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Commit c3cb4709 authored by Jan Beulich's avatar Jan Beulich Committed by Konrad Rzeszutek Wilk
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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: default avatarJan Beulich <jbeulich@suse.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent ecc635f9

drivers/xen/xen-pciback/pci_stub.c

+82 −7
Original line number Diff line number Diff line
@@ -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;

			}