[XEN PATCH v1 1/1] x86/vlapic: match broadcasts for logical destination mode

[Victor Lira <victorm.lira@xxxxxxx>]

amd64 vol 3
16.6.1: "In both the flat model and the cluster model, if the
destination field = FFh, the interrupt is accepted by all local APICs."
16.14: "A DEST value of FFFF_FFFFh in the ICR is used to broadcast
IPIs to all local APICs."

intel 64 vol 3
12.6.2.2: "Broadcast to all local APICs is achieved by setting all
destination bits to one."
12.12.9: "A destination ID value of FFFF_FFFFH is used
for broadcast of interrupts in both logical destination and physical
destination modes."

The specs say 0xFFFFFFFF/0xFF should be a broadcast to all APICs in
logical destination mode but it is matched only for cluster 0xFFFF/0xFF
(or as flat mode in xAPIC).

Add a check in vlapic_match_dest similar to what is done for physical
destination mode.

Signed-off-by: Victor Lira <victorm.lira@xxxxxxx>
---
 xen/arch/x86/hvm/vlapic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 79697487ba..1208cd21f0 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -248,7 +248,8 @@ bool vlapic_match_dest(
     {
     case APIC_DEST_NOSHORT:
         if ( dest_mode )
-            return vlapic_match_logical_addr(target, dest);
+            return (dest == _VLAPIC_ID(target, 0xffffffffU)) ||
+                   vlapic_match_logical_addr(target, dest);
         return (dest == _VLAPIC_ID(target, 0xffffffffU)) ||
                (dest == VLAPIC_ID(target));

--
2.51.GIT