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authorOliver Upton2023-10-26 20:53:06 +0000
committerOliver Upton2023-10-30 20:17:22 +0000
commitd11974dc5f208ae1c0fe62a9bcb47c0cdcd7b081 (patch)
tree04c86b9135e06c5901f49947690115ba33ef215c /arch/arm64
parent06899aa5dd3d76e888b28d7e8d7304c0a7ec6262 (diff)
KVM: arm64: Add tracepoint for MMIO accesses where ISV==0
It is a pretty well known fact that KVM does not support MMIO emulation without valid instruction syndrome information (ESR_EL2.ISV == 0). The current kvm_pr_unimpl() is pretty useless, as it contains zero context to relate the event to a vCPU. Replace it with a precise tracepoint that dumps the relevant context so the user can make sense of what the guest is doing. Acked-by: Zenghui Yu <yuzenghui@huawei.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231026205306.3045075-1-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/kvm/mmio.c4
-rw-r--r--arch/arm64/kvm/trace_arm.h25
2 files changed, 28 insertions, 1 deletions
diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
index 3dd38a151d2a..200c8019a82a 100644
--- a/arch/arm64/kvm/mmio.c
+++ b/arch/arm64/kvm/mmio.c
@@ -135,6 +135,9 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
* volunteered to do so, and bail out otherwise.
*/
if (!kvm_vcpu_dabt_isvalid(vcpu)) {
+ trace_kvm_mmio_nisv(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu),
+ kvm_vcpu_get_hfar(vcpu), fault_ipa);
+
if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER,
&vcpu->kvm->arch.flags)) {
run->exit_reason = KVM_EXIT_ARM_NISV;
@@ -143,7 +146,6 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
return 0;
}
- kvm_pr_unimpl("Data abort outside memslots with no valid syndrome info\n");
return -ENOSYS;
}
diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h
index 8ad53104934d..c18c1a95831e 100644
--- a/arch/arm64/kvm/trace_arm.h
+++ b/arch/arm64/kvm/trace_arm.h
@@ -136,6 +136,31 @@ TRACE_EVENT(kvm_mmio_emulate,
__entry->vcpu_pc, __entry->instr, __entry->cpsr)
);
+TRACE_EVENT(kvm_mmio_nisv,
+ TP_PROTO(unsigned long vcpu_pc, unsigned long esr,
+ unsigned long far, unsigned long ipa),
+ TP_ARGS(vcpu_pc, esr, far, ipa),
+
+ TP_STRUCT__entry(
+ __field( unsigned long, vcpu_pc )
+ __field( unsigned long, esr )
+ __field( unsigned long, far )
+ __field( unsigned long, ipa )
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_pc = vcpu_pc;
+ __entry->esr = esr;
+ __entry->far = far;
+ __entry->ipa = ipa;
+ ),
+
+ TP_printk("ipa %#016lx, esr %#016lx, far %#016lx, pc %#016lx",
+ __entry->ipa, __entry->esr,
+ __entry->far, __entry->vcpu_pc)
+);
+
+
TRACE_EVENT(kvm_set_way_flush,
TP_PROTO(unsigned long vcpu_pc, bool cache),
TP_ARGS(vcpu_pc, cache),