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Refine PCI device passthrogh routine
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Refine PCI device passthrogh routine

Signed-off-by: Yadong Qi <yadong.qi@intel.com>
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@YadongQi
YadongQi committed Nov 19, 2021
1 parent f203b7c commit 58e3694
Showing 1 changed file with 47 additions and 55 deletions.
102 changes: 47 additions & 55 deletions src/guest/start.c
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Original file line number Diff line number Diff line change
Expand Up @@ -97,26 +97,22 @@ static int create_vgpu(GKeyFile *gkf)
static int is_vfio_driver(const char *driver)
{
ssize_t nbytes;
ssize_t bufsiz = PATH_MAX;
struct stat st;
char *buf;
char buf[PATH_MAX] = { 0 };
char *driver_name;
if (!driver)
return -1;

if (lstat(driver, &st) == -1)
return -1;

if (st.st_size != 0)
bufsiz = st.st_size + 1;

buf = calloc(bufsiz, 1);
if (buf == NULL)
if (lstat(driver, &st) == -1) {
printf("%s: lstat failed, errno=%d!\n", __func__, errno);
return -1;
}

nbytes = readlink(driver, buf, bufsiz);
if (nbytes == -1)
nbytes = readlink(driver, buf, PATH_MAX);
if (nbytes == -1) {
printf("%s: readlink fail! errno=%d\n", __func__, errno);
return -1;
}

driver_name = basename(buf);
if (strncmp(driver_name, "vfio-pci", 8) == 0)
Expand Down Expand Up @@ -215,6 +211,10 @@ static int passthrough_gpu(void)
return -1;
}

pci_pt_record[pci_count] = malloc(PT_MAX);
strncpy(pci_pt_record[pci_count], INTEL_GPU_BDF, PT_MAX-1);
pci_count++;

return 0;
}

Expand All @@ -240,7 +240,7 @@ void system_call(const char *process, const char *args) {
static int setup_passthrough(char *pci_device, int unset);

static void cleanup_passthrough(void) {
for (int i=0; i<1; i++) {
for (int i=0; i < pci_count; i++) {
fprintf(stderr, "pci unset: %s\n", pci_pt_record[i]);
setup_passthrough(pci_pt_record[i], 1);
free(pci_pt_record[i]);
Expand Down Expand Up @@ -272,7 +272,7 @@ static int check_driver_unbinded(const char *driver) {

static int setup_passthrough(char *pci_device, int unset) {

char iommu_grp_dev[64] = {0};
char iommu_grp_dev[128] = {0};
DIR *dp;
struct dirent *ep;

Expand All @@ -286,79 +286,74 @@ static int setup_passthrough(char *pci_device, int unset) {

/* Iterate through devices in iommu group directory */
while ((ep = readdir (dp))) {
char *pci_device = ep->d_name;
if (strcmp(pci_device, ".") == 0 || strcmp(pci_device, "..") == 0) {
char *grp_dev = ep->d_name;
if (strcmp(grp_dev, ".") == 0 || strcmp(grp_dev, "..") == 0) {
continue;
}
char buffer[512] = {0}, device[64] = {0}, vendor[64] = {0};
char *rp = NULL;

/* Get device_id and vendor_id */
snprintf(buffer, 512, "%s/%s/device", iommu_grp_dev, pci_device);
fprintf(stderr, "%s\n", buffer);
rp = canonicalize_file_name(buffer);
if (!rp)
continue;
FILE *f = fopen(rp, "r");
snprintf(buffer, 512, "%s/%s/device", iommu_grp_dev, grp_dev);
FILE *f = fopen(buffer, "r");
if (f == NULL)
continue;
if (!fgets(device, sizeof(device), f)) {
fprintf(stderr, "Cannot get device name for device %s.", pci_device);
fprintf(stderr, "Cannot get device name for device %s.", grp_dev);
fclose(f);
continue;
}
fclose(f);
free(rp); rp = NULL;

memset(buffer, 0, sizeof(buffer));
snprintf(buffer, 512, "%s/%s/vendor", iommu_grp_dev, pci_device);
rp = canonicalize_file_name(buffer);
if (!rp)
continue;
f = fopen(rp, "r");
snprintf(buffer, 512, "%s/%s/vendor", iommu_grp_dev, grp_dev);
f = fopen(buffer, "r");
if (f == NULL)
continue;
if (!fgets(vendor, sizeof(vendor), f)) {
fprintf(stderr, "Cannot get vendor name for device %s.", pci_device);
fprintf(stderr, "Cannot get vendor name for device %s.", grp_dev);
fclose(f);
continue;
}
fclose(f);
free(rp); rp = NULL;

if (unset) {
memset(buffer, 0, sizeof(buffer));
snprintf(buffer, 512, "%s/%s/driver", iommu_grp_dev, pci_device);
snprintf(buffer, 512, "%s/%s/driver", iommu_grp_dev, grp_dev);

char *driver_in_use = basename(canonicalize_file_name(buffer));
fprintf(stderr, "driverinuse %s %d\n", driver_in_use, strcmp(driver_in_use, "vfio-pci"));
if (strcmp(driver_in_use, "vfio-pci") == 0) {
fprintf(stderr, "unbind %s\n", pci_device);
write_to_file("/sys/bus/pci/drivers/vfio-pci/unbind", pci_device);
if (is_vfio_driver(buffer) == 0) {
memset(buffer, 0, sizeof(buffer));
snprintf(buffer, sizeof(buffer), "%.6s %.6s", vendor, device);
// "echo %s %s > /sys/bus/pci/drivers/vfio-pci/remove_id"
fprintf(stderr, "remove_id %s\n", buffer);
write_to_file("/sys/bus/pci/drivers/vfio-pci/remove_id", buffer);
if (write_to_file("/sys/bus/pci/drivers/vfio-pci/remove_id", buffer)) {
fprintf(stderr, "Cannot remove original GPU vfio id\n");
return -1;
}
/* Unbind original driver */
if (write_to_file("/sys/bus/pci/drivers/vfio-pci/unbind", grp_dev)) {
fprintf(stderr, "%s: Cannot unbind original driver!\n", __func__);
}
}
// free(driver_in_use);
if (check_driver_unbinded(pci_device) == 0) {
fprintf(stderr, "drivers_probe reset %s\n", pci_device);
write_to_file("/sys/bus/pci/drivers_probe", pci_device);

if (check_driver_unbinded(grp_dev) == 0) {
fprintf(stderr, "drivers_probe reset %s\n", grp_dev);
write_to_file("/sys/bus/pci/drivers_probe", grp_dev);
} else {
fprintf(stderr, "Failed to unbind driver or did not finish in the given time frame.\n");
}
} else {
/* Check if driver exists, unbind if it exists */
memset(buffer, 0, sizeof(buffer));
snprintf(buffer, 512, "%s/%s/driver", iommu_grp_dev, pci_device);
rp = canonicalize_file_name(buffer);
if (!rp)
continue;
DIR* dir = opendir(rp);
snprintf(buffer, 512, "%s/%s/driver", iommu_grp_dev, grp_dev);
DIR* dir = opendir(buffer);
if (dir) {
/* Driver directory exists. */
snprintf(buffer, 512, "%s/%s/driver/unbind", iommu_grp_dev, pci_device);
write_to_file(buffer, pci_device);
if (is_vfio_driver(buffer) == 0) {
memset(buffer, 0, sizeof(buffer));
snprintf(buffer, sizeof(buffer), "%.6s %.6s", vendor, device);
write_to_file("/sys/bus/pci/drivers/vfio-pci/remove_id", buffer);
}
memset(buffer, 0, sizeof(buffer));
snprintf(buffer, 512, "%s/%s/driver/unbind", iommu_grp_dev, grp_dev);
write_to_file(buffer, grp_dev);

closedir(dir);
} else if (ENOENT == errno) {
Expand All @@ -370,11 +365,9 @@ static int setup_passthrough(char *pci_device, int unset) {
// fprintf(stderr, "%s pci device could not unbind from current driver. Driver directory does not exist. ", pci_device);
// continue;
}
free(rp); rp = NULL;

memset(buffer, 0, sizeof(buffer));
snprintf(buffer, sizeof(buffer), "%s %s", vendor, device);

write_to_file(PCI_DRIVER_PATH"vfio-pci/new_id", buffer);
}
}
Expand Down Expand Up @@ -725,7 +718,6 @@ int start_guest(char *name)
}

int res_count = find_pci("", PT_MAX, temp);
pci_count = 0;

if (res_count > 0) {
/* Add vfio-pci kernel module, needs sudo privilege */
Expand Down

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