Re: [RFC PATCH for 8.1 5/6] vdpa: move CVQ isolation check to net_init_vhost_vdpa

[Stefano Garzarella <sgarzare@redhat.com>]

On Fri, Mar 17, 2023 at 03:55:41PM +0100, Eugenio Pérez wrote:
>Evaluating it at start time instead of initialization time may make the
>guest capable of dynamically adding or removing migration blockers.
>
>Also, moving to initialization reduces the number of ioctls in the
>migration, reducing failure possibilities.
>
>Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
>---
> net/vhost-vdpa.c | 200 +++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 157 insertions(+), 43 deletions(-)
>
>diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
>index 4397c0d4b3..818a24fb0e 100644
>--- a/net/vhost-vdpa.c
>+++ b/net/vhost-vdpa.c
>@@ -43,6 +43,13 @@ typedef struct VhostVDPAState {
>
>     /* The device always have SVQ enabled */
>     bool always_svq;
>+
>+    /* The device can isolate CVQ in its own ASID if MQ is negotiated */
>+    bool cvq_isolated_mq;
>+
>+    /* The device can isolate CVQ in its own ASID if MQ is not negotiated */
>+    bool cvq_isolated;
>+

I am not familiar with how CVQ works, so my question might be trivial
;-) but why do we need to have 2 variables depending on F_MQ?

Thanks,
Stefano