From b63bebe2355cf2632a2979fd2982c88d080c44b6 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Wed, 10 Aug 2016 10:49:42 +0100 Subject: [PATCH] arm64: KVM: remove misleading comment on pmu status Comment about how PMU access is handled is not relavant since v4.6 where proper PMU support was added in. Signed-off-by: Vladimir Murzin Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm64/kvm/sys_regs.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b0b225ceca18..af5ea86d1c19 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -823,14 +823,6 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, * Architected system registers. * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 * - * We could trap ID_DFR0 and tell the guest we don't support performance - * monitoring. Unfortunately the patch to make the kernel check ID_DFR0 was - * NAKed, so it will read the PMCR anyway. - * - * Therefore we tell the guest we have 0 counters. Unfortunately, we - * must always support PMCCNTR (the cycle counter): we just RAZ/WI for - * all PM registers, which doesn't crash the guest kernel at least. - * * Debug handling: We do trap most, if not all debug related system * registers. The implementation is good enough to ensure that a guest * can use these with minimal performance degradation. The drawback is -- 2.20.1