[RFC KERNEL PATCH v5 0/3] Support device passthrough when dom0 is PVH on Xen

[RFC KERNEL PATCH v5 0/3] Support device passthrough when dom0 is PVH on Xen

[Jiqian Chen]

Hi All,
This is v5 series to support passthrough on Xen when dom0 is PVH.
patch#2 change function acpi_pci_irq_lookup from a static function to non-static, need ACPI Maintainer to give some comments.
patch#3 linux internal changes, need PCI and ACPI Maintainer to give more comments.
v4->v5 changes:
* patch#1: Add Reviewed-by Stefano
* patch#2: Add Reviewed-by Stefano
* patch#3: No changes

v3->v4 changes:
* patch#1: change the comment of PHYSDEVOP_pci_device_state_reset; use a new function pcistub_reset_device_state to wrap __pci_reset_function_locked and xen_reset_device_state, and call pcistub_reset_device_state in pci_stub.c
* patch#2: remove map_pirq from xen_pvh_passthrough_gsi

v3 link:
https://lore.kernel.org/lkml/20231210161519.1550860-1-Jiqian.Chen@amd.com/T/#t
v2->v3 changes:
* patch#1: add condition to limit do xen_reset_device_state for no-pv domain in pcistub_init_device.
* patch#2: Abandoning previous implementations that call unmask_irq. To setup gsi and map pirq for passthrough device in pcistub_init_device.
* patch#3: Abandoning previous implementations that adds new syscall to get gsi from irq. To add a new sysfs for gsi, then userspace can get gsi number from sysfs.


v2 link:
https://lore.kernel.org/lkml/20231124103123.3263471-1-Jiqian.Chen@amd.com/T/#t

Below is the description of v2 cover letter:
This series of patches are the v2 of the implementation of passthrough when dom0 is PVH on Xen.
We sent the v1 to upstream before, but the v1 had so many problems and we got lots of suggestions.
I will introduce all issues that these patches try to fix and the differences between v1 and v2.

Issues we encountered:
1. pci_stub failed to write bar for a passthrough device.
Problem: when we run “sudo xl pci-assignable-add <sbdf>” to assign a device, pci_stub will call “pcistub_init_device() -> pci_restore_state() -> pci_restore_config_space() ->
pci_restore_config_space_range() -> pci_restore_config_dword() -> pci_write_config_dword()”, the pci config write will trigger an io interrupt to bar_write() in the xen, but the
bar->enabled was set before, the write is not allowed now, and then when 
bar->Qemu config the
passthrough device in xen_pt_realize(), it gets invalid bar values.

Reason: the reason is that we don't tell vPCI that the device has been reset, so the current cached state in pdev->vpci is all out of date and is different from the real device state.

Solution: to solve this problem, the first patch of kernel(xen/pci: Add xen_reset_device_state
function) and the fist patch of xen(xen/vpci: Clear all vpci status of device) add a new hypercall to reset the state stored in vPCI when the state of real device has changed.
Thank Roger for the suggestion of this v2, and it is different from v1 (https://lore.kernel.org/xen-devel/20230312075455.450187-3-ray.huang@amd.com/), v1 simply allow domU to write pci bar, it does not comply with the design principles of vPCI.

2. failed to do PHYSDEVOP_map_pirq when dom0 is PVH
Problem: HVM domU will do PHYSDEVOP_map_pirq for a passthrough device by using gsi. See xen_pt_realize->xc_physdev_map_pirq and pci_add_dm_done->xc_physdev_map_pirq. Then xc_physdev_map_pirq will call into Xen, but in hvm_physdev_op(), PHYSDEVOP_map_pirq is not allowed.

Reason: In hvm_physdev_op(), the variable "currd" is PVH dom0 and PVH has no X86_EMU_USE_PIRQ flag, it will fail at has_pirq check.

Solution: I think we may need to allow PHYSDEVOP_map_pirq when "currd" is dom0 (at present dom0 is PVH). The second patch of xen(x86/pvh: Open PHYSDEVOP_map_pirq for PVH dom0) allow PVH dom0 do PHYSDEVOP_map_pirq. This v2 patch is better than v1, v1 simply remove the has_pirq check(xen https://lore.kernel.org/xen-devel/20230312075455.450187-4-ray.huang@amd.com/).

3. the gsi of a passthrough device doesn't be unmasked
 3.1 failed to check the permission of pirq
 3.2 the gsi of passthrough device was not registered in PVH dom0

Problem:
3.1 callback function pci_add_dm_done() will be called when qemu config a passthrough device for domU.
This function will call xc_domain_irq_permission()-> pirq_access_permitted() to check if the gsi has corresponding mappings in dom0. But it didn’t, so failed. See XEN_DOMCTL_irq_permission->pirq_access_permitted, "current" is PVH dom0 and it return irq is 0.
3.2 it's possible for a gsi (iow: vIO-APIC pin) to never get registered on PVH dom0, because the devices of PVH are using MSI(-X) interrupts. However, the IO-APIC pin must be configured for it to be able to be mapped into a domU.

Reason: After searching codes, I find "map_pirq" and "register_gsi" will be done in function vioapic_write_redirent->vioapic_hwdom_map_gsi when the gsi(aka ioapic's pin) is unmasked in PVH dom0.
So the two problems can be concluded to that the gsi of a passthrough device doesn't be unmasked.

Solution: to solve these problems, the second patch of kernel(xen/pvh: Unmask irq for passthrough device in PVH dom0) call the unmask_irq() when we assign a device to be passthrough. So that passthrough devices can have the mapping of gsi on PVH dom0 and gsi can be registered. This v2 patch is different from the v1( kernel https://lore.kernel.org/xen-devel/20230312120157.452859-5-ray.huang@amd.com/,
kernel https://lore.kernel.org/xen-devel/20230312120157.452859-5-ray.huang@amd.com/ and xen https://lore.kernel.org/xen-devel/20230312075455.450187-5-ray.huang@amd.com/),
v1 performed "map_pirq" and "register_gsi" on all pci devices on PVH dom0, which is unnecessary and may cause multiple registration.

4. failed to map pirq for gsi
Problem: qemu will call xc_physdev_map_pirq() to map a passthrough device’s gsi to pirq in function xen_pt_realize(). But failed.

Reason: According to the implement of xc_physdev_map_pirq(), it needs gsi instead of irq, but qemu pass irq to it and treat irq as gsi, it is got from file /sys/bus/pci/devices/xxxx:xx:xx.x/irq in function xen_host_pci_device_get(). But actually the gsi number is not equal with irq. On PVH dom0, when it allocates irq for a gsi in function acpi_register_gsi_ioapic(), allocation is dynamic, and follow the principle of applying first, distributing first. And if you debug the kernel codes(see function __irq_alloc_descs), you will find the irq number is allocated from small to large by order, but the applying gsi number is not, gsi 38 may come before gsi 28, that causes gsi 38 get a smaller irq number than gsi 28, and then gsi != irq.

Solution: we can record the relation between gsi and irq, then when userspace(qemu) want to use gsi, we can do a translation. The third patch of kernel(xen/privcmd: Add new syscall to get gsi from irq) records all the relations in acpi_register_gsi_xen_pvh() when dom0 initialize pci devices, and provide a syscall for userspace to get the gsi from irq. The third patch of xen(tools: Add new function to get gsi from irq) add a new function xc_physdev_gsi_from_irq() to call the new syscall added on kernel side.
And then userspace can use that function to get gsi. Then xc_physdev_map_pirq() will success. This v2 patch is the same as v1( kernel https://lore.kernel.org/xen-devel/20230312120157.452859-6-ray.huang@amd.com/ and xen https://lore.kernel.org/xen-devel/20230312075455.450187-6-ray.huang@amd.com/)

About the v2 patch of qemu, just change an included head file, other are similar to the v1 ( qemu https://lore.kernel.org/xen-devel/20230312092244.451465-19-ray.huang@amd.com/), just call
xc_physdev_gsi_from_irq() to get gsi from irq.


Jiqian Chen (3):
  xen/pci: Add xen_reset_device_state function
  xen/pvh: Setup gsi for passthrough device
  PCI/sysfs: Add gsi sysfs for pci_dev

 arch/x86/xen/enlighten_pvh.c       | 92 ++++++++++++++++++++++++++++++
 drivers/acpi/pci_irq.c             |  3 +-
 drivers/pci/pci-sysfs.c            | 11 ++++
 drivers/xen/pci.c                  | 12 ++++
 drivers/xen/xen-pciback/pci_stub.c | 26 ++++++++-
 include/linux/acpi.h               |  1 +
 include/linux/pci.h                |  2 +
 include/xen/acpi.h                 |  6 ++
 include/xen/interface/physdev.h    |  7 +++
 include/xen/pci.h                  |  6 ++
 10 files changed, 162 insertions(+), 4 deletions(-)

-- 
2.34.1

[KERNEL PATCH v5 1/3] xen/pci: Add xen_reset_device_state function

[Jiqian Chen]

When device on dom0 side has been reset, the vpci on Xen side
won't get notification, so that the cached state in vpci is
all out of date with the real device state.
To solve that problem, add a new function to clear all vpci
device state when device is reset on dom0 side.

And call that function in pcistub_init_device. Because when
using "pci-assignable-add" to assign a passthrough device in
Xen, it will reset passthrough device and the vpci state will
out of date, and then device will fail to restore bar state.

Co-developed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
 drivers/xen/pci.c                  | 12 ++++++++++++
 drivers/xen/xen-pciback/pci_stub.c | 18 +++++++++++++++---
 include/xen/interface/physdev.h    |  7 +++++++
 include/xen/pci.h                  |  6 ++++++
 4 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
index 72d4e3f193af..e9b30bc09139 100644
--- a/drivers/xen/pci.c
+++ b/drivers/xen/pci.c
@@ -177,6 +177,18 @@ static int xen_remove_device(struct device *dev)
 	return r;
 }
 
+int xen_reset_device_state(const struct pci_dev *dev)
+{
+	struct physdev_pci_device device = {
+		.seg = pci_domain_nr(dev->bus),
+		.bus = dev->bus->number,
+		.devfn = dev->devfn
+	};
+
+	return HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_state_reset, &device);
+}
+EXPORT_SYMBOL_GPL(xen_reset_device_state);
+
 static int xen_pci_notifier(struct notifier_block *nb,
 			    unsigned long action, void *data)
 {
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index e34b623e4b41..46c40ec8a18e 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -89,6 +89,16 @@ static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
 	return psdev;
 }
 
+static int pcistub_reset_device_state(struct pci_dev *dev)
+{
+	__pci_reset_function_locked(dev);
+
+	if (!xen_pv_domain())
+		return xen_reset_device_state(dev);
+	else
+		return 0;
+}
+
 /* Don't call this directly as it's called by pcistub_device_put */
 static void pcistub_device_release(struct kref *kref)
 {
@@ -107,7 +117,7 @@ static void pcistub_device_release(struct kref *kref)
 	/* Call the reset function which does not take lock as this
 	 * is called from "unbind" which takes a device_lock mutex.
 	 */
-	__pci_reset_function_locked(dev);
+	pcistub_reset_device_state(dev);
 	if (dev_data &&
 	    pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state))
 		dev_info(&dev->dev, "Could not reload PCI state\n");
@@ -284,7 +294,7 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
 	 * (so it's ready for the next domain)
 	 */
 	device_lock_assert(&dev->dev);
-	__pci_reset_function_locked(dev);
+	pcistub_reset_device_state(dev);
 
 	dev_data = pci_get_drvdata(dev);
 	ret = pci_load_saved_state(dev, dev_data->pci_saved_state);
@@ -420,7 +430,9 @@ static int pcistub_init_device(struct pci_dev *dev)
 		dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
 	else {
 		dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n");
-		__pci_reset_function_locked(dev);
+		err = pcistub_reset_device_state(dev);
+		if (err)
+			goto config_release;
 		pci_restore_state(dev);
 	}
 	/* Now disable the device (this also ensures some private device
diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h
index a237af867873..8609770e28f5 100644
--- a/include/xen/interface/physdev.h
+++ b/include/xen/interface/physdev.h
@@ -256,6 +256,13 @@ struct physdev_pci_device_add {
  */
 #define PHYSDEVOP_prepare_msix          30
 #define PHYSDEVOP_release_msix          31
+/*
+ * Notify the hypervisor that a PCI device has been reset, so that any
+ * internally cached state is regenerated.  Should be called after any
+ * device reset performed by the hardware domain.
+ */
+#define PHYSDEVOP_pci_device_state_reset     32
+
 struct physdev_pci_device {
     /* IN */
     uint16_t seg;
diff --git a/include/xen/pci.h b/include/xen/pci.h
index b8337cf85fd1..b2e2e856efd6 100644
--- a/include/xen/pci.h
+++ b/include/xen/pci.h
@@ -4,10 +4,16 @@
 #define __XEN_PCI_H__
 
 #if defined(CONFIG_XEN_DOM0)
+int xen_reset_device_state(const struct pci_dev *dev);
 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_reset_device_state(const struct pci_dev *dev)
+{
+	return -1;
+}
+
 static inline int xen_find_device_domain_owner(struct pci_dev *dev)
 {
 	return -1;
-- 
2.34.1

[RFC KERNEL PATCH v5 2/3] xen/pvh: Setup gsi for passthrough device

[Jiqian Chen]

In PVH dom0, the gsis don't get registered, but the gsi of
a passthrough device must be configured for it to be able to be
mapped into a domU.

When assign a device to passthrough, proactively setup the gsi
of the device during that process.

Co-developed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
RFC: This patch change function acpi_pci_irq_lookup from a static function to non-static, need ACPI Maintainer to give some comments.

---
 arch/x86/xen/enlighten_pvh.c       | 92 ++++++++++++++++++++++++++++++
 drivers/acpi/pci_irq.c             |  2 +-
 drivers/xen/xen-pciback/pci_stub.c |  8 +++
 include/linux/acpi.h               |  1 +
 include/xen/acpi.h                 |  6 ++
 5 files changed, 108 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index c28f073c1df5..12be665b27d8 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -2,6 +2,7 @@
 #include <linux/acpi.h>
 #include <linux/export.h>
 #include <linux/mm.h>
+#include <linux/pci.h>
 
 #include <xen/hvc-console.h>
 
@@ -26,6 +27,97 @@
 bool __ro_after_init xen_pvh;
 EXPORT_SYMBOL_GPL(xen_pvh);
 
+typedef struct gsi_info {
+	int gsi;
+	int trigger;
+	int polarity;
+} gsi_info_t;
+
+struct acpi_prt_entry {
+	struct acpi_pci_id	id;
+	u8			pin;
+	acpi_handle		link;
+	u32			index;		/* GSI, or link _CRS index */
+};
+
+static int xen_pvh_get_gsi_info(struct pci_dev *dev,
+								gsi_info_t *gsi_info)
+{
+	int gsi;
+	u8 pin;
+	struct acpi_prt_entry *entry;
+	int trigger = ACPI_LEVEL_SENSITIVE;
+	int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
+				      ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
+
+	if (!dev || !gsi_info)
+		return -EINVAL;
+
+	pin = dev->pin;
+	if (!pin)
+		return -EINVAL;
+
+	entry = acpi_pci_irq_lookup(dev, pin);
+	if (entry) {
+		if (entry->link)
+			gsi = acpi_pci_link_allocate_irq(entry->link,
+							 entry->index,
+							 &trigger, &polarity,
+							 NULL);
+		else
+			gsi = entry->index;
+	} else
+		gsi = -1;
+
+	if (gsi < 0)
+		return -EINVAL;
+
+	gsi_info->gsi = gsi;
+	gsi_info->trigger = trigger;
+	gsi_info->polarity = polarity;
+
+	return 0;
+}
+
+static int xen_pvh_setup_gsi(gsi_info_t *gsi_info)
+{
+	struct physdev_setup_gsi setup_gsi;
+
+	if (!gsi_info)
+		return -EINVAL;
+
+	setup_gsi.gsi = gsi_info->gsi;
+	setup_gsi.triggering = (gsi_info->trigger == ACPI_EDGE_SENSITIVE ? 0 : 1);
+	setup_gsi.polarity = (gsi_info->polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+
+	return HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
+}
+
+int xen_pvh_passthrough_gsi(struct pci_dev *dev)
+{
+	int ret;
+	gsi_info_t gsi_info;
+
+	if (!dev)
+		return -EINVAL;
+
+	ret = xen_pvh_get_gsi_info(dev, &gsi_info);
+	if (ret) {
+		xen_raw_printk("Fail to get gsi info!\n");
+		return ret;
+	}
+
+	ret = xen_pvh_setup_gsi(&gsi_info);
+	if (ret == -EEXIST) {
+		xen_raw_printk("Already setup the GSI :%d\n", gsi_info.gsi);
+		ret = 0;
+	} else if (ret)
+		xen_raw_printk("Fail to setup GSI (%d)!\n", gsi_info.gsi);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(xen_pvh_passthrough_gsi);
+
 void __init xen_pvh_init(struct boot_params *boot_params)
 {
 	u32 msr;
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index ff30ceca2203..630fe0a34bc6 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -288,7 +288,7 @@ static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
 }
 #endif /* CONFIG_X86_IO_APIC */
 
-static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
+struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
 {
 	struct acpi_prt_entry *entry = NULL;
 	struct pci_dev *bridge;
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 46c40ec8a18e..22d4380d2b04 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -20,6 +20,7 @@
 #include <linux/atomic.h>
 #include <xen/events.h>
 #include <xen/pci.h>
+#include <xen/acpi.h>
 #include <xen/xen.h>
 #include <asm/xen/hypervisor.h>
 #include <xen/interface/physdev.h>
@@ -435,6 +436,13 @@ static int pcistub_init_device(struct pci_dev *dev)
 			goto config_release;
 		pci_restore_state(dev);
 	}
+
+	if (xen_initial_domain() && xen_pvh_domain()) {
+		err = xen_pvh_passthrough_gsi(dev);
+		if (err)
+			goto config_release;
+	}
+
 	/* Now disable the device (this also ensures some private device
 	 * data is setup before we export)
 	 */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index b7165e52b3c6..08f1e316bf27 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -361,6 +361,7 @@ void acpi_unregister_gsi (u32 gsi);
 
 struct pci_dev;
 
+struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin);
 int acpi_pci_irq_enable (struct pci_dev *dev);
 void acpi_penalize_isa_irq(int irq, int active);
 bool acpi_isa_irq_available(int irq);
diff --git a/include/xen/acpi.h b/include/xen/acpi.h
index b1e11863144d..17c4d37f1e60 100644
--- a/include/xen/acpi.h
+++ b/include/xen/acpi.h
@@ -67,10 +67,16 @@ static inline void xen_acpi_sleep_register(void)
 		acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
 	}
 }
+int xen_pvh_passthrough_gsi(struct pci_dev *dev);
 #else
 static inline void xen_acpi_sleep_register(void)
 {
 }
+
+static inline int xen_pvh_passthrough_gsi(struct pci_dev *dev)
+{
+	return -1;
+}
 #endif
 
 #endif	/* _XEN_ACPI_H */
-- 
2.34.1

[RFC KERNEL PATCH v5 3/3] PCI/sysfs: Add gsi sysfs for pci_dev

[Jiqian Chen]

There is a need for some scenarios to use gsi sysfs.
For example, when xen passthrough a device to dumU, it will
use gsi to map pirq, but currently userspace can't get gsi
number.
So, add gsi sysfs for that and for other potential scenarios.

Co-developed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
---
RFC: No feasible suggestions were obtained in the discussion of v4.
Discussions are still needed where/how to expose the gsi.
Looking forward to get more comments and suggestions from PCI/ACPI Maintainers.

---
 drivers/acpi/pci_irq.c  |  1 +
 drivers/pci/pci-sysfs.c | 11 +++++++++++
 include/linux/pci.h     |  2 ++
 3 files changed, 14 insertions(+)

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 630fe0a34bc6..739a58755df2 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -449,6 +449,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
 		kfree(entry);
 		return 0;
 	}
+	dev->gsi = gsi;
 
 	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
 	if (rc < 0) {
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 2321fdfefd7d..c51df88d079e 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -71,6 +71,16 @@ static ssize_t irq_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(irq);
 
+static ssize_t gsi_show(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return sysfs_emit(buf, "%u\n", pdev->gsi);
+}
+static DEVICE_ATTR_RO(gsi);
+
 static ssize_t broken_parity_status_show(struct device *dev,
 					 struct device_attribute *attr,
 					 char *buf)
@@ -596,6 +606,7 @@ static struct attribute *pci_dev_attrs[] = {
 	&dev_attr_revision.attr,
 	&dev_attr_class.attr,
 	&dev_attr_irq.attr,
+	&dev_attr_gsi.attr,
 	&dev_attr_local_cpus.attr,
 	&dev_attr_local_cpulist.attr,
 	&dev_attr_modalias.attr,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7ab0d13672da..457043cfdfce 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -529,6 +529,8 @@ struct pci_dev {
 
 	/* These methods index pci_reset_fn_methods[] */
 	u8 reset_methods[PCI_NUM_RESET_METHODS]; /* In priority order */
+
+	unsigned int	gsi;
 };
 
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
-- 
2.34.1

Re: [RFC KERNEL PATCH v5 2/3] xen/pvh: Setup gsi for passthrough device

[kernel test robot]

Hi Jiqian,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on pci/next pci/for-linus rafael-pm/linux-next linus/master v6.9-rc1 next-20240328]
[cannot apply to tip/x86/core rafael-pm/acpi-bus rafael-pm/devprop]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Jiqian-Chen/xen-pci-Add-xen_reset_device_state-function/20240328-145956
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
patch link:    https://lore.kernel.org/r/20240328065646.354782-3-Jiqian.Chen%40amd.com
patch subject: [RFC KERNEL PATCH v5 2/3] xen/pvh: Setup gsi for passthrough device
config: arm64-defconfig (https://download.01.org/0day-ci/archive/20240331/202403310809.zuyZiCEM-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240331/202403310809.zuyZiCEM-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202403310809.zuyZiCEM-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/xen/xen-pciback/pci_stub.c:23:
   include/xen/acpi.h: In function 'xen_acpi_sleep_register':
>> include/xen/acpi.h:67:17: error: 'acpi_suspend_lowlevel' undeclared (first use in this function); did you mean 'xen_acpi_suspend_lowlevel'?
      67 |                 acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
         |                 ^~~~~~~~~~~~~~~~~~~~~
         |                 xen_acpi_suspend_lowlevel
   include/xen/acpi.h:67:17: note: each undeclared identifier is reported only once for each function it appears in


vim +67 include/xen/acpi.h

068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  58  
268a207563f933 Liu Jinsong           2013-02-14  59  static inline void xen_acpi_sleep_register(void)
268a207563f933 Liu Jinsong           2013-02-14  60  {
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  61  	if (xen_initial_domain()) {
268a207563f933 Liu Jinsong           2013-02-14  62  		acpi_os_set_prepare_sleep(
be6b25d15f5e67 Ben Guthro            2013-07-30  63  			&xen_acpi_notify_hypervisor_sleep);
be6b25d15f5e67 Ben Guthro            2013-07-30  64  		acpi_os_set_prepare_extended_sleep(
be6b25d15f5e67 Ben Guthro            2013-07-30  65  			&xen_acpi_notify_hypervisor_extended_sleep);
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  66  
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14 @67  		acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  68  	}
268a207563f933 Liu Jinsong           2013-02-14  69  }
818bdd39dbd468 Jiqian Chen           2024-03-28  70  int xen_pvh_passthrough_gsi(struct pci_dev *dev);
268a207563f933 Liu Jinsong           2013-02-14  71  #else
268a207563f933 Liu Jinsong           2013-02-14  72  static inline void xen_acpi_sleep_register(void)
268a207563f933 Liu Jinsong           2013-02-14  73  {
268a207563f933 Liu Jinsong           2013-02-14  74  }
818bdd39dbd468 Jiqian Chen           2024-03-28  75  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [RFC KERNEL PATCH v5 2/3] xen/pvh: Setup gsi for passthrough device

[kernel test robot]

Hi Jiqian,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on pci/next pci/for-linus rafael-pm/linux-next linus/master v6.9-rc1 next-20240328]
[cannot apply to tip/x86/core rafael-pm/acpi-bus rafael-pm/devprop]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Jiqian-Chen/xen-pci-Add-xen_reset_device_state-function/20240328-145956
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
patch link:    https://lore.kernel.org/r/20240328065646.354782-3-Jiqian.Chen%40amd.com
patch subject: [RFC KERNEL PATCH v5 2/3] xen/pvh: Setup gsi for passthrough device
config: arm64-randconfig-001-20240331 (https://download.01.org/0day-ci/archive/20240331/202403310932.nmHEif4W-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240331/202403310932.nmHEif4W-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202403310932.nmHEif4W-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/xen/xen-pciback/pci_stub.c:23:
   include/xen/acpi.h: In function 'xen_acpi_sleep_register':
>> include/xen/acpi.h:63:58: error: macro "acpi_os_set_prepare_sleep" requires 3 arguments, but only 1 given
      63 |                         &xen_acpi_notify_hypervisor_sleep);
         |                                                          ^
   In file included from include/xen/acpi.h:41:
   include/linux/acpi.h:1121: note: macro "acpi_os_set_prepare_sleep" defined here
    1121 | #define acpi_os_set_prepare_sleep(func, pm1a_ctrl, pm1b_ctrl) do { } while (0)
         | 
>> include/xen/acpi.h:62:17: error: 'acpi_os_set_prepare_sleep' undeclared (first use in this function); did you mean 'acpi_os_enter_sleep'?
      62 |                 acpi_os_set_prepare_sleep(
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~
         |                 acpi_os_enter_sleep
   include/xen/acpi.h:62:17: note: each undeclared identifier is reported only once for each function it appears in
>> include/xen/acpi.h:64:17: error: implicit declaration of function 'acpi_os_set_prepare_extended_sleep'; did you mean 'acpi_os_set_prepare_sleep'? [-Werror=implicit-function-declaration]
      64 |                 acpi_os_set_prepare_extended_sleep(
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         |                 acpi_os_set_prepare_sleep
   include/xen/acpi.h:67:17: error: 'acpi_suspend_lowlevel' undeclared (first use in this function); did you mean 'xen_acpi_suspend_lowlevel'?
      67 |                 acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
         |                 ^~~~~~~~~~~~~~~~~~~~~
         |                 xen_acpi_suspend_lowlevel
   cc1: some warnings being treated as errors


vim +/acpi_os_set_prepare_sleep +63 include/xen/acpi.h

068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  58  
268a207563f933 Liu Jinsong           2013-02-14  59  static inline void xen_acpi_sleep_register(void)
268a207563f933 Liu Jinsong           2013-02-14  60  {
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  61  	if (xen_initial_domain()) {
268a207563f933 Liu Jinsong           2013-02-14 @62  		acpi_os_set_prepare_sleep(
be6b25d15f5e67 Ben Guthro            2013-07-30 @63  			&xen_acpi_notify_hypervisor_sleep);
be6b25d15f5e67 Ben Guthro            2013-07-30 @64  		acpi_os_set_prepare_extended_sleep(
be6b25d15f5e67 Ben Guthro            2013-07-30  65  			&xen_acpi_notify_hypervisor_extended_sleep);
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  66  
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  67  		acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
068e0dc7b7c1db Konrad Rzeszutek Wilk 2013-05-14  68  	}
268a207563f933 Liu Jinsong           2013-02-14  69  }
818bdd39dbd468 Jiqian Chen           2024-03-28  70  int xen_pvh_passthrough_gsi(struct pci_dev *dev);
268a207563f933 Liu Jinsong           2013-02-14  71  #else
268a207563f933 Liu Jinsong           2013-02-14  72  static inline void xen_acpi_sleep_register(void)
268a207563f933 Liu Jinsong           2013-02-14  73  {
268a207563f933 Liu Jinsong           2013-02-14  74  }
818bdd39dbd468 Jiqian Chen           2024-03-28  75  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki