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    SubjectRe: [Xen-devel] [PATCH 1/3] pci/xen: Use xen_allocate_pirq_msi
    On Fri, 18 Feb 2011, Ian Campbell wrote:
    > On Fri, 2011-02-18 at 14:07 +0000, Konrad Rzeszutek Wilk wrote:
    > > On Thu, Feb 17, 2011 at 09:30:03AM -0500, Konrad Rzeszutek Wilk wrote:
    > > > On Thu, Feb 17, 2011 at 08:41:31AM +0000, Ian Campbell wrote:
    > > > > On Wed, 2011-02-16 at 22:17 +0000, Konrad Rzeszutek Wilk wrote:
    > > > > > There is no need to use the old interface.
    > > > >
    > > > > xen_allocate_pirq -> xen_map_pirq_gsi -> PHYSDEVOP_alloc_irq_vector IFF
    > > > > xen_initial_domain() in addition to the kernel side book-keeping side of
    > > > > things (set chip and handler, update irq_info etc) whereas
    > > > > xen_allocate_pirq_msi just does the kernel book keeping.
    > > > >
    > > > > Also xen_allocate_pirq allocates an IRQ in the 1-1 GSI space whereas
    > > > > xen_allocate_pirq_msi allocates a dynamic one in the >GSI IRQ space.
    > > >
    > > > Which is OK. These are MSIs.
    > > > >
    > > > > So this change is actually a semantic change and not just a switch to a
    > > > > new interface. I think the change is OK (because the caller is domU
    > > >
    > > > Right.
    > > >
    > > > > only?) but a comment explaining this would be appreciated.
    > > >
    > > > Correct: "domU side".
    > > >
    > > > Will fix it up.
    > >
    > > How does this look to you?
    > >
    > > From eb832bece3131ecbdb509f7f2a9bc53f6692177c Mon Sep 17 00:00:00 2001
    > > From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
    > > Date: Wed, 16 Feb 2011 13:43:04 -0500
    > > Subject: [PATCH 3/5] pci/xen: Use xen_allocate_pirq_msi instead of xen_allocate_pirq
    > >
    > > xen_allocate_pirq -> xen_map_pirq_gsi -> PHYSDEVOP_alloc_irq_vector IFF
    > > xen_initial_domain() in addition to the kernel side book-keeping side of
    > > things (set chip and handler, update irq_info etc) whereas
    > > xen_allocate_pirq_msi just does the kernel book keeping.
    > >
    > > Also xen_allocate_pirq allocates an IRQ in the 1-1 GSI space whereas
    > > xen_allocate_pirq_msi allocates a dynamic one in the >GSI IRQ space.
    > >
    > > All of this is uneccessary as this code path is only executed
    > > when we run as a domU PV guest with an MSI/MSI-X PCI card passed in.
    > > Hence we can jump straight to allocating an dynamic IRQ (and
    > > binding it to the proper PIRQ) and skip the rest.
    > >
    > > In short: this change is a cosmetic one.
    > >
    > > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
    >
    > Looks good,
    >
    > Reviewed-by: Ian Campbell <ian.campbell@citrix.com>

    You can add my reviewed-by too.



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