KVM ARM Archive on lore.kernel.org
 help / color / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: Zenghui Yu <yuzenghui@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Jason Cooper <jason@lakedaemon.net>,
	linux-kernel@vger.kernel.org,
	Robert Richter <rrichter@marvell.com>,
	Jayachandran C <jnair@marvell.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH v2 09/36] irqchip/gic-v3: Add GICv4.1 VPEID size discovery
Date: Fri, 01 Nov 2019 15:13:37 +0000
Message-ID: <86eeyry6hq.wl-maz@kernel.org> (raw)
In-Reply-To: <ec979d9b-cfe8-bfd8-fc4c-c41a602b2494@huawei.com>

On Thu, 31 Oct 2019 12:02:24 +0000,
Zenghui Yu <yuzenghui@huawei.com> wrote:
> 
> Hi Marc,
> 
> On 2019/10/27 22:42, Marc Zyngier wrote:
> > While GICv4.0 mandates 16 bit worth of VPEIDs, GICv4.1 allows smaller
> > implementations to be built. Add the required glue to dynamically
> > compute the limit.
> > 
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > ---
> >   drivers/irqchip/irq-gic-v3-its.c   | 11 ++++++++++-
> >   drivers/irqchip/irq-gic-v3.c       |  3 +++
> >   include/linux/irqchip/arm-gic-v3.h |  5 +++++
> >   3 files changed, 18 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> > index 94c9c2e9f917..40912b3fb0e1 100644
> > --- a/drivers/irqchip/irq-gic-v3-its.c
> > +++ b/drivers/irqchip/irq-gic-v3-its.c
> > @@ -121,7 +121,16 @@ struct its_node {
> >   #define ITS_ITT_ALIGN		SZ_256
> >     /* The maximum number of VPEID bits supported by VLPI commands
> > */
> > -#define ITS_MAX_VPEID_BITS	(16)
> > +#define ITS_MAX_VPEID_BITS						\
> > +	({								\
> > +		int nvpeid = 16;					\
> > +		if (gic_rdists->has_rvpeid &&				\
> > +		    gic_rdists->gicd_typer2 & GICD_TYPER2_VIL)		\
> > +			nvpeid = 1 + (gic_rdists->gicd_typer2 &		\
> > +				      GICD_TYPER2_VID);			\
> 
> Does it make sense to let nvpeid not more than 16 here? As the spec says
> "Values above 0x0F are RESERVED". But I don't know why should we have
> this restriction ;-)

This is something that Andrew raised in the previous version. My take
on this is that properly implemented HW should give us something that
matches the spec (in the 0-15 range), and I don't think that guarding
against that is useful at this stage.

My understanding is that once the architecture allows using the 16-31
range, we'll either use it directly because it is just a natural
extension to the existing range, or they mean something different
altogether and we'll get a new discovery bit somewhere.

> Either way,
> 
> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>

Thanks,

	M.

-- 
Jazz is not dead, it just smells funny.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  reply index

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-27 14:41 [PATCH v2 00/36] irqchip/gic-v4: GICv4.1 architecture support Marc Zyngier
2019-10-27 14:41 ` [PATCH v2 01/36] KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 02/36] irqchip/gic-v3-its: Factor out wait_for_syncr primitive Marc Zyngier
2019-10-28  9:20   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 03/36] irqchip/gic-v3-its: Allow LPI invalidation via the DirectLPI interface Marc Zyngier
2019-10-31  8:49   ` Zenghui Yu
2019-11-01 13:26     ` Marc Zyngier
2019-11-05 10:30       ` Zenghui Yu
2019-11-05 12:12         ` Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 04/36] irqchip/gic-v3-its: Make is_v4 use a TYPER copy Marc Zyngier
2019-10-28  9:34   ` Zenghui Yu
2019-10-28 10:52     ` Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 05/36] irqchip/gic-v3-its: Kill its->ite_size and use TYPER copy instead Marc Zyngier
2019-10-28  9:40   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 06/36] irqchip/gic-v3-its: Kill its->device_ids " Marc Zyngier
2019-10-31  6:33   ` Zenghui Yu
2019-10-31  8:30     ` Marc Zyngier
2019-10-31  9:08       ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 07/36] irqchip/gic-v3-its: Add get_vlpi_map() helper Marc Zyngier
2019-10-31  3:54   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 08/36] irqchip/gic-v3: Detect GICv4.1 supporting RVPEID Marc Zyngier
2019-10-31 11:34   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 09/36] irqchip/gic-v3: Add GICv4.1 VPEID size discovery Marc Zyngier
2019-10-31 12:02   ` Zenghui Yu
2019-11-01 15:13     ` Marc Zyngier [this message]
2019-10-27 14:42 ` [PATCH v2 10/36] irqchip/gic-v3: Workaround Cavium TX1 erratum when reading GICD_TYPER2 Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 11/36] irqchip/gic-v4.1: VPE table (aka GICR_VPROPBASER) allocation Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 12/36] irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP Marc Zyngier
2019-11-01 10:58   ` Zenghui Yu
2019-11-13  8:02   ` Zenghui Yu
2019-11-13  9:47     ` Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 13/36] irqchip/gic-v4.1: Don't use the VPE proxy if RVPEID is set Marc Zyngier
2019-11-01 11:05   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 14/36] irqchip/gic-v4.1: Implement the v4.1 flavour of VMOVP Marc Zyngier
2019-11-01 11:10   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 15/36] irqchip/gic-v4.1: Plumb skeletal VPE irqchip Marc Zyngier
2019-11-01 11:13   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 16/36] irqchip/gic-v4.1: Add mask/unmask doorbell callbacks Marc Zyngier
2019-11-01 11:23   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 17/36] irqchip/gic-v4.1: Add VPE residency callback Marc Zyngier
2019-11-01 11:34   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 18/36] irqchip/gic-v4.1: Add VPE eviction callback Marc Zyngier
2019-11-01 11:39   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 19/36] irqchip/gic-v4.1: Add VPE INVALL callback Marc Zyngier
2019-11-01 11:51   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 20/36] irqchip/gic-v4.1: Suppress per-VLPI doorbell Marc Zyngier
2019-11-01 12:17   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 21/36] irqchip/gic-v4.1: Allow direct invalidation of VLPIs Marc Zyngier
2019-11-01 12:30   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 22/36] irqchip/gic-v4.1: Advertise support v4.1 to KVM Marc Zyngier
2019-11-01 12:55   ` Zenghui Yu
2019-10-27 14:42 ` [PATCH v2 23/36] irqchip/gic-v4.1: Map the ITS SGIR register page Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 24/36] irqchip/gic-v4.1: Plumb skeletal VSGI irqchip Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 25/36] irqchip/gic-v4.1: Add initial SGI configuration Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 26/36] irqchip/gic-v4.1: Plumb mask/unmask SGI callbacks Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 27/36] irqchip/gic-v4.1: Plumb get/set_irqchip_state " Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 28/36] irqchip/gic-v4.1: Plumb set_vcpu_affinity " Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 29/36] irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 30/36] irqchip/gic-v4.1: Add VSGI allocation/teardown Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 31/36] irqchip/gic-v4.1: Add VSGI property setup Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 32/36] irqchip/gic-v4.1: Eagerly vmap vPEs Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 33/36] KVM: arm64: GICv4.1: Let doorbells be auto-enabled Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 34/36] KVM: arm64: GICv4.1: Add direct injection capability to SGI registers Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 35/36] KVM: arm64: GICv4.1: Configure SGIs as HW interrupts Marc Zyngier
2019-10-27 14:42 ` [PATCH v2 36/36] KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs Marc Zyngier

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=86eeyry6hq.wl-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=jason@lakedaemon.net \
    --cc=jnair@marvell.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=rrichter@marvell.com \
    --cc=tglx@linutronix.de \
    --cc=yuzenghui@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

KVM ARM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvmarm/0 kvmarm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvmarm kvmarm/ https://lore.kernel.org/kvmarm \
		kvmarm@lists.cs.columbia.edu
	public-inbox-index kvmarm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/edu.columbia.cs.lists.kvmarm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git