| Message ID | 20180305160415.16760-3-andre.przywara@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | New VGIC(-v2) implementation | expand |
Hi Andre, On 05/03/18 16:03, Andre Przywara wrote: > Normally there is only one GICv3 redistributor region, and we use > that for DomU guests using a GICv3. > Explain the background in a comment and why we need to keep the number > of hardware regions for Dom0. > > Signed-off-by: Andre Przywara <andre.przywara@linaro.org> Acked-by: Julien Grall <julien.grall@arm.com> Cheers, > --- > Changelog RFC ... v1: > - Keep GUEST_GICV3_RDIST_REGIONS symbol around, just extend comments > > xen/arch/arm/vgic-v3.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c > index 2ad8a6be62..d5b34a7d0f 100644 > --- a/xen/arch/arm/vgic-v3.c > +++ b/xen/arch/arm/vgic-v3.c > @@ -1632,6 +1632,16 @@ static int vgic_v3_vcpu_init(struct vcpu *v) > > static inline unsigned int vgic_v3_rdist_count(struct domain *d) > { > + /* > + * Normally there is only one GICv3 redistributor region. > + * The GICv3 DT binding provisions for multiple regions, since there are > + * platforms out there which need those (multi-socket systems). > + * For Dom0 we have to live with the MMIO layout the hardware provides, > + * so we have to copy the multiple regions - as the first region may not > + * provide enough space to hold all redistributors we need. > + * However DomU get a constructed memory map, so we can go with > + * the architected single redistributor region. > + */ > return is_hardware_domain(d) ? vgic_v3_hw.nr_rdist_regions : > GUEST_GICV3_RDIST_REGIONS; > } > @@ -1692,7 +1702,7 @@ static int vgic_v3_domain_init(struct domain *d) > { > d->arch.vgic.dbase = GUEST_GICV3_GICD_BASE; > > - /* XXX: Only one Re-distributor region mapped for the guest */ > + /* A single Re-distributor region is mapped for the guest. */ > BUILD_BUG_ON(GUEST_GICV3_RDIST_REGIONS != 1); > > d->arch.vgic.rdist_stride = GUEST_GICV3_RDIST_STRIDE; >
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c index 2ad8a6be62..d5b34a7d0f 100644 --- a/xen/arch/arm/vgic-v3.c +++ b/xen/arch/arm/vgic-v3.c @@ -1632,6 +1632,16 @@ static int vgic_v3_vcpu_init(struct vcpu *v) static inline unsigned int vgic_v3_rdist_count(struct domain *d) { + /* + * Normally there is only one GICv3 redistributor region. + * The GICv3 DT binding provisions for multiple regions, since there are + * platforms out there which need those (multi-socket systems). + * For Dom0 we have to live with the MMIO layout the hardware provides, + * so we have to copy the multiple regions - as the first region may not + * provide enough space to hold all redistributors we need. + * However DomU get a constructed memory map, so we can go with + * the architected single redistributor region. + */ return is_hardware_domain(d) ? vgic_v3_hw.nr_rdist_regions : GUEST_GICV3_RDIST_REGIONS; } @@ -1692,7 +1702,7 @@ static int vgic_v3_domain_init(struct domain *d) { d->arch.vgic.dbase = GUEST_GICV3_GICD_BASE; - /* XXX: Only one Re-distributor region mapped for the guest */ + /* A single Re-distributor region is mapped for the guest. */ BUILD_BUG_ON(GUEST_GICV3_RDIST_REGIONS != 1); d->arch.vgic.rdist_stride = GUEST_GICV3_RDIST_STRIDE;
Normally there is only one GICv3 redistributor region, and we use that for DomU guests using a GICv3. Explain the background in a comment and why we need to keep the number of hardware regions for Dom0. Signed-off-by: Andre Przywara <andre.przywara@linaro.org> --- Changelog RFC ... v1: - Keep GUEST_GICV3_RDIST_REGIONS symbol around, just extend comments xen/arch/arm/vgic-v3.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)