[PULL 11/12] arm64: KVM: remove misleading comment on pmu status
Christoffer Dall
christoffer.dall at linaro.org
Wed Aug 17 12:38:58 PDT 2016
From: Vladimir Murzin <vladimir.murzin at arm.com>
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 <vladimir.murzin at arm.com>
Acked-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
---
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 b0b225c..af5ea86 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
--
2.9.0
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