Re: [PATCH 05/15] x86/irq: Reserve a per CPU IDT vector for posted MSIs

Robert Hoo
2024-04-04T13:38:46Z

On 1/27/2024 7:42 AM, Jacob Pan wrote:
> When posted MSI is enabled, all device MSIs are multiplexed into a single
> notification vector. MSI handlers will be de-multiplexed at run-time by
> system software without IDT delivery.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
> arch/x86/include/asm/irq_vectors.h | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
> index 3a19904c2db6..08329bef5b1d 100644
> --- a/arch/x86/include/asm/irq_vectors.h
> +++ b/arch/x86/include/asm/irq_vectors.h
> @@ -99,9 +99,16 @@
>
> #define LOCAL_TIMER_VECTOR 0xec
>
> +/*
> + * Posted interrupt notification vector for all device MSIs delivered to
> + * the host kernel.
> + */
> +#define POSTED_MSI_NOTIFICATION_VECTOR 0xeb
> #define NR_VECTORS 256
>
> -#ifdef CONFIG_X86_LOCAL_APIC
> +#ifdef X86_POSTED_MSI

X86_POSTED_MSI --> CONFIG_X86_POSTED_MSI?

> +#define FIRST_SYSTEM_VECTOR POSTED_MSI_NOTIFICATION_VECTOR
> +#elif defined(CONFIG_X86_LOCAL_APIC)
> #define FIRST_SYSTEM_VECTOR LOCAL_TIMER_VECTOR
> #else
> #define FIRST_SYSTEM_VECTOR NR_VECTORS