Jan Beulich
2012-Sep-18 11:29 UTC
[PATCH] 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>
---
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;
}
Konrad Rzeszutek Wilk
2012-Sep-18 16:25 UTC
Re: [PATCH] xen-pciback: support wild cards in slot specifications
On Tue, Sep 18, 2012 at 12:29:03PM +0100, Jan Beulich wrote:> 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).applied for 3.7> > 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; > } > >