[Qemu-devel] [PATCH qemu v2] kvm: Add kvm_set_user_memory tracepoint

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This adds a tracepoint to trace the KVM_SET_USER_MEMORY_REGION ioctl
parameters which is quite useful for debugging VFIO memory regions
being actually registered with KVM.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2:
* added forgotten change to trace-events
---
 accel/kvm/kvm-all.c    | 6 +++++-
 accel/kvm/trace-events | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index f290f48..b91fcb7 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -235,6 +235,7 @@ static int kvm_set_user_memory_region(KVMMemoryListener *kml, KVMSlot *slot)
 {
     KVMState *s = kvm_state;
     struct kvm_userspace_memory_region mem;
+    int ret;
 
     mem.slot = slot->slot | (kml->as_id << 16);
     mem.guest_phys_addr = slot->start_addr;
@@ -248,7 +249,10 @@ static int kvm_set_user_memory_region(KVMMemoryListener *kml, KVMSlot *slot)
         kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
     }
     mem.memory_size = slot->memory_size;
-    return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
+    ret = kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
+    trace_kvm_set_user_memory(mem.slot, mem.flags, mem.guest_phys_addr,
+                              mem.memory_size, mem.userspace_addr, ret);
+    return ret;
 }
 
 int kvm_destroy_vcpu(CPUState *cpu)
diff --git a/accel/kvm/trace-events b/accel/kvm/trace-events
index f89ba55..58e98ef 100644
--- a/accel/kvm/trace-events
+++ b/accel/kvm/trace-events
@@ -12,4 +12,5 @@ kvm_irqchip_commit_routes(void) ""
 kvm_irqchip_add_msi_route(char *name, int vector, int virq) "dev %s vector %d virq %d"
 kvm_irqchip_update_msi_route(int virq) "Updating MSI route virq=%d"
 kvm_irqchip_release_virq(int virq) "virq %d"
+kvm_set_user_memory(uint32_t slot, uint32_t flags, uint64_t guest_phys_addr, uint64_t memory_size, uint64_t userspace_addr, int ret) "Slot#%d flags=0x%x gpa=0x%"PRIx64 " size=0x%"PRIx64 " ua=0x%"PRIx64 " ret=%d"
 
-- 
2.11.0