Commit 20492a62 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: pmu: Restore compilation when HW_PERF_EVENTS isn't selected 



Moving kvm_pmu_events into the vcpu (and refering to it) broke the
somewhat unusual case where the kernel has no support for a PMU
at all.

In order to solve this, move things around a bit so that we can
easily avoid refering to the pmu structure outside of PMU-aware
code. As a bonus, pmu.c isn't compiled in when HW_PERF_EVENTS
isn't selected.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Reviewed-by: default avatarFuad Tabba <tabba@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/202205161814.KQHpOzsJ-lkp@intel.com
parent 722625c6

arch/arm64/include/asm/kvm_host.h

+0 −6
Original line number Diff line number Diff line
@@ -789,10 +789,6 @@ void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu); 
#ifdef CONFIG_KVM

void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr);

void kvm_clr_pmu_events(u32 clr);



struct kvm_pmu_events *kvm_get_pmu_events(void);

void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu);

void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);

#else

static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {}

static inline void kvm_clr_pmu_events(u32 clr) {}
@@ -824,8 +820,6 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); 
#define kvm_has_mte(kvm)					\

	(system_supports_mte() &&				\

	 test_bit(KVM_ARCH_FLAG_MTE_ENABLED, &(kvm)->arch.flags))

#define kvm_vcpu_has_pmu(vcpu)					\

	(test_bit(KVM_ARM_VCPU_PMU_V3, (vcpu)->arch.features))



int kvm_trng_call(struct kvm_vcpu *vcpu);

#ifdef CONFIG_KVM

arch/arm64/kvm/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ obj-$(CONFIG_KVM) += hyp/ 
kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \

	 inject_fault.o va_layout.o handle_exit.o \

	 guest.o debug.o reset.o sys_regs.o \

	 vgic-sys-reg-v3.o fpsimd.o pmu.o pkvm.o \

	 vgic-sys-reg-v3.o fpsimd.o pkvm.o \

	 arch_timer.o trng.o vmid.o \

	 vgic/vgic.o vgic/vgic-init.o \

	 vgic/vgic-irqfd.o vgic/vgic-v2.o \
@@ -22,7 +22,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ 
	 vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \

	 vgic/vgic-its.o vgic/vgic-debug.o



kvm-$(CONFIG_HW_PERF_EVENTS)  += pmu-emul.o

kvm-$(CONFIG_HW_PERF_EVENTS)  += pmu-emul.o pmu.o



always-y := hyp_constants.h hyp-constants.s

arch/arm64/kvm/arm.c

+0 −13
Original line number Diff line number Diff line
@@ -751,19 +751,6 @@ static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu) 
	return ret;

}



/*

 * Updates the vcpu's view of the pmu events for this cpu.

 * Must be called before every vcpu run after disabling interrupts, to ensure

 * that an interrupt cannot fire and update the structure.

 */

static void kvm_pmu_update_vcpu_events(struct kvm_vcpu *vcpu)

{

	if (has_vhe() || !kvm_vcpu_has_pmu(vcpu))

		return;



	vcpu->arch.pmu.events = *kvm_get_pmu_events();

}



/**

 * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code

 * @vcpu:	The VCPU pointer

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

+5 −0
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu) 
/**

 * Disable host events, enable guest events

 */

#ifdef CONFIG_HW_PERF_EVENTS

static bool __pmu_switch_to_guest(struct kvm_vcpu *vcpu)

{

	struct kvm_pmu_events *pmu = &vcpu->arch.pmu.events;
@@ -149,6 +150,10 @@ static void __pmu_switch_to_host(struct kvm_vcpu *vcpu) 
	if (pmu->events_host)

		write_sysreg(pmu->events_host, pmcntenset_el0);

}

#else

#define __pmu_switch_to_guest(v)	({ false; })

#define __pmu_switch_to_host(v)		do {} while (0)

#endif



/**

 * Handler for protected VM MSR, MRS or System instruction execution in AArch64.

include/kvm/arm_pmu.h

+24 −0
Original line number Diff line number Diff line
@@ -72,6 +72,25 @@ int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, 
int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu,

			    struct kvm_device_attr *attr);

int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu);



struct kvm_pmu_events *kvm_get_pmu_events(void);

void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu);

void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);



#define kvm_vcpu_has_pmu(vcpu)					\

	(test_bit(KVM_ARM_VCPU_PMU_V3, (vcpu)->arch.features))



/*

 * Updates the vcpu's view of the pmu events for this cpu.

 * Must be called before every vcpu run after disabling interrupts, to ensure

 * that an interrupt cannot fire and update the structure.

 */

#define kvm_pmu_update_vcpu_events(vcpu)				\

	do {								\

		if (!has_vhe() && kvm_vcpu_has_pmu(vcpu))		\

			vcpu->arch.pmu.events = *kvm_get_pmu_events();	\

	} while (0)



#else

struct kvm_pmu {

};
@@ -133,6 +152,11 @@ static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) 
	return 0;

}



#define kvm_vcpu_has_pmu(vcpu)		({ false; })

static inline void kvm_pmu_update_vcpu_events(struct kvm_vcpu *vcpu) {}

static inline void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu) {}

static inline void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) {}



#endif



#endif