[Qemu-devel] [PATCH v7 03/17] hw/arm/virt: Split the memory map description

[Eric Auger <eric.auger@redhat.com>]

In the prospect to introduce an extended memory map supporting more
RAM, let's split the memory map array into two parts:

- the former a15memmap contains regions below and including the RAM
- extended_memmap, only initialized with entries located after the RAM.
  Only the size of the region is initialized there since their base
  address will be dynamically computed, depending on the top of the
  RAM (initial RAM at the moment), with same alignment as their size.

This new split will allow to grow the RAM size without changing the
description of the high regions.

The patch also moves the memory map setup into machvirt_init().
The rationale is the memory map will be soon affected by the
kvm_type() call that happens after virt_instance_init() and
before machvirt_init().

The memory map is unchanged (the top of the initial RAM still is
256GiB). Then come the high IO regions with same layout as before.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

---
v6 -> v7:
- s/a15memmap/base_memmap
- slight rewording of the commit message
- add "if there is less than 256GiB of RAM then the floating area
  starts at the 256GiB mark" in the comment associated to the floating
  memory map
- Added Peter's R-b

v5 -> v6
- removal of many macros in units.h
- introduce the virt_set_memmap helper
- new computation for offsets of high IO regions
- add comments
---
 hw/arm/virt.c         | 48 +++++++++++++++++++++++++++++++++++++------
 include/hw/arm/virt.h | 14 +++++++++----
 2 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index a1955e7764..12039a0367 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -29,6 +29,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/units.h"
 #include "qapi/error.h"
 #include "hw/sysbus.h"
 #include "hw/arm/arm.h"
@@ -121,7 +122,7 @@
  * Note that devices should generally be placed at multiples of 0x10000,
  * to accommodate guests using 64K pages.
  */
-static const MemMapEntry a15memmap[] = {
+static const MemMapEntry base_memmap[] = {
     /* Space up to 0x8000000 is reserved for a boot ROM */
     [VIRT_FLASH] =              {          0, 0x08000000 },
     [VIRT_CPUPERIPHS] =         { 0x08000000, 0x00020000 },
@@ -149,11 +150,21 @@ static const MemMapEntry a15memmap[] = {
     [VIRT_PCIE_PIO] =           { 0x3eff0000, 0x00010000 },
     [VIRT_PCIE_ECAM] =          { 0x3f000000, 0x01000000 },
     [VIRT_MEM] =                { 0x40000000, RAMLIMIT_BYTES },
+};
+
+/*
+ * Highmem IO Regions: This memory map is floating, located after the RAM.
+ * Each IO region offset will be dynamically computed, depending on the
+ * top of the RAM, so that its base get the same alignment as the size,
+ * ie. a 512GiB region will be aligned on a 512GiB boundary. If there is
+ * less than 256GiB of RAM, the floating area starts at the 256GiB mark.
+ */
+static MemMapEntry extended_memmap[] = {
     /* Additional 64 MB redist region (can contain up to 512 redistributors) */
-    [VIRT_HIGH_GIC_REDIST2] =   { 0x4000000000ULL, 0x4000000 },
-    [VIRT_HIGH_PCIE_ECAM] =     { 0x4010000000ULL, 0x10000000 },
-    /* Second PCIe window, 512GB wide at the 512GB boundary */
-    [VIRT_HIGH_PCIE_MMIO] =     { 0x8000000000ULL, 0x8000000000ULL },
+    [VIRT_HIGH_GIC_REDIST2] =   { 0x0, 64 * MiB },
+    [VIRT_HIGH_PCIE_ECAM] =     { 0x0, 256 * MiB },
+    /* Second PCIe window */
+    [VIRT_HIGH_PCIE_MMIO] =     { 0x0, 512 * GiB },
 };
 
 static const int a15irqmap[] = {
@@ -1354,6 +1365,30 @@ static uint64_t virt_cpu_mp_affinity(VirtMachineState *vms, int idx)
     return arm_cpu_mp_affinity(idx, clustersz);
 }
 
+static void virt_set_memmap(VirtMachineState *vms)
+{
+    hwaddr base;
+    int i;
+
+    vms->memmap = extended_memmap;
+
+    for (i = 0; i < ARRAY_SIZE(base_memmap); i++) {
+        vms->memmap[i] = base_memmap[i];
+    }
+
+    vms->high_io_base = 256 * GiB; /* Top of the legacy initial RAM region */
+    base = vms->high_io_base;
+
+    for (i = VIRT_LOWMEMMAP_LAST; i < ARRAY_SIZE(extended_memmap); i++) {
+        hwaddr size = extended_memmap[i].size;
+
+        base = ROUND_UP(base, size);
+        vms->memmap[i].base = base;
+        vms->memmap[i].size = size;
+        base += size;
+    }
+}
+
 static void machvirt_init(MachineState *machine)
 {
     VirtMachineState *vms = VIRT_MACHINE(machine);
@@ -1368,6 +1403,8 @@ static void machvirt_init(MachineState *machine)
     bool firmware_loaded = bios_name || drive_get(IF_PFLASH, 0, 0);
     bool aarch64 = true;
 
+    virt_set_memmap(vms);
+
     /* We can probe only here because during property set
      * KVM is not available yet
      */
@@ -1843,7 +1880,6 @@ static void virt_instance_init(Object *obj)
                                     "Valid values are none and smmuv3",
                                     NULL);
 
-    vms->memmap = a15memmap;
     vms->irqmap = a15irqmap;
 }
 
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index a27086d524..3dc7a6c5d5 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -64,7 +64,6 @@ enum {
     VIRT_GIC_VCPU,
     VIRT_GIC_ITS,
     VIRT_GIC_REDIST,
-    VIRT_HIGH_GIC_REDIST2,
     VIRT_SMMU,
     VIRT_UART,
     VIRT_MMIO,
@@ -74,12 +73,18 @@ enum {
     VIRT_PCIE_MMIO,
     VIRT_PCIE_PIO,
     VIRT_PCIE_ECAM,
-    VIRT_HIGH_PCIE_ECAM,
     VIRT_PLATFORM_BUS,
-    VIRT_HIGH_PCIE_MMIO,
     VIRT_GPIO,
     VIRT_SECURE_UART,
     VIRT_SECURE_MEM,
+    VIRT_LOWMEMMAP_LAST,
+};
+
+/* indices of IO regions located after the RAM */
+enum {
+    VIRT_HIGH_GIC_REDIST2 =  VIRT_LOWMEMMAP_LAST,
+    VIRT_HIGH_PCIE_ECAM,
+    VIRT_HIGH_PCIE_MMIO,
 };
 
 typedef enum VirtIOMMUType {
@@ -116,7 +121,7 @@ typedef struct {
     int32_t gic_version;
     VirtIOMMUType iommu;
     struct arm_boot_info bootinfo;
-    const MemMapEntry *memmap;
+    MemMapEntry *memmap;
     const int *irqmap;
     int smp_cpus;
     void *fdt;
@@ -126,6 +131,7 @@ typedef struct {
     uint32_t msi_phandle;
     uint32_t iommu_phandle;
     int psci_conduit;
+    hwaddr high_io_base;
 } VirtMachineState;
 
 #define VIRT_ECAM_ID(high) (high ? VIRT_HIGH_PCIE_ECAM : VIRT_PCIE_ECAM)
-- 
2.20.1