Re: 3.2.1 Unable to reset IRR messages on boot

[Suresh Siddha <suresh.b.siddha@intel.com>]

On Tue, 2012-03-20 at 14:58 -0400, Konrad Rzeszutek Wilk wrote:
> Then this fixes the issue - thought if there are more checks in the future
> it will have to be redone..:
> 
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index 988828b..b8e2794 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -1859,6 +1859,7 @@ pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
>  #endif	/* CONFIG_X86_64 */
>  
>  static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss;
> +static unsigned char fake_ioapic_mapping[PAGE_SIZE] __page_aligned_bss;
>  
>  static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
>  {
> @@ -1899,7 +1900,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
>  		 * We just don't map the IO APIC - all access is via
>  		 * hypercalls.  Keep the address in the pte for reference.
>  		 */
> -		pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
> +		pte = pfn_pte(PFN_DOWN(__pa(fake_ioapic_mapping)), PAGE_KERNEL);
>  		break;
>  #endif
>  
> @@ -2064,6 +2065,7 @@ void __init xen_init_mmu_ops(void)
>  	pv_mmu_ops = xen_mmu_ops;
>  
>  	memset(dummy_mapping, 0xff, PAGE_SIZE);
> +	memset(fake_ioapic_mapping, 0xfd, PAGE_SIZE);

heh ;)

I was referring to setting up something little more valid. Like
IO_APIC_reg_01 showing value of 0x00170020 etc. As the gsi computation
actually refers to the number of redirection table entries supported by
the IO-APIC.

Also does the dom0 see all the GSI's/io-apic's that the host sees or is
it going to be just one io-apic? I was just wondering if the reg 01 need
to be same as what the host sees?

Anyways, instead of 0xfd, having sane fake register values will be a
better start.

thanks,
suresh