Commit 2623b3dc authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Merge tag 'kvmarm-fixes-6.4-4' of... 

Merge tag 'kvmarm-fixes-6.4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.4, take #4

- Correctly save/restore PMUSERNR_EL0 when host userspace is using
  PMU counters directly

- Fix GICv2 emulation on GICv3 after the locking rework

- Don't use smp_processor_id() in kvm_pmu_probe_armpmu(), and
  document why...
parents 2230f9e1 30c60dda

arch/arm/include/asm/arm_pmuv3.h

+5 −0
Original line number Diff line number Diff line
@@ -222,6 +222,11 @@ static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr) 
	return false;

}



static inline bool kvm_set_pmuserenr(u64 val)

{

	return false;

}



/* PMU Version in DFR Register */

#define ARMV8_PMU_DFR_VER_NI        0

#define ARMV8_PMU_DFR_VER_V3P4      0x5

arch/arm64/include/asm/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -699,6 +699,8 @@ struct kvm_vcpu_arch { 
#define SYSREGS_ON_CPU		__vcpu_single_flag(sflags, BIT(4))

/* Software step state is Active-pending */

#define DBG_SS_ACTIVE_PENDING	__vcpu_single_flag(sflags, BIT(5))

/* PMUSERENR for the guest EL0 is on physical CPU */

#define PMUSERENR_ON_CPU	__vcpu_single_flag(sflags, BIT(6))





/* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
@@ -1065,9 +1067,14 @@ 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);

bool kvm_set_pmuserenr(u64 val);

#else

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

static inline void kvm_clr_pmu_events(u32 clr) {}

static inline bool kvm_set_pmuserenr(u64 val)

{

	return false;

}

#endif



void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu);

arch/arm64/kvm/hyp/include/hyp/switch.h

+13 −2
Original line number Diff line number Diff line
@@ -82,8 +82,14 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) 
	 * EL1 instead of being trapped to EL2.

	 */

	if (kvm_arm_support_pmu_v3()) {

		struct kvm_cpu_context *hctxt;



		write_sysreg(0, pmselr_el0);



		hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;

		ctxt_sys_reg(hctxt, PMUSERENR_EL0) = read_sysreg(pmuserenr_el0);

		write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);

		vcpu_set_flag(vcpu, PMUSERENR_ON_CPU);

	}



	vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2);
@@ -106,8 +112,13 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) 
	write_sysreg(vcpu->arch.mdcr_el2_host, mdcr_el2);



	write_sysreg(0, hstr_el2);

	if (kvm_arm_support_pmu_v3())

		write_sysreg(0, pmuserenr_el0);

	if (kvm_arm_support_pmu_v3()) {

		struct kvm_cpu_context *hctxt;



		hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;

		write_sysreg(ctxt_sys_reg(hctxt, PMUSERENR_EL0), pmuserenr_el0);

		vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU);

	}



	if (cpus_have_final_cap(ARM64_SME)) {

		sysreg_clear_set_s(SYS_HFGRTR_EL2, 0,

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

+14 −0
Original line number Diff line number Diff line
@@ -92,14 +92,28 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu) 
}

NOKPROBE_SYMBOL(__deactivate_traps);



/*

 * Disable IRQs in {activate,deactivate}_traps_vhe_{load,put}() to

 * prevent a race condition between context switching of PMUSERENR_EL0

 * in __{activate,deactivate}_traps_common() and IPIs that attempts to

 * update PMUSERENR_EL0. See also kvm_set_pmuserenr().

 */

void activate_traps_vhe_load(struct kvm_vcpu *vcpu)

{

	unsigned long flags;



	local_irq_save(flags);

	__activate_traps_common(vcpu);

	local_irq_restore(flags);

}



void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu)

{

	unsigned long flags;



	local_irq_save(flags);

	__deactivate_traps_common(vcpu);

	local_irq_restore(flags);

}



static const exit_handler_fn hyp_exit_handlers[] = {

arch/arm64/kvm/pmu-emul.c

+19 −1
Original line number Diff line number Diff line
@@ -700,7 +700,25 @@ static struct arm_pmu *kvm_pmu_probe_armpmu(void) 


	mutex_lock(&arm_pmus_lock);



	cpu = smp_processor_id();

	/*

	 * It is safe to use a stale cpu to iterate the list of PMUs so long as

	 * the same value is used for the entirety of the loop. Given this, and

	 * the fact that no percpu data is used for the lookup there is no need

	 * to disable preemption.

	 *

	 * It is still necessary to get a valid cpu, though, to probe for the

	 * default PMU instance as userspace is not required to specify a PMU

	 * type. In order to uphold the preexisting behavior KVM selects the

	 * PMU instance for the core where the first call to the

	 * KVM_ARM_VCPU_PMU_V3_CTRL attribute group occurs. A dependent use case

	 * would be a user with disdain of all things big.LITTLE that affines

	 * the VMM to a particular cluster of cores.

	 *

	 * In any case, userspace should just do the sane thing and use the UAPI

	 * to select a PMU type directly. But, be wary of the baggage being

	 * carried here.

	 */

	cpu = raw_smp_processor_id();

	list_for_each_entry(entry, &arm_pmus, entry) {

		tmp = entry->arm_pmu;