On Tue, Sep 06, 2011 at 09:18:13AM +0200, Jan Kiszka wrote: > >> @@ -401,36 +403,58 @@ int pci_vpd_truncate(struct pci_dev *dev, size_t size) > >> EXPORT_SYMBOL(pci_vpd_truncate); > >> > >> /** > >> - * pci_block_user_cfg_access - Block userspace PCI config reads/writes > >> + * pci_block_cfg_access - Block PCI config reads/writes > > > > This comment seems confusing. We don't in fact block all config > > reads writes. Instead we block userspace accesses and > > concurrent block requests. > > I'm open for a better suggestion that summarize the more verbose (and > hopefully clearer) explanation below. I think the problem is, it doesn't block config access and we call it pci_block_cfg_access. Thinking about it, doesn't this behave somewhat like a lock? How about pci_user_cfg_access_trylock pci_user_cfg_access_lock pci_user_cfg_access_unlock And then: * pci_user_cfg_access_lock - Lock userspace PCI config access * * When locked, any userspace reads or writes to config space * and concurrent lock requests will sleep, and trylock requests * will fail, until pci_user_cfg_access_unlock is called. I had a brief thought of using an rwsem internally, but this would make trylock fail if userspace does config read, changing semantics. -- MST -- 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
