On Wed, Dec 04, 2024 at 02:20:02PM +0000, Eliav Farber wrote:
> Consolidate the machine_kexec_mask_interrupts implementation into a common
> function located in a new file: kernel/irq/kexec.c. This removes duplicate
> implementations from architecture-specific files in arch/arm, arch/arm64,
> arch/powerpc, and arch/riscv, reducing code duplication and improving
> maintainability.
>
> The new implementation retains architecture-specific behavior for
> CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD, which was previously implemented
> for ARM64. When enabled (currently for ARM64), it clears the active state
> of interrupts forwarded to virtual machines (VMs) before handling other
> interrupt masking operations.
>
> Signed-off-by: Eliav Farber <farb...@amazon.com>
> ---
> V5 -> V6:
> - Change GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD to not be user selectable.
>
> arch/arm/kernel/machine_kexec.c | 23 ------------------
> arch/arm64/Kconfig | 1 +
> arch/arm64/kernel/machine_kexec.c | 31 ------------------------
> arch/powerpc/include/asm/kexec.h | 1 -
> arch/powerpc/kexec/core.c | 22 -----------------
> arch/powerpc/kexec/core_32.c | 1 +
> arch/riscv/kernel/machine_kexec.c | 23 ------------------
> include/linux/irq.h | 3 +++
> kernel/irq/Kconfig | 6 +++++
> kernel/irq/Makefile | 2 +-
> kernel/irq/kexec.c | 40 +++++++++++++++++++++++++++++++
> 11 files changed, 52 insertions(+), 101 deletions(-)
> create mode 100644 kernel/irq/kexec.c
>
> diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
> index 80ceb5bd2680..dd430477e7c1 100644
> --- a/arch/arm/kernel/machine_kexec.c
> +++ b/arch/arm/kernel/machine_kexec.c
> @@ -127,29 +127,6 @@ void crash_smp_send_stop(void)
> cpus_stopped = 1;
> }
>
> -static void machine_kexec_mask_interrupts(void)
> -{
> - unsigned int i;
> - struct irq_desc *desc;
> -
> - for_each_irq_desc(i, desc) {
> - struct irq_chip *chip;
> -
> - chip = irq_desc_get_chip(desc);
> - if (!chip)
> - continue;
> -
> - if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
> - chip->irq_eoi(&desc->irq_data);
> -
> - if (chip->irq_mask)
> - chip->irq_mask(&desc->irq_data);
> -
> - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
> - chip->irq_disable(&desc->irq_data);
> - }
> -}
> -
> void machine_crash_shutdown(struct pt_regs *regs)
> {
> local_irq_disable();
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 100570a048c5..dcc3551cf6c2 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -149,6 +149,7 @@ config ARM64
> select GENERIC_IDLE_POLL_SETUP
> select GENERIC_IOREMAP
> select GENERIC_IRQ_IPI
> + select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
Is this really specific to VMs? In the new code, it's just controlling
this part of the old code:
> diff --git a/arch/arm64/kernel/machine_kexec.c
> b/arch/arm64/kernel/machine_kexec.c
> index 82e2203d86a3..6f121a0164a4 100644
> --- a/arch/arm64/kernel/machine_kexec.c
> +++ b/arch/arm64/kernel/machine_kexec.c
> @@ -207,37 +207,6 @@ void machine_kexec(struct kimage *kimage)
> BUG(); /* Should never get here. */
> }
>
> -static void machine_kexec_mask_interrupts(void)
> -{
> - unsigned int i;
> - struct irq_desc *desc;
> -
> - for_each_irq_desc(i, desc) {
> - struct irq_chip *chip;
> - int ret;
> -
> - chip = irq_desc_get_chip(desc);
> - if (!chip)
> - continue;
> -
> - /*
> - * First try to remove the active state. If this
> - * fails, try to EOI the interrupt.
> - */
> - ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
which is about active interrupts. Why can't that happen for the host?
Will
