virt inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7BQMW CVE: NA

-----------------------------------------------------------------

The deafault value of NR_IRQS is not sufficient to support GICv4.1 features and ~56K 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 56K LPIs and 262144 vSGIs (16vPEs x 16).

------------------------------------------------------------------

Tips: This is a temporary fix[1], but it has been able to solve the problem. The latest upstream version[2] depends on the 'maple tree', which is inappropriately introduced to the current kernel.

-------------------------------------------------------------------

Another Tips: According to Chao Liu and Chang Liao's suggestion, modifying IRQ_BITMAP_BITS can achieve the same effect with less impact. Compared with solution[2], solution[1] has a disadvantage: the memory foot print increases as the number of VMs increases.

Link: https://lore.kernel.org/linux-arm-kernel/20230104023738.1258925-1-sdonthinen... [1] Link: https://lore.kernel.org/all/20230519134902.1495562-1-sdonthineni@nvidia.com/... [2] Signed-off-by: Shanker Donthineni sdonthineni@nvidia.com Signed-off-by: Chao Liu liuchao173@huawei.com Signed-off-by: Chang Liao liaochang1@huawei.com Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com --- kernel/irq/internals.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index e58342ace11f..79f22b018c6b 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -12,7 +12,7 @@ #include <linux/sched/clock.h>

#ifdef CONFIG_SPARSE_IRQ -# define IRQ_BITMAP_BITS (NR_IRQS + 8196) +# define IRQ_BITMAP_BITS (1 << 19) #else # define IRQ_BITMAP_BITS NR_IRQS #endif