On Mon, Jul 08, 2024 at 07:41:23PM +0800, Jiqian Chen wrote: > When passthrough a device to domU, QEMU and xl tools use its gsi > number to do pirq mapping, see QEMU code > xen_pt_realize->xc_physdev_map_pirq, and xl code > pci_add_dm_done->xc_physdev_map_pirq, but the gsi number is got > from file /sys/bus/pci/devices/<sbdf>/irq, that is wrong, because > irq is not equal with gsi, they are in different spaces, so pirq > mapping fails. > > And in current codes, there is no method to get gsi for userspace. > For above purpose, add new function to get gsi, and the > corresponding ioctl is implemented on linux kernel side. > > Signed-off-by: Jiqian Chen <jiqian.c...@amd.com> > Signed-off-by: Huang Rui <ray.hu...@amd.com> > Signed-off-by: Chen Jiqian <jiqian.c...@amd.com> > --- > RFC: it needs to wait for the corresponding third patch on linux kernel side > to be merged. > https://lore.kernel.org/xen-devel/20240607075109.126277-4-jiqian.c...@amd.com/ > This patch must be merged after the patch on linux kernel side > > CC: Anthony PERARD <anth...@xenproject.org> > Remaining comment @Anthony PERARD: > Do I need to make " opening of /dev/xen/privcmd " as a single function, then > use it in this > patch and other libraries? > --- > tools/include/xen-sys/Linux/privcmd.h | 7 ++++++ > tools/include/xenctrl.h | 2 ++ > tools/libs/ctrl/xc_physdev.c | 35 +++++++++++++++++++++++++++ > 3 files changed, 44 insertions(+) > > diff --git a/tools/include/xen-sys/Linux/privcmd.h > b/tools/include/xen-sys/Linux/privcmd.h > index bc60e8fd55eb..4cf719102116 100644 > --- a/tools/include/xen-sys/Linux/privcmd.h > +++ b/tools/include/xen-sys/Linux/privcmd.h > @@ -95,6 +95,11 @@ typedef struct privcmd_mmap_resource { > __u64 addr; > } privcmd_mmap_resource_t; > > +typedef struct privcmd_gsi_from_pcidev { > + __u32 sbdf; > + __u32 gsi; > +} privcmd_gsi_from_pcidev_t; > + > /* > * @cmd: IOCTL_PRIVCMD_HYPERCALL > * @arg: &privcmd_hypercall_t > @@ -114,6 +119,8 @@ typedef struct privcmd_mmap_resource { > _IOC(_IOC_NONE, 'P', 6, sizeof(domid_t)) > #define IOCTL_PRIVCMD_MMAP_RESOURCE \ > _IOC(_IOC_NONE, 'P', 7, sizeof(privcmd_mmap_resource_t)) > +#define IOCTL_PRIVCMD_GSI_FROM_PCIDEV \ > + _IOC(_IOC_NONE, 'P', 10, sizeof(privcmd_gsi_from_pcidev_t)) > #define IOCTL_PRIVCMD_UNIMPLEMENTED \ > _IOC(_IOC_NONE, 'P', 0xFF, 0) > > diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h > index 9ceca0cffc2f..3720e22b399a 100644 > --- a/tools/include/xenctrl.h > +++ b/tools/include/xenctrl.h > @@ -1641,6 +1641,8 @@ int xc_physdev_unmap_pirq(xc_interface *xch, > uint32_t domid, > int pirq); > > +int xc_physdev_gsi_from_pcidev(xc_interface *xch, uint32_t sbdf); > + > /* > * LOGGING AND ERROR REPORTING > */ > diff --git a/tools/libs/ctrl/xc_physdev.c b/tools/libs/ctrl/xc_physdev.c > index e9fcd755fa62..54edb0f3c0dc 100644 > --- a/tools/libs/ctrl/xc_physdev.c > +++ b/tools/libs/ctrl/xc_physdev.c > @@ -111,3 +111,38 @@ int xc_physdev_unmap_pirq(xc_interface *xch, > return rc; > } > > +int xc_physdev_gsi_from_pcidev(xc_interface *xch, uint32_t sbdf)
FWIW, I'm not sure it's fine to use the xc_physdev prefix here, as this is not a PHYSDEVOP hypercall. As Anthony suggested, it would be better placed in xc_linux.c, and possibly named xc_pcidev_get_gsi() or similar, to avoid polluting the xc_physdev namespace. Thanks, Roger.
