Re: [libvirt] [PATCH 3/3] conf: restrict where dmi-to-pci-bridge can be connected

On Fri, 2016-08-05 at 23:01 -0400, Laine Stump wrote: > libvirt had allowed a dmi-to-pci-bridge to be plugged in anywhere a > normal PCIe endpoint can be connected, but this is wrong - it will > only work if it's plugged into pcie-root (the PCIe root complex) or a > pcie-expander-bus (the qemu device pxb-pcie). This patch adjusts the > connection flags accordingly. > > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1363648 Doesn't https://bugzilla.redhat.com/1363648#c4 tell us that we *need* to use a pcie-root-port when plugging stuff into a pcie-expander-bus?

(In reply to Laine Stump fromcomment #2 <https://bugzilla.redhat.com/show_bug.cgi?id=1363648#c2>) > Marcel - is this actually supported by qemu? Yes, and if doesn't work is a bug. The best way to think of pxb/pbx-pcie is that it exposes a new pcie.0 like bus. The only difference is that you cannot have devices plugged directly into it (integrated device).

Looks good otherwise, but I'd like to have Marcel's confirm that plugging a dmi-to-pci-bridge directly into a pcie-expander-bus is something we want before you push it.

> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c > index d594836..933f9be 100644 > --- a/tests/qemuxml2argvtest.c > +++ b/tests/qemuxml2argvtest.c > @@ -1631,6 +1631,22 @@ mymain(void) > QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_ICH9_USB_EHCI1, > QEMU_CAPS_DEVICE_VIDEO_PRIMARY, > QEMU_CAPS_VGA_QXL, QEMU_CAPS_DEVICE_QXL); > + DO_TEST_PARSE_ERROR("q35-dmi-bad-address1", > + QEMU_CAPS_DEVICE_PCI_BRIDGE, > + QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, > + QEMU_CAPS_DEVICE_IOH3420, > + QEMU_CAPS_ICH9_AHCI, > + QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_ICH9_USB_EHCI1, > + QEMU_CAPS_DEVICE_VIDEO_PRIMARY, > + QEMU_CAPS_VGA_QXL, QEMU_CAPS_DEVICE_QXL); > + DO_TEST_PARSE_ERROR("q35-dmi-bad-address2", > + QEMU_CAPS_DEVICE_PCI_BRIDGE, > + QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, > + QEMU_CAPS_DEVICE_IOH3420, > + QEMU_CAPS_ICH9_AHCI, > + QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_ICH9_USB_EHCI1, > + QEMU_CAPS_DEVICE_VIDEO_PRIMARY, > + QEMU_CAPS_VGA_QXL, QEMU_CAPS_DEVICE_QXL); > DO_TEST("q35-pm-disable", > QEMU_CAPS_DEVICE_PCI_BRIDGE, > QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, QEMU_CAPS_ICH9_AHCI, Can you maybe trim the capabilities a bit? QEMU_CAPS_VGA_QXL and friends look like they're hardly a requirement for a test case about PCI bridges.

Of course I'm okay with this if you're already planning to post a follow-up patch that trims the capabilities of all q35-* test cases ;)