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[Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset |
Date: |
Wed, 24 Nov 2010 07:27:58 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Wed, Nov 24, 2010 at 11:37:25AM +0900, Isaku Yamahata wrote:
> On Tue, Nov 23, 2010 at 08:10:26PM +0200, Michael S. Tsirkin wrote:
> > On Tue, Nov 23, 2010 at 12:53:12AM +0200, Michael S. Tsirkin wrote:
> > > On Mon, Nov 22, 2010 at 07:43:37PM +0900, Isaku Yamahata wrote:
> > > > On Mon, Nov 22, 2010 at 09:54:02AM +0200, Michael S. Tsirkin wrote:
> > > > > On Fri, Nov 19, 2010 at 06:55:57PM +0900, Isaku Yamahata wrote:
> > > > > > Here is v2. I updated the comments, and dropped the pci qdev reset
> > > > > > patch.
> > > > > >
> > > > > > Patch description:
> > > > > > The goal of this patch series is to implement secondary bus reset
> > > > > > emulation in pci-to-pci bridge.
> > > > > > At first, this patch series refactors qdev reset,
> > > > > > and then cleans up pci bus reset. Lastly implements pci bridge
> > > > > > control
> > > > > > secondary bus reset bit.
> > > > > >
> > > > > > This patch series is for pci bus reset, which is ported
> > > > > > from the following repo.
> > > > > > git://repo.or.cz/qemu/aliguori.git qdev-refactor
> > > > >
> > > > > I've put the series on my pci branch, tweaking patches 5 and 6 in the
> > > > > process. Out of time to compile-tested only for now.
> > > >
> > > > Thank you. The tweaking looks good.
> > > > Do you still want me to send another patch to add a comment on RST#?
> > >
> > > OK, I got response, and yes, we need to fix code to avoid claiming
> > > transactions by devices on the secondary bus while secondary bus is in
> > > RST# for both pci and express.
> >
> > I guess the following fixes it?
>
> Almost. The following if claouse also needs modification.
>
> commit 120fe782a198b787e13a9d4681afae8dc66dee50
> Author: "Michael S. Tsirkin" <address@hidden>
> Date: Wed Nov 24 11:34:59 2010 +0900
>
> pci: don't access bus while it's reset
>
> Devices on a bus should not respond while RST#
> is asserted, which is controlled by PCI_BRIDGE_CTL_BUS_RESET.
> Simply skip such a bus when propagating the configuration cycle.
>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> Signed-off-by: Isaku Yamahata <address@hidden>
>
> diff --git a/hw/pci.c b/hw/pci.c
> index d02f980..e7df612 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -1554,7 +1554,9 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
>
> /* try child bus */
> if (!bus->parent_dev /* host pci bridge */ ||
> - (bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
> + (!(pci_get_word(bus->parent_dev->config + PCI_BRIDGE_CONTROL) &
> + PCI_BRIDGE_CTL_BUS_RESET) /* Don't walk the bus if it's reset. */
> &&
> + bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
> bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS])) {
> for (; bus; bus = sec) {
> QLIST_FOREACH(sec, &bus->child, sibling) {
> @@ -1562,8 +1564,11 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
> if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) {
> return sec;
> }
> - if (sec->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
> - bus_num <= sec->parent_dev->config[PCI_SUBORDINATE_BUS])
> {
> + if (pci_get_word(sec->parent_dev->config +
> + PCI_BRIDGE_CONTROL) &
> PCI_BRIDGE_CTL_BUS_RESET
> + /* Don't walk the bus if it's reset. */ ||
> + bus_num < sec->parent_dev->config[PCI_SECONDARY_BUS] ||
> + sec->parent_dev->config[PCI_SUBORDINATE_BUS] < bus_num) {
> break;
> }
> }
Right. So let's add an inline helper to avoid code duplication here?
pci: fix bus walk under secondary bus reset
Take into account secondary bus reset bit for
bus walk: devices behind a reset bus should not
respond to configuration cycles.
Signed-off-by: Michael S. Tsirkin <address@hidden>
diff --git a/hw/pci.c b/hw/pci.c
index d02f980..0c15b13 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -1540,6 +1540,16 @@ void pci_bridge_update_mappings(PCIBus *b)
}
}
+/* Whether a given bus number is in range of the secondary
+ * bus of the given bridge device. */
+static bool pci_secondary_bus_in_range(PCIDevice *dev, int bus_num)
+{
+ return !(pci_get_word(dev->config + PCI_BRIDGE_CONTROL) &
+ PCI_BRIDGE_CTL_BUS_RESET) /* Don't walk the bus if it's reset. */
&&
+ dev->config[PCI_SECONDARY_BUS] < bus_num &&
+ bus_num <= dev->config[PCI_SUBORDINATE_BUS];
+}
+
PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
{
PCIBus *sec;
@@ -1552,20 +1562,21 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
return bus;
}
+ /* Consider all bus numbers in range for the host pci bridge. */
+ if (bus->parent_dev &&
+ !pci_secondary_bus_in_range(bus->parent_dev, bus_num)) {
+ return NULL;
+ }
+
/* try child bus */
- if (!bus->parent_dev /* host pci bridge */ ||
- (bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
- bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS])) {
- for (; bus; bus = sec) {
- QLIST_FOREACH(sec, &bus->child, sibling) {
- assert(sec->parent_dev);
- if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) {
- return sec;
- }
- if (sec->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
- bus_num <= sec->parent_dev->config[PCI_SUBORDINATE_BUS]) {
- break;
- }
+ for (; bus; bus = sec) {
+ QLIST_FOREACH(sec, &bus->child, sibling) {
+ assert(sec->parent_dev);
+ if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) {
+ return sec;
+ }
+ if (pci_secondary_bus_in_range(sec->parent_dev, bus_num)) {
+ break;
}
}
}
> --
> yamahata
- [Qemu-devel] Re: [PATCH v2 6/6] pci bridge: implement secondary bus reset, (continued)
- [Qemu-devel] [PATCH v2 5/6] pci: make use of qdev reset frame work to pci bus reset., Isaku Yamahata, 2010/11/19
- [Qemu-devel] [PATCH v2 1/6] qbus: add functions to walk both devices and busses, Isaku Yamahata, 2010/11/19
- [Qemu-devel] [PATCH v2 3/6] qdev: introduce reset call back for qbus level, Isaku Yamahata, 2010/11/19
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Michael S. Tsirkin, 2010/11/22
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Isaku Yamahata, 2010/11/22
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Michael S. Tsirkin, 2010/11/22
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Michael S. Tsirkin, 2010/11/22
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Michael S. Tsirkin, 2010/11/23
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Isaku Yamahata, 2010/11/23
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset,
Michael S. Tsirkin <=
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Isaku Yamahata, 2010/11/24
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Michael S. Tsirkin, 2010/11/24
- [Qemu-devel] Re: [PATCH v2 0/6] qdev reset refactoring and pci bus reset, Isaku Yamahata, 2010/11/24