Commit 288eb554 authored by Fuad Tabba's avatar Fuad Tabba Committed by Marc Zyngier
Browse files

KVM: arm64: Fix Trace Buffer trapping for protected VMs 



For protected VMs in pKVM, the hypervisor should trap accesses to trace
buffer system registers if Trace Buffer isn't supported by the VM.
However, the current code only traps if Trace Buffer External Mode isn't
supported.

Fix this by checking for FEAT_TRBE (Trace Buffer) rather than
FEAT_TRBE_EXT.

Fixes: 9d526126 ("KVM: arm64: Trap external trace for protected VMs")
Reported-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarFuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20251211104710.151771-2-tabba@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 9ace4753

arch/arm64/kvm/hyp/nvhe/pkvm.c

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ static void pvm_init_traps_mdcr(struct kvm_vcpu *vcpu) 
	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceFilt, IMP))

		val |= MDCR_EL2_TTRF;



	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, ExtTrcBuff, IMP))

	if (!kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceBuffer, IMP))

		val |= MDCR_EL2_E2TB_MASK;



	/* Trap Debug Communications Channel registers */