Mailing List Archive

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.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
xen/arch/x86/hvm/hypercall.c | 2 ++
xen/arch/x86/physdev.c | 24 ++++++++++++++++++++++++
2 files changed, 26 insertions(+)

diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index 56fbb69ab201..d49fb8b548a3 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 7efa17cf4c1e..1367abc61e54 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -305,11 +305,23 @@ 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 it is an HVM guest, check if it has PIRQs */
+ if ( !is_pv_domain(d) && !has_pirq(d) )
+ {
+ rcu_unlock_domain(d);
+ return -EOPNOTSUPP;
+ }
+ rcu_unlock_domain(d);
+
switch ( map.type )
{
case MAP_PIRQ_TYPE_MSI_SEG:
@@ -343,11 +355,23 @@ 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 it is an HVM guest, check if it has PIRQs */
+ if ( !is_pv_domain(d) && !has_pirq(d) )
+ {
+ rcu_unlock_domain(d);
+ return -EOPNOTSUPP;
+ }
+ rcu_unlock_domain(d);
+
ret = physdev_unmap_pirq(unmap.domid, unmap.pirq);
break;
}
--
2.34.1