Patch 1 fixes an issue when avic=0 (current default) where
APICV_INHIBIT_REASON_ABSENT remains set even after an in-kernel local APIC has
been created. e.g. tracing the inhibition tracepoint shows:
<...>-196432 [247] ..... 70380.628931: kvm_apicv_inhibit_changed: set reason=2, inhibits=0x4
<...>-196432 [247] ..... 70380.628941: kvm_apicv_inhibit_changed: set reason=0, inhibits=0x5
and the reason=2 inhibit is not removed after the local APIC is created.
Patch 2 modifies the wording in the pi_irte_update tracepoint to make it clear
that it is used by the posted interrupt implementation of both vendors. I have
reservations about modifying the tracepoint output and breaking user scripts,
but according to recent discussions tracepoints are not strictly a stable ABI,
so I'd consider this minor change to avoid confusion around this area.
Thank you,
Alejandro
Alejandro Jimenez (2):
KVM: x86: Only set APICV_INHIBIT_REASON_ABSENT if APICv is enabled
KVM: x86: Remove VT-d mention in posted interrupt tracepoint
arch/x86/kvm/trace.h | 4 ++--
arch/x86/kvm/x86.c | 15 ++++++++++++++-
2 files changed, 16 insertions(+), 3 deletions(-)
base-commit: 2d181d84af38146748042a6974c577fc46c3f1c3
--
2.39.3
The kvm_pi_irte_update tracepoint is called from both SVM and VMX vendor
code, and while the "posted interrupt" naming is also adopted by SVM in
several places, VT-d specifically refers to Intel's "Virtualization
Technology for Directed I/O".
Signed-off-by: Alejandro Jimenez <[email protected]>
---
arch/x86/kvm/trace.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index c6b4b1728006..9d0b02ef307e 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1074,7 +1074,7 @@ TRACE_EVENT(kvm_smm_transition,
);
/*
- * Tracepoint for VT-d posted-interrupts.
+ * Tracepoint for VT-d posted-interrupts and AMD-Vi Guest Virtual APIC.
*/
TRACE_EVENT(kvm_pi_irte_update,
TP_PROTO(unsigned int host_irq, unsigned int vcpu_id,
@@ -1100,7 +1100,7 @@ TRACE_EVENT(kvm_pi_irte_update,
__entry->set = set;
),
- TP_printk("VT-d PI is %s for irq %u, vcpu %u, gsi: 0x%x, "
+ TP_printk("PI is %s for irq %u, vcpu %u, gsi: 0x%x, "
"gvec: 0x%x, pi_desc_addr: 0x%llx",
__entry->set ? "enabled and being updated" : "disabled",
__entry->host_irq,
--
2.39.3