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| author | Marc Zyngier <maz@kernel.org> | 2023-03-30 18:47:44 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2023-03-30 19:01:09 +0100 |
| commit | 2b4825a8694018901e641ccc2eafd0fff58d1415 (patch) | |
| tree | a0746e93d0a29d57a8f841bd8ec8776da42a6abc /arch/arm64 | |
| parent | 326349943ed181890b8b2af2755bd0eac93bd66d (diff) | |
| download | linux-2b4825a8694018901e641ccc2eafd0fff58d1415.tar.gz linux-2b4825a8694018901e641ccc2eafd0fff58d1415.tar.bz2 linux-2b4825a8694018901e641ccc2eafd0fff58d1415.zip | |
KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer
With ECV and CNTPOFF_EL2, it is very easy to offer an offset for
the physical timer. So let's do just that.
Nothing can set the offset yet, so this should have no effect
whatsoever (famous last words...).
Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-5-maz@kernel.org
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kvm/arch_timer.c | 18 | ||||
| -rw-r--r-- | arch/arm64/kvm/hypercalls.c | 2 |
2 files changed, 18 insertions, 2 deletions
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 9515c645f03d..3118ea0a1b41 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -52,6 +52,11 @@ static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu, struct arch_timer_context *timer, enum kvm_arch_timer_regs treg); +static bool has_cntpoff(void) +{ + return (has_vhe() && cpus_have_final_cap(ARM64_HAS_ECV_CNTPOFF)); +} + u32 timer_get_ctl(struct arch_timer_context *ctxt) { struct kvm_vcpu *vcpu = ctxt->vcpu; @@ -84,7 +89,7 @@ u64 timer_get_cval(struct arch_timer_context *ctxt) static u64 timer_get_offset(struct arch_timer_context *ctxt) { - if (ctxt->offset.vm_offset) + if (ctxt && ctxt->offset.vm_offset) return *ctxt->offset.vm_offset; return 0; @@ -432,6 +437,12 @@ static void set_cntvoff(u64 cntvoff) kvm_call_hyp(__kvm_timer_set_cntvoff, cntvoff); } +static void set_cntpoff(u64 cntpoff) +{ + if (has_cntpoff()) + write_sysreg_s(cntpoff, SYS_CNTPOFF_EL2); +} + static void timer_save_state(struct arch_timer_context *ctx) { struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu); @@ -480,6 +491,7 @@ static void timer_save_state(struct arch_timer_context *ctx) write_sysreg_el0(0, SYS_CNTP_CTL); isb(); + set_cntpoff(0); break; case NR_KVM_TIMERS: BUG(); @@ -550,6 +562,7 @@ static void timer_restore_state(struct arch_timer_context *ctx) write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTV_CTL); break; case TIMER_PTIMER: + set_cntpoff(timer_get_offset(ctx)); write_sysreg_el0(timer_get_cval(ctx), SYS_CNTP_CVAL); isb(); write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTP_CTL); @@ -767,6 +780,7 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) vtimer->vcpu = vcpu; vtimer->offset.vm_offset = &vcpu->kvm->arch.timer_data.voffset; ptimer->vcpu = vcpu; + ptimer->offset.vm_offset = &vcpu->kvm->arch.timer_data.poffset; /* Synchronize cntvoff across all vtimers of a VM. */ timer_set_offset(vtimer, kvm_phys_timer_read()); @@ -1297,6 +1311,8 @@ void kvm_timer_init_vhe(void) val = read_sysreg(cnthctl_el2); val |= (CNTHCTL_EL1PCEN << cnthctl_shift); val |= (CNTHCTL_EL1PCTEN << cnthctl_shift); + if (cpus_have_final_cap(ARM64_HAS_ECV_CNTPOFF)) + val |= CNTHCTL_ECV; write_sysreg(val, cnthctl_el2); } diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 5da884e11337..39a4707e081d 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -47,7 +47,7 @@ static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val) cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.voffset; break; case KVM_PTP_PHYS_COUNTER: - cycles = systime_snapshot.cycles; + cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.poffset; break; default: return; |