Re: [libvirt] [PATCH v2 2/7] tests: pci: Mock the iommu groups and vfio

From: Shivaprasad G Bhat <sbhat(a)linux.vnet.ibm.com&gt; The iommu group, /dev/vfio/<iommuGroupNumber> behaviors of the host are mocked. This patch implements support for multifunction/multiple devices per iommu groups and emulates the /dev/vfio/<iommuGroupNumber> file correctly. This code helps adding necessary testcases for pci-hotplug code. Signed-off-by: Shivaprasad G Bhat <sbhat(a)linux.vnet.ibm.com&gt; Signed-off-by: Daniel Henrique Barboza <danielhb413(a)gmail.com&gt; --- tests/virpcimock.c | 177 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 162 insertions(+), 15 deletions(-)

diff --git a/tests/virpcimock.c b/tests/virpcimock.c index 5ec9abe05f..1b44ed0a44 100644 --- a/tests/virpcimock.c +++ b/tests/virpcimock.c @@ -44,6 +44,8 @@ char *fakerootdir; char *fakesysfspcidir; # define SYSFS_PCI_PREFIX "/sys/bus/pci/" +# define SYSFS_KERNEL_PREFIX "/sys/kernel/" + # define STDERR(...) \ fprintf(stderr, "%s %zu: ", __FUNCTION__, (size_t) __LINE__); \ @@ -123,6 +125,11 @@ struct pciDevice { struct pciDriver *driver; /* Driver attached. NULL if attached to no driver */ }; +struct pciIommuGroup { + int iommu; + size_t nDevicesBoundToVFIO; /* Indicates the devices in the group */ +}; + struct fdCallback { int fd; char *path; @@ -134,6 +141,9 @@ size_t nPCIDevices = 0; struct pciDriver **pciDrivers = NULL; size_t nPCIDrivers = 0; +struct pciIommuGroup **pciIommuGroups = NULL; +size_t npciIommuGroups = 0; + struct fdCallback *callbacks = NULL; size_t nCallbacks = 0; @@ -247,6 +257,13 @@ getrealpath(char **newpath, errno = ENOMEM; return -1; } + } else if (STRPREFIX(path, SYSFS_KERNEL_PREFIX)) { + if (virAsprintfQuiet(newpath, "%s/%s", + fakerootdir, + path) < 0) { + errno = ENOMEM; + return -1; + } } else { if (VIR_STRDUP_QUIET(*newpath, path) < 0) return -1; @@ -460,6 +477,101 @@ pci_device_autobind(struct pciDevice *dev) return pci_driver_bind(driver, dev); } +static void +pci_iommu_new(int num) +{ + char *iommupath, *kerneldir; + struct pciIommuGroup *iommuGroup; + + if (VIR_ALLOC_QUIET(iommuGroup) < 0) + ABORT_OOM(); + + iommuGroup->iommu = num; + iommuGroup->nDevicesBoundToVFIO = 0; /* No device bound to vfio by default */ + + if (virAsprintfQuiet(&kerneldir, "%s%s", + fakerootdir, SYSFS_KERNEL_PREFIX) < 0) + ABORT_OOM(); + + if (virAsprintfQuiet(&iommupath, "%s/iommu_groups/%d/devices", kerneldir, num) < 0) + ABORT_OOM(); + VIR_FREE(kerneldir); + + if (virFileMakePath(iommupath) < 0) + ABORT("Unable to create: %s", iommupath); + VIR_FREE(iommupath); + + if (VIR_APPEND_ELEMENT_QUIET(pciIommuGroups, npciIommuGroups, iommuGroup) < 0) + ABORT_OOM(); +} + +static int +pci_vfio_release_iommu(struct pciDevice *device) +{ + char *vfiopath = NULL; + int ret = -1; + size_t i = 0; + + for (i = 0; i < npciIommuGroups; i++) { + if (pciIommuGroups[i]->iommu == device->iommuGroup) + break; + } + + if (i != npciIommuGroups) { + if (pciIommuGroups[i]->nDevicesBoundToVFIO == 0) { + ret = 0; + goto cleanup; + } + pciIommuGroups[i]->nDevicesBoundToVFIO--; + if (!pciIommuGroups[i]->nDevicesBoundToVFIO) { + if (virAsprintfQuiet(&vfiopath, "%s/dev/vfio/%d", + fakesysfspcidir, device->iommuGroup) < 0) { + errno = ENOMEM; + goto cleanup; + } + if (unlink(vfiopath) < 0) + goto cleanup; + } + } + + ret = 0; + cleanup: + VIR_FREE(vfiopath); + return ret; +} + +static int +pci_vfio_lock_iommu(struct pciDevice *device) +{ + char *vfiopath = NULL; + int ret = -1; + size_t i = 0; + int fd = -1; + + for (i = 0; i < npciIommuGroups; i++) { + if (pciIommuGroups[i]->iommu == device->iommuGroup) + break; + } + + if (i != npciIommuGroups) { + if (!pciIommuGroups[i]->nDevicesBoundToVFIO) { + if (virAsprintfQuiet(&vfiopath, "%s/dev/vfio/%d", + fakesysfspcidir, device->iommuGroup) < 0) { + errno = ENOMEM; + goto cleanup; + } + if ((fd = real_open(vfiopath, O_CREAT)) < 0) + goto cleanup; + } + pciIommuGroups[i]->nDevicesBoundToVFIO++; + } + + ret = 0; + cleanup: + real_close(fd); + VIR_FREE(vfiopath); + return ret; +} /* * PCI Driver functions @@ -583,6 +695,10 @@ pci_driver_bind(struct pciDriver *driver, if (symlink(devpath, driverpath) < 0) goto cleanup; + if (STREQ(driver->name, "vfio-pci")) + if (pci_vfio_lock_iommu(dev) < 0) + goto cleanup; + dev->driver = driver; ret = 0; cleanup: @@ -617,6 +733,10 @@ pci_driver_unbind(struct pciDriver *driver, unlink(driverpath) < 0) goto cleanup; + if (STREQ(driver->name, "vfio-pci")) + if (pci_vfio_release_iommu(dev) < 0) + goto cleanup; + dev->driver = NULL; ret = 0; cleanup: @@ -813,6 +933,8 @@ init_syms(void) static void init_env(void) { + char *devVFIO; + if (fakerootdir && fakesysfspcidir) return; @@ -828,6 +950,29 @@ init_env(void) make_file(fakesysfspcidir, "drivers_probe", NULL, -1); + if (virAsprintfQuiet(&devVFIO, "%s/dev/vfio", fakesysfspcidir) < 0) + ABORT_OOM(); + + if (virFileMakePath(devVFIO) < 0) + ABORT("Unable to create: %s", devVFIO); + + /* Create /dev/vfio/vfio file */ + make_file(devVFIO, "vfio", NULL, -1); + VIR_FREE(devVFIO); + + pci_iommu_new(0); + pci_iommu_new(1); + pci_iommu_new(2); + pci_iommu_new(3); + pci_iommu_new(4); + pci_iommu_new(5); + pci_iommu_new(6); + pci_iommu_new(7); + pci_iommu_new(8); + pci_iommu_new(9); + pci_iommu_new(10); + pci_iommu_new(11);