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authorLinus Torvalds <torvalds@linux-foundation.org>2020-02-05 17:44:14 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-05 17:44:14 +0000
commitd271ab29230b1d0ceb426f374c221c4eb2c91c64 (patch)
tree9c97e0196c5c1bab8bfbee95a052dbfd0fd0d6d2 /drivers/xen
parent2634744bf38ab20d17fe8220f1f83b6f3801386f (diff)
parent8557bbe5156e5fba022d5a5220004b1e016227ee (diff)
Merge tag 'for-linus-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross: - fix a bug introduced in 5.5 in the Xen gntdev driver - fix the Xen balloon driver when running on ancient Xen versions - allow Xen stubdoms to control interrupt enable flags of passed-through PCI cards - release resources in Xen backends under memory pressure * tag 'for-linus-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/blkback: Consistently insert one empty line between functions xen/blkback: Remove unnecessary static variable name prefixes xen/blkback: Squeeze page pools if a memory pressure is detected xenbus/backend: Protect xenbus callback with lock xenbus/backend: Add memory pressure handler callback xen/gntdev: Do not use mm notifiers with autotranslating guests xen/balloon: Support xend-based toolstack take two xen-pciback: optionally allow interrupt enable flag writes
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/gntdev.c24
-rw-r--r--drivers/xen/xen-balloon.c2
-rw-r--r--drivers/xen/xen-pciback/conf_space.c37
-rw-r--r--drivers/xen/xen-pciback/conf_space.h7
-rw-r--r--drivers/xen/xen-pciback/conf_space_capability.c89
-rw-r--r--drivers/xen/xen-pciback/conf_space_header.c19
-rw-r--r--drivers/xen/xen-pciback/pci_stub.c66
-rw-r--r--drivers/xen/xen-pciback/pciback.h1
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c8
-rw-r--r--drivers/xen/xenbus/xenbus_probe_backend.c38
10 files changed, 277 insertions, 14 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 4fc83e3f5ad3..0258415ca0b2 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -1006,19 +1006,19 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
}
mutex_unlock(&priv->lock);
- /*
- * gntdev takes the address of the PTE in find_grant_ptes() and passes
- * it to the hypervisor in gntdev_map_grant_pages(). The purpose of
- * the notifier is to prevent the hypervisor pointer to the PTE from
- * going stale.
- *
- * Since this vma's mappings can't be touched without the mmap_sem,
- * and we are holding it now, there is no need for the notifier_range
- * locking pattern.
- */
- mmu_interval_read_begin(&map->notifier);
-
if (use_ptemod) {
+ /*
+ * gntdev takes the address of the PTE in find_grant_ptes() and
+ * passes it to the hypervisor in gntdev_map_grant_pages(). The
+ * purpose of the notifier is to prevent the hypervisor pointer
+ * to the PTE from going stale.
+ *
+ * Since this vma's mappings can't be touched without the
+ * mmap_sem, and we are holding it now, there is no need for
+ * the notifier_range locking pattern.
+ */
+ mmu_interval_read_begin(&map->notifier);
+
map->pages_vm_start = vma->vm_start;
err = apply_to_page_range(vma->vm_mm, vma->vm_start,
vma->vm_end - vma->vm_start,
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index 6d12fc368210..a8d24433c8e9 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -94,7 +94,7 @@ static void watch_target(struct xenbus_watch *watch,
"%llu", &static_max) == 1))
static_max >>= PAGE_SHIFT - 10;
else
- static_max = new_target;
+ static_max = balloon_stats.current_pages;
target_diff = (xen_pv_domain() || xen_initial_domain()) ? 0
: static_max - balloon_stats.target_pages;
diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c
index 60111719b01f..b20e43e148ce 100644
--- a/drivers/xen/xen-pciback/conf_space.c
+++ b/drivers/xen/xen-pciback/conf_space.c
@@ -286,6 +286,43 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
return xen_pcibios_err_to_errno(err);
}
+int xen_pcibk_get_interrupt_type(struct pci_dev *dev)
+{
+ int err;
+ u16 val;
+ int ret = 0;
+
+ err = pci_read_config_word(dev, PCI_COMMAND, &val);
+ if (err)
+ return err;
+ if (!(val & PCI_COMMAND_INTX_DISABLE))
+ ret |= INTERRUPT_TYPE_INTX;
+
+ /*
+ * Do not trust dev->msi(x)_enabled here, as enabling could be done
+ * bypassing the pci_*msi* functions, by the qemu.
+ */
+ if (dev->msi_cap) {
+ err = pci_read_config_word(dev,
+ dev->msi_cap + PCI_MSI_FLAGS,
+ &val);
+ if (err)
+ return err;
+ if (val & PCI_MSI_FLAGS_ENABLE)
+ ret |= INTERRUPT_TYPE_MSI;
+ }
+ if (dev->msix_cap) {
+ err = pci_read_config_word(dev,
+ dev->msix_cap + PCI_MSIX_FLAGS,
+ &val);
+ if (err)
+ return err;
+ if (val & PCI_MSIX_FLAGS_ENABLE)
+ ret |= INTERRUPT_TYPE_MSIX;
+ }
+ return ret;
+}
+
void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev)
{
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
diff --git a/drivers/xen/xen-pciback/conf_space.h b/drivers/xen/xen-pciback/conf_space.h
index 22db630717ea..28c45180a12e 100644
--- a/drivers/xen/xen-pciback/conf_space.h
+++ b/drivers/xen/xen-pciback/conf_space.h
@@ -65,6 +65,11 @@ struct config_field_entry {
void *data;
};
+#define INTERRUPT_TYPE_NONE (1<<0)
+#define INTERRUPT_TYPE_INTX (1<<1)
+#define INTERRUPT_TYPE_MSI (1<<2)
+#define INTERRUPT_TYPE_MSIX (1<<3)
+
extern bool xen_pcibk_permissive;
#define OFFSET(cfg_entry) ((cfg_entry)->base_offset+(cfg_entry)->field->offset)
@@ -126,4 +131,6 @@ int xen_pcibk_config_capability_init(void);
int xen_pcibk_config_header_add_fields(struct pci_dev *dev);
int xen_pcibk_config_capability_add_fields(struct pci_dev *dev);
+int xen_pcibk_get_interrupt_type(struct pci_dev *dev);
+
#endif /* __XEN_PCIBACK_CONF_SPACE_H__ */
diff --git a/drivers/xen/xen-pciback/conf_space_capability.c b/drivers/xen/xen-pciback/conf_space_capability.c
index e5694133ebe5..22f13abbe913 100644
--- a/drivers/xen/xen-pciback/conf_space_capability.c
+++ b/drivers/xen/xen-pciback/conf_space_capability.c
@@ -189,6 +189,85 @@ static const struct config_field caplist_pm[] = {
{}
};
+static struct msi_msix_field_config {
+ u16 enable_bit; /* bit for enabling MSI/MSI-X */
+ unsigned int int_type; /* interrupt type for exclusiveness check */
+} msi_field_config = {
+ .enable_bit = PCI_MSI_FLAGS_ENABLE,
+ .int_type = INTERRUPT_TYPE_MSI,
+}, msix_field_config = {
+ .enable_bit = PCI_MSIX_FLAGS_ENABLE,
+ .int_type = INTERRUPT_TYPE_MSIX,
+};
+
+static void *msi_field_init(struct pci_dev *dev, int offset)
+{
+ return &msi_field_config;
+}
+
+static void *msix_field_init(struct pci_dev *dev, int offset)
+{
+ return &msix_field_config;
+}
+
+static int msi_msix_flags_write(struct pci_dev *dev, int offset, u16 new_value,
+ void *data)
+{
+ int err;
+ u16 old_value;
+ const struct msi_msix_field_config *field_config = data;
+ const struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
+
+ if (xen_pcibk_permissive || dev_data->permissive)
+ goto write;
+
+ err = pci_read_config_word(dev, offset, &old_value);
+ if (err)
+ return err;
+
+ if (new_value == old_value)
+ return 0;
+
+ if (!dev_data->allow_interrupt_control ||
+ (new_value ^ old_value) & ~field_config->enable_bit)
+ return PCIBIOS_SET_FAILED;
+
+ if (new_value & field_config->enable_bit) {
+ /* don't allow enabling together with other interrupt types */
+ int int_type = xen_pcibk_get_interrupt_type(dev);
+
+ if (int_type == INTERRUPT_TYPE_NONE ||
+ int_type == field_config->int_type)
+ goto write;
+ return PCIBIOS_SET_FAILED;
+ }
+
+write:
+ return pci_write_config_word(dev, offset, new_value);
+}
+
+static const struct config_field caplist_msix[] = {
+ {
+ .offset = PCI_MSIX_FLAGS,
+ .size = 2,
+ .init = msix_field_init,
+ .u.w.read = xen_pcibk_read_config_word,
+ .u.w.write = msi_msix_flags_write,
+ },
+ {}
+};
+
+static const struct config_field caplist_msi[] = {
+ {
+ .offset = PCI_MSI_FLAGS,
+ .size = 2,
+ .init = msi_field_init,
+ .u.w.read = xen_pcibk_read_config_word,
+ .u.w.write = msi_msix_flags_write,
+ },
+ {}
+};
+
static struct xen_pcibk_config_capability xen_pcibk_config_capability_pm = {
.capability = PCI_CAP_ID_PM,
.fields = caplist_pm,
@@ -197,11 +276,21 @@ static struct xen_pcibk_config_capability xen_pcibk_config_capability_vpd = {
.capability = PCI_CAP_ID_VPD,
.fields = caplist_vpd,
};
+static struct xen_pcibk_config_capability xen_pcibk_config_capability_msi = {
+ .capability = PCI_CAP_ID_MSI,
+ .fields = caplist_msi,
+};
+static struct xen_pcibk_config_capability xen_pcibk_config_capability_msix = {
+ .capability = PCI_CAP_ID_MSIX,
+ .fields = caplist_msix,
+};
int xen_pcibk_config_capability_init(void)
{
register_capability(&xen_pcibk_config_capability_vpd);
register_capability(&xen_pcibk_config_capability_pm);
+ register_capability(&xen_pcibk_config_capability_msi);
+ register_capability(&xen_pcibk_config_capability_msix);
return 0;
}
diff --git a/drivers/xen/xen-pciback/conf_space_header.c b/drivers/xen/xen-pciback/conf_space_header.c
index 10ae24b5a76e..fb4fccb4aecc 100644
--- a/drivers/xen/xen-pciback/conf_space_header.c
+++ b/drivers/xen/xen-pciback/conf_space_header.c
@@ -117,6 +117,25 @@ static int command_write(struct pci_dev *dev, int offset, u16 value, void *data)
pci_clear_mwi(dev);
}
+ if (dev_data && dev_data->allow_interrupt_control) {
+ if ((cmd->val ^ value) & PCI_COMMAND_INTX_DISABLE) {
+ if (value & PCI_COMMAND_INTX_DISABLE) {
+ pci_intx(dev, 0);
+ } else {
+ /* Do not allow enabling INTx together with MSI or MSI-X. */
+ switch (xen_pcibk_get_interrupt_type(dev)) {
+ case INTERRUPT_TYPE_NONE:
+ pci_intx(dev, 1);
+ break;
+ case INTERRUPT_TYPE_INTX:
+ break;
+ default:
+ return PCIBIOS_SET_FAILED;
+ }
+ }
+ }
+ }
+
cmd->val = value;
if (!xen_pcibk_permissive && (!dev_data || !dev_data->permissive))
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 097410a7cdb7..7af93d65ed51 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -304,6 +304,8 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
xen_pcibk_config_reset_dev(dev);
xen_pcibk_config_free_dyn_fields(dev);
+ dev_data->allow_interrupt_control = 0;
+
xen_unregister_device_domain_owner(dev);
spin_lock_irqsave(&found_psdev->lock, flags);
@@ -1431,6 +1433,65 @@ static ssize_t permissive_show(struct device_driver *drv, char *buf)
}
static DRIVER_ATTR_RW(permissive);
+static ssize_t allow_interrupt_control_store(struct device_driver *drv,
+ const char *buf, size_t count)
+{
+ int domain, bus, slot, func;
+ int err;
+ struct pcistub_device *psdev;
+ struct xen_pcibk_dev_data *dev_data;
+
+ err = str_to_slot(buf, &domain, &bus, &slot, &func);
+ if (err)
+ goto out;
+
+ psdev = pcistub_device_find(domain, bus, slot, func);
+ if (!psdev) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ dev_data = pci_get_drvdata(psdev->dev);
+ /* the driver data for a device should never be null at this point */
+ if (!dev_data) {
+ err = -ENXIO;
+ goto release;
+ }
+ dev_data->allow_interrupt_control = 1;
+release:
+ pcistub_device_put(psdev);
+out:
+ if (!err)
+ err = count;
+ return err;
+}
+
+static ssize_t allow_interrupt_control_show(struct device_driver *drv,
+ char *buf)
+{
+ struct pcistub_device *psdev;
+ struct xen_pcibk_dev_data *dev_data;
+ size_t count = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pcistub_devices_lock, flags);
+ list_for_each_entry(psdev, &pcistub_devices, dev_list) {
+ if (count >= PAGE_SIZE)
+ break;
+ if (!psdev->dev)
+ continue;
+ dev_data = pci_get_drvdata(psdev->dev);
+ if (!dev_data || !dev_data->allow_interrupt_control)
+ continue;
+ count +=
+ scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
+ pci_name(psdev->dev));
+ }
+ spin_unlock_irqrestore(&pcistub_devices_lock, flags);
+ return count;
+}
+static DRIVER_ATTR_RW(allow_interrupt_control);
+
static void pcistub_exit(void)
{
driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
@@ -1441,6 +1502,8 @@ static void pcistub_exit(void)
driver_remove_file(&xen_pcibk_pci_driver.driver,
&driver_attr_permissive);
driver_remove_file(&xen_pcibk_pci_driver.driver,
+ &driver_attr_allow_interrupt_control);
+ driver_remove_file(&xen_pcibk_pci_driver.driver,
&driver_attr_irq_handlers);
driver_remove_file(&xen_pcibk_pci_driver.driver,
&driver_attr_irq_handler_state);
@@ -1530,6 +1593,9 @@ static int __init pcistub_init(void)
if (!err)
err = driver_create_file(&xen_pcibk_pci_driver.driver,
&driver_attr_permissive);
+ if (!err)
+ err = driver_create_file(&xen_pcibk_pci_driver.driver,
+ &driver_attr_allow_interrupt_control);
if (!err)
err = driver_create_file(&xen_pcibk_pci_driver.driver,
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index 263c059bff90..ce1077e32466 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -45,6 +45,7 @@ struct xen_pcibk_dev_data {
struct list_head config_fields;
struct pci_saved_state *pci_saved_state;
unsigned int permissive:1;
+ unsigned int allow_interrupt_control:1;
unsigned int warned_on_write:1;
unsigned int enable_intx:1;
unsigned int isr_on:1; /* Whether the IRQ handler is installed. */
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 378486b79f96..66975da4f3b6 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -239,7 +239,9 @@ int xenbus_dev_probe(struct device *_dev)
goto fail;
}
+ spin_lock(&dev->reclaim_lock);
err = drv->probe(dev, id);
+ spin_unlock(&dev->reclaim_lock);
if (err)
goto fail_put;
@@ -268,8 +270,11 @@ int xenbus_dev_remove(struct device *_dev)
free_otherend_watch(dev);
- if (drv->remove)
+ if (drv->remove) {
+ spin_lock(&dev->reclaim_lock);
drv->remove(dev);
+ spin_unlock(&dev->reclaim_lock);
+ }
module_put(drv->driver.owner);
@@ -468,6 +473,7 @@ int xenbus_probe_node(struct xen_bus_type *bus,
goto fail;
dev_set_name(&xendev->dev, "%s", devname);
+ spin_lock_init(&xendev->reclaim_lock);
/* Register with generic device framework. */
err = device_register(&xendev->dev);
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 14876faff3b0..791f6fe01e91 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -247,6 +247,41 @@ static int backend_probe_and_watch(struct notifier_block *notifier,
return NOTIFY_DONE;
}
+static int backend_reclaim_memory(struct device *dev, void *data)
+{
+ const struct xenbus_driver *drv;
+ struct xenbus_device *xdev;
+
+ if (!dev->driver)
+ return 0;
+ drv = to_xenbus_driver(dev->driver);
+ if (drv && drv->reclaim_memory) {
+ xdev = to_xenbus_device(dev);
+ if (!spin_trylock(&xdev->reclaim_lock))
+ return 0;
+ drv->reclaim_memory(xdev);
+ spin_unlock(&xdev->reclaim_lock);
+ }
+ return 0;
+}
+
+/*
+ * Returns 0 always because we are using shrinker to only detect memory
+ * pressure.
+ */
+static unsigned long backend_shrink_memory_count(struct shrinker *shrinker,
+ struct shrink_control *sc)
+{
+ bus_for_each_dev(&xenbus_backend.bus, NULL, NULL,
+ backend_reclaim_memory);
+ return 0;
+}
+
+static struct shrinker backend_memory_shrinker = {
+ .count_objects = backend_shrink_memory_count,
+ .seeks = DEFAULT_SEEKS,
+};
+
static int __init xenbus_probe_backend_init(void)
{
static struct notifier_block xenstore_notifier = {
@@ -263,6 +298,9 @@ static int __init xenbus_probe_backend_init(void)
register_xenstore_notifier(&xenstore_notifier);
+ if (register_shrinker(&backend_memory_shrinker))
+ pr_warn("shrinker registration failed\n");
+
return 0;
}
subsys_initcall(xenbus_probe_backend_init);