From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Han, Weidong" <weidong.han@intel.com>
Subject: RE: [rfc 1/2] pt_irq_time_out() should act on all
	machine_irq
Date: Tue, 10 Mar 2009 15:40:21 +0800
Message-ID: <715D42877B251141A38726ABF5CABF2C0195B5C568@pdsmsx503.ccr.corp.intel.com>
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	<20090309091434.543270605@vergenet.net>
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To: 'Simon Horman' <horms@verge.net.au>, 'Xen-devel' <xen-devel@lists.xensource.com>
Cc: 'Yuji Shimada' <shimada-yxb@necst.nec.co.jp>, 'Keir Fraser' <keir.fraser@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

Simon Horman wrote:
> In pt_irq_time_out() the following code loops through all used
> guest_gsi:
>=20
>     list_for_each_entry ( digl, &irq_map->digl_list, list )
>     {
>         guest_gsi =3D digl->gsi;
>         machine_gsi =3D dpci->girq[guest_gsi].machine_gsi;
> 	...
>     }
>=20
> And a little later on machine_gsi is used.
> That is the last machine_gsi found is used,
> rather than all of the machine_gsi that are found.
>=20
> This seems to be incorrect to me,
> but I am unsure of how to test this.
>

Timer is set for each machine GSI, so all the machine_gsi found in loop are=
 the same. More than one devices may share machine GSI, but assume they won=
't share guest gsi. digl_list contains all guest GSIs which are correspond =
to this a machine GSI.

Now you want pass-throughed devices share guest gsi, you needs to change it=
 obviously. Your below change looks fine for me.

Regards,
Weidong

=20
> This code appears to have been introduced in
> "vt-d: Support intra-domain shared interrupt" by Weidong Han.
>=20
> Cc: Weidong Han <weidong.han@intel.com>
> Cc: Yuji Shimada <shimada-yxb@necst.nec.co.jp>
> Signed-off-by: Simon Horman <horms@verge.net.au>
>=20
> Index: xen-unstable.hg/xen/drivers/passthrough/io.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- xen-unstable.hg.orig/xen/drivers/passthrough/io.c	2009-03-09
> 12:44:48.000000000 +1100 +++
> xen-unstable.hg/xen/drivers/passthrough/io.c	2009-03-09
>      12:58:28.000000000 +1100 @@ -37,6 +37,9 @@ static void
>      pt_irq_time_out(void *data) struct hvm_irq_dpci *dpci =3D NULL;
>      struct dev_intx_gsi_link *digl; uint32_t device, intx;
> +    DECLARE_BITMAP(machine_gsi_map, NR_IRQS);
> +
> +    bitmap_zero(machine_gsi_map, NR_IRQS);
>=20
>      spin_lock(&irq_map->dom->event_lock);
>=20
> @@ -46,16 +49,31 @@ static void pt_irq_time_out(void *data)
>      {
>          guest_gsi =3D digl->gsi;
>          machine_gsi =3D dpci->girq[guest_gsi].machine_gsi;
> +        set_bit(machine_gsi, machine_gsi_map);
>          device =3D digl->device;
>          intx =3D digl->intx;
>          hvm_pci_intx_deassert(irq_map->dom, device, intx);
>      }
>=20
> -    clear_bit(machine_gsi, dpci->dirq_mask);
> -    vector =3D domain_irq_to_vector(irq_map->dom, machine_gsi);
> -    dpci->mirq[machine_gsi].pending =3D 0;
> +    for ( machine_gsi =3D find_first_bit(machine_gsi_map, NR_IRQS);
> +          machine_gsi < NR_IRQS;
> +          machine_gsi =3D find_next_bit(machine_gsi_map, NR_IRQS,
> +                                      machine_gsi + 1) )
> +    {
> +        clear_bit(machine_gsi, dpci->dirq_mask);
> +        vector =3D domain_irq_to_vector(irq_map->dom, machine_gsi);
> +        dpci->mirq[machine_gsi].pending =3D 0;
> +    }
> +
>      spin_unlock(&irq_map->dom->event_lock);
> -    pirq_guest_eoi(irq_map->dom, machine_gsi);
> +
> +    for ( machine_gsi =3D find_first_bit(machine_gsi_map, NR_IRQS);
> +          machine_gsi < NR_IRQS;
> +          machine_gsi =3D find_next_bit(machine_gsi_map, NR_IRQS,
> +                                      machine_gsi + 1) )
> +    {
> +        pirq_guest_eoi(irq_map->dom, machine_gsi);
> +    }
>  }
>=20
>  int pt_irq_create_bind_vtd(
>=20
> --