Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-27 Thread Marcel Apfelbaum
On 26/07/2017 21:49, Michael S. Tsirkin wrote: On Wed, Jul 26, 2017 at 07:22:42PM +0300, Marcel Apfelbaum wrote: On 26/07/2017 18:20, Laszlo Ersek wrote: On 07/26/17 08:48, Marcel Apfelbaum wrote: On 25/07/2017 18:46, Laszlo Ersek wrote: [snip] (2) Bus range reservation, and hotplugging

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-27 Thread Marcel Apfelbaum
On 26/07/2017 21:31, Laszlo Ersek wrote: On 07/26/17 18:22, Marcel Apfelbaum wrote: On 26/07/2017 18:20, Laszlo Ersek wrote: [snip] However, what does the hot-pluggability of the PCIe-PCI bridge buy us? In other words, what does it buy us when we do not add the PCIe-PCI bridge immediately

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-26 Thread Michael S. Tsirkin
On Wed, Jul 26, 2017 at 07:22:42PM +0300, Marcel Apfelbaum wrote: > On 26/07/2017 18:20, Laszlo Ersek wrote: > > On 07/26/17 08:48, Marcel Apfelbaum wrote: > > > On 25/07/2017 18:46, Laszlo Ersek wrote: > > > > [snip] > > > > > > (2) Bus range reservation, and hotplugging bridges. What's the > >

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-26 Thread Laszlo Ersek
On 07/26/17 18:22, Marcel Apfelbaum wrote: > On 26/07/2017 18:20, Laszlo Ersek wrote: [snip] >> However, what does the hot-pluggability of the PCIe-PCI bridge buy us? >> In other words, what does it buy us when we do not add the PCIe-PCI >> bridge immediately at guest startup, as an integrated

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-26 Thread Marcel Apfelbaum
On 26/07/2017 18:20, Laszlo Ersek wrote: On 07/26/17 08:48, Marcel Apfelbaum wrote: On 25/07/2017 18:46, Laszlo Ersek wrote: [snip] (2) Bus range reservation, and hotplugging bridges. What's the motivation? Our recommendations in "docs/pcie.txt" suggest flat hierarchies. It remains flat.

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-26 Thread Laszlo Ersek
On 07/26/17 08:48, Marcel Apfelbaum wrote: > On 25/07/2017 18:46, Laszlo Ersek wrote: [snip] >> (2) Bus range reservation, and hotplugging bridges. What's the >> motivation? Our recommendations in "docs/pcie.txt" suggest flat >> hierarchies. >> > > It remains flat. You have one single PCIE-PCI

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-26 Thread Marcel Apfelbaum
On 25/07/2017 18:46, Laszlo Ersek wrote: On 07/23/17 00:11, Aleksandr Bezzubikov wrote: Now PCI bridges get a bus range number on a system init, basing on currently plugged devices. That's why when one wants to hotplug another bridge, it needs his child bus, which the parent is unable to

Re: [Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-25 Thread Laszlo Ersek
On 07/23/17 00:11, Aleksandr Bezzubikov wrote: > Now PCI bridges get a bus range number on a system init, basing on > currently plugged devices. That's why when one wants to hotplug > another bridge, it needs his child bus, which the parent is unable to > provide (speaking about virtual device).

[Qemu-devel] [RFC PATCH v2 0/4] Allow RedHat PCI bridges reserve more buses than necessary during init

2017-07-22 Thread Aleksandr Bezzubikov
Now PCI bridges get a bus range number on a system init, basing on currently plugged devices. That's why when one wants to hotplug another bridge, it needs his child bus, which the parent is unable to provide (speaking about virtual device). The suggested workaround is to have vendor-specific