From: Greg Kurz <groug@kaod.org> To: "Cédric Le Goater" <clg@kaod.org> Cc: <linuxppc-dev@lists.ozlabs.org>, Michael Ellerman <mpe@ellerman.id.au>, Marc Zyngier <maz@kernel.org>, <stable@vger.kernel.org> Subject: Re: [PATCH] powerpc/xive: Change IRQ domain to a tree domain Date: Tue, 16 Nov 2021 15:23:43 +0100 [thread overview] Message-ID: <20211116152343.782c687c@bahia> (raw) In-Reply-To: <20211116134022.420412-1-clg@kaod.org> On Tue, 16 Nov 2021 14:40:22 +0100 Cédric Le Goater <clg@kaod.org> wrote: > Commit 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains > exclusive") introduced an IRQ_DOMAIN_FLAG_NO_MAP flag to isolate the > 'nomap' domains still in use under the powerpc arch. With this new > flag, the revmap_tree of the IRQ domain is not used anymore. This > change broke the support of shared LSIs [1] in the XIVE driver because > it was relying on a lookup in the revmap_tree to query previously > mapped interrupts. Linux now creates two distinct IRQ mappings on the > same HW IRQ which can lead to unexpected behavior in the drivers. > > The XIVE IRQ domain is not a direct mapping domain and its HW IRQ > interrupt number space is rather large : 1M/socket on POWER9 and > POWER10, change the XIVE driver to use a 'tree' domain type instead. > > [1] For instance, a linux KVM guest with virtio-rng and virtio-balloon > devices. > > Cc: Marc Zyngier <maz@kernel.org> > Cc: stable@vger.kernel.org # v5.14+ > Fixes: 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains exclusive") > Signed-off-by: Cédric Le Goater <clg@kaod.org> > --- > Tested-by: Greg Kurz <groug@kaod.org> with a KVM guest + virtio-rng + virtio-balloon on a POWER9 host. > Marc, > > The Fixes tag is there because the patch in question revealed that > something was broken in XIVE. genirq is not in cause. However, I > don't know for PS3 and Cell. May be less critical for now. > > arch/powerpc/sysdev/xive/common.c | 3 +-- > arch/powerpc/sysdev/xive/Kconfig | 1 - > 2 files changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c > index fed6fd16c8f4..9d0f0fe25598 100644 > --- a/arch/powerpc/sysdev/xive/common.c > +++ b/arch/powerpc/sysdev/xive/common.c > @@ -1536,8 +1536,7 @@ static const struct irq_domain_ops xive_irq_domain_ops = { > > static void __init xive_init_host(struct device_node *np) > { > - xive_irq_domain = irq_domain_add_nomap(np, XIVE_MAX_IRQ, > - &xive_irq_domain_ops, NULL); > + xive_irq_domain = irq_domain_add_tree(np, &xive_irq_domain_ops, NULL); > if (WARN_ON(xive_irq_domain == NULL)) > return; > irq_set_default_host(xive_irq_domain); > diff --git a/arch/powerpc/sysdev/xive/Kconfig b/arch/powerpc/sysdev/xive/Kconfig > index 97796c6b63f0..785c292d104b 100644 > --- a/arch/powerpc/sysdev/xive/Kconfig > +++ b/arch/powerpc/sysdev/xive/Kconfig > @@ -3,7 +3,6 @@ config PPC_XIVE > bool > select PPC_SMP_MUXED_IPI > select HARDIRQS_SW_RESEND > - select IRQ_DOMAIN_NOMAP > > config PPC_XIVE_NATIVE > bool
WARNING: multiple messages have this Message-ID (diff)
From: Greg Kurz <groug@kaod.org> To: "Cédric Le Goater" <clg@kaod.org> Cc: linuxppc-dev@lists.ozlabs.org, stable@vger.kernel.org, Marc Zyngier <maz@kernel.org> Subject: Re: [PATCH] powerpc/xive: Change IRQ domain to a tree domain Date: Tue, 16 Nov 2021 15:23:43 +0100 [thread overview] Message-ID: <20211116152343.782c687c@bahia> (raw) In-Reply-To: <20211116134022.420412-1-clg@kaod.org> On Tue, 16 Nov 2021 14:40:22 +0100 Cédric Le Goater <clg@kaod.org> wrote: > Commit 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains > exclusive") introduced an IRQ_DOMAIN_FLAG_NO_MAP flag to isolate the > 'nomap' domains still in use under the powerpc arch. With this new > flag, the revmap_tree of the IRQ domain is not used anymore. This > change broke the support of shared LSIs [1] in the XIVE driver because > it was relying on a lookup in the revmap_tree to query previously > mapped interrupts. Linux now creates two distinct IRQ mappings on the > same HW IRQ which can lead to unexpected behavior in the drivers. > > The XIVE IRQ domain is not a direct mapping domain and its HW IRQ > interrupt number space is rather large : 1M/socket on POWER9 and > POWER10, change the XIVE driver to use a 'tree' domain type instead. > > [1] For instance, a linux KVM guest with virtio-rng and virtio-balloon > devices. > > Cc: Marc Zyngier <maz@kernel.org> > Cc: stable@vger.kernel.org # v5.14+ > Fixes: 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains exclusive") > Signed-off-by: Cédric Le Goater <clg@kaod.org> > --- > Tested-by: Greg Kurz <groug@kaod.org> with a KVM guest + virtio-rng + virtio-balloon on a POWER9 host. > Marc, > > The Fixes tag is there because the patch in question revealed that > something was broken in XIVE. genirq is not in cause. However, I > don't know for PS3 and Cell. May be less critical for now. > > arch/powerpc/sysdev/xive/common.c | 3 +-- > arch/powerpc/sysdev/xive/Kconfig | 1 - > 2 files changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c > index fed6fd16c8f4..9d0f0fe25598 100644 > --- a/arch/powerpc/sysdev/xive/common.c > +++ b/arch/powerpc/sysdev/xive/common.c > @@ -1536,8 +1536,7 @@ static const struct irq_domain_ops xive_irq_domain_ops = { > > static void __init xive_init_host(struct device_node *np) > { > - xive_irq_domain = irq_domain_add_nomap(np, XIVE_MAX_IRQ, > - &xive_irq_domain_ops, NULL); > + xive_irq_domain = irq_domain_add_tree(np, &xive_irq_domain_ops, NULL); > if (WARN_ON(xive_irq_domain == NULL)) > return; > irq_set_default_host(xive_irq_domain); > diff --git a/arch/powerpc/sysdev/xive/Kconfig b/arch/powerpc/sysdev/xive/Kconfig > index 97796c6b63f0..785c292d104b 100644 > --- a/arch/powerpc/sysdev/xive/Kconfig > +++ b/arch/powerpc/sysdev/xive/Kconfig > @@ -3,7 +3,6 @@ config PPC_XIVE > bool > select PPC_SMP_MUXED_IPI > select HARDIRQS_SW_RESEND > - select IRQ_DOMAIN_NOMAP > > config PPC_XIVE_NATIVE > bool
next prev parent reply other threads:[~2021-11-16 14:23 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-16 13:40 [PATCH] powerpc/xive: Change IRQ domain to a tree domain Cédric Le Goater 2021-11-16 13:40 ` Cédric Le Goater 2021-11-16 14:23 ` Greg Kurz [this message] 2021-11-16 14:23 ` Greg Kurz 2021-11-16 14:49 ` Cédric Le Goater 2021-11-16 14:49 ` Cédric Le Goater 2021-11-16 14:50 ` Greg Kurz 2021-11-16 14:50 ` Greg Kurz 2021-11-16 16:58 ` Marc Zyngier 2021-11-16 16:58 ` Marc Zyngier 2021-11-16 17:56 ` Cédric Le Goater 2021-11-16 17:56 ` Cédric Le Goater 2021-11-21 3:46 ` Michael Ellerman
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