Re: [libvirt] [RFC PATCH v3] qemu: Add suport for pci-assign.configfd option

This allows libvirt to open the PCI device sysfs config file prior to dropping privileges so qemu can access the full config space. Without this, a de-privileged qemu can only access the first 64 bytes of config space. Signed-off-by: Alex Williamson <alex.williamson(a)redhat.com&gt; --- Note: this is still dependent on the configfd option being accepted into qemu/kvm. v2: - fix qemuargs, two separate args (thanks Chris) - don't hardcode pci segment - error message of open() fail v3: - add hotplug support - incorporate Daniel's comments src/qemu/qemu_conf.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++- src/qemu/qemu_conf.h | 6 ++- src/qemu/qemu_driver.c | 28 +++++++++++++- 3 files changed, 128 insertions(+), 4 deletions(-) @@ -7685,8 +7687,26 @@ static int qemudDomainAttachHostPciDevice(struct qemud_driver *driver, goto error; if (qemuDomainPCIAddressEnsureAddr(priv->pciaddrs, &hostdev->info) < 0) goto error; + if (qemuCmdFlags & QEMUD_CMD_FLAG_PCI_CONFIGFD) { + configfd = qemudOpenPCIConfig(hostdev); + if (configfd >= 0) { + if (virAsprintf(&configfd_name, "fd-%s", + hostdev->info.alias) < 0) { + virReportOOMError(); + goto error; + } + + qemuDomainObjEnterMonitorWithDriver(driver, vm); + if (qemuMonitorSendFileHandle(priv->mon, configfd_name, + configfd) < 0) { + qemuDomainObjExitMonitorWithDriver(driver, vm); + goto error; + } + qemuDomainObjExitMonitorWithDriver(driver, vm); + } + }

- if (!(devstr = qemuBuildPCIHostdevDevStr(hostdev))) + if (!(devstr = qemuBuildPCIHostdevDevStr(hostdev, configfd_name))) goto error; qemuDomainObjEnterMonitorWithDriver(driver, vm);