From: andre.przywara@arm.com (Andre Przywara)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 36/55] KVM: arm/arm64: vgic-new: Add GICv3 IROUTER register handlers
Date: Thu, 12 May 2016 15:00:47 +0100 [thread overview]
Message-ID: <57348C8F.6080409@arm.com> (raw)
In-Reply-To: <57347925.2030902@arm.com>
Hi,
On 12/05/16 13:37, Marc Zyngier wrote:
> On 12/05/16 13:21, Christoffer Dall wrote:
>> On Fri, May 06, 2016 at 11:45:49AM +0100, Andre Przywara wrote:
>>> Since GICv3 supports much more than the 8 CPUs the GICv2 ITARGETSR
>>> register can handle, the new IROUTER register covers the whole range
>>> of possible target (V)CPUs by using the same MPIDR that the cores
>>> report themselves.
>>> In addition to translating this MPIDR into a vcpu pointer we store
>>> the originally written value as well. The architecture allows to
>>> write any values into the register, which must be read back as written.
>>>
>>> Since we don't support affinity level 3, we don't need to take care
>>> about the upper word of this 64-bit register, which simplifies the
>>> handling a bit.
>>>
>>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>>> ---
>>> Changelog RFC..v1:
>>> - fold in and simplify vgic_v3_irq_change_affinity
>>>
>>> Changelog v1 .. v2:
>>> - adapt to new MMIO framework
>>>
>>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 65 +++++++++++++++++++++++++++++++++++++++-
>>> 1 file changed, 64 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>>> index 48fba9c..3bcc2c4 100644
>>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>>> @@ -86,6 +86,69 @@ static u32 compress_mpidr(unsigned long mpidr)
>>> return ret;
>>> }
>>>
>>> +static unsigned long decompress_mpidr(u32 value)
>>> +{
>>> + unsigned long mpidr;
>>> +
>>> + mpidr = ((value >> 0) & 0xFF) << MPIDR_LEVEL_SHIFT(0);
>>> + mpidr |= ((value >> 8) & 0xFF) << MPIDR_LEVEL_SHIFT(1);
>>> + mpidr |= ((value >> 16) & 0xFF) << MPIDR_LEVEL_SHIFT(2);
>>> + mpidr |= (u64)((value >> 24) & 0xFF) << MPIDR_LEVEL_SHIFT(3);
>>> +
>>> + return mpidr;
>>> +}
>>> +
>>> +static unsigned long vgic_mmio_read_irouter(struct kvm_vcpu *vcpu,
>>> + gpa_t addr, unsigned int len)
>>> +{
>>> + int intid = (addr & 0x1fff) / 8;
>>> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid);
>>> + unsigned long mpidr;
>>> +
>>> + if (!irq)
>>> + return 0;
>>> +
>>> + mpidr = decompress_mpidr(irq->mpidr);
>>
>> I'm unsure here; do we ned a READ_ONCE() in lieu taking the lock or are
>> we guaranteed that this is a single memory access even with compiler
>> inlining etc.?
>
> I can't imagine the compiler being stupid enough to read this multiple
> times, but better safe than sorry. +1 for READ_ONCE().
>
>>
>>> + return extract_bytes(mpidr, addr & 7, len);
>>> +}
>>> +
>>> +static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
>>> + gpa_t addr, unsigned int len,
>>> + unsigned long val)
>>> +{
>>> + int intid = (addr & 0x1fff) / 8;
>>> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid);
>>> + unsigned long mask = 0xffffffff; /* upper word is WI */
>>> + u64 mpidr;
>>> +
>>> + if (!irq)
>>> + return;
>>> +
>>> + /*
>>> + * There are only two supported options:
>>> + * (1) aligned 64-bit access
>>> + * (2) aligned 32-bit access
>>> + *
>>> + * TODO: make this check generic and move it to dispatch_...()
>>> + */
>>> + if (len != 4 && len != 8)
>>> + return;
>>> +
>>> +
>>> + /* The upper word is WI for us since we don't implement Aff3. */
>>> + if (addr & 4)
>>> + return;
>>> +
>>> + spin_lock(&irq->irq_lock);
>>> +
>>> + mpidr = decompress_mpidr(irq->mpidr);
>>> + mpidr = (mpidr & ~mask) | (val & mask);
>>> + irq->mpidr = compress_mpidr(mpidr);
>>> + irq->target_vcpu = kvm_mpidr_to_vcpu(vcpu->kvm, mpidr);
>>
>> this is weird because it doesn't preserve read-as-written semantics but
>> allows a guest to write something into the RES0 field and read that back
>> in the Aff3 field...
Technically Aff3 is not RES0, even if the A3V bit is cleared.
The A3V bit just disables Aff3 on the CPU interface side, specifically
for ICC_SGI0R_EL1 & friends.
I think we agreed some time ago that we have to support read-as-written
for this register and don't forward this IRQ if the MPIDR is not valid,
as the spec demands.
> I don't see how we get this RES0/Aff3 mixup, but I can see other issues:
>
>>> + unsigned long mask = 0xffffffff; /* upper word is WI */
>
> followed by:
>
>>> + mpidr = (mpidr & ~mask) | (val & mask);
>
> is not going to preserve the top bits on 32bit (assuming we could
> perform a 64bit access on 32bit, but still).
Which would be fixed by making mask a u64?
> Also, the mask preserves
> the IRM bit, which is wrong (we don't support 1-of-n distribution).
Agreed on this.
>
> Why don't we just have
>
> mpidr = val & GENMASK_ULL(23, 0);
>
> and let's be done with it? I must be missing something about this whole
> Aff3 thing...
Well, this would be a simple solution if we don't have to preserve bogus
MPIDRs.
The spec is a bit vague here:
"For each interrupt, a GIC implementation might support fewer than 256
values for an affinity level. In this case, some bits of the
corresponding affinity level field might be RO."
Not sure if this can apply to _all_ bits of an affinity level or not.
I think the key question is: do we need to preserve any MPIDR value
written into this register?
Cheers,
Andre.
next prev parent reply other threads:[~2016-05-12 14:00 UTC|newest]
Thread overview: 200+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-06 10:45 [PATCH v3 00/55] KVM: arm/arm64: Rework virtual GIC emulation Andre Przywara
2016-05-06 10:45 ` [PATCH v3 01/55] KVM: arm/arm64: vgic: streamline vgic_update_irq_pending() interface Andre Przywara
2016-05-06 10:45 ` [PATCH v3 02/55] KVM: arm/arm64: vgic: avoid map in kvm_vgic_inject_mapped_irq() Andre Przywara
2016-05-06 10:45 ` [PATCH v3 03/55] KVM: arm/arm64: vgic: avoid map in kvm_vgic_map_is_active() Andre Przywara
2016-05-06 10:45 ` [PATCH v3 04/55] KVM: arm/arm64: vgic: avoid map in kvm_vgic_unmap_phys_irq() Andre Przywara
2016-05-06 10:45 ` [PATCH v3 05/55] KVM: arm/arm64: Remove the IRQ field from struct irq_phys_map Andre Przywara
2016-05-06 10:45 ` [PATCH v3 06/55] KVM: arm/arm64: arch_timer: Remove irq_phys_map Andre Przywara
2016-05-10 8:33 ` Eric Auger
2016-05-06 10:45 ` [PATCH v3 07/55] KVM: arm/arm64: vgic: Remove irq_phys_map from interface Andre Przywara
2016-05-06 10:45 ` [PATCH v3 08/55] KVM: arm/arm64: Get rid of vgic_cpu->nr_lr Andre Przywara
2016-05-18 10:43 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 09/55] KVM: arm/arm64: Fix MMIO emulation data handling Andre Przywara
2016-05-10 8:57 ` Marc Zyngier
2016-05-18 11:02 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 10/55] KVM: arm/arm64: Export mmio_read/write_bus Andre Przywara
2016-05-10 8:59 ` Marc Zyngier
2016-05-18 14:18 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 11/55] KVM: arm/arm64: pmu: abstract access to number of SPIs Andre Przywara
2016-05-10 9:00 ` Marc Zyngier
2016-05-10 9:52 ` Eric Auger
2016-05-10 10:04 ` Marc Zyngier
2016-05-10 14:35 ` [PATCH v3a] " Andre Przywara
2016-05-10 14:58 ` Andrew Jones
2016-05-11 13:52 ` Andre Przywara
2016-05-10 15:22 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 12/55] KVM: arm/arm64: move GICv2 emulation defines into arm-gic-v3.h Andre Przywara
2016-05-10 9:02 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 13/55] KVM: arm/arm64: vgic-new: Add data structure definitions Andre Przywara
2016-05-10 9:05 ` Marc Zyngier
2016-05-12 12:12 ` Christoffer Dall
2016-05-12 12:17 ` Marc Zyngier
2016-05-12 12:23 ` Christoffer Dall
2016-05-12 13:25 ` Andre Przywara
2016-05-12 13:48 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 14/55] KVM: arm/arm64: vgic-new: Add acccessor to new struct vgic_irq instance Andre Przywara
2016-05-10 9:22 ` Marc Zyngier
2016-05-11 9:20 ` Andre Przywara
2016-05-10 9:35 ` Eric Auger
2016-05-06 10:45 ` [PATCH v3 15/55] KVM: arm/arm64: vgic-new: Implement virtual IRQ injection Andre Przywara
2016-05-10 9:25 ` Eric Auger
2016-05-10 9:39 ` Marc Zyngier
2016-05-10 12:08 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 16/55] KVM: arm/arm64: vgic-new: Add IRQ sorting Andre Przywara
2016-05-10 9:29 ` Eric Auger
2016-05-10 9:48 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 17/55] KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework Andre Przywara
2016-05-10 13:11 ` Christoffer Dall
2016-05-10 13:53 ` Eric Auger
2016-05-10 15:20 ` Eric Auger
2016-05-10 17:32 ` Marc Zyngier
2016-05-12 11:46 ` Christoffer Dall
2016-05-12 15:08 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 18/55] KVM: arm/arm64: vgic-new: Add GICv2 world switch backend Andre Przywara
2016-05-10 13:30 ` Christoffer Dall
2016-05-10 13:42 ` Marc Zyngier
2016-05-10 13:49 ` Eric Auger
2016-05-10 14:11 ` Christoffer Dall
2016-05-10 14:35 ` Marc Zyngier
2016-05-10 14:45 ` Marc Zyngier
2016-05-11 9:38 ` Christoffer Dall
2016-05-10 14:10 ` Eric Auger
2016-05-11 11:30 ` Andre Przywara
2016-05-11 11:38 ` Eric Auger
2016-05-11 13:09 ` Andre Przywara
2016-05-11 12:26 ` Christoffer Dall
2016-05-11 13:13 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 19/55] KVM: arm/arm64: vgic-new: Add GICv3 " Andre Przywara
2016-05-06 19:07 ` Tom Hanson
2016-05-10 14:04 ` Christoffer Dall
2016-05-10 14:15 ` Peter Maydell
2016-05-10 14:22 ` Marc Zyngier
2016-05-11 9:39 ` Christoffer Dall
2016-05-10 15:28 ` Eric Auger
2016-05-10 17:35 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 20/55] KVM: arm/arm64: vgic-new: Implement kvm_vgic_vcpu_pending_irq Andre Przywara
2016-05-10 10:22 ` Marc Zyngier
2016-05-10 14:18 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 21/55] KVM: arm/arm64: vgic-new: Add MMIO handling framework Andre Przywara
2016-05-11 9:46 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 22/55] KVM: arm/arm64: vgic-new: Add GICv2 " Andre Przywara
2016-05-11 9:50 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 23/55] KVM: arm/arm64: vgic-new: Add CTLR, TYPER and IIDR handlers Andre Przywara
2016-05-11 12:05 ` Christoffer Dall
2016-05-11 12:47 ` Andre Przywara
2016-05-11 12:51 ` Marc Zyngier
2016-05-11 13:15 ` Christoffer Dall
2016-05-11 13:27 ` Marc Zyngier
2016-05-11 13:36 ` Andre Przywara
2016-05-11 14:40 ` Marc Zyngier
2016-05-11 13:38 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 24/55] KVM: arm/arm64: vgic-new: Add ENABLE registers handlers Andre Przywara
2016-05-10 10:28 ` Marc Zyngier
2016-05-11 12:34 ` Christoffer Dall
2016-05-11 13:04 ` Andre Przywara
2016-05-11 13:14 ` Christoffer Dall
2016-05-11 13:24 ` Andre Przywara
2016-05-11 13:41 ` Christoffer Dall
2016-05-11 13:16 ` Christoffer Dall
2016-05-11 13:13 ` Marc Zyngier
2016-05-11 13:39 ` Andre Przywara
2016-05-11 14:26 ` Marc Zyngier
2016-05-11 13:47 ` Christoffer Dall
2016-05-11 14:18 ` Andre Przywara
2016-05-11 14:28 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 25/55] KVM: arm/arm64: vgic-new: Add PENDING " Andre Przywara
2016-05-10 10:49 ` Marc Zyngier
2016-05-11 13:11 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 26/55] KVM: arm/arm64: vgic-new: Add ACTIVE " Andre Przywara
2016-05-10 12:09 ` Christoffer Dall
2016-05-10 12:14 ` Marc Zyngier
2016-05-10 13:04 ` Andre Przywara
2016-05-10 13:12 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 27/55] KVM: arm/arm64: vgic-new: Add PRIORITY " Andre Przywara
2016-05-11 13:37 ` Christoffer Dall
2016-05-12 9:10 ` Marc Zyngier
2016-05-12 9:56 ` Peter Maydell
2016-05-12 10:09 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 28/55] KVM: arm/arm64: vgic-new: Add CONFIG " Andre Przywara
2016-05-12 8:32 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 29/55] KVM: arm/arm64: vgic-new: Add TARGET " Andre Przywara
2016-05-12 8:35 ` Christoffer Dall
2016-05-12 8:39 ` Marc Zyngier
2016-05-12 8:54 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 30/55] KVM: arm/arm64: vgic-new: Add SGIR register handler Andre Przywara
2016-05-12 8:40 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 31/55] KVM: arm/arm64: vgic-new: Add SGIPENDR register handlers Andre Przywara
2016-05-12 9:09 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 32/55] KVM: arm/arm64: vgic-new: Add GICv3 MMIO handling framework Andre Przywara
2016-05-09 17:18 ` Marc Zyngier
2016-05-09 17:51 ` Chalamarla, Tirumalesh
2016-05-10 10:58 ` [PATCH] KVM: arm/arm64: vgic-new: fix overlap check for device addresses Andre Przywara
2016-05-10 13:16 ` Marc Zyngier
2016-05-10 17:18 ` [PATCH v2] " Andre Przywara
2016-05-12 19:43 ` Christoffer Dall
2016-05-12 10:26 ` [PATCH v3 32/55] KVM: arm/arm64: vgic-new: Add GICv3 MMIO handling framework Christoffer Dall
2016-05-12 10:52 ` Andre Przywara
2016-05-12 10:58 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 33/55] KVM: arm/arm64: vgic-new: Add GICv3 CTLR, IIDR, TYPER handlers Andre Przywara
2016-05-12 11:47 ` Christoffer Dall
2016-05-12 12:33 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 34/55] KVM: arm/arm64: vgic-new: Add GICv3 redistributor IIDR and TYPER handler Andre Przywara
2016-05-12 11:59 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 35/55] KVM: arm/arm64: vgic-new: Add GICv3 IDREGS register handler Andre Przywara
2016-05-12 12:12 ` Christoffer Dall
2016-05-12 12:37 ` Andre Przywara
2016-05-06 10:45 ` [PATCH v3 36/55] KVM: arm/arm64: vgic-new: Add GICv3 IROUTER register handlers Andre Przywara
2016-05-12 12:21 ` Christoffer Dall
2016-05-12 12:37 ` Marc Zyngier
2016-05-12 13:41 ` Christoffer Dall
2016-05-12 14:00 ` Andre Przywara [this message]
2016-05-12 14:20 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 37/55] KVM: arm/arm64: vgic-new: Add GICv3 SGI system register trap handler Andre Przywara
2016-05-12 12:40 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 38/55] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM device ops registration Andre Przywara
2016-05-13 10:11 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 39/55] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_NR_IRQS Andre Przywara
2016-05-13 10:11 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 40/55] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_CTRL Andre Przywara
2016-05-13 10:11 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 41/55] KVM: arm/arm64: vgic-new: vgic_kvm_device: implement kvm_vgic_addr Andre Przywara
2016-05-13 10:12 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 42/55] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_ADDR Andre Przywara
2016-05-13 10:12 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 43/55] KVM: arm/arm64: vgic-new: vgic_kvm_device: access to VGIC registers Andre Przywara
2016-05-12 18:30 ` Christoffer Dall
2016-05-13 12:24 ` Andre Przywara
2016-05-13 12:29 ` Christoffer Dall
2016-05-13 12:30 ` Marc Zyngier
2016-05-06 10:45 ` [PATCH v3 44/55] KVM: arm/arm64: vgic-new: Export register access interface Andre Przywara
2016-05-06 10:45 ` [PATCH v3 45/55] KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers Andre Przywara
2016-05-12 18:41 ` Christoffer Dall
2016-05-12 19:10 ` Andre Przywara
2016-05-13 7:51 ` Christoffer Dall
2016-05-06 10:45 ` [PATCH v3 46/55] KVM: arm/arm64: vgic-new: Add GICH_VMCR accessors Andre Przywara
2016-05-12 18:43 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 47/55] KVM: arm/arm64: vgic-new: Add userland GIC CPU interface access Andre Przywara
2016-05-09 17:27 ` Marc Zyngier
2016-05-11 8:24 ` Andre Przywara
2016-05-12 18:47 ` Christoffer Dall
2016-05-12 18:52 ` Andre Przywara
2016-05-13 7:53 ` Christoffer Dall
2016-05-13 10:44 ` Andre Przywara
2016-05-13 11:54 ` Christoffer Dall
2016-05-13 12:23 ` Andre Przywara
2016-05-13 12:32 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 48/55] KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init Andre Przywara
2016-05-12 19:00 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 49/55] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create Andre Przywara
2016-05-12 19:08 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 50/55] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init Andre Przywara
2016-05-12 19:25 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 51/55] KVM: arm/arm64: vgic-new: vgic_init: implement map_resources Andre Przywara
2016-05-12 19:28 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 52/55] KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable Andre Przywara
2016-05-12 19:30 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 53/55] KVM: arm/arm64: vgic-new: Wire up irqfd injection Andre Przywara
2016-05-12 19:33 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 54/55] KVM: arm/arm64: vgic-new: implement mapped IRQ handling Andre Przywara
2016-05-12 19:36 ` Christoffer Dall
2016-05-06 10:46 ` [PATCH v3 55/55] KVM: arm/arm64: vgic-new: enable build Andre Przywara
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