1 files changed, 189 insertions, 168 deletions

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 6dcdae4d38cb..99a07972068d 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -30,6 +30,7 @@ static u32 host_vtimer_irq_flags;
 static u32 host_ptimer_irq_flags;
 
 static DEFINE_STATIC_KEY_FALSE(has_gic_active_state);
+DEFINE_STATIC_KEY_FALSE(broken_cntvoff_key);
 
 static const u8 default_ppi[] = {
 	[TIMER_PTIMER]  = 30,
@@ -55,11 +56,6 @@ static struct irq_ops arch_timer_irq_ops = {
 	.get_input_level = kvm_arch_timer_get_input_level,
 };
 
-static bool has_cntpoff(void)
-{
-	return (has_vhe() && cpus_have_final_cap(ARM64_HAS_ECV_CNTPOFF));
-}
-
 static int nr_timers(struct kvm_vcpu *vcpu)
 {
 	if (!vcpu_has_nv(vcpu))
@@ -70,7 +66,7 @@ static int nr_timers(struct kvm_vcpu *vcpu)
 
 u32 timer_get_ctl(struct arch_timer_context *ctxt)
 {
-	struct kvm_vcpu *vcpu = ctxt->vcpu;
+	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctxt);
 
 	switch(arch_timer_ctx_index(ctxt)) {
 	case TIMER_VTIMER:
@@ -89,7 +85,7 @@ u32 timer_get_ctl(struct arch_timer_context *ctxt)
 
 u64 timer_get_cval(struct arch_timer_context *ctxt)
 {
-	struct kvm_vcpu *vcpu = ctxt->vcpu;
+	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctxt);
 
 	switch(arch_timer_ctx_index(ctxt)) {
 	case TIMER_VTIMER:
@@ -106,37 +102,22 @@ u64 timer_get_cval(struct arch_timer_context *ctxt)
 	}
 }
 
-static u64 timer_get_offset(struct arch_timer_context *ctxt)
-{
-	u64 offset = 0;
-
-	if (!ctxt)
-		return 0;
-
-	if (ctxt->offset.vm_offset)
-		offset += *ctxt->offset.vm_offset;
-	if (ctxt->offset.vcpu_offset)
-		offset += *ctxt->offset.vcpu_offset;
-
-	return offset;
-}
-
 static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
 {
-	struct kvm_vcpu *vcpu = ctxt->vcpu;
+	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctxt);
 
 	switch(arch_timer_ctx_index(ctxt)) {
 	case TIMER_VTIMER:
-		__vcpu_sys_reg(vcpu, CNTV_CTL_EL0) = ctl;
+		__vcpu_assign_sys_reg(vcpu, CNTV_CTL_EL0, ctl);
 		break;
 	case TIMER_PTIMER:
-		__vcpu_sys_reg(vcpu, CNTP_CTL_EL0) = ctl;
+		__vcpu_assign_sys_reg(vcpu, CNTP_CTL_EL0, ctl);
 		break;
 	case TIMER_HVTIMER:
-		__vcpu_sys_reg(vcpu, CNTHV_CTL_EL2) = ctl;
+		__vcpu_assign_sys_reg(vcpu, CNTHV_CTL_EL2, ctl);
 		break;
 	case TIMER_HPTIMER:
-		__vcpu_sys_reg(vcpu, CNTHP_CTL_EL2) = ctl;
+		__vcpu_assign_sys_reg(vcpu, CNTHP_CTL_EL2, ctl);
 		break;
 	default:
 		WARN_ON(1);
@@ -145,42 +126,32 @@ static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
 
 static void timer_set_cval(struct arch_timer_context *ctxt, u64 cval)
 {
-	struct kvm_vcpu *vcpu = ctxt->vcpu;
+	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctxt);
 
 	switch(arch_timer_ctx_index(ctxt)) {
 	case TIMER_VTIMER:
-		__vcpu_sys_reg(vcpu, CNTV_CVAL_EL0) = cval;
+		__vcpu_assign_sys_reg(vcpu, CNTV_CVAL_EL0, cval);
 		break;
 	case TIMER_PTIMER:
-		__vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = cval;
+		__vcpu_assign_sys_reg(vcpu, CNTP_CVAL_EL0, cval);
 		break;
 	case TIMER_HVTIMER:
-		__vcpu_sys_reg(vcpu, CNTHV_CVAL_EL2) = cval;
+		__vcpu_assign_sys_reg(vcpu, CNTHV_CVAL_EL2, cval);
 		break;
 	case TIMER_HPTIMER:
-		__vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2) = cval;
+		__vcpu_assign_sys_reg(vcpu, CNTHP_CVAL_EL2, cval);
 		break;
 	default:
 		WARN_ON(1);
 	}
 }
 
-static void timer_set_offset(struct arch_timer_context *ctxt, u64 offset)
-{
-	if (!ctxt->offset.vm_offset) {
-		WARN(offset, "timer %ld\n", arch_timer_ctx_index(ctxt));
-		return;
-	}
-
-	WRITE_ONCE(*ctxt->offset.vm_offset, offset);
-}
-
 u64 kvm_phys_timer_read(void)
 {
 	return timecounter->cc->read(timecounter->cc);
 }
 
-static void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
+void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
 {
 	if (vcpu_has_nv(vcpu)) {
 		if (is_hyp_ctxt(vcpu)) {
@@ -211,8 +182,7 @@ static void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
 
 static inline bool userspace_irqchip(struct kvm *kvm)
 {
-	return static_branch_unlikely(&userspace_irqchip_in_use) &&
-		unlikely(!irqchip_in_kernel(kvm));
+	return unlikely(!irqchip_in_kernel(kvm));
 }
 
 static void soft_timer_start(struct hrtimer *hrt, u64 ns)
@@ -300,8 +270,7 @@ static u64 wfit_delay_ns(struct kvm_vcpu *vcpu)
 	u64 val = vcpu_get_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu));
 	struct arch_timer_context *ctx;
 
-	ctx = (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) ? vcpu_hvtimer(vcpu)
-						       : vcpu_vtimer(vcpu);
+	ctx = is_hyp_ctxt(vcpu) ? vcpu_hvtimer(vcpu) : vcpu_vtimer(vcpu);
 
 	return kvm_counter_compute_delta(ctx, val);
 }
@@ -364,7 +333,7 @@ static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt)
 	u64 ns;
 
 	ctx = container_of(hrt, struct arch_timer_context, hrtimer);
-	vcpu = ctx->vcpu;
+	vcpu = timer_context_to_vcpu(ctx);
 
 	trace_kvm_timer_hrtimer_expire(ctx);
 
@@ -448,22 +417,40 @@ void kvm_timer_update_run(struct kvm_vcpu *vcpu)
 		regs->device_irq_level |= KVM_ARM_DEV_EL1_PTIMER;
 }
 
+static void kvm_timer_update_status(struct arch_timer_context *ctx, bool level)
+{
+	/*
+	 * Paper over NV2 brokenness by publishing the interrupt status
+	 * bit. This still results in a poor quality of emulation (guest
+	 * writes will have no effect until the next exit).
+	 *
+	 * But hey, it's fast, right?
+	 */
+	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctx);
+	if (is_hyp_ctxt(vcpu) &&
+	    (ctx == vcpu_vtimer(vcpu) || ctx == vcpu_ptimer(vcpu))) {
+		unsigned long val = timer_get_ctl(ctx);
+		__assign_bit(__ffs(ARCH_TIMER_CTRL_IT_STAT), &val, level);
+		timer_set_ctl(ctx, val);
+	}
+}
+
 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
 				 struct arch_timer_context *timer_ctx)
 {
-	int ret;
+	kvm_timer_update_status(timer_ctx, new_level);
 
 	timer_ctx->irq.level = new_level;
 	trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_irq(timer_ctx),
 				   timer_ctx->irq.level);
 
-	if (!userspace_irqchip(vcpu->kvm)) {
-		ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
-					  timer_irq(timer_ctx),
-					  timer_ctx->irq.level,
-					  timer_ctx);
-		WARN_ON(ret);
-	}
+	if (userspace_irqchip(vcpu->kvm))
+		return;
+
+	kvm_vgic_inject_irq(vcpu->kvm, vcpu,
+			    timer_irq(timer_ctx),
+			    timer_ctx->irq.level,
+			    timer_ctx);
 }
 
 /* Only called for a fully emulated timer */
@@ -473,10 +460,10 @@ static void timer_emulate(struct arch_timer_context *ctx)
 
 	trace_kvm_timer_emulate(ctx, should_fire);
 
-	if (should_fire != ctx->irq.level) {
-		kvm_timer_update_irq(ctx->vcpu, should_fire, ctx);
-		return;
-	}
+	if (should_fire != ctx->irq.level)
+		kvm_timer_update_irq(timer_context_to_vcpu(ctx), should_fire, ctx);
+
+	kvm_timer_update_status(ctx, should_fire);
 
 	/*
 	 * If the timer can fire now, we don't need to have a soft timer
@@ -502,7 +489,7 @@ static void set_cntpoff(u64 cntpoff)
 
 static void timer_save_state(struct arch_timer_context *ctx)
 {
-	struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
+	struct arch_timer_cpu *timer = vcpu_timer(timer_context_to_vcpu(ctx));
 	enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
 	unsigned long flags;
 
@@ -520,7 +507,12 @@ static void timer_save_state(struct arch_timer_context *ctx)
 	case TIMER_VTIMER:
 	case TIMER_HVTIMER:
 		timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTV_CTL));
-		timer_set_cval(ctx, read_sysreg_el0(SYS_CNTV_CVAL));
+		cval = read_sysreg_el0(SYS_CNTV_CVAL);
+
+		if (has_broken_cntvoff())
+			cval -= timer_get_offset(ctx);
+
+		timer_set_cval(ctx, cval);
 
 		/* Disable the timer */
 		write_sysreg_el0(0, SYS_CNTV_CTL);
@@ -548,8 +540,7 @@ static void timer_save_state(struct arch_timer_context *ctx)
 		timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTP_CTL));
 		cval = read_sysreg_el0(SYS_CNTP_CVAL);
 
-		if (!has_cntpoff())
-			cval -= timer_get_offset(ctx);
+		cval -= timer_get_offset(ctx);
 
 		timer_set_cval(ctx, cval);
 
@@ -609,7 +600,7 @@ static void kvm_timer_unblocking(struct kvm_vcpu *vcpu)
 
 static void timer_restore_state(struct arch_timer_context *ctx)
 {
-	struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
+	struct arch_timer_cpu *timer = vcpu_timer(timer_context_to_vcpu(ctx));
 	enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
 	unsigned long flags;
 
@@ -626,8 +617,15 @@ static void timer_restore_state(struct arch_timer_context *ctx)
 
 	case TIMER_VTIMER:
 	case TIMER_HVTIMER:
-		set_cntvoff(timer_get_offset(ctx));
-		write_sysreg_el0(timer_get_cval(ctx), SYS_CNTV_CVAL);
+		cval = timer_get_cval(ctx);
+		offset = timer_get_offset(ctx);
+		if (has_broken_cntvoff()) {
+			set_cntvoff(0);
+			cval += offset;
+		} else {
+			set_cntvoff(offset);
+		}
+		write_sysreg_el0(cval, SYS_CNTV_CVAL);
 		isb();
 		write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTV_CTL);
 		break;
@@ -636,8 +634,7 @@ static void timer_restore_state(struct arch_timer_context *ctx)
 		cval = timer_get_cval(ctx);
 		offset = timer_get_offset(ctx);
 		set_cntpoff(offset);
-		if (!has_cntpoff())
-			cval += offset;
+		cval += offset;
 		write_sysreg_el0(cval, SYS_CNTP_CVAL);
 		isb();
 		write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTP_CTL);
@@ -662,7 +659,7 @@ static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
 
 static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
 {
-	struct kvm_vcpu *vcpu = ctx->vcpu;
+	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctx);
 	bool phys_active = false;
 
 	/*
@@ -671,7 +668,7 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
 	 * this point and the register restoration, we'll take the
 	 * interrupt anyway.
 	 */
-	kvm_timer_update_irq(ctx->vcpu, kvm_timer_should_fire(ctx), ctx);
+	kvm_timer_update_irq(vcpu, kvm_timer_should_fire(ctx), ctx);
 
 	if (irqchip_in_kernel(vcpu->kvm))
 		phys_active = kvm_vgic_map_is_active(vcpu, timer_irq(ctx));
@@ -751,27 +748,12 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
 					    timer_irq(map->direct_ptimer),
 					    &arch_timer_irq_ops);
 		WARN_ON_ONCE(ret);
-
-		/*
-		 * The virtual offset behaviour is "interresting", as it
-		 * always applies when HCR_EL2.E2H==0, but only when
-		 * accessed from EL1 when HCR_EL2.E2H==1. So make sure we
-		 * track E2H when putting the HV timer in "direct" mode.
-		 */
-		if (map->direct_vtimer == vcpu_hvtimer(vcpu)) {
-			struct arch_timer_offset *offs = &map->direct_vtimer->offset;
-
-			if (vcpu_el2_e2h_is_set(vcpu))
-				offs->vcpu_offset = NULL;
-			else
-				offs->vcpu_offset = &__vcpu_sys_reg(vcpu, CNTVOFF_EL2);
-		}
 	}
 }
 
 static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 {
-	bool tpt, tpc;
+	bool tvt, tpt, tvc, tpc, tvt02, tpt02;
 	u64 clr, set;
 
 	/*
@@ -786,7 +768,29 @@ static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 	 * within this function, reality kicks in and we start adding
 	 * traps based on emulation requirements.
 	 */
-	tpt = tpc = false;
+	tvt = tpt = tvc = tpc = false;
+	tvt02 = tpt02 = false;
+
+	/*
+	 * NV2 badly breaks the timer semantics by redirecting accesses to
+	 * the EL1 timer state to memory, so let's call ECV to the rescue if
+	 * available: we trap all CNT{P,V}_{CTL,CVAL,TVAL}_EL0 accesses.
+	 *
+	 * The treatment slightly varies depending whether we run a nVHE or
+	 * VHE guest: nVHE will use the _EL0 registers directly, while VHE
+	 * will use the _EL02 accessors. This translates in different trap
+	 * bits.
+	 *
+	 * None of the trapping is required when running in non-HYP context,
+	 * unless required by the L1 hypervisor settings once we advertise
+	 * ECV+NV in the guest, or that we need trapping for other reasons.
+	 */
+	if (cpus_have_final_cap(ARM64_HAS_ECV) && is_hyp_ctxt(vcpu)) {
+		if (vcpu_el2_e2h_is_set(vcpu))
+			tvt02 = tpt02 = true;
+		else
+			tvt = tpt = true;
+	}
 
 	/*
 	 * We have two possibility to deal with a physical offset:
@@ -802,11 +806,22 @@ static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 		tpt = tpc = true;
 
 	/*
+	 * For the poor sods that could not correctly subtract one value
+	 * from another, trap the full virtual timer and counter.
+	 */
+	if (has_broken_cntvoff() && timer_get_offset(map->direct_vtimer))
+		tvt = tvc = true;
+
+	/*
 	 * Apply the enable bits that the guest hypervisor has requested for
 	 * its own guest. We can only add traps that wouldn't have been set
 	 * above.
+	 * Implementation choices: we do not support NV when E2H=0 in the
+	 * guest, and we don't support configuration where E2H is writable
+	 * by the guest (either FEAT_VHE or FEAT_E2H0 is implemented, but
+	 * not both). This simplifies the handling of the EL1NV* bits.
 	 */
-	if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
+	if (is_nested_ctxt(vcpu)) {
 		u64 val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
 
 		/* Use the VHE format for mental sanity */
@@ -815,6 +830,9 @@ static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 
 		tpt |= !(val & (CNTHCTL_EL1PCEN << 10));
 		tpc |= !(val & (CNTHCTL_EL1PCTEN << 10));
+
+		tpt02 |= (val & CNTHCTL_EL1NVPCT);
+		tvt02 |= (val & CNTHCTL_EL1NVVCT);
 	}
 
 	/*
@@ -826,6 +844,10 @@ static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 
 	assign_clear_set_bit(tpt, CNTHCTL_EL1PCEN << 10, set, clr);
 	assign_clear_set_bit(tpc, CNTHCTL_EL1PCTEN << 10, set, clr);
+	assign_clear_set_bit(tvt, CNTHCTL_EL1TVT, clr, set);
+	assign_clear_set_bit(tvc, CNTHCTL_EL1TVCT, clr, set);
+	assign_clear_set_bit(tvt02, CNTHCTL_EL1NVVCT, clr, set);
+	assign_clear_set_bit(tpt02, CNTHCTL_EL1NVPCT, clr, set);
 
 	/* This only happens on VHE, so use the CNTHCTL_EL2 accessor. */
 	sysreg_clear_set(cnthctl_el2, clr, set);
@@ -914,6 +936,44 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
 		kvm_timer_blocking(vcpu);
 }
 
+void kvm_timer_sync_nested(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * When NV2 is on, guest hypervisors have their EL1 timer register
+	 * accesses redirected to the VNCR page. Any guest action taken on
+	 * the timer is postponed until the next exit, leading to a very
+	 * poor quality of emulation.
+	 *
+	 * This is an unmitigated disaster, only papered over by FEAT_ECV,
+	 * which allows trapping of the timer registers even with NV2.
+	 * Still, this is still worse than FEAT_NV on its own. Meh.
+	 */
+	if (!cpus_have_final_cap(ARM64_HAS_ECV)) {
+		/*
+		 * For a VHE guest hypervisor, the EL2 state is directly
+		 * stored in the host EL1 timers, while the emulated EL1
+		 * state is stored in the VNCR page. The latter could have
+		 * been updated behind our back, and we must reset the
+		 * emulation of the timers.
+		 *
+		 * A non-VHE guest hypervisor doesn't have any direct access
+		 * to its timers: the EL2 registers trap despite being
+		 * notionally direct (we use the EL1 HW, as for VHE), while
+		 * the EL1 registers access memory.
+		 *
+		 * In both cases, process the emulated timers on each guest
+		 * exit. Boo.
+		 */
+		struct timer_map map;
+		get_timer_map(vcpu, &map);
+
+		soft_timer_cancel(&map.emul_vtimer->hrtimer);
+		soft_timer_cancel(&map.emul_ptimer->hrtimer);
+		timer_emulate(map.emul_vtimer);
+		timer_emulate(map.emul_ptimer);
+	}
+}
+
 /*
  * With a userspace irqchip we have to check if the guest de-asserted the
  * timer and if so, unmask the timer irq signal on the host interrupt
@@ -943,7 +1003,7 @@ void kvm_timer_sync_user(struct kvm_vcpu *vcpu)
 		unmask_vtimer_irq_user(vcpu);
 }
 
-int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
+void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
 {
 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 	struct timer_map map;
@@ -967,7 +1027,7 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
 	if (vcpu_has_nv(vcpu)) {
 		struct arch_timer_offset *offs = &vcpu_vtimer(vcpu)->offset;
 
-		offs->vcpu_offset = &__vcpu_sys_reg(vcpu, CNTVOFF_EL2);
+		offs->vcpu_offset = __ctxt_sys_reg(&vcpu->arch.ctxt, CNTVOFF_EL2);
 		offs->vm_offset = &vcpu->kvm->arch.timer_data.poffset;
 	}
 
@@ -987,8 +1047,6 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
 		soft_timer_cancel(&map.emul_vtimer->hrtimer);
 	if (map.emul_ptimer)
 		soft_timer_cancel(&map.emul_ptimer->hrtimer);
-
-	return 0;
 }
 
 static void timer_context_init(struct kvm_vcpu *vcpu, int timerid)
@@ -996,15 +1054,14 @@ static void timer_context_init(struct kvm_vcpu *vcpu, int timerid)
 	struct arch_timer_context *ctxt = vcpu_get_timer(vcpu, timerid);
 	struct kvm *kvm = vcpu->kvm;
 
-	ctxt->vcpu = vcpu;
+	ctxt->timer_id = timerid;
 
 	if (timerid == TIMER_VTIMER)
 		ctxt->offset.vm_offset = &kvm->arch.timer_data.voffset;
 	else
 		ctxt->offset.vm_offset = &kvm->arch.timer_data.poffset;
 
-	hrtimer_init(&ctxt->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
-	ctxt->hrtimer.function = kvm_hrtimer_expire;
+	hrtimer_setup(&ctxt->hrtimer, kvm_hrtimer_expire, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 
 	switch (timerid) {
 	case TIMER_PTIMER:
@@ -1031,8 +1088,8 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
 		timer_set_offset(vcpu_ptimer(vcpu), 0);
 	}
 
-	hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
-	timer->bg_timer.function = kvm_bg_timer_expire;
+	hrtimer_setup(&timer->bg_timer, kvm_bg_timer_expire, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_ABS_HARD);
 }
 
 void kvm_timer_init_vm(struct kvm *kvm)
@@ -1055,49 +1112,6 @@ void kvm_timer_cpu_down(void)
 		disable_percpu_irq(host_ptimer_irq);
 }
 
-int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
-{
-	struct arch_timer_context *timer;
-
-	switch (regid) {
-	case KVM_REG_ARM_TIMER_CTL:
-		timer = vcpu_vtimer(vcpu);
-		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
-		break;
-	case KVM_REG_ARM_TIMER_CNT:
-		if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET,
-			      &vcpu->kvm->arch.flags)) {
-			timer = vcpu_vtimer(vcpu);
-			timer_set_offset(timer, kvm_phys_timer_read() - value);
-		}
-		break;
-	case KVM_REG_ARM_TIMER_CVAL:
-		timer = vcpu_vtimer(vcpu);
-		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
-		break;
-	case KVM_REG_ARM_PTIMER_CTL:
-		timer = vcpu_ptimer(vcpu);
-		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
-		break;
-	case KVM_REG_ARM_PTIMER_CNT:
-		if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET,
-			      &vcpu->kvm->arch.flags)) {
-			timer = vcpu_ptimer(vcpu);
-			timer_set_offset(timer, kvm_phys_timer_read() - value);
-		}
-		break;
-	case KVM_REG_ARM_PTIMER_CVAL:
-		timer = vcpu_ptimer(vcpu);
-		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
-		break;
-
-	default:
-		return -1;
-	}
-
-	return 0;
-}
-
 static u64 read_timer_ctl(struct arch_timer_context *timer)
 {
 	/*
@@ -1114,31 +1128,6 @@ static u64 read_timer_ctl(struct arch_timer_context *timer)
 	return ctl;
 }
 
-u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
-{
-	switch (regid) {
-	case KVM_REG_ARM_TIMER_CTL:
-		return kvm_arm_timer_read(vcpu,
-					  vcpu_vtimer(vcpu), TIMER_REG_CTL);
-	case KVM_REG_ARM_TIMER_CNT:
-		return kvm_arm_timer_read(vcpu,
-					  vcpu_vtimer(vcpu), TIMER_REG_CNT);
-	case KVM_REG_ARM_TIMER_CVAL:
-		return kvm_arm_timer_read(vcpu,
-					  vcpu_vtimer(vcpu), TIMER_REG_CVAL);
-	case KVM_REG_ARM_PTIMER_CTL:
-		return kvm_arm_timer_read(vcpu,
-					  vcpu_ptimer(vcpu), TIMER_REG_CTL);
-	case KVM_REG_ARM_PTIMER_CNT:
-		return kvm_arm_timer_read(vcpu,
-					  vcpu_ptimer(vcpu), TIMER_REG_CNT);
-	case KVM_REG_ARM_PTIMER_CVAL:
-		return kvm_arm_timer_read(vcpu,
-					  vcpu_ptimer(vcpu), TIMER_REG_CVAL);
-	}
-	return (u64)-1;
-}
-
 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
 			      struct arch_timer_context *timer,
 			      enum kvm_arch_timer_regs treg)
@@ -1374,6 +1363,37 @@ static int kvm_irq_init(struct arch_timer_kvm_info *info)
 	return 0;
 }
 
+static void kvm_timer_handle_errata(void)
+{
+	u64 mmfr0, mmfr1, mmfr4;
+
+	/*
+	 * CNTVOFF_EL2 is broken on some implementations. For those, we trap
+	 * all virtual timer/counter accesses, requiring FEAT_ECV.
+	 *
+	 * However, a hypervisor supporting nesting is likely to mitigate the
+	 * erratum at L0, and not require other levels to mitigate it (which
+	 * would otherwise be a terrible performance sink due to trap
+	 * amplification).
+	 *
+	 * Given that the affected HW implements both FEAT_VHE and FEAT_E2H0,
+	 * and that NV is likely not to (because of limitations of the
+	 * architecture), only enable the workaround when FEAT_VHE and
+	 * FEAT_E2H0 are both detected. Time will tell if this actually holds.
+	 */
+	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
+	mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+	mmfr4 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR4_EL1);
+	if (SYS_FIELD_GET(ID_AA64MMFR1_EL1, VH, mmfr1)		&&
+	    !SYS_FIELD_GET(ID_AA64MMFR4_EL1, E2H0, mmfr4)	&&
+	    SYS_FIELD_GET(ID_AA64MMFR0_EL1, ECV, mmfr0)		&&
+	    (has_vhe() || has_hvhe())				&&
+	    cpus_have_final_cap(ARM64_WORKAROUND_QCOM_ORYON_CNTVOFF)) {
+		static_branch_enable(&broken_cntvoff_key);
+		kvm_info("Broken CNTVOFF_EL2, trapping virtual timer\n");
+	}
+}
+
 int __init kvm_timer_hyp_init(bool has_gic)
 {
 	struct arch_timer_kvm_info *info;
@@ -1442,6 +1462,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
 		goto out_free_vtimer_irq;
 	}
 
+	kvm_timer_handle_errata();
 	return 0;
 
 out_free_ptimer_irq:
@@ -1668,7 +1689,7 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,
 
 	mutex_lock(&kvm->lock);
 
-	if (lock_all_vcpus(kvm)) {
+	if (!kvm_trylock_all_vcpus(kvm)) {
 		set_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &kvm->arch.flags);
 
 		/*
@@ -1680,7 +1701,7 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,
 		kvm->arch.timer_data.voffset = offset->counter_offset;
 		kvm->arch.timer_data.poffset = offset->counter_offset;
 
-		unlock_all_vcpus(kvm);
+		kvm_unlock_all_vcpus(kvm);
 	} else {
 		ret = -EBUSY;
 	}