When using -pcidevice on a device that is already in use by a kernel driver
all the user gets is the following (very useful) information:
Failed to assign device "04:00.0" : Device or resource busy
Failed to deassign device "04:00.0" : Invalid argument
Error initializing device pci-assign
Since I usually prefer to have my computer do the thinking for me, I figured
it might be a good idea to check and see if a device is actually used by a
driver. If so, tell the user.
So with this patch applied you get the following output:
Failed to assign device "04:00.0" : Device or resource busy
*** The driver 'igb' is occupying your device 04:00.0.
***
*** You can try the following commands to free it:
***
*** $ echo "8086 150a" > /sys/bus/pci/drivers/pci-stub/new_id
*** $ echo "04:00.0" > /sys/bus/pci/drivers/igb/unbind
*** $ echo "04:00.0" > /sys/bus/pci/drivers/pci-stub/bind
*** $ echo "8086 150a" > /sys/bus/pci/drivers/pci-stub/remove_id
***
Failed to deassign device "04:00.0" : Invalid argument
Error initializing device pci-assign
That should keep people like me from doing the most obvious misuses :-).
CC: Daniel P. Berrange <berrange@xxxxxxxxxx>
Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
v1 -> v2:
- add more helpful guidance thanks to Daniel Berrange
---
hw/device-assignment.c | 106 +++++++++++++++++++++++++++++++++++++----------
1 files changed, 83 insertions(+), 23 deletions(-)
diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index beb488c..9fbddcf 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -572,6 +572,36 @@ static int assigned_dev_register_regions(PCIRegion *io_regions,
return 0;
}
+static int get_real_id(const char *devpath, const char *idname, uint16_t *val)
+{
+ FILE *f;
+ char name[128];
+ long id;
+
+ snprintf(name, sizeof(name), "%s%s", devpath, idname);
+ f = fopen(name, "r");
+ if (f == NULL) {
+ fprintf(stderr, "%s: %s: %m\n", __func__, name);
+ return -1;
+ }
+ if (fscanf(f, "%li\n", &id) == 1) {
+ *val = id;
+ }
+ fclose(f);
+
+ return 0;
+}
+
+static int get_real_vendor_id(const char *devpath, uint16_t *val)
+{
+ return get_real_id(devpath, "vendor", val);
+}
+
+static int get_real_device_id(const char *devpath, uint16_t *val)
+{
+ return get_real_id(devpath, "device", val);
+}
+
static int get_real_device(AssignedDevice *pci_dev, uint8_t r_bus,
uint8_t r_dev, uint8_t r_func)
{
@@ -579,7 +609,7 @@ static int get_real_device(AssignedDevice *pci_dev, uint8_t r_bus,
int fd, r = 0;
FILE *f;
unsigned long long start, end, size, flags;
- unsigned long id;
+ uint16_t id;
struct stat statbuf;
PCIRegion *rp;
PCIDevRegions *dev = &pci_dev->real_device;
@@ -645,31 +675,21 @@ again:
fclose(f);
- /* read and fill device ID */
- snprintf(name, sizeof(name), "%svendor", dir);
- f = fopen(name, "r");
- if (f == NULL) {
- fprintf(stderr, "%s: %s: %m\n", __func__, name);
+ /* read and fill vendor ID */
+ r = get_real_vendor_id(dir, &id);
+ if (r) {
return 1;
}
- if (fscanf(f, "%li\n", &id) == 1) {
- pci_dev->dev.config[0] = id & 0xff;
- pci_dev->dev.config[1] = (id & 0xff00) >> 8;
- }
- fclose(f);
+ pci_dev->dev.config[0] = id & 0xff;
+ pci_dev->dev.config[1] = (id & 0xff00) >> 8;
- /* read and fill vendor ID */
- snprintf(name, sizeof(name), "%sdevice", dir);
- f = fopen(name, "r");
- if (f == NULL) {
- fprintf(stderr, "%s: %s: %m\n", __func__, name);
+ /* read and fill device ID */
+ r = get_real_device_id(dir, &id);
+ if (r) {
return 1;
}
- if (fscanf(f, "%li\n", &id) == 1) {
- pci_dev->dev.config[2] = id & 0xff;
- pci_dev->dev.config[3] = (id & 0xff00) >> 8;
- }
- fclose(f);
+ pci_dev->dev.config[2] = id & 0xff;
+ pci_dev->dev.config[3] = (id & 0xff00) >> 8;
/* dealing with virtual function device */
snprintf(name, sizeof(name), "%sphysfn/", dir);
@@ -747,7 +767,9 @@ static uint32_t calc_assigned_dev_id(uint8_t bus, uint8_t devfn)
static int assign_device(AssignedDevice *dev)
{
struct kvm_assigned_pci_dev assigned_dev_data;
- int r;
+ char name[128], dir[128], driver[128], *ns;
+ uint16_t vendor_id, device_id;
+ int r, v;
memset(&assigned_dev_data, 0, sizeof(assigned_dev_data));
assigned_dev_data.assigned_dev_id =
@@ -769,9 +791,47 @@ static int assign_device(AssignedDevice *dev)
#endif
r = kvm_assign_pci_device(kvm_context, &assigned_dev_data);
- if (r < 0)
+ if (r < 0) {
fprintf(stderr, "Failed to assign device \"%s\" : %s\n",
dev->dev.qdev.id, strerror(-r));
+
+ snprintf(dir, sizeof(dir),
+ "/sys/bus/pci/devices/0000:%02x:%02x.%x/",
+ dev->host.bus, dev->host.dev, dev->host.func);
+
+ snprintf(name, sizeof(name), "%sdriver", dir);
+
+ v = readlink(name, driver, sizeof(driver));
+ if ((v <= 0) || !(ns = strrchr(driver, '/'))) {
+ return r;
+ }
+
+ ns++;
+
+ if (get_real_vendor_id(dir, &vendor_id) ||
+ get_real_device_id(dir, &device_id)) {
+ return r;
+ }
+
+ fprintf(stderr, "*** The driver '%s' is occupying your device "
+ "%02x:%02x.%x.\n",
+ ns, dev->host.bus, dev->host.dev, dev->host.func);
+ fprintf(stderr, "***\n");
+ fprintf(stderr, "*** You can try the following commands to free "
+ "it:\n");
+ fprintf(stderr, "***\n");
+ fprintf(stderr, "*** $ echo \"%04x %04x\" > /sys/bus/pci/drivers/"
+ "pci-stub/new_id\n", vendor_id, device_id);
+ fprintf(stderr, "*** $ echo \"%02x:%02x.%x\" > /sys/bus/pci/drivers/%s"
+ "/unbind\n", dev->host.bus, dev->host.dev,
+ dev->host.func, ns);
+ fprintf(stderr, "*** $ echo \"%02x:%02x.%x\" > /sys/bus/pci/drivers/"
+ "pci-stub/bind\n", dev->host.bus, dev->host.dev,
+ dev->host.func);
+ fprintf(stderr, "*** $ echo \"%x %x\" > /sys/bus/pci/drivers/pci-stub"
+ "/remove_id\n", vendor_id, device_id);
+ fprintf(stderr, "***\n");
+ }
return r;
}
--
1.6.0.2
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