From: Mike Christie Date: Fri, 8 Jul 2022 03:05:24 +0000 (-0500) Subject: vhost-scsi: Fix max number of virtqueues X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5a4b0420b28fed7e8df81ac7e3b53834142053dd;p=linux.git vhost-scsi: Fix max number of virtqueues Qemu takes it's num_queues limit then adds the fixed queues (control and event) to the total it will request from the kernel. So when a user requests 128 (or qemu does it's num_queues calculation based on vCPUS and other system limits), we hit errors due to userspace trying to setup 130 queues when vhost-scsi has a hard coded limit of 128. This has vhost-scsi adjust it's max so we can do a total of 130 virtqueues (128 IO and 2 fixed). For the case where the user has 128 vCPUs the guest OS can then nicely map each IO virtqueue to a vCPU and not have the odd case where 2 vCPUs share a virtqueue. Signed-off-by: Mike Christie Message-Id: <20220708030525.5065-2-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang --- diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index ffd9e6c2ffc15..8d6b4eef554d9 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -159,7 +159,7 @@ enum { }; #define VHOST_SCSI_MAX_TARGET 256 -#define VHOST_SCSI_MAX_VQ 128 +#define VHOST_SCSI_MAX_VQ 128 + VHOST_SCSI_VQ_IO #define VHOST_SCSI_MAX_EVENT 128 struct vhost_scsi_virtqueue {