Mailing List Archive

Particularly for hiding sets of SR-IOV devices, specifying them all
individually is rather cumbersome. Therefore, allow function and slot
numbers to be replaced by a wildcard character ('*').

Unfortunately this gets complicated by the in-kernel sscanf()
implementation not being really standard conformant - matching of
plain text tails cannot be checked by the caller (a patch to overcome
this will be sent shortly, and a follow-up patch for simplifying the
code is planned to be sent when that fixed went upstream).

Signed-off-by: Jan Beulich <jbeulich@suse.com>

---
drivers/xen/xen-pciback/pci_stub.c | 89 ++++++++++++++++++++++++++++++++++---
1 file changed, 82 insertions(+), 7 deletions(-)

--- 3.6-rc6/drivers/xen/xen-pciback/pci_stub.c
+++ 3.6-rc6-xen-pciback-wildcard/drivers/xen/xen-pciback/pci_stub.c
@@ -897,17 +897,41 @@ static inline int str_to_slot(const char
int *slot, int *func)
{
int err;
+ char wc = '*';

err = sscanf(buf, " %x:%x:%x.%x", domain, bus, slot, func);
- if (err == 4)
+ switch (err) {
+ case 3:
+ *func = -1;
+ err = sscanf(buf, " %x:%x:%x.%c", domain, bus, slot, &wc);
+ break;
+ case 2:
+ *slot = *func = -1;
+ err = sscanf(buf, " %x:%x:*.%c", domain, bus, &wc);
+ if (err >= 2)
+ ++err;
+ break;
+ }
+ if (err == 4 && wc == '*')
return 0;
else if (err < 0)
return -EINVAL;

/* try again without domain */
*domain = 0;
+ wc = '*';
err = sscanf(buf, " %x:%x.%x", bus, slot, func);
- if (err == 3)
+ switch (err) {
+ case 2:
+ *func = -1;
+ err = sscanf(buf, " %x:%x.%c", bus, slot, &wc);
+ break;
+ case 1:
+ *slot = *func = -1;
+ err = sscanf(buf, " %x:*.%c", bus, &wc) + 1;
+ break;
+ }
+ if (err == 3 && wc == '*')
return 0;

return -EINVAL;
@@ -930,6 +954,19 @@ static int pcistub_device_id_add(int dom
{
struct pcistub_device_id *pci_dev_id;
unsigned long flags;
+ int rc = 0;
+
+ if (slot < 0) {
+ for (slot = 0; !rc && slot < 32; ++slot)
+ rc = pcistub_device_id_add(domain, bus, slot, func);
+ return rc;
+ }
+
+ if (func < 0) {
+ for (func = 0; !rc && func < 8; ++func)
+ rc = pcistub_device_id_add(domain, bus, slot, func);
+ return rc;
+ }

pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
if (!pci_dev_id)
@@ -952,15 +989,15 @@ static int pcistub_device_id_add(int dom
static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
{
struct pcistub_device_id *pci_dev_id, *t;
- int devfn = PCI_DEVFN(slot, func);
int err = -ENOENT;
unsigned long flags;

spin_lock_irqsave(&device_ids_lock, flags);
list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
slot_list) {
- if (pci_dev_id->domain == domain
- && pci_dev_id->bus == bus && pci_dev_id->devfn == devfn) {
+ if (pci_dev_id->domain == domain && pci_dev_id->bus == bus
+ && (slot < 0 || PCI_SLOT(pci_dev_id->devfn) == slot)
+ && (func < 0 || PCI_FUNC(pci_dev_id->devfn) == func)) {
/* Don't break; here because it's possible the same
* slot could be in the list more than once
*/
@@ -1216,6 +1253,10 @@ static ssize_t permissive_add(struct dev
err = str_to_slot(buf, &domain, &bus, &slot, &func);
if (err)
goto out;
+ if (slot < 0 || func < 0) {
+ err = -EINVAL;
+ goto out;
+ }
psdev = pcistub_device_find(domain, bus, slot, func);
if (!psdev) {
err = -ENODEV;
@@ -1297,17 +1338,51 @@ static int __init pcistub_init(void)

if (pci_devs_to_hide && *pci_devs_to_hide) {
do {
+ char wc = '*';
+
parsed = 0;

err = sscanf(pci_devs_to_hide + pos,
" (%x:%x:%x.%x) %n",
&domain, &bus, &slot, &func, &parsed);
- if (err != 4) {
+ switch (err) {
+ case 3:
+ func = -1;
+ err = sscanf(pci_devs_to_hide + pos,
+ " (%x:%x:%x.%c) %n",
+ &domain, &bus, &slot, &wc,
+ &parsed);
+ break;
+ case 2:
+ slot = func = -1;
+ err = sscanf(pci_devs_to_hide + pos,
+ " (%x:%x:*.%c) %n",
+ &domain, &bus, &wc, &parsed) + 1;
+ break;
+ }
+
+ if (err != 4 || wc != '*') {
domain = 0;
+ wc = '*';
err = sscanf(pci_devs_to_hide + pos,
" (%x:%x.%x) %n",
&bus, &slot, &func, &parsed);
- if (err != 3)
+ switch (err) {
+ case 2:
+ func = -1;
+ err = sscanf(pci_devs_to_hide + pos,
+ " (%x:%x.%c) %n",
+ &bus, &slot, &wc,
+ &parsed);
+ break;
+ case 1:
+ slot = func = -1;
+ err = sscanf(pci_devs_to_hide + pos,
+ " (%x:*.%c) %n",
+ &bus, &wc, &parsed) + 1;
+ break;
+ }
+ if (err != 3 || wc != '*')
goto parse_error;
}




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