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

Jacob Pan
2024-04-04T17:13:10Z

Hi Robert,

On Thu, 4 Apr 2024 21:38:34 +0800, Robert Hoo <robert.hoo.linux@gmail.com>
wrote:

> 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?
Indeed, thanks for catching that!

> > +#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
>

Thanks,

Jacob