[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2017-03-04 Thread Richard Jones
I don't know how to close bugs in launchpad, but this one can be closed for a couple of reasons: (1) I benchmarked virtio-mmio the other day using qemu-speed-test on aarch64 and I did not encounter the bug. (2) aarch64 has supported virtio-pci for a while, for virtio-mmio is effectively obsolete.

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2017-03-04 Thread Richard Jones
Fixed upstream, see previous comment. ** Changed in: qemu Status: New => Fix Released -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/122 Title: virtio-serial loses writes when used over

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2014-07-29 Thread Richard Jones
FWIW I am able to reproduce this quite easily on aarch64 too. My test program is: https://github.com/libguestfs/libguestfs/blob/master/tests/qemu/qemu-speed-test.c and you use it like this: qemu-speed-test --virtio-serial-upload (You can also test virtio-serial downloads and a few other things,

Re: [Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-17 Thread Laszlo Ersek (Red Hat)
On 09/17/13 11:51, Richard Jones wrote: >> There's at least three cases here I guess (KVM + eventfd, KVM without >> eventfd (enforceable eg. with the "ioeventfd" property for virtio >> devices), and TCG). We're probably talking about the third case. > > To clarify on this point: I have reproduced

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-17 Thread Richard Jones
> There's at least three cases here I guess (KVM + eventfd, KVM without > eventfd (enforceable eg. with the "ioeventfd" property for virtio > devices), and TCG). We're probably talking about the third case. To clarify on this point: I have reproduced this bug on two different ARM machines, one usi

Re: [Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-17 Thread Laszlo Ersek (Red Hat)
On 09/17/13 10:09, Peter Maydell wrote: > On 16 September 2013 17:13, Laszlo Ersek wrote: >> H. Normally (as in, virtio-pci), when a VCPU thread (running KVM) >> executes guest code that sends data to the host via virtio, KVM kicks >> the "host notifier" eventfd. > > What happens in the virti

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-17 Thread Richard Jones
> What happens if you add a five second delay to libguestfs, > before writing the response? No change. Still hangs in the same place. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/122 Title:

Re: [Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-17 Thread Peter Maydell
On 16 September 2013 17:13, Laszlo Ersek wrote: > H. Normally (as in, virtio-pci), when a VCPU thread (running KVM) > executes guest code that sends data to the host via virtio, KVM kicks > the "host notifier" eventfd. What happens in the virtio-pci without eventfd case? (eg virtio-pci on a n

Re: [Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-16 Thread Laszlo Ersek (Red Hat)
On 09/16/13 16:39, Richard Jones wrote: >> Is this a socket that libguestfs pre-creates on the host-side? > > Yes it is: > https://github.com/libguestfs/libguestfs/blob/master/src/launch-direct.c#L208 > > You mention a scenario that might cause this. But that appears to be > when the socket is o

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-16 Thread Richard Jones
> Is this a socket that libguestfs pre-creates on the host-side? Yes it is: https://github.com/libguestfs/libguestfs/blob/master/src/launch-direct.c#L208 You mention a scenario that might cause this. But that appears to be when the socket is opened. Note that the guest did send 4 bytes successf

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-13 Thread Richard Jones
I can reproduce this bug on a second ARM machine which doesn't have KVM (ie. using TCG). Note it's still linked to virtio-mmio. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/122 Title: virtio-

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-12 Thread Richard Jones
strace -f of qemu when it fails. Notes: - fd = 6 is the Unix domain socket connected to virtio-serial - only one 4 byte write occurs to this socket (expected guest -> host communication) - the socket isn't read at all (even though the library on the other side has written) - the socket is n

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-12 Thread Richard Jones
Recall this bug only happens intermittently. This is an strace -f of qemu when it happens to work. Notes: - fd = 6 is the Unix domain socket - there are an expected number of recvmsg & writes, all with the correct sizes - this time qemu adds the socket to ppoll ** Attachment added: "working

[Qemu-devel] [Bug 1224444] Re: virtio-serial loses writes when used over virtio-mmio

2013-09-12 Thread Richard Jones
** Description changed: virtio-serial appears to lose writes, but only when used on top of virtio-mmio. The scenario is this: /home/rjones/d/qemu/arm-softmmu/qemu-system-arm \ -global virtio-blk-device.scsi=off \ -nodefconfig \ -nodefaults \ -nographic \ -M