[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-28 Thread Amit Shah
On (Thu) 24 Feb 2011 [08:44:07], Anthony Liguori wrote: For instance, if the host side disconnects, then reconnects before we read(), we may never get the read()=0, and our FD remains valid. Whereas with a tcp/unix socket our FD is no longer valid, and the read()=0 is an event we can check for

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-28 Thread Amit Shah
On (Fri) 25 Feb 2011 [14:25:20], Michael Roth wrote: On 02/24/2011 06:48 AM, Amit Shah wrote: On (Wed) 23 Feb 2011 [08:31:52], Michael Roth wrote: On 02/22/2011 10:59 PM, Amit Shah wrote: On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-25 Thread Michael Roth
On 02/24/2011 06:48 AM, Amit Shah wrote: On (Wed) 23 Feb 2011 [08:31:52], Michael Roth wrote: On 02/22/2011 10:59 PM, Amit Shah wrote: On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to read/write from the virtio-serial device, and nothing is

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-24 Thread Amit Shah
On (Wed) 23 Feb 2011 [08:31:52], Michael Roth wrote: On 02/22/2011 10:59 PM, Amit Shah wrote: On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to read/write from the virtio-serial device, and nothing is connected to virtio-serial's host character

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-24 Thread Anthony Liguori
On 02/24/2011 06:48 AM, Amit Shah wrote: On (Wed) 23 Feb 2011 [08:31:52], Michael Roth wrote: On 02/22/2011 10:59 PM, Amit Shah wrote: On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to read/write from the virtio-serial device,

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-23 Thread Michael Roth
On 02/22/2011 10:59 PM, Amit Shah wrote: On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to read/write from the virtio-serial device, and nothing is connected to virtio-serial's host character device (say, a socket) 1. writes will block until

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-23 Thread Michael Roth
On 02/23/2011 08:31 AM, Michael Roth wrote: On 02/22/2011 10:59 PM, Amit Shah wrote: On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to read/write from the virtio-serial device, and nothing is connected to virtio-serial's host character device (say,

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-22 Thread Anthony Liguori
My basic understanding here is--there's no way for a virtio-serial client (in-guest) to reliably reset a session such that if the client in the guest crashes, the protocol needs to have some recovery mechanism. This seems like a huge oversight in the design of virtio-serial. Are we missing

[Qemu-devel] Re: virtio-serial semantics for binary data and guest agents

2011-02-22 Thread Amit Shah
On (Tue) 22 Feb 2011 [16:40:55], Michael Roth wrote: If something in the guest is attempting to read/write from the virtio-serial device, and nothing is connected to virtio-serial's host character device (say, a socket) 1. writes will block until something connect()s, at which point the