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xen: Remove dependency between pciback and privcmd

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Commit 2fae6bb7be ("xen/privcmd: Add new syscall to get gsi from dev")
adds a weak reverse dependency to the config XEN_PRIVCMD definition, that
dependency causes xen-privcmd can't be loaded on domU, because dependent
xen-pciback isn't always be loaded successfully on domU.

To solve above problem, remove that dependency, and do not call
pcistub_get_gsi_from_sbdf() directly, instead add a hook in
drivers/xen/apci.c, xen-pciback register the real call function, then in
privcmd_ioctl_pcidev_get_gsi call that hook.

Fixes: 2fae6bb7be ("xen/privcmd: Add new syscall to get gsi from dev")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Message-ID: <20241012084537.1543059-1-Jiqian.Chen@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Jiqian Chen 2024-10-12 16:45:37 +08:00 committed by Juergen Gross
parent bf56c41016
commit 0fd2a74330
5 changed files with 44 additions and 12 deletions
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1
drivers/xen/Kconfig
View File

@ -261,7 +261,6 @@ config XEN_SCSI_BACKEND
config XEN_PRIVCMD
tristate "Xen hypercall passthrough driver"
depends on XEN
imply XEN_PCIDEV_BACKEND
default m
help
The hypercall passthrough driver allows privileged user programs to

24
drivers/xen/acpi.c
View File

@ -125,3 +125,27 @@ int xen_acpi_get_gsi_info(struct pci_dev *dev,
return 0;
}
EXPORT_SYMBOL_GPL(xen_acpi_get_gsi_info);
static get_gsi_from_sbdf_t get_gsi_from_sbdf;
static DEFINE_RWLOCK(get_gsi_from_sbdf_lock);
void xen_acpi_register_get_gsi_func(get_gsi_from_sbdf_t func)
{
write_lock(&get_gsi_from_sbdf_lock);
get_gsi_from_sbdf = func;
write_unlock(&get_gsi_from_sbdf_lock);
}
EXPORT_SYMBOL_GPL(xen_acpi_register_get_gsi_func);
int xen_acpi_get_gsi_from_sbdf(u32 sbdf)
{
int ret = -EOPNOTSUPP;
read_lock(&get_gsi_from_sbdf_lock);
if (get_gsi_from_sbdf)
ret = get_gsi_from_sbdf(sbdf);
read_unlock(&get_gsi_from_sbdf_lock);
return ret;
}
EXPORT_SYMBOL_GPL(xen_acpi_get_gsi_from_sbdf);

6
drivers/xen/privcmd.c
View File

@ -850,15 +850,13 @@ out:
static long privcmd_ioctl_pcidev_get_gsi(struct file *file, void __user *udata)
{
#if defined(CONFIG_XEN_ACPI)
int rc = -EINVAL;
int rc;
struct privcmd_pcidev_get_gsi kdata;
if (copy_from_user(&kdata, udata, sizeof(kdata)))
return -EFAULT;
if (IS_REACHABLE(CONFIG_XEN_PCIDEV_BACKEND))
rc = pcistub_get_gsi_from_sbdf(kdata.sbdf);
rc = xen_acpi_get_gsi_from_sbdf(kdata.sbdf);
if (rc < 0)
return rc;

11
drivers/xen/xen-pciback/pci_stub.c
View File

@ -227,7 +227,7 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev,
}
#ifdef CONFIG_XEN_ACPI
int pcistub_get_gsi_from_sbdf(unsigned int sbdf)
static int pcistub_get_gsi_from_sbdf(unsigned int sbdf)
{
struct pcistub_device *psdev;
int domain = (sbdf >> 16) & 0xffff;
@ -242,7 +242,6 @@ int pcistub_get_gsi_from_sbdf(unsigned int sbdf)
return psdev->gsi;
}
EXPORT_SYMBOL_GPL(pcistub_get_gsi_from_sbdf);
#endif
struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
@ -1757,11 +1756,19 @@ static int __init xen_pcibk_init(void)
bus_register_notifier(&pci_bus_type, &pci_stub_nb);
#endif
#ifdef CONFIG_XEN_ACPI
xen_acpi_register_get_gsi_func(pcistub_get_gsi_from_sbdf);
#endif
return err;
}
static void __exit xen_pcibk_cleanup(void)
{
#ifdef CONFIG_XEN_ACPI
xen_acpi_register_get_gsi_func(NULL);
#endif
#ifdef CONFIG_PCI_IOV
bus_unregister_notifier(&pci_bus_type, &pci_stub_nb);
#endif

14
include/xen/acpi.h
View File

@ -35,6 +35,8 @@
#include <linux/types.h>
typedef int (*get_gsi_from_sbdf_t)(u32 sbdf);
#ifdef CONFIG_XEN_DOM0
#include <asm/xen/hypervisor.h>
#include <xen/xen.h>
@ -72,6 +74,8 @@ int xen_acpi_get_gsi_info(struct pci_dev *dev,
int *gsi_out,
int *trigger_out,
int *polarity_out);
void xen_acpi_register_get_gsi_func(get_gsi_from_sbdf_t func);
int xen_acpi_get_gsi_from_sbdf(u32 sbdf);
#else
static inline void xen_acpi_sleep_register(void)
{
@ -89,12 +93,12 @@ static inline int xen_acpi_get_gsi_info(struct pci_dev *dev,
{
return -1;
}
#endif
#ifdef CONFIG_XEN_PCI_STUB
int pcistub_get_gsi_from_sbdf(unsigned int sbdf);
#else
static inline int pcistub_get_gsi_from_sbdf(unsigned int sbdf)
static inline void xen_acpi_register_get_gsi_func(get_gsi_from_sbdf_t func)
{
}
static inline int xen_acpi_get_gsi_from_sbdf(u32 sbdf)
{
return -1;
}