Commit 5eba523e authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

KVM: arm64: Reload stage-2 for VMID change on VHE 



Naturally, a change to the VMID for an MMU implies a new value for
VTTBR. Reload on VMID change in anticipation of loading stage-2 on
vcpu_load() instead of every guest entry.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231018233212.2888027-4-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 4288ff7b

arch/arm64/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -1025,7 +1025,7 @@ int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu, 
extern unsigned int __ro_after_init kvm_arm_vmid_bits;

int __init kvm_arm_vmid_alloc_init(void);

void __init kvm_arm_vmid_alloc_free(void);

void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid);

bool kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid);

void kvm_arm_vmid_clear_active(void);



static inline void kvm_arm_pvtime_vcpu_init(struct kvm_vcpu_arch *vcpu_arch)

arch/arm64/kvm/arm.c

+4 −1
Original line number Diff line number Diff line
@@ -950,7 +950,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
		 * making a thread's VMID inactive. So we need to call

		 * kvm_arm_vmid_update() in non-premptible context.

		 */

		kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid);

		if (kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid) &&

		    has_vhe())

			__load_stage2(vcpu->arch.hw_mmu,

				      vcpu->arch.hw_mmu->arch);



		kvm_pmu_flush_hwstate(vcpu);

arch/arm64/kvm/vmid.c

+8 −3
Original line number Diff line number Diff line
@@ -135,10 +135,11 @@ void kvm_arm_vmid_clear_active(void) 
	atomic64_set(this_cpu_ptr(&active_vmids), VMID_ACTIVE_INVALID);

}



void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid)

bool kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid)

{

	unsigned long flags;

	u64 vmid, old_active_vmid;

	bool updated = false;



	vmid = atomic64_read(&kvm_vmid->id);
@@ -156,17 +157,21 @@ void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid) 
	if (old_active_vmid != 0 && vmid_gen_match(vmid) &&

	    0 != atomic64_cmpxchg_relaxed(this_cpu_ptr(&active_vmids),

					  old_active_vmid, vmid))

		return;

		return false;



	raw_spin_lock_irqsave(&cpu_vmid_lock, flags);



	/* Check that our VMID belongs to the current generation. */

	vmid = atomic64_read(&kvm_vmid->id);

	if (!vmid_gen_match(vmid))

	if (!vmid_gen_match(vmid)) {

		vmid = new_vmid(kvm_vmid);

		updated = true;

	}



	atomic64_set(this_cpu_ptr(&active_vmids), vmid);

	raw_spin_unlock_irqrestore(&cpu_vmid_lock, flags);



	return updated;

}



/*