hw/intc/arm_gicv3: Support multiple redistributor regions

Our GICv3 QOM interface includes an array property
redist-region-count which allows board models to specify that the
registributor registers are not in a single contiguous range, but
split into multiple pieces.  We implemented this for KVM, but
currently the TCG GICv3 model insists that there is only one region.
You can see the limit being hit with a setup like:
  qemu-system-aarch64 -machine virt,gic-version=3 -smp 124

Add support for split regions to the TCG GICv3.  To do this we switch
from allocating a simple array of MemoryRegions to an array of
GICv3RedistRegion structs so that we can use the GICv3RedistRegion as
the opaque pointer in the MemoryRegion read/write callbacks.  Each
GICv3RedistRegion contains the MemoryRegion, a backpointer allowing
the read/write callback to get hold of the GICv3State, and an index
which allows us to calculate which CPU's redistributor is being
accessed.

Note that arm_gicv3_kvm always passes in NULL as the ops argument
to gicv3_init_irqs_and_mmio(), so the only MemoryRegion read/write
callbacks we need to update to handle this new scheme are the
gicv3_redist_read/write functions used by the emulated GICv3.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/include/hw/intc/arm_gicv3_common.h b/include/hw/intc/arm_gicv3_common.h
index cb2b0d0..fc38e4b 100644
--- a/include/hw/intc/arm_gicv3_common.h
+++ b/include/hw/intc/arm_gicv3_common.h
@@ -215,13 +215,23 @@ struct GICv3CPUState {
     bool seenbetter;
 };
 
+/*
+ * The redistributor pages might be split into more than one region
+ * on some machine types if there are many CPUs.
+ */
+typedef struct GICv3RedistRegion {
+    GICv3State *gic;
+    MemoryRegion iomem;
+    uint32_t cpuidx; /* index of first CPU this region covers */
+} GICv3RedistRegion;
+
 struct GICv3State {
     /*< private >*/
     SysBusDevice parent_obj;
     /*< public >*/
 
     MemoryRegion iomem_dist; /* Distributor */
-    MemoryRegion *iomem_redist; /* Redistributor Regions */
+    GICv3RedistRegion *redist_regions; /* Redistributor Regions */
     uint32_t *redist_region_count; /* redistributor count within each region */
     uint32_t nb_redist_regions; /* number of redist regions */