| Message ID | 20220704102514.1284827-1-rvkagan@yandex-team.ru |
|---|---|
| State | New |
| Headers | show |
| Series | hw/pci/pci_bridge: ensure PCIe slots have only one slot | expand |
On 7/4/22 13:25, Roman Kagan wrote: > It's possible to create non-working configurations by attaching a device > to a derivative of PCIe slot (pcie-root-port, ioh3420, etc) and > specifying a slot number other that zero, e.g.: > > -device pcie-root-port,id=s0,... \ > -device virtio-blk-pci,bus=s0,addr=4,... > > Make QEMU reject such configurations and only allow addr=0 on the > secondary bus of a PCIe slot. > > Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru> > --- > hw/pci/pci_bridge.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c > index da34c8ebcd..8b38d5ad3d 100644 > --- a/hw/pci/pci_bridge.c > +++ b/hw/pci/pci_bridge.c > @@ -33,6 +33,7 @@ > #include "qemu/units.h" > #include "hw/pci/pci_bridge.h" > #include "hw/pci/pci_bus.h" > +#include "hw/pci/pcie_port.h" > #include "qemu/module.h" > #include "qemu/range.h" > #include "qapi/error.h" > @@ -386,6 +387,10 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename) > br->windows = pci_bridge_region_init(br); > QLIST_INIT(&sec_bus->child); > QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling); > + > + if (PCIE_SLOT(dev)) { Hmm, wouldn't PCIE_SLOT just crash if dev is not pcie slot? As I understand, PCIE_SLOT is finally an OBJECT_CHECK(), which say: * If an invalid object is passed to this function, a run time assert will be * generated. > + sec_bus->slot_reserved_mask = ~1u; > + } > } > > /* default qdev clean up function for PCI-to-PCI bridge */
On Wed, Jul 06, 2022 at 09:38:39PM +0300, Vladimir Sementsov-Ogievskiy wrote: > On 7/4/22 13:25, Roman Kagan wrote: > > It's possible to create non-working configurations by attaching a device > > to a derivative of PCIe slot (pcie-root-port, ioh3420, etc) and > > specifying a slot number other that zero, e.g.: > > > > -device pcie-root-port,id=s0,... \ > > -device virtio-blk-pci,bus=s0,addr=4,... > > > > Make QEMU reject such configurations and only allow addr=0 on the > > secondary bus of a PCIe slot. > > > > Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru> > > --- > > hw/pci/pci_bridge.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c > > index da34c8ebcd..8b38d5ad3d 100644 > > --- a/hw/pci/pci_bridge.c > > +++ b/hw/pci/pci_bridge.c > > @@ -33,6 +33,7 @@ > > #include "qemu/units.h" > > #include "hw/pci/pci_bridge.h" > > #include "hw/pci/pci_bus.h" > > +#include "hw/pci/pcie_port.h" > > #include "qemu/module.h" > > #include "qemu/range.h" > > #include "qapi/error.h" > > @@ -386,6 +387,10 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename) > > br->windows = pci_bridge_region_init(br); > > QLIST_INIT(&sec_bus->child); > > QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling); > > + > > + if (PCIE_SLOT(dev)) { > > Hmm, wouldn't PCIE_SLOT just crash if dev is not pcie slot? As I understand, PCIE_SLOT is finally an OBJECT_CHECK(), which say: > > * If an invalid object is passed to this function, a run time assert will be > * generated. Well, the assertion is there only if configured with --enable-qom-cast-debug which is off by default, that's why it even passed make check. As it stands, it's just a typecast which is a no-op here, and basically it makes every bridge have only a single slot, which is wrong of course. Will rework, thanks! Roman.
On Wed, Jul 06, 2022 at 10:43:12PM +0300, Roman Kagan wrote: > On Wed, Jul 06, 2022 at 09:38:39PM +0300, Vladimir Sementsov-Ogievskiy wrote: > > On 7/4/22 13:25, Roman Kagan wrote: > > > It's possible to create non-working configurations by attaching a device > > > to a derivative of PCIe slot (pcie-root-port, ioh3420, etc) and > > > specifying a slot number other that zero, e.g.: > > > > > > -device pcie-root-port,id=s0,... \ > > > -device virtio-blk-pci,bus=s0,addr=4,... > > > > > > Make QEMU reject such configurations and only allow addr=0 on the > > > secondary bus of a PCIe slot. > > > > > > Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru> > > > --- > > > hw/pci/pci_bridge.c | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > > > diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c > > > index da34c8ebcd..8b38d5ad3d 100644 > > > --- a/hw/pci/pci_bridge.c > > > +++ b/hw/pci/pci_bridge.c > > > @@ -33,6 +33,7 @@ > > > #include "qemu/units.h" > > > #include "hw/pci/pci_bridge.h" > > > #include "hw/pci/pci_bus.h" > > > +#include "hw/pci/pcie_port.h" > > > #include "qemu/module.h" > > > #include "qemu/range.h" > > > #include "qapi/error.h" > > > @@ -386,6 +387,10 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename) > > > br->windows = pci_bridge_region_init(br); > > > QLIST_INIT(&sec_bus->child); > > > QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling); > > > + > > > + if (PCIE_SLOT(dev)) { > > > > Hmm, wouldn't PCIE_SLOT just crash if dev is not pcie slot? As I understand, PCIE_SLOT is finally an OBJECT_CHECK(), which say: > > > > * If an invalid object is passed to this function, a run time assert will be > > * generated. > > Well, the assertion is there only if configured with > --enable-qom-cast-debug which is off by default, that's why it even > passed make check. As it stands, it's just a typecast which is a no-op > here, and basically it makes every bridge have only a single slot, which > is wrong of course. > > Will rework, thanks! > Roman. Which probably means it was not actually tested that the patch rejects the invalid configuration, was it?
On Mon, Jul 04, 2022 at 01:25:14PM +0300, Roman Kagan wrote: > It's possible to create non-working configurations by attaching a device > to a derivative of PCIe slot (pcie-root-port, ioh3420, etc) and > specifying a slot number other that zero, e.g.: > > -device pcie-root-port,id=s0,... \ > -device virtio-blk-pci,bus=s0,addr=4,... > > Make QEMU reject such configurations and only allow addr=0 on the > secondary bus of a PCIe slot. > > Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru> > --- > hw/pci/pci_bridge.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c > index da34c8ebcd..8b38d5ad3d 100644 > --- a/hw/pci/pci_bridge.c > +++ b/hw/pci/pci_bridge.c > @@ -33,6 +33,7 @@ > #include "qemu/units.h" > #include "hw/pci/pci_bridge.h" > #include "hw/pci/pci_bus.h" > +#include "hw/pci/pcie_port.h" > #include "qemu/module.h" > #include "qemu/range.h" > #include "qapi/error.h" > @@ -386,6 +387,10 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename) > br->windows = pci_bridge_region_init(br); > QLIST_INIT(&sec_bus->child); > QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling); > + > + if (PCIE_SLOT(dev)) { > + sec_bus->slot_reserved_mask = ~1u; > + } Please add comments explaining what's going on. > } > > /* default qdev clean up function for PCI-to-PCI bridge */ > -- > 2.36.1
On Thu, Jul 07, 2022 at 01:19:18AM -0400, Michael S. Tsirkin wrote: > On Wed, Jul 06, 2022 at 10:43:12PM +0300, Roman Kagan wrote: > > On Wed, Jul 06, 2022 at 09:38:39PM +0300, Vladimir Sementsov-Ogievskiy wrote: > > > On 7/4/22 13:25, Roman Kagan wrote: > > > > It's possible to create non-working configurations by attaching a device > > > > to a derivative of PCIe slot (pcie-root-port, ioh3420, etc) and > > > > specifying a slot number other that zero, e.g.: > > > > > > > > -device pcie-root-port,id=s0,... \ > > > > -device virtio-blk-pci,bus=s0,addr=4,... > > > > > > > > Make QEMU reject such configurations and only allow addr=0 on the > > > > secondary bus of a PCIe slot. > > > > > > > > Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru> > > > > --- > > > > hw/pci/pci_bridge.c | 5 +++++ > > > > 1 file changed, 5 insertions(+) > > > > > > > > diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c > > > > index da34c8ebcd..8b38d5ad3d 100644 > > > > --- a/hw/pci/pci_bridge.c > > > > +++ b/hw/pci/pci_bridge.c > > > > @@ -33,6 +33,7 @@ > > > > #include "qemu/units.h" > > > > #include "hw/pci/pci_bridge.h" > > > > #include "hw/pci/pci_bus.h" > > > > +#include "hw/pci/pcie_port.h" > > > > #include "qemu/module.h" > > > > #include "qemu/range.h" > > > > #include "qapi/error.h" > > > > @@ -386,6 +387,10 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename) > > > > br->windows = pci_bridge_region_init(br); > > > > QLIST_INIT(&sec_bus->child); > > > > QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling); > > > > + > > > > + if (PCIE_SLOT(dev)) { > > > > > > Hmm, wouldn't PCIE_SLOT just crash if dev is not pcie slot? As I understand, PCIE_SLOT is finally an OBJECT_CHECK(), which say: > > > > > > * If an invalid object is passed to this function, a run time assert will be > > > * generated. > > > > Well, the assertion is there only if configured with > > --enable-qom-cast-debug which is off by default, that's why it even > > passed make check. As it stands, it's just a typecast which is a no-op > > here, and basically it makes every bridge have only a single slot, which > > is wrong of course. > > > > Will rework, thanks! > > Roman. > > Which probably means it was not actually tested that the patch > rejects the invalid configuration, was it? Yes it was. What wasn't tested was that other PCI bridges remained unaffected. In the default configuration (--enable-qom-cast-debug=no) the patch turns every bridge using pci_bridge_initfn into single-slot bridges. This renders e.g. switches like x3130 useless, but the testsuite doesn't trigger that path. I'll try and add a test for this in the next iteration. Thanks, Roman.
diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c index da34c8ebcd..8b38d5ad3d 100644 --- a/hw/pci/pci_bridge.c +++ b/hw/pci/pci_bridge.c @@ -33,6 +33,7 @@ #include "qemu/units.h" #include "hw/pci/pci_bridge.h" #include "hw/pci/pci_bus.h" +#include "hw/pci/pcie_port.h" #include "qemu/module.h" #include "qemu/range.h" #include "qapi/error.h" @@ -386,6 +387,10 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename) br->windows = pci_bridge_region_init(br); QLIST_INIT(&sec_bus->child); QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling); + + if (PCIE_SLOT(dev)) { + sec_bus->slot_reserved_mask = ~1u; + } } /* default qdev clean up function for PCI-to-PCI bridge */
It's possible to create non-working configurations by attaching a device to a derivative of PCIe slot (pcie-root-port, ioh3420, etc) and specifying a slot number other that zero, e.g.: -device pcie-root-port,id=s0,... \ -device virtio-blk-pci,bus=s0,addr=4,... Make QEMU reject such configurations and only allow addr=0 on the secondary bus of a PCIe slot. Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru> --- hw/pci/pci_bridge.c | 5 +++++ 1 file changed, 5 insertions(+)