[PATCH v11 07/21] KVM: arm64: PMU: Preserve EL2 bitmap state during migration

[Akihiko Odaki]

KVM_GET_ONE_REG and KVM_SET_ONE_REG transfer raw vCPU state for
migration. Masking PMU bitmap registers with counters accessible at the
current EL drops EL2-reserved bits when the vCPU is stopped in EL1 or
EL0.

Use the implemented counter mask for these userspace accesses so the
complete bitmap state survives migration. Guest register accesses
continue to use the accessible counter mask.

Assisted-by: Codex:gpt-5.6-sol
Fixes: 9a1c58cfefb0 ("KVM: arm64: nv: Adjust range of accessible PMCs according to HPMN")
Closes: https://sashiko.dev/#/patchset/20260720-hybrid-v9-0-2b713ca1b5dc@xxxxxxxxxxxxxxxxxxxxxx?part=5
Signed-off-by: Akihiko Odaki <odaki@xxxxxxxxxxxxxxxxxxxxxx>
---
 arch/arm64/kvm/sys_regs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 68339eb8a2bb..1481dd5c99a8 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1326,7 +1326,7 @@ static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 
 static int set_pmreg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, u64 val)
 {
-	u64 mask = kvm_pmu_accessible_counter_mask(vcpu);
+	u64 mask = kvm_pmu_implemented_counter_mask(vcpu);
 
 	__vcpu_assign_sys_reg(vcpu, r->reg, val & mask);
 	kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu);
@@ -1336,7 +1336,7 @@ static int set_pmreg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, u64 va
 
 static int get_pmreg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, u64 *val)
 {
-	u64 mask = kvm_pmu_accessible_counter_mask(vcpu);
+	u64 mask = kvm_pmu_implemented_counter_mask(vcpu);
 
 	*val = __vcpu_sys_reg(vcpu, r->reg) & mask;
 	return 0;

-- 
2.55.0