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From: marc.zyngier@arm.com (Marc Zyngier)
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 13:37:57 +0100	[thread overview]
Message-ID: <57347925.2030902@arm.com> (raw)
In-Reply-To: <20160512122119.GH27623@cbox>

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...

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). Also, the mask preserves
the IRM bit, which is wrong (we don't support 1-of-n distribution).

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...

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2016-05-12 12:37 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 [this message]
2016-05-12 13:41       ` Christoffer Dall
2016-05-12 14:00       ` Andre Przywara
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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