On Thu, Mar 19, 2026 at 17:36:51 +0100, Pavel Hrdina via Devel wrote:
> From: Pavel Hrdina <[email protected]>
>
> This function is used to figure out if VM needs access to /dev/vfio/vfio.
> In case of PCI host devices that is true only if IOMMUFD is not enabled.
>
> This fixes error when hotplugging PCI host device with IOMMUFD disabled
> to a VM that already has PCI host device with IOMMIFD enabled:
>
> Could not open '/dev/vfio/vfio': No such file or directory
>
> The function is used in this case to check if /dev/vfio/vfio was already
> made available to QEMU or not.
>
> Signed-off-by: Pavel Hrdina <[email protected]>
> ---
> src/conf/domain_conf.c | 14 ++++++++++++++
> src/conf/domain_conf.h | 3 +++
> src/libvirt_private.syms | 1 +
> src/qemu/qemu_domain.c | 2 +-
> 4 files changed, 19 insertions(+), 1 deletion(-)
[...]
> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
> index 4520c3c28d..1d00ff2845 100644
> --- a/src/qemu/qemu_domain.c
> +++ b/src/qemu/qemu_domain.c
> @@ -9284,7 +9284,7 @@ qemuDomainSupportsVideoVga(const virDomainVideoDef
> *video,
This function really now needs a comment stating why/what and the
quirks.
> bool
> qemuDomainNeedsVFIO(const virDomainDef *def)
> {
> - return virDomainDefHasPCIHostdev(def) ||
> + return virDomainDefHasPCIHostdevWithoutIOMMUFD(def) ||
> virDomainDefHasMdevHostdev(def) ||
> virDomainDefHasNVMeDisk(def);
> }
Reviewed-by: Peter Krempa <[email protected]>
