Re: [Xen-devel] [PATCH] qemu-xen-trad: free all the pirqs for msi/msix when driver unloads

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Thu, Jul 03, 2014 at 11:12:18AM +0800, Zhenzhong Duan wrote:
> There is a patch dependency missed.

Is that one upstream as well? Or does it not need to be?
If it is upstream, what is the title/commit id of that one?

Thank you!
> 
> commit adf74189dd58014744a4b8c9d64407d629da5e2f
> Author: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> Date:   Mon Dec 10 12:43:33 2012 +0000
> 
>     qemu-xen-trad/pt_msi_disable: do not clear all MSI flags
> 
>     "qemu-xen-trad: fix msi_translate with PV event delivery" added a
>     pt_msi_disable() call into pt_msgctrl_reg_write, clearing the MSI flags
>     as a consequence. MSIs get enabled again soon after by calling
>     pt_msi_setup.
> 
>     However the MSI flags are only setup once in the pt_msgctrl_reg_init
>     function, so from the QEMU point of view the device has lost some
>     important properties, like for example PCI_MSI_FLAGS_64BIT.
> 
>     This patch fixes the bug by clearing only the MSI
>     enabled/mapped/initialized flags in pt_msi_disable.
> 
>     Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
>     Tested-by: G.R. <firemeteor@xxxxxxxxxxxxxxxxxxxxx>
>     Xen-devel: http://marc.info/?l=xen-devel&m=135489879503075
> 
> diff --git a/hw/pt-msi.c b/hw/pt-msi.c
> index 73f737d..b03b989 100644
> --- a/hw/pt-msi.c
> +++ b/hw/pt-msi.c
> @@ -213,7 +213,7 @@ void pt_msi_disable(struct pt_dev *dev)
> 
>  out:
>      /* clear msi info */
> -    dev->msi->flags = 0;
> +    dev->msi->flags &= ~(MSI_FLAG_UNINIT | PT_MSI_MAPPED |
> PCI_MSI_FLAGS_ENABLE);
>      dev->msi->pirq = -1;
>      dev->msi_trans_en = 0;
>  }
> 
> On 2014-7-2 23:06, Ian Jackson wrote:
> >Konrad Rzeszutek Wilk writes ("[Xen-devel] [PATCH] qemu-xen-trad: free all 
> >the pirqs for msi/msix when driver unloads"):
> >>From: Zhenzhong Duan<zhenzhong.duan@xxxxxxxxxx>
> >>
> >>Pirqs are not freed when driver unloads, then new pirqs are allocated when
> >>driver reloads. This could exhaust pirqs if do it in a loop.
> >>
> >>This patch fixes the bug by freeing pirqs when ENABLE bit is cleared in
> >>msi/msix control reg.
> >I have backported this to 4.4 and 4.3.  It did not apply cleanly to
> >4.2 (and I have not investgated why).
> >
> >Thanks,
> >Ian.
> 

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