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xen-pciback: support wild cards in slot specifications 

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>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Jan Beulich 2012-09-18 12:29:03 +01:00 committed by Konrad Rzeszutek Wilk
parent ecc635f90a
commit c3cb470980
1 changed files with 82 additions and 7 deletions
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89
drivers/xen/xen-pciback/pci_stub.c
View File

@ -897,17 +897,41 @@ static inline int str_to_slot(const char *buf, int *domain, int *bus,
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 domain, int bus, int slot, int func)
{
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 domain, int bus, int slot, int func)
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 device_driver *drv, const char *buf,
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;
}