[PATCH v5 13/24] KVM: arm64: Writethrough trapped PMOVS register
From: Colton Lewis <hidden>
Date: 2025-12-09 20:52:40
Also in:
kvm, kvmarm, linux-doc, linux-kselftest, linux-perf-users, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Because PMOVS remains trapped, it needs to be written through when partitioned to affect PMU hardware when expected. Signed-off-by: Colton Lewis <redacted> --- arch/arm64/include/asm/arm_pmuv3.h | 10 ++++++++++ arch/arm64/kvm/sys_regs.c | 17 ++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/arm_pmuv3.h b/arch/arm64/include/asm/arm_pmuv3.h
index 60600f04b5902..3e25c0313263c 100644
--- a/arch/arm64/include/asm/arm_pmuv3.h
+++ b/arch/arm64/include/asm/arm_pmuv3.h@@ -140,6 +140,16 @@ static inline u64 read_pmicfiltr(void) return read_sysreg_s(SYS_PMICFILTR_EL0); } +static inline void write_pmovsset(u64 val) +{ + write_sysreg(val, pmovsset_el0); +} + +static inline u64 read_pmovsset(void) +{ + return read_sysreg(pmovsset_el0); +} + static inline void write_pmovsclr(u64 val) { write_sysreg(val, pmovsclr_el0);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2e6d907fa8af2..bee892db9ca8b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -1307,6 +1307,19 @@ static bool access_pminten(struct kvm_vcpu *vcpu, struct sys_reg_params *p, return true; } +static void writethrough_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, bool set) +{ + u64 mask = kvm_pmu_accessible_counter_mask(vcpu); + + if (set) { + __vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, |=, (p->regval & mask)); + write_pmovsset(p->regval & mask); + } else { + __vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, &=, ~(p->regval & mask)); + write_pmovsclr(p->regval & mask); + } +} + static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) {
@@ -1315,7 +1328,9 @@ static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, if (pmu_access_el0_disabled(vcpu)) return false; - if (p->is_write) { + if (kvm_vcpu_pmu_is_partitioned(vcpu) && p->is_write) { + writethrough_pmovs(vcpu, p, r->CRm & 0x2); + } else if (p->is_write) { if (r->CRm & 0x2) /* accessing PMOVSSET_EL0 */ __vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, |=, (p->regval & mask));
--
2.52.0.239.gd5f0c6e74e-goog