On Mon, Aug 29, 2011 at 06:14:39PM +0200, Jan Kiszka wrote: > On 2011-08-29 17:58, Michael S. Tsirkin wrote: > > On Mon, Aug 29, 2011 at 05:42:16PM +0200, Jan Kiszka wrote: > >> I still don't get what prevents converting ipr to allow plain mutex > >> synchronization. My vision is: > >> - push reset-on-error of ipr into workqueue (or threaded IRQ?) > >> - require mutex synchronization for common config space access > > > > Meaning pci_user_ read/write config? > > And pci_dev_reset, yes. > > > > >> and the > >> full reset cycle > >> - only exception: INTx status/masking access > >> => use pci_lock + test for reset_in_progress, skip operation if > >> that is the case > >> > >> That would allow to drop the whole block_user_cfg infrastructure. > >> > >> Jan > > > > We still need to block userspace access while INTx does > > the status/masking access, right? > > Yes, pci_lock would do that for us. Well this means block_user_cfg is not going away, this is what it really is: pci_lock + a bit to lock out userspace. > We should consider making the related bits for INTx test & mask/unmask > generic PCI services so that no user (uio_pci_generic, kvm, vfio) needs > to worry about the locking details. > > Jan > > -- > Siemens AG, Corporate Technology, CT T DE IT 1 > Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
