From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4658D2569 for ; Mon, 13 Mar 2023 13:10:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F382AC4339C; Mon, 13 Mar 2023 13:10:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678713059; bh=Dhk1WwqIYXkb0XNQy4GnNHRtYK0dJvEIgjEH8GeYHe4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VdhCKvWBYI0ZsooO2g7YKQS1Jrc3G2DHBPi2lMwsdF8EF4HmTLCdCBIe0CtyILO8k dxjVP99+qKw4zeB1dGg2yq6ns21jYQ/g/UHYftWMXekLl0baAK5abSX4WsdsUVufp2 IzZll8FQ1J1PI/3g7yyXiWMMhz5a6VF+lPA6B6I1wugtOApKAn2I+WhlRvgLDcicqH t/OAAiIv6FNWYIHWaRui/ri2UK3LRj/twTsQAVzwfkK7t3rDA+Z2AMLpjsJfYnpsi8 D7rsPPR1Xt0GwgpAbpHCNCu4F4VzIfx0kEdzB5Op2LI3Vp70LTJQo2PsFCGFWtbUr0 khw7nPD8CPu7g== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pbhbi-00HEdE-Bu; Mon, 13 Mar 2023 12:48:54 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Ricardo Koller , Simon Veith , Reiji Watanabe , Colton Lewis , Joey Gouly , dwmw2@infradead.org Subject: [PATCH v2 12/19] KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data Date: Mon, 13 Mar 2023 12:48:30 +0000 Message-Id: <20230313124837.2264882-13-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230313124837.2264882-1-maz@kernel.org> References: <20230313124837.2264882-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, ricarkol@google.com, sveith@amazon.de, reijiw@google.com, coltonlewis@google.com, joey.gouly@arm.com, dwmw2@infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Having the timer iRQs duplicated into each vcpu isn't great, and becomes absolutely awful with NV. So let's move these into the per-VM arch_timer_vm_data structure. This simplifies a lot of code, but requires us to introduce a mutex so that we can reason about userspace trying to change an interrupt number while another vcpu is running, something that wasn't really well handled so far. Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/kvm/arch_timer.c | 104 +++++++++++++++++------------- arch/arm64/kvm/arm.c | 2 + include/kvm/arm_arch_timer.h | 18 ++++-- 4 files changed, 78 insertions(+), 48 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 116233a390e9..1280154c9ef3 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -223,6 +223,8 @@ struct kvm_arch { #define KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED 5 /* VM counter offset */ #define KVM_ARCH_FLAG_VM_COUNTER_OFFSET 6 + /* Timer PPIs made immutable */ +#define KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE 7 unsigned long flags; diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 7cd0b0947454..88a38d45d352 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -851,7 +851,6 @@ static void timer_context_init(struct kvm_vcpu *vcpu, int timerid) hrtimer_init(&ctxt->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); ctxt->hrtimer.function = kvm_hrtimer_expire; - timer_irq(ctxt) = default_ppi[timerid]; switch (timerid) { case TIMER_PTIMER: @@ -880,6 +879,13 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) timer->bg_timer.function = kvm_bg_timer_expire; } +void kvm_timer_init_vm(struct kvm *kvm) +{ + mutex_init(&kvm->arch.timer_data.lock); + for (int i = 0; i < NR_KVM_TIMERS; i++) + kvm->arch.timer_data.ppi[i] = default_ppi[i]; +} + void kvm_timer_cpu_up(void) { enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags); @@ -1292,44 +1298,52 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu) { - int vtimer_irq, ptimer_irq, ret; - unsigned long i; + u32 ppis = 0; - vtimer_irq = timer_irq(vcpu_vtimer(vcpu)); - ret = kvm_vgic_set_owner(vcpu, vtimer_irq, vcpu_vtimer(vcpu)); - if (ret) - return false; + mutex_lock(&vcpu->kvm->arch.timer_data.lock); - ptimer_irq = timer_irq(vcpu_ptimer(vcpu)); - ret = kvm_vgic_set_owner(vcpu, ptimer_irq, vcpu_ptimer(vcpu)); - if (ret) - return false; + for (int i = 0; i < NR_KVM_TIMERS; i++) { + struct arch_timer_context *ctx; + int irq; - kvm_for_each_vcpu(i, vcpu, vcpu->kvm) { - if (timer_irq(vcpu_vtimer(vcpu)) != vtimer_irq || - timer_irq(vcpu_ptimer(vcpu)) != ptimer_irq) - return false; + ctx = vcpu_get_timer(vcpu, i); + irq = timer_irq(ctx); + if (kvm_vgic_set_owner(vcpu, irq, ctx)) + break; + + /* + * We know by construction that we only have PPIs, so + * all values are less than 32. + */ + ppis |= BIT(irq); } - return true; + set_bit(KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE, &vcpu->kvm->arch.flags); + + mutex_unlock(&vcpu->kvm->arch.timer_data.lock); + + return hweight32(ppis) == NR_KVM_TIMERS; } bool kvm_arch_timer_get_input_level(int vintid) { struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); - struct arch_timer_context *timer; if (WARN(!vcpu, "No vcpu context!\n")) return false; - if (vintid == timer_irq(vcpu_vtimer(vcpu))) - timer = vcpu_vtimer(vcpu); - else if (vintid == timer_irq(vcpu_ptimer(vcpu))) - timer = vcpu_ptimer(vcpu); - else - BUG(); + for (int i = 0; i < NR_KVM_TIMERS; i++) { + struct arch_timer_context *ctx; + + ctx = vcpu_get_timer(vcpu, i); + if (timer_irq(ctx) == vintid) + return kvm_timer_should_fire(ctx); + } - return kvm_timer_should_fire(timer); + /* A timer IRQ has fired, but no matching timer was found? */ + WARN_RATELIMIT(1, "timer INTID%d unknown\n", vintid); + + return false; } int kvm_timer_enable(struct kvm_vcpu *vcpu) @@ -1385,23 +1399,10 @@ void kvm_timer_init_vhe(void) sysreg_clear_set(cntkctl_el1, 0, CNTHCTL_ECV); } -static void set_timer_irqs(struct kvm *kvm, int vtimer_irq, int ptimer_irq) -{ - struct kvm_vcpu *vcpu; - unsigned long i; - - kvm_for_each_vcpu(i, vcpu, kvm) { - timer_irq(vcpu_vtimer(vcpu)) = vtimer_irq; - timer_irq(vcpu_ptimer(vcpu)) = ptimer_irq; - } -} - int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { int __user *uaddr = (int __user *)(long)attr->addr; - struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); - struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); - int irq; + int irq, idx, ret = 0; if (!irqchip_in_kernel(vcpu->kvm)) return -EINVAL; @@ -1412,21 +1413,36 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) if (!(irq_is_ppi(irq))) return -EINVAL; - if (vcpu->arch.timer_cpu.enabled) - return -EBUSY; + mutex_lock(&vcpu->kvm->arch.timer_data.lock); + + if (test_bit(KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE, + &vcpu->kvm->arch.flags)) { + ret = -EBUSY; + goto out; + } switch (attr->attr) { case KVM_ARM_VCPU_TIMER_IRQ_VTIMER: - set_timer_irqs(vcpu->kvm, irq, timer_irq(ptimer)); + idx = TIMER_VTIMER; break; case KVM_ARM_VCPU_TIMER_IRQ_PTIMER: - set_timer_irqs(vcpu->kvm, timer_irq(vtimer), irq); + idx = TIMER_PTIMER; break; default: - return -ENXIO; + ret = -ENXIO; + goto out; } - return 0; + /* + * We cannot validate the IRQ unicity before we run, so take it at + * face value. The verdict will be given on first vcpu run, for each + * vcpu. Yes this is late. Blame it on the stupid API. + */ + vcpu->kvm->arch.timer_data.ppi[idx] = irq; + +out: + mutex_unlock(&vcpu->kvm->arch.timer_data.lock); + return ret; } int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 1d1c54d1ec15..dc8c2568bc74 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -148,6 +148,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm_vgic_early_init(kvm); + kvm_timer_init_vm(kvm); + /* The maximum number of VCPUs is limited by the host's GIC model */ kvm->max_vcpus = kvm_arm_default_max_vcpus(); diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 27cada09f588..f093ea9f540d 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -36,14 +36,16 @@ struct arch_timer_vm_data { u64 voffset; /* Offset applied to the physical timer/counter */ u64 poffset; + + struct mutex lock; + + /* The PPI for each timer, global to the VM */ + u8 ppi[NR_KVM_TIMERS]; }; struct arch_timer_context { struct kvm_vcpu *vcpu; - /* Timer IRQ */ - struct kvm_irq_level irq; - /* Emulated Timer (may be unused) */ struct hrtimer hrtimer; u64 ns_frac; @@ -57,6 +59,11 @@ struct arch_timer_context { */ bool loaded; + /* Output level of the timer IRQ */ + struct { + bool level; + } irq; + /* Duplicated state from arch_timer.c for convenience */ u32 host_timer_irq; }; @@ -86,6 +93,8 @@ bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu); void kvm_timer_update_run(struct kvm_vcpu *vcpu); void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu); +void kvm_timer_init_vm(struct kvm *kvm); + u64 kvm_arm_timer_get_reg(struct kvm_vcpu *, u64 regid); int kvm_arm_timer_set_reg(struct kvm_vcpu *, u64 regid, u64 value); @@ -109,7 +118,8 @@ bool kvm_arch_timer_get_input_level(int vintid); #define arch_timer_ctx_index(ctx) ((ctx) - vcpu_timer((ctx)->vcpu)->timers) -#define timer_irq(ctx) ((ctx)->irq.irq) +#define timer_vm_data(ctx) (&(ctx)->vcpu->kvm->arch.timer_data) +#define timer_irq(ctx) (timer_vm_data(ctx)->ppi[arch_timer_ctx_index(ctx)]) u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu, enum kvm_arch_timers tmr, -- 2.34.1