and 262144
> vSGIs (16K vPEs x 16).

Sorry, created a patch from the wrong kernel branch.
Please review v2 patch.
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index 168d710a7b70..741e0e9148ed 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -4,6 +4,10 @@ 
 
 #ifndef __ASSEMBLER__
 
+#if defined(CONFIG_ARM_GIC_V3_ITS)
+#define  NR_IRQS  (1 << 19)
+#endif
+
 #include <asm-generic/irq.h>
 #include <linux/irqchip/arm-gic-common.h>