After discussion in the RFC thread[0], the following items were identified as
desirable to expose via the stats interface:
- APICv status: (apicv_enabled, boolean, per-vCPU)
- Guest using SynIC's AutoEOI: (synic_auto_eoi_used, boolean, per-VM)
- KVM PIT in reinject mode inhibits AVIC: (pit_reinject_mode, boolean, per-VM)
- APICv unaccelerated injections causing a vmexit (i.e. AVIC_INCOMPLETE_IPI,
AVIC_UNACCELERATED_ACCESS, APIC_WRITE): (apicv_unaccelerated_inj, counter,
per-vCPU)
Example retrieving the newly introduced stats for guest running on AMD Genoa
host, with AVIC enabled:
(QEMU) query-stats target=vcpu vcpus=['/machine/unattached/device[0]'] providers=[{'provider':'kvm','names':['apicv_unaccelerated_inj','apicv_active']}]
{
"return": [
{
"provider": "kvm",
"qom-path": "/machine/unattached/device[0]",
"stats": [
{
"name": "apicv_unaccelerated_inj",
"value": 2561
},
{
"name": "apicv_active",
"value": true
}
]
}
]
}
(QEMU) query-stats target=vm providers=[{'provider':'kvm','names':['pit_reinject_mode','synic_auto_eoi_used']}]
{
"return": [
{
"provider": "kvm",
"stats": [
{
"name": "pit_reinject_mode",
"value": false
},
{
"name": "synic_auto_eoi_used",
"value": false
}
]
}
]
}
Changes were also sanity tested on Intel Sapphire Rapids platform, with/without
IPI virtualization.
Regards,
Alejandro
[0] https://lore.kernel.org/all/20240215160136.1256084-1-alejandro.j.jimenez@xxxxxxxxxx/
Alejandro Jimenez (4):
KVM: x86: Expose per-vCPU APICv status
KVM: x86: Add a VM stat exposing when SynIC AutoEOI is in use
KVM: x86: Add a VM stat exposing when KVM PIT is set to reinject mode
KVM: x86: Add vCPU stat for APICv interrupt injections causing #VMEXIT
arch/x86/include/asm/kvm_host.h | 4 ++++
arch/x86/kvm/hyperv.c | 2 ++
arch/x86/kvm/i8254.c | 2 ++
arch/x86/kvm/lapic.c | 1 +
arch/x86/kvm/svm/avic.c | 7 +++++++
arch/x86/kvm/vmx/vmx.c | 2 ++
arch/x86/kvm/x86.c | 7 ++++++-
7 files changed, 24 insertions(+), 1 deletion(-)
base-commit: 7b076c6a308ec5bce9fc96e2935443ed228b9148
--
2.39.3
