From: Oliver Upton <oliver.upton@linux.dev>
Date: Mon, 30 Oct 2023 20:24:07 +0000 (+0000)
Subject: Merge branch kvm-arm64/pmu_pmcr_n into kvmarm/next
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=123f42f0ad6815014f54d0cc6eb9039c46ee2907;p=linux.git

Merge branch kvm-arm64/pmu_pmcr_n into kvmarm/next

* kvm-arm64/pmu_pmcr_n:
  : User-defined PMC limit, courtesy Raghavendra Rao Ananta
  :
  : Certain VMMs may want to reserve some PMCs for host use while running a
  : KVM guest. This was a bit difficult before, as KVM advertised all
  : supported counters to the guest. Userspace can now limit the number of
  : advertised PMCs by writing to PMCR_EL0.N, as KVM's sysreg and PMU
  : emulation enforce the specified limit for handling guest accesses.
  KVM: selftests: aarch64: vPMU test for validating user accesses
  KVM: selftests: aarch64: vPMU register test for unimplemented counters
  KVM: selftests: aarch64: vPMU register test for implemented counters
  KVM: selftests: aarch64: Introduce vpmu_counter_access test
  tools: Import arm_pmuv3.h
  KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
  KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
  KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU
  KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0
  KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handler
  KVM: arm64: PMU: Introduce helpers to set the guest's PMU

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---

123f42f0ad6815014f54d0cc6eb9039c46ee2907
diff --cc arch/arm64/kvm/arm.c
index c6cad400490f9,f6307afc5036b..317964bad1e16
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@@ -1315,10 -1225,24 +1314,25 @@@ static bool kvm_vcpu_init_changed(struc
  {
  	unsigned long features = init->features[0];
  
 -	return !bitmap_equal(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES);
 +	return !bitmap_equal(vcpu->kvm->arch.vcpu_features, &features,
 +			     KVM_VCPU_MAX_FEATURES);
  }
  
+ static int kvm_setup_vcpu(struct kvm_vcpu *vcpu)
+ {
+ 	struct kvm *kvm = vcpu->kvm;
+ 	int ret = 0;
+ 
+ 	/*
+ 	 * When the vCPU has a PMU, but no PMU is set for the guest
+ 	 * yet, set the default one.
+ 	 */
+ 	if (kvm_vcpu_has_pmu(vcpu) && !kvm->arch.arm_pmu)
+ 		ret = kvm_arm_set_default_pmu(kvm);
+ 
+ 	return ret;
+ }
+ 
  static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
  				 const struct kvm_vcpu_init *init)
  {
@@@ -1329,17 -1253,25 +1343,21 @@@
  	mutex_lock(&kvm->arch.config_lock);
  
  	if (test_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags) &&
 -	    !bitmap_equal(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES))
 +	    kvm_vcpu_init_changed(vcpu, init))
  		goto out_unlock;
  
 -	bitmap_copy(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES);
 +	bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);
  
+ 	ret = kvm_setup_vcpu(vcpu);
+ 	if (ret)
+ 		goto out_unlock;
+ 
  	/* Now we know what it is, we can reset it. */
 -	ret = kvm_reset_vcpu(vcpu);
 -	if (ret) {
 -		bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
 -		goto out_unlock;
 -	}
 +	kvm_reset_vcpu(vcpu);
  
 -	bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);
  	set_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags);
  	vcpu_set_flag(vcpu, VCPU_INITIALIZED);
 +	ret = 0;
  out_unlock:
  	mutex_unlock(&kvm->arch.config_lock);
  	return ret;
diff --cc include/kvm/arm_pmu.h
index 4df71290b676b,abb1e8215ca8d..4b9d8fb393a84
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@@ -101,8 -101,10 +101,11 @@@ void kvm_vcpu_pmu_resync_el0(void)
  })
  
  u8 kvm_arm_pmu_get_pmuver_limit(void);
 +u64 kvm_pmu_evtyper_mask(struct kvm *kvm);
+ int kvm_arm_set_default_pmu(struct kvm *kvm);
+ u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm);
  
+ u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu);
  #else
  struct kvm_pmu {
  };
@@@ -173,12 -176,23 +177,27 @@@ static inline u8 kvm_arm_pmu_get_pmuver
  {
  	return 0;
  }
 +static inline u64 kvm_pmu_evtyper_mask(struct kvm *kvm)
 +{
 +	return 0;
 +}
  static inline void kvm_vcpu_pmu_resync_el0(void) {}
  
+ static inline int kvm_arm_set_default_pmu(struct kvm *kvm)
+ {
+ 	return -ENODEV;
+ }
+ 
+ static inline u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm)
+ {
+ 	return 0;
+ }
+ 
+ static inline u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu)
+ {
+ 	return 0;
+ }
+ 
  #endif
  
  #endif