[PATCH v4 2/2] xen-pciback: allow compiling on other archs than x86

From: Oleksandr Andrushchenko
Date: Mon Sep 27 2021 - 02:58:32 EST

Next message: Christian Borntraeger: "Re: [PATCH 05/14] KVM: s390: Clear valid_wakeup in kvm_s390_handle_wait(), not in arch hook"
Previous message: Oleksandr Andrushchenko: "[PATCH v4 1/2] xen-pciback: prepare for the split for stub and PV"
In reply to: Oleksandr Andrushchenko: "[PATCH v4 1/2] xen-pciback: prepare for the split for stub and PV"
Next in thread: Jan Beulich: "Re: [PATCH v4 1/2] xen-pciback: prepare for the split for stub and PV"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Xen-pciback driver was designed to be built for x86 only. But it
can also be used by other architectures, e.g. Arm.
Re-structure the driver in a way that it can be built for other
platforms as well.

Add new configuration option CONFIG_XEN_PCIDEV_STUB, so the driver
can be limited in its functionality, e.g. no support for
para-virtualised scenario when it acts as PCI backend.
x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND
for the fully featured backend driver.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@xxxxxxxx>

---
Since v3:
- Fix >>32 shift for 32-bit architectures
- Move CONFIG_XEN_PCIDEV_STUB into this patch
Since v2:
- swap the patch order
Since v1:
- Do not move pci_xen_initial_domain as it is x86 specific
---
arch/x86/include/asm/xen/pci.h | 16 -----
arch/x86/pci/xen.c | 74 +-------------------
drivers/xen/Kconfig | 20 ++++++
drivers/xen/pci.c | 75 +++++++++++++++++++++
drivers/xen/xen-pciback/conf_space_header.c | 8 ++-
drivers/xen/xen-pciback/pci_stub.c | 3 +-
drivers/xen/xen-pciback/xenbus.c | 2 +-
include/xen/pci.h | 28 ++++++++
8 files changed, 133 insertions(+), 93 deletions(-)
create mode 100644 include/xen/pci.h

diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index 3506d8c598c1..4b08c2b809ea 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -16,27 +16,11 @@ static inline int pci_xen_hvm_init(void)
#endif
#if defined(CONFIG_XEN_DOM0)
int __init pci_xen_initial_domain(void);
-int xen_find_device_domain_owner(struct pci_dev *dev);
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
-int xen_unregister_device_domain_owner(struct pci_dev *dev);
#else
static inline int __init pci_xen_initial_domain(void)
{
return -1;
}
-static inline int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-static inline int xen_register_device_domain_owner(struct pci_dev *dev,
- uint16_t domain)
-{
- return -1;
-}
-static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
#endif

#if defined(CONFIG_PCI_MSI)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 3d41a09c2c14..4a45b0bf9ae4 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -23,6 +23,7 @@

#include <xen/features.h>
#include <xen/events.h>
+#include <xen/pci.h>
#include <asm/xen/pci.h>
#include <asm/xen/cpuid.h>
#include <asm/apic.h>
@@ -583,77 +584,4 @@ int __init pci_xen_initial_domain(void)
}
return 0;
}
-
-struct xen_device_domain_owner {
- domid_t domain;
- struct pci_dev *dev;
- struct list_head list;
-};
-
-static DEFINE_SPINLOCK(dev_domain_list_spinlock);
-static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
-
-static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- list_for_each_entry(owner, &dev_domain_list, list) {
- if (owner->dev == dev)
- return owner;
- }
- return NULL;
-}
-
-int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
- int domain = -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (owner)
- domain = owner->domain;
- spin_unlock(&dev_domain_list_spinlock);
- return domain;
-}
-EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
-
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
-{
- struct xen_device_domain_owner *owner;
-
- owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
- if (!owner)
- return -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- if (find_device(dev)) {
- spin_unlock(&dev_domain_list_spinlock);
- kfree(owner);
- return -EEXIST;
- }
- owner->domain = domain;
- owner->dev = dev;
- list_add_tail(&owner->list, &dev_domain_list);
- spin_unlock(&dev_domain_list_spinlock);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
-
-int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (!owner) {
- spin_unlock(&dev_domain_list_spinlock);
- return -ENODEV;
- }
- list_del(&owner->list);
- spin_unlock(&dev_domain_list_spinlock);
- kfree(owner);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
#endif
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 4efc95ddda41..75b9330dc6fd 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -184,6 +184,26 @@ config SWIOTLB_XEN
config XEN_PCI_STUB
bool

+config XEN_PCIDEV_STUB
+ tristate "Xen PCI-device stub driver"
+ depends on PCI && !X86 && XEN
+ depends on XEN_BACKEND
+ select XEN_PCI_STUB
+ default m
+ help
+ The PCI device stub driver provides limited version of the PCI
+ device backend driver without para-virtualized support for guests.
+ If you select this to be a module, you will need to make sure no
+ other driver has bound to the device(s) you want to make visible to
+ other guests.
+
+ The "hide" parameter (only applicable if backend driver is compiled
+ into the kernel) allows you to bind the PCI devices to this module
+ from the default device drivers. The argument is the list of PCI BDFs:
+ xen-pciback.hide=(03:00.0)(04:00.0)
+
+ If in doubt, say m.
+
config XEN_PCIDEV_BACKEND
tristate "Xen PCI-device backend driver"
depends on PCI && X86 && XEN
diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
index 224df03ce42e..fc8c1249d49f 100644
--- a/drivers/xen/pci.c
+++ b/drivers/xen/pci.c
@@ -254,3 +254,78 @@ static int xen_mcfg_late(void)
return 0;
}
#endif
+
+#ifdef CONFIG_XEN_DOM0
+struct xen_device_domain_owner {
+ domid_t domain;
+ struct pci_dev *dev;
+ struct list_head list;
+};
+
+static DEFINE_SPINLOCK(dev_domain_list_spinlock);
+static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
+
+static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
+{
+ struct xen_device_domain_owner *owner;
+
+ list_for_each_entry(owner, &dev_domain_list, list) {
+ if (owner->dev == dev)
+ return owner;
+ }
+ return NULL;
+}
+
+int xen_find_device_domain_owner(struct pci_dev *dev)
+{
+ struct xen_device_domain_owner *owner;
+ int domain = -ENODEV;
+
+ spin_lock(&dev_domain_list_spinlock);
+ owner = find_device(dev);
+ if (owner)
+ domain = owner->domain;
+ spin_unlock(&dev_domain_list_spinlock);
+ return domain;
+}
+EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
+
+int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
+{
+ struct xen_device_domain_owner *owner;
+
+ owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
+ if (!owner)
+ return -ENODEV;
+
+ spin_lock(&dev_domain_list_spinlock);
+ if (find_device(dev)) {
+ spin_unlock(&dev_domain_list_spinlock);
+ kfree(owner);
+ return -EEXIST;
+ }
+ owner->domain = domain;
+ owner->dev = dev;
+ list_add_tail(&owner->list, &dev_domain_list);
+ spin_unlock(&dev_domain_list_spinlock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
+
+int xen_unregister_device_domain_owner(struct pci_dev *dev)
+{
+ struct xen_device_domain_owner *owner;
+
+ spin_lock(&dev_domain_list_spinlock);
+ owner = find_device(dev);
+ if (!owner) {
+ spin_unlock(&dev_domain_list_spinlock);
+ return -ENODEV;
+ }
+ list_del(&owner->list);
+ spin_unlock(&dev_domain_list_spinlock);
+ kfree(owner);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
+#endif
diff --git a/drivers/xen/xen-pciback/conf_space_header.c b/drivers/xen/xen-pciback/conf_space_header.c
index ac45cdc38e85..981435103af1 100644
--- a/drivers/xen/xen-pciback/conf_space_header.c
+++ b/drivers/xen/xen-pciback/conf_space_header.c
@@ -236,8 +236,12 @@ static void *bar_init(struct pci_dev *dev, int offset)
else {
pos = (offset - PCI_BASE_ADDRESS_0) / 4;
if (pos && (res[pos - 1].flags & IORESOURCE_MEM_64)) {
- bar->val = res[pos - 1].start >> 32;
- bar->len_val = -resource_size(&res[pos - 1]) >> 32;
+ /*
+ * Use ">> 16 >> 16" instead of direct ">> 32" shift
+ * to avoid warnings on 32-bit architectures.
+ */
+ bar->val = res[pos - 1].start >> 16 >> 16;
+ bar->len_val = -resource_size(&res[pos - 1]) >> 16 >> 16;
return bar;
}
}
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index f8e4faa96ad6..bba527620507 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -19,7 +19,8 @@
#include <linux/sched.h>
#include <linux/atomic.h>
#include <xen/events.h>
-#include <asm/xen/pci.h>
+#include <xen/pci.h>
+#include <xen/xen.h>
#include <asm/xen/hypervisor.h>
#include <xen/interface/physdev.h>
#include "pciback.h"
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index f8ba2903a3ff..bde63ef677b8 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -14,7 +14,7 @@
#include <linux/workqueue.h>
#include <xen/xenbus.h>
#include <xen/events.h>
-#include <asm/xen/pci.h>
+#include <xen/pci.h>
#include "pciback.h"

#define INVALID_EVTCHN_IRQ (-1)
diff --git a/include/xen/pci.h b/include/xen/pci.h
new file mode 100644
index 000000000000..b8337cf85fd1
--- /dev/null
+++ b/include/xen/pci.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __XEN_PCI_H__
+#define __XEN_PCI_H__
+
+#if defined(CONFIG_XEN_DOM0)
+int xen_find_device_domain_owner(struct pci_dev *dev);
+int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
+int xen_unregister_device_domain_owner(struct pci_dev *dev);
+#else
+static inline int xen_find_device_domain_owner(struct pci_dev *dev)
+{
+ return -1;
+}
+
+static inline int xen_register_device_domain_owner(struct pci_dev *dev,
+ uint16_t domain)
+{
+ return -1;
+}
+
+static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
+{
+ return -1;
+}
+#endif
+
+#endif
--
2.25.1

Next message: Christian Borntraeger: "Re: [PATCH 05/14] KVM: s390: Clear valid_wakeup in kvm_s390_handle_wait(), not in arch hook"
Previous message: Oleksandr Andrushchenko: "[PATCH v4 1/2] xen-pciback: prepare for the split for stub and PV"
In reply to: Oleksandr Andrushchenko: "[PATCH v4 1/2] xen-pciback: prepare for the split for stub and PV"
Next in thread: Jan Beulich: "Re: [PATCH v4 1/2] xen-pciback: prepare for the split for stub and PV"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]