Jai Arora <arorajai2...@gmail.com> writes:
> Patch removes DRPINTF macro and adds multiple tracepoints
> to capture different kvm events.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1827
>
> Signed-off-by: Jai Arora <arorajai2...@gmail.com>
> ---
> accel/kvm/kvm-all.c | 33 +++++++++++----------------------
> accel/kvm/trace-events | 8 +++++++-
> 2 files changed, 18 insertions(+), 23 deletions(-)
>
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index e39a810a4e..0801ca7933 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -69,16 +69,6 @@
> #define KVM_GUESTDBG_BLOCKIRQ 0
> #endif
>
> -//#define DEBUG_KVM
> -
> -#ifdef DEBUG_KVM
> -#define DPRINTF(fmt, ...) \
> - do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
> -#else
> -#define DPRINTF(fmt, ...) \
> - do { } while (0)
> -#endif
> -
> struct KVMParkedVcpu {
> unsigned long vcpu_id;
> int kvm_fd;
> @@ -331,7 +321,7 @@ static int do_kvm_destroy_vcpu(CPUState *cpu)
> struct KVMParkedVcpu *vcpu = NULL;
> int ret = 0;
>
> - DPRINTF("kvm_destroy_vcpu\n");
> + trace_kvm_destroy_vcpu();
>
> ret = kvm_arch_destroy_vcpu(cpu);
> if (ret < 0) {
> @@ -341,7 +331,7 @@ static int do_kvm_destroy_vcpu(CPUState *cpu)
> mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
> if (mmap_size < 0) {
> ret = mmap_size;
> - DPRINTF("KVM_GET_VCPU_MMAP_SIZE failed\n");
> + trace_kvm_failed_get_vcpu_mmap_size();
> goto err;
> }
>
> @@ -443,7 +433,6 @@ int kvm_init_vcpu(CPUState *cpu, Error **errp)
> PAGE_SIZE * KVM_DIRTY_LOG_PAGE_OFFSET);
> if (cpu->kvm_dirty_gfns == MAP_FAILED) {
> ret = -errno;
> - DPRINTF("mmap'ing vcpu dirty gfns failed: %d\n", ret);
> goto err;
> }
> }
> @@ -2821,7 +2810,7 @@ int kvm_cpu_exec(CPUState *cpu)
> struct kvm_run *run = cpu->kvm_run;
> int ret, run_ret;
>
> - DPRINTF("kvm_cpu_exec()\n");
> + trace_kvm_cpu_exec();
>
> if (kvm_arch_process_async_events(cpu)) {
> qatomic_set(&cpu->exit_request, 0);
> @@ -2848,7 +2837,7 @@ int kvm_cpu_exec(CPUState *cpu)
>
> kvm_arch_pre_run(cpu, run);
> if (qatomic_read(&cpu->exit_request)) {
> - DPRINTF("interrupt exit requested\n");
> + trace_kvm_interrupt_exit_request();
> /*
> * KVM requires us to reenter the kernel after IO exits to
> complete
> * instruction emulation. This self-signal will ensure that we
> @@ -2878,7 +2867,7 @@ int kvm_cpu_exec(CPUState *cpu)
>
> if (run_ret < 0) {
> if (run_ret == -EINTR || run_ret == -EAGAIN) {
> - DPRINTF("io window exit\n");
> + trace_kvm_io_window_exit();
> kvm_eat_signals(cpu);
> ret = EXCP_INTERRUPT;
> break;
> @@ -2900,7 +2889,7 @@ int kvm_cpu_exec(CPUState *cpu)
> trace_kvm_run_exit(cpu->cpu_index, run->exit_reason);
As we trace the ->exit_reason here I think the individual legs that just
echo a static string don't add much value. Maybe delete them rather than
convert them?
> switch (run->exit_reason) {
> case KVM_EXIT_IO:
> - DPRINTF("handle_io\n");
> + trace_kvm_run_exit_reason("handle_io\n");
> /* Called outside BQL */
> kvm_handle_io(run->io.port, attrs,
> (uint8_t *)run + run->io.data_offset,
> @@ -2910,7 +2899,7 @@ int kvm_cpu_exec(CPUState *cpu)
> ret = 0;
> break;
> case KVM_EXIT_MMIO:
> - DPRINTF("handle_mmio\n");
> + trace_kvm_run_exit_reason("handle_mmio\n");
> /* Called outside BQL */
> address_space_rw(&address_space_memory,
> run->mmio.phys_addr, attrs,
> @@ -2920,11 +2909,11 @@ int kvm_cpu_exec(CPUState *cpu)
> ret = 0;
> break;
> case KVM_EXIT_IRQ_WINDOW_OPEN:
> - DPRINTF("irq_window_open\n");
> + trace_kvm_run_exit_reason("irq_window_open\n");
> ret = EXCP_INTERRUPT;
> break;
> case KVM_EXIT_SHUTDOWN:
> - DPRINTF("shutdown\n");
> + trace_kvm_run_exit_reason("shutdown\n");
> qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
> ret = EXCP_INTERRUPT;
> break;
> @@ -2976,14 +2965,14 @@ int kvm_cpu_exec(CPUState *cpu)
> ret = 0;
> break;
> default:
> - DPRINTF("kvm_arch_handle_exit\n");
> + trace_kvm_exit_system_event("kvm_arch_handle_exit\n");
Instead of this it would be more useful trace run->system_event.type in
the leg above.
> ret = kvm_arch_handle_exit(cpu, run);
> break;
> }
> break;
> default:
> - DPRINTF("kvm_arch_handle_exit\n");
> ret = kvm_arch_handle_exit(cpu, run);
> + trace_kvm_run_exit_reason("kvm_arch_handle_exit\n");
I think this can be deleted as we'll know the path it takes based on
exit_reason/system_event.type
> break;
> }
> } while (ret == 0);
> diff --git a/accel/kvm/trace-events b/accel/kvm/trace-events
> index 399aaeb0ec..e7b9e9bcc1 100644
> --- a/accel/kvm/trace-events
> +++ b/accel/kvm/trace-events
> @@ -25,4 +25,10 @@ kvm_dirty_ring_reaper(const char *s) "%s"
> kvm_dirty_ring_reap(uint64_t count, int64_t t) "reaped %"PRIu64" pages (took
> %"PRIi64" us)"
> kvm_dirty_ring_reaper_kick(const char *reason) "%s"
> kvm_dirty_ring_flush(int finished) "%d"
> -
> +kvm_destroy_vcpu(void) ""
> +kvm_failed_get_vcpu_mmap_size(void) ""
> +kvm_cpu_exec(void) ""
> +kvm_interrupt_exit_request(void) ""
> +kvm_io_window_exit(void) ""
> +kvm_run_exit_reason(const char *s) "%s"
> +kvm_exit_system_event(const char *s) "%s"
Otherwise it looks like a good clean-up.
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
