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

[Darren Kenny]

On Fri, Dec 15, 2017 at 04:23:26PM +1100, Alexey Kardashevskiy wrote:
> 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 <address@hidden>
> ---
> 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"

Should the slot not be %u?:

  "Slot#%u ...

Otherwise,

Reviewed-by: Darren Kenny <address@hidden>

Thanks,

Darren.