MSI: Fix msi delivery for hvm guest

Some parameters like "dest_mode",  "delivery_mode" and "trig_mode"
seem to have been miscalculated before delivering MSI interrupt into
hvm passthru guest. This will cause guest driver to roll back to
legacy interrupt mode.

Signed-off-by: Wei Wang <wei.wang2@amd.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/xen/arch/x86/hvm/vmsi.c b/xen/arch/x86/hvm/vmsi.c
index 60497e4b10..d6ad008f4a 100644
--- a/xen/arch/x86/hvm/vmsi.c
+++ b/xen/arch/x86/hvm/vmsi.c
@@ -110,15 +110,21 @@ static void vmsi_inj_irq(
 #define VMSI_DELIV_MASK   0x7000
 #define VMSI_TRIG_MODE    0x8000
 
+#define GFLAGS_SHIFT_DEST_ID        0
+#define GFLAGS_SHIFT_RH             8
+#define GFLAGS_SHIFT_DM             9
+#define GLFAGS_SHIFT_DELIV_MODE     12
+#define GLFAGS_SHIFT_TRG_MODE       15
+
 int vmsi_deliver(struct domain *d, int pirq)
 {
     struct hvm_irq_dpci *hvm_irq_dpci = d->arch.hvm_domain.irq.dpci;
     uint32_t flags = hvm_irq_dpci->mirq[pirq].gmsi.gflags;
     int vector = hvm_irq_dpci->mirq[pirq].gmsi.gvec;
-    uint16_t dest = flags & VMSI_DEST_ID_MASK;
-    uint8_t dest_mode = flags & VMSI_DM_MASK;
-    uint8_t delivery_mode = flags & VMSI_DELIV_MASK;
-    uint8_t trig_mode = flags & VMSI_TRIG_MODE;
+    uint16_t dest = (flags & VMSI_DEST_ID_MASK) >> GFLAGS_SHIFT_DEST_ID;
+    uint8_t dest_mode = (flags & VMSI_DM_MASK) >> GFLAGS_SHIFT_DM;
+    uint8_t delivery_mode = (flags & VMSI_DELIV_MASK) >> GLFAGS_SHIFT_DELIV_MODE;
+    uint8_t trig_mode = (flags & VMSI_TRIG_MODE) >> GLFAGS_SHIFT_TRG_MODE;
     uint32_t deliver_bitmask;
     struct vlapic *target;
     struct vcpu *v;