[PATCH v3 6/7] [not for merge] kvm: example of stats_fs_value show function

Emanuele Giuseppe Esposito
2020-05-26T11:05:43Z

Add an example of the show function using the mp_state value.

mp_state is an enum that represents the VCPU state,
so instead of displaying its integer representation,
the show function takes care of translating the integer into a
more meaningful string representation.

The VCPU status is shown in the kvm/<vmid>/vcpu<cpuid>/mp_state file

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
arch/x86/kvm/stats_fs.c | 54 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

diff --git a/arch/x86/kvm/stats_fs.c b/arch/x86/kvm/stats_fs.c
index f6edebb9c559..902be18562da 100644
--- a/arch/x86/kvm/stats_fs.c
+++ b/arch/x86/kvm/stats_fs.c
@@ -39,11 +39,65 @@ struct stats_fs_value stats_fs_vcpu_arch_tsc_frac[] = {
{ NULL } /* base is &kvm_tsc_scaling_ratio_frac_bits */
};

+char *stats_fs_vcpu_get_mpstate(uint64_t state)
+{
+ char *state_str;
+
+ state_str = kzalloc(20, GFP_KERNEL);
+ if (!state_str)
+ return ERR_PTR(-ENOMEM);
+
+ switch (state) {
+ case KVM_MP_STATE_RUNNABLE:
+ strcpy(state_str, "RUNNABLE");
+ break;
+ case KVM_MP_STATE_UNINITIALIZED:
+ strcpy(state_str, "UNINITIALIZED");
+ break;
+ case KVM_MP_STATE_INIT_RECEIVED:
+ strcpy(state_str, "INIT_RECEIVED");
+ break;
+ case KVM_MP_STATE_HALTED:
+ strcpy(state_str, "HALTED");
+ break;
+ case KVM_MP_STATE_SIPI_RECEIVED:
+ strcpy(state_str, "SIPI_RECEIVED");
+ break;
+ case KVM_MP_STATE_STOPPED:
+ strcpy(state_str, "STOPPED");
+ break;
+ case KVM_MP_STATE_CHECK_STOP:
+ strcpy(state_str, "CHECK_STOP");
+ break;
+ case KVM_MP_STATE_OPERATING:
+ strcpy(state_str, "OPERATING");
+ break;
+ case KVM_MP_STATE_LOAD:
+ strcpy(state_str, "LOAD");
+ break;
+ default:
+ strcpy(state_str, "UNRECOGNIZED");
+ break;
+ }
+
+ return state_str;
+}
+
+struct stats_fs_value stats_fs_vcpu_mp_state[] = {
+ VCPU_ARCH_STATS_FS("mp_state", kvm_vcpu_arch, mp_state,
+ .type = &stats_fs_type_u32,
+ .show = stats_fs_vcpu_get_mpstate),
+ { NULL }
+};
+
void kvm_arch_create_vcpu_stats_fs(struct kvm_vcpu *vcpu)
{
stats_fs_source_add_values(vcpu->stats_fs_src, stats_fs_vcpu_tsc_offset,
&vcpu->arch, 0);

+ stats_fs_source_add_values(vcpu->stats_fs_src, stats_fs_vcpu_mp_state,
+ &vcpu->arch, 0);
+
if (lapic_in_kernel(vcpu))
stats_fs_source_add_values(vcpu->stats_fs_src,
stats_fs_vcpu_arch_lapic_timer,
--
2.25.4