On Fri, 12 Jan 2024, Jiqian Chen wrote:
> If run Xen with PVH dom0 and hvm domU, hvm will map a 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 because currd is PVH dom0 and PVH has no
> X86_EMU_USE_PIRQ flag, it will fail at has_pirq check.
>
> So, allow PHYSDEVOP_map_pirq when dom0 is PVH and also allow
> PHYSDEVOP_unmap_pirq for the failed path to unmap pirq. And
> add a new check to prevent self map when caller has no PIRQ
> flag.
>
> Co-developed-by: Huang Rui <ray.hu...@amd.com>
> Signed-off-by: Jiqian Chen <jiqian.c...@amd.com>
> ---
> xen/arch/x86/hvm/hypercall.c | 2 ++
> xen/arch/x86/physdev.c | 22 ++++++++++++++++++++++
> 2 files changed, 24 insertions(+)
>
> diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
> index 6ad5b4d5f11f..493998b42ec5 100644
> --- a/xen/arch/x86/hvm/hypercall.c
> +++ b/xen/arch/x86/hvm/hypercall.c
> @@ -74,6 +74,8 @@ long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void)
> arg)
> {
> case PHYSDEVOP_map_pirq:
> case PHYSDEVOP_unmap_pirq:
> + break;
> +
> case PHYSDEVOP_eoi:
> case PHYSDEVOP_irq_status_query:
> case PHYSDEVOP_get_free_pirq:
> diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
> index 47c4da0af7e1..7f2422c2a483 100644
> --- a/xen/arch/x86/physdev.c
> +++ b/xen/arch/x86/physdev.c
> @@ -303,11 +303,22 @@ ret_t do_physdev_op(int cmd,
> XEN_GUEST_HANDLE_PARAM(void) arg)
> case PHYSDEVOP_map_pirq: {
> physdev_map_pirq_t map;
> struct msi_info msi;
> + struct domain *d;
>
> ret = -EFAULT;
> if ( copy_from_guest(&map, arg, 1) != 0 )
> break;
>
> + d = rcu_lock_domain_by_any_id(map.domid);
> + if ( d == NULL )
> + return -ESRCH;
> + if ( !is_pv_domain(d) && !has_pirq(d) )
I think this could just be:
if ( !has_pirq(d) )
Right?
> + {
> + rcu_unlock_domain(d);
> + return -EOPNOTSUPP;
> + }
> + rcu_unlock_domain(d);
> +
> switch ( map.type )
> {
> case MAP_PIRQ_TYPE_MSI_SEG:
> @@ -341,11 +352,22 @@ ret_t do_physdev_op(int cmd,
> XEN_GUEST_HANDLE_PARAM(void) arg)
>
> case PHYSDEVOP_unmap_pirq: {
> struct physdev_unmap_pirq unmap;
> + struct domain *d;
>
> ret = -EFAULT;
> if ( copy_from_guest(&unmap, arg, 1) != 0 )
> break;
>
> + d = rcu_lock_domain_by_any_id(unmap.domid);
> + if ( d == NULL )
> + return -ESRCH;
> + if ( !is_pv_domain(d) && !has_pirq(d) )
same here
Other than that, everything looks fine to me
> + {
> + rcu_unlock_domain(d);
> + return -EOPNOTSUPP;
> + }
> + rcu_unlock_domain(d);
> +
> ret = physdev_unmap_pirq(unmap.domid, unmap.pirq);
> break;
> }
> --
> 2.34.1
>
