[PATCH v2] vpci/header: cope with devices not having vpci allocated

[PATCH v2] vpci/header: cope with devices not having vpci allocated

[Roger Pau Monne]

When traversing the list of pci devices assigned to a domain cope with
some of them not having the vpci struct allocated. It should be
possible for the hardware domain to have read-only devices assigned
that are not handled by vPCI, such support will be added by further
patches.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v1:
 - Do not mention domU plans.
---
 xen/drivers/vpci/header.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index ec2e978a4e6b..766fd98b2196 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -289,6 +289,14 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t cmd, bool rom_only)
      */
     for_each_pdev ( pdev->domain, tmp )
     {
+        if ( !tmp->vpci )
+            /*
+             * For the hardware domain it's possible to have devices assigned
+             * to it that are not handled by vPCI, either because those are
+             * read-only devices, or because vPCI setup has failed.
+             */
+            continue;
+
         if ( tmp == pdev )
         {
             /*
-- 
2.40.0

Re: [PATCH v2] vpci/header: cope with devices not having vpci allocated

[Jan Beulich]

On 25.05.2023 16:54, Roger Pau Monne wrote:
> When traversing the list of pci devices assigned to a domain cope with
> some of them not having the vpci struct allocated. It should be
> possible for the hardware domain to have read-only devices assigned
> that are not handled by vPCI, such support will be added by further
> patches.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>

I was wondering whether to put an assertion in (permitting both DomXEN
and hwdom, i.e. slightly more relaxed than I had it).

Jan

Re: [PATCH v2] vpci/header: cope with devices not having vpci allocated

[Roger Pau Monné]

On Thu, May 25, 2023 at 05:22:53PM +0200, Jan Beulich wrote:
> On 25.05.2023 16:54, Roger Pau Monne wrote:
> > When traversing the list of pci devices assigned to a domain cope with
> > some of them not having the vpci struct allocated. It should be
> > possible for the hardware domain to have read-only devices assigned
> > that are not handled by vPCI, such support will be added by further
> > patches.
> > 
> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> 
> Reviewed-by: Jan Beulich <jbeulich@suse.com>

Thanks.

> I was wondering whether to put an assertion in (permitting both DomXEN
> and hwdom, i.e. slightly more relaxed than I had it).

I also wondered it, but didn't think it was very helpful, but that was
back when I had the comment about how I envisioned this to work for
domUs.

Let me know if you want me to add it.

Thanks, Roger.