Re: [RFC PATCH 03/11] PCI/MSI: Refactor pci_dev_msi_enabled()
On 2014/8/6 6:35, Stuart Yoder wrote: > On Fri, Jul 25, 2014 at 10:08 PM, Yijing Wang wrote: >> Pci_dev_msi_enabled() is used to check whether device >> MSI/MSIX enabled. Refactor this function to suuport >> checking only device MSI or MSIX enabled. >> >> Signed-off-by: Yijing Wang > > So this patch refactors things so that checks like this: >> - if (!dev->msi_enabled) > > are moved into a function: >> + if (!pci_dev_msi_enabled(dev, MSI_TYPE)) > > Can you explain a bit more why this needed. Is it just cleanup? Hi Stuart, it's not just cleanup, because "[RFC PATCH 08/11] PCI/MSI: Introduce new struct msi_irqs and struct msi_ops" introduced struct msi_irqs, so the code will change to if (!dev->msi_irqs->msi_enabled) I think driver should not need to know the details of MSI members. So I try to rework the pci_dev_msi_enabled() to hide the detailed MSI info. Thanks! Yijing. > > . > -- Thanks! Yijing ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [RFC PATCH 03/11] PCI/MSI: Refactor pci_dev_msi_enabled()
On Fri, Jul 25, 2014 at 10:08 PM, Yijing Wang wrote: > Pci_dev_msi_enabled() is used to check whether device > MSI/MSIX enabled. Refactor this function to suuport > checking only device MSI or MSIX enabled. > > Signed-off-by: Yijing Wang So this patch refactors things so that checks like this: > - if (!dev->msi_enabled) are moved into a function: > + if (!pci_dev_msi_enabled(dev, MSI_TYPE)) Can you explain a bit more why this needed. Is it just cleanup? Thanks, Stuart ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: When I boot two virtio-rng devices, guest will hang
On Tue, Aug 05, 2014 at 06:28:54PM +0800, Amos Kong wrote: > 3.16 (guest hangs with two rng devices) > 3.16 + quick fix (can startup with two rng devices) (hotplug issue 1 + > hotplug issue 2 exist) > lates torvalds/linux.git + amit 4 patches (can startup with two rng devices) > (only hotplug issue 2 exists) > > However, the 4 patches also fixed the hang issue, the hotplug issue was fixed > a little. > The hotplug issue is effected by the backend, or maybe it's not a real issue, > because > the rng device can be hot-removed after dd process is killed. > > > Hotplug issue 1: > 1. boot up guest with two rng device (rng0 uses /dev/urandom, rng1 uses > /dev/random) > 2. read data by dd in guest > 3 (option 1). hot-remove rng0, then hot-remove rng1 -> result: _only rng1_ > can't be removed until dd process is killed > 3 (option 2). hot-remove rng1, then hot-remove rng0 -> result: two devices > can be removed successfully, dd process will exit automatically. > > If we use /dev/urandom for rng0 and rng1, _rng0 & rng1_ can be removed, dd > process will exit automatically. > > Hotplug issue 2: > If we use /dev/random for rng0 and rng1, _rng0 & rng1_ can't be removed > until dd process is killed. > > Hotplug issue 3: > If we use /dev/random for rng0 and rng1, _only rng1_ can't be removed until > dd process is killed. Hi Amit, I finally found the root problem and posted a fix to upstream: http://lists.linuxfoundation.org/pipermail/virtualization/2014-August/027049.html It can help to fix the hotplug issues on 3.16 & latest kernel, so stable kernel is CCed. > (The difference between /dev/random and /dev/urandom is the speed.) > > Thanks, Amos -- Amos. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
[PATCH] virtio-rng: complete have_data completion in removing device
When we try to hot-remove a busy virtio-rng device from QEMU monitor, the device can't be hot-removed. Because virtio-rng driver hangs at wait_for_completion_killable(). This patch fixed the hang by completing have_data completion before unregistering a virtio-rng device. Signed-off-by: Amos Kong Cc: sta...@vger.kernel.org --- drivers/char/hw_random/virtio-rng.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 0027137..416b15c 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -137,6 +137,7 @@ static void remove_common(struct virtio_device *vdev) struct virtrng_info *vi = vdev->priv; vdev->config->reset(vdev); + complete(&vi->have_data); vi->busy = false; if (vi->hwrng_register_done) hwrng_unregister(&vi->hwrng); -- 1.9.3 ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: When I boot two virtio-rng devices, guest will hang
3.16 (guest hangs with two rng devices) 3.16 + quick fix (can startup with two rng devices) (hotplug issue 1 + hotplug issue 2 exist) lates torvalds/linux.git + amit 4 patches (can startup with two rng devices) (only hotplug issue 2 exists) However, the 4 patches also fixed the hang issue, the hotplug issue was fixed a little. The hotplug issue is effected by the backend, or maybe it's not a real issue, because the rng device can be hot-removed after dd process is killed. Hotplug issue 1: 1. boot up guest with two rng device (rng0 uses /dev/urandom, rng1 uses /dev/random) 2. read data by dd in guest 3 (option 1). hot-remove rng0, then hot-remove rng1 -> result: _only rng1_ can't be removed until dd process is killed 3 (option 2). hot-remove rng1, then hot-remove rng0 -> result: two devices can be removed successfully, dd process will exit automatically. If we use /dev/urandom for rng0 and rng1, _rng0 & rng1_ can be removed, dd process will exit automatically. Hotplug issue 2: If we use /dev/random for rng0 and rng1, _rng0 & rng1_ can't be removed until dd process is killed. Hotplug issue 3: If we use /dev/random for rng0 and rng1, _only rng1_ can't be removed until dd process is killed. (The difference between /dev/random and /dev/urandom is the speed.) Thanks, Amos ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
