[Xen-devel] [PATCH] x86/vMsi-x: check whether msixtbl_list in msixtbl_pt_register()

[Chao Gao <chao.gao@xxxxxxxxx>]

MSI-x tables' initializtion had been deferred in the commit
74c6dc2d0ac4dcab0c6243cdf6ed550c1532b798. If an assigned device does not support
MSI-x, the msixtbl_list won't be initialized. However, the following paths
    XEN_DOMCTL_bind_pt_irq
        pt_irq_create_bind
            msixtbl_pt_register
do not check this case. Some errors(malwares, etc.) may lead to calling
XEN_DOMCTL_bind_pt_irq without a clear gtable and will cause Xen panic.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/vmsi.c b/xen/arch/x86/hvm/vmsi.c
index ef1dfff..d81c5d4 100644
--- a/xen/arch/x86/hvm/vmsi.c
+++ b/xen/arch/x86/hvm/vmsi.c
@@ -459,7 +459,7 @@ int msixtbl_pt_register(struct domain *d, struct pirq 
*pirq, uint64_t gtable)
     ASSERT(pcidevs_locked());
     ASSERT(spin_is_locked(&d->event_lock));
 
-    if ( !has_vlapic(d) )
+    if ( !msixtbl_initialised(d) )
         return -ENODEV;
 
     /*
-- 
1.8.3.1


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