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

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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: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231018233212.2888027-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
This commit is contained in:
Marc Zyngier 2023-10-18 23:32:10 +00:00 committed by Oliver Upton
parent 4288ff7ba1
commit 5eba523e1e
3 changed files with 13 additions and 5 deletions
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2
arch/arm64/include/asm/kvm_host.h
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@ -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)

5
arch/arm64/kvm/arm.c
View File

@ -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);

11
arch/arm64/kvm/vmid.c
View File

@ -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;
}
/*