From mboxrd@z Thu Jan 1 00:00:00 1970 From: andrew.murray@arm.com (Andrew Murray) Date: Thu, 15 Nov 2018 12:55:49 +0000 Subject: [PATCH 4/4] arm64: KVM: Enable support for :G/:H perf event modifiers In-Reply-To: <1542286549-4501-1-git-send-email-andrew.murray@arm.com> References: <1542286549-4501-1-git-send-email-andrew.murray@arm.com> Message-ID: <1542286549-4501-5-git-send-email-andrew.murray@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Enable/disable event counters as appropriate when entering and exiting the guest to enable support for guest or host only event counting. For both VHE and non-VHE we switch the counters between host/guest at EL2. EL2 is filtered out by the PMU when we are using the :G modifier. Signed-off-by: Andrew Murray --- arch/arm64/kvm/hyp/switch.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index d496ef5..ebf0aac 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -373,6 +373,32 @@ static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu) return true; } +static bool __hyp_text __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt) +{ + u32 host_only = host_ctxt->events_host_only; + u32 guest_only = host_ctxt->events_guest_only; + + if (host_only) + write_sysreg(host_only, pmcntenclr_el0); + + if (guest_only) + write_sysreg(guest_only, pmcntenset_el0); + + return (host_only || guest_only); +} + +static void __hyp_text __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt) +{ + u32 host_only = host_ctxt->events_host_only; + u32 guest_only = host_ctxt->events_guest_only; + + if (guest_only) + write_sysreg(guest_only, pmcntenclr_el0); + + if (host_only) + write_sysreg(host_only, pmcntenset_el0); +} + /* * Return true when we were able to fixup the guest exit and should return to * the guest, false when we should restore the host state and return to the @@ -488,12 +514,15 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt; + bool pmu_switch_needed; u64 exit_code; host_ctxt = vcpu->arch.host_cpu_context; host_ctxt->__hyp_running_vcpu = vcpu; guest_ctxt = &vcpu->arch.ctxt; + pmu_switch_needed = __pmu_switch_to_guest(host_ctxt); + sysreg_save_host_state_vhe(host_ctxt); __activate_traps(vcpu); @@ -524,6 +553,9 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) __debug_switch_to_host(vcpu); + if (pmu_switch_needed) + __pmu_switch_to_host(host_ctxt); + return exit_code; } @@ -532,6 +564,7 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt; + bool pmu_switch_needed; u64 exit_code; vcpu = kern_hyp_va(vcpu); @@ -540,6 +573,8 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) host_ctxt->__hyp_running_vcpu = vcpu; guest_ctxt = &vcpu->arch.ctxt; + pmu_switch_needed = __pmu_switch_to_guest(host_ctxt); + __sysreg_save_state_nvhe(host_ctxt); __activate_traps(vcpu); @@ -586,6 +621,9 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) */ __debug_switch_to_host(vcpu); + if (pmu_switch_needed) + __pmu_switch_to_host(host_ctxt); + return exit_code; } -- 2.7.4