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Subject: Re: [virtio-dev] Re: [PATCH v1] virtio-mmio: Specify wait needed in driver during reset
* Srivatsa Vaddagiri <firstname.lastname@example.org> [2021-08-17 15:33:33]: > Handling reset is the only open issue we have, as guest triggering reset has > currently no provision to poll for reset completion and hypervisor itself cannot > handle reset completly. This is where we observed discrepancy between PCI vs > MMIO in handling reset, which we wanted to address with this discussion. > > I think the option we discussed earlier of a new feature bit seems less > intrusive than incrementing MMIO version? > > https://lists.oasis-open.org/archives/virtio-dev/202107/msg00168.html Alternately would it be fine to merge a change like this to Linux virtio_mmio driver w/o requiring any further changes to spec? diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 56128b9..9db81e6 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -262,6 +262,9 @@ static void vm_reset(struct virtio_device *vdev) /* 0 status means a reset. */ writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); + + while (vm_get_status(vdev)) + msleep(1); } -- Qualcomm Innovation Center, Inc. is submitting the attached "feedback" as a non-member to the virtio-dev mailing list for consideration and inclusion.