Messages in this thread | | | Date | Fri, 11 Jun 2021 09:01:40 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH] irqchip/irq-gic-v3-its: Add the checking of ITS version for KVM |
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On Fri, 11 Jun 2021 06:52:26 +0100, Shaokun Zhang <zhangshaokun@hisilicon.com> wrote: > > From: Wudi Wang <wangwudi@hisilicon.com> > > The version of GIC used by KVM is provided by gic_v3_kvm_info. > The KVM that supports GICv4 or GICv4.1 only checks GIC > version. Actually, the GIC and ITS need to work together. > So we add the checking of ITS version for KVM: If and only if > both GIC & ITS support GICv4, gic_kvm_info.has_v4 is true. > If and only if both GIC & ITS support GICv4.1, > gic_kvm_info.has_v4_1 is true. > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Marc Zyngier <maz@kernel.org> > Signed-off-by: Wudi Wang <wangwudi@hisilicon.com> > Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> > --- > drivers/irqchip/irq-gic-common.h | 2 ++ > drivers/irqchip/irq-gic-v3-its.c | 3 +++ > drivers/irqchip/irq-gic-v3.c | 10 +++++----- > 3 files changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h > index ccba8b0fe0f5..e5d44998445a 100644 > --- a/drivers/irqchip/irq-gic-common.h > +++ b/drivers/irqchip/irq-gic-common.h > @@ -10,6 +10,8 @@ > #include <linux/irqdomain.h> > #include <linux/irqchip/arm-gic-common.h> > > +extern struct gic_kvm_info gic_v3_kvm_info; > + > struct gic_quirk { > const char *desc; > const char *compatible; > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 2e6923c2c8a8..45d6163c14d5 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -5419,6 +5419,9 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists, > has_v4_1 |= is_v4_1(its); > } > > + gic_v3_kvm_info.has_v4 = has_v4; > + gic_v3_kvm_info.has_v4_1 = has_v4_1;
If you are going down that road: what if you have multiple ITSs, implementing a variety of v3, v4, v4.1? We currently support this to some extent, but this is breaking it.
What case are you exactly trying to fix?
> + > /* Don't bother with inconsistent systems */ > if (WARN_ON(!has_v4_1 && rdists->has_rvpeid)) > rdists->has_rvpeid = false; > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > index 37a23aa6de37..7454f99bf580 100644 > --- a/drivers/irqchip/irq-gic-v3.c > +++ b/drivers/irqchip/irq-gic-v3.c > @@ -103,7 +103,7 @@ EXPORT_SYMBOL(gic_nonsecure_priorities); > /* ppi_nmi_refs[n] == number of cpus having ppi[n + 16] set as NMI */ > static refcount_t *ppi_nmi_refs; > > -static struct gic_kvm_info gic_v3_kvm_info; > +struct gic_kvm_info gic_v3_kvm_info;
This will conflict with the rework that is in -next, and maybe cause some lifetime issue (see how the structure is now tagged __initdata).
> static DEFINE_PER_CPU(bool, has_rss); > > #define MPIDR_RS(mpidr) (((mpidr) & 0xF0UL) >> 4) > @@ -1850,8 +1850,8 @@ static void __init gic_of_setup_kvm_info(struct device_node *node) > if (!ret) > gic_v3_kvm_info.vcpu = r; > > - gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis; > - gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid; > + gic_v3_kvm_info.has_v4 &= gic_data.rdists.has_vlpis; > + gic_v3_kvm_info.has_v4_1 &= gic_data.rdists.has_rvpeid; > gic_set_kvm_info(&gic_v3_kvm_info); > } > > @@ -2166,8 +2166,8 @@ static void __init gic_acpi_setup_kvm_info(void) > vcpu->end = vcpu->start + ACPI_GICV2_VCPU_MEM_SIZE - 1; > } > > - gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis; > - gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid; > + gic_v3_kvm_info.has_v4 &= gic_data.rdists.has_vlpis; > + gic_v3_kvm_info.has_v4_1 &= gic_data.rdists.has_rvpeid; > gic_set_kvm_info(&gic_v3_kvm_info); > }
Thanks,
M.
-- Without deviation from the norm, progress is not possible.
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