hw/arm/virt: Support TCG GICv4
Add support for the TCG GICv4 to the virt board. For the board,
the GICv4 is very similar to the GICv3, with the only difference
being the size of the redistributor frame. The changes here are thus:
* calculating virt_redist_capacity correctly for GICv4
* changing various places which were "if GICv3" to be "if not GICv2"
* the commandline option handling
Note that using GICv4 reduces the maximum possible number of CPUs on
the virt board from 512 to 317, because we can now only fit half as
many redistributors into the redistributor regions we have defined.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220408141550.1271295-42-peter.maydell@linaro.org
diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
index 1297dff..5fe045c 100644
--- a/docs/system/arm/virt.rst
+++ b/docs/system/arm/virt.rst
@@ -99,11 +99,14 @@
GICv2. Note that this limits the number of CPUs to 8.
``3``
GICv3. This allows up to 512 CPUs.
+ ``4``
+ GICv4. Requires ``virtualization`` to be ``on``; allows up to 317 CPUs.
``host``
Use the same GIC version the host provides, when using KVM
``max``
Use the best GIC version possible (same as host when using KVM;
- currently same as ``3``` for TCG, but this may change in future)
+ with TCG this is currently ``3`` if ``virtualization`` is ``off`` and
+ ``4`` if ``virtualization`` is ``on``, but this may change in future)
its
Set ``on``/``off`` to enable/disable ITS instantiation. The default is ``on``
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 1227c64..5bdd98e 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -522,7 +522,7 @@
qemu_fdt_setprop_cell(ms->fdt, nodename, "#address-cells", 0x2);
qemu_fdt_setprop_cell(ms->fdt, nodename, "#size-cells", 0x2);
qemu_fdt_setprop(ms->fdt, nodename, "ranges", NULL, 0);
- if (vms->gic_version == VIRT_GIC_VERSION_3) {
+ if (vms->gic_version != VIRT_GIC_VERSION_2) {
int nb_redist_regions = virt_gicv3_redist_region_count(vms);
qemu_fdt_setprop_string(ms->fdt, nodename, "compatible",
@@ -708,6 +708,9 @@
case VIRT_GIC_VERSION_3:
revision = 3;
break;
+ case VIRT_GIC_VERSION_4:
+ revision = 4;
+ break;
default:
g_assert_not_reached();
}
@@ -722,7 +725,7 @@
qdev_prop_set_bit(vms->gic, "has-security-extensions", vms->secure);
}
- if (vms->gic_version == VIRT_GIC_VERSION_3) {
+ if (vms->gic_version != VIRT_GIC_VERSION_2) {
uint32_t redist0_capacity = virt_redist_capacity(vms, VIRT_GIC_REDIST);
uint32_t redist0_count = MIN(smp_cpus, redist0_capacity);
@@ -756,7 +759,7 @@
gicbusdev = SYS_BUS_DEVICE(vms->gic);
sysbus_realize_and_unref(gicbusdev, &error_fatal);
sysbus_mmio_map(gicbusdev, 0, vms->memmap[VIRT_GIC_DIST].base);
- if (vms->gic_version == VIRT_GIC_VERSION_3) {
+ if (vms->gic_version != VIRT_GIC_VERSION_2) {
sysbus_mmio_map(gicbusdev, 1, vms->memmap[VIRT_GIC_REDIST].base);
if (nb_redist_regions == 2) {
sysbus_mmio_map(gicbusdev, 2,
@@ -794,7 +797,7 @@
ppibase + timer_irq[irq]));
}
- if (vms->gic_version == VIRT_GIC_VERSION_3) {
+ if (vms->gic_version != VIRT_GIC_VERSION_2) {
qemu_irq irq = qdev_get_gpio_in(vms->gic,
ppibase + ARCH_GIC_MAINT_IRQ);
qdev_connect_gpio_out_named(cpudev, "gicv3-maintenance-interrupt",
@@ -820,7 +823,7 @@
fdt_add_gic_node(vms);
- if (vms->gic_version == VIRT_GIC_VERSION_3 && vms->its) {
+ if (vms->gic_version != VIRT_GIC_VERSION_2 && vms->its) {
create_its(vms);
} else if (vms->gic_version == VIRT_GIC_VERSION_2) {
create_v2m(vms);
@@ -1672,10 +1675,10 @@
* purposes are to make TCG consistent (with 64-bit KVM hosts)
* and to improve SGI efficiency.
*/
- if (vms->gic_version == VIRT_GIC_VERSION_3) {
- clustersz = GICV3_TARGETLIST_BITS;
- } else {
+ if (vms->gic_version == VIRT_GIC_VERSION_2) {
clustersz = GIC_TARGETLIST_BITS;
+ } else {
+ clustersz = GICV3_TARGETLIST_BITS;
}
}
return arm_cpu_mp_affinity(idx, clustersz);
@@ -1808,6 +1811,10 @@
error_report(
"gic-version=3 is not supported with kernel-irqchip=off");
exit(1);
+ case VIRT_GIC_VERSION_4:
+ error_report(
+ "gic-version=4 is not supported with kernel-irqchip=off");
+ exit(1);
}
}
@@ -1845,6 +1852,9 @@
case VIRT_GIC_VERSION_2:
case VIRT_GIC_VERSION_3:
break;
+ case VIRT_GIC_VERSION_4:
+ error_report("gic-version=4 is not supported with KVM");
+ exit(1);
}
/* Check chosen version is effectively supported by the host */
@@ -1868,7 +1878,12 @@
case VIRT_GIC_VERSION_MAX:
if (module_object_class_by_name("arm-gicv3")) {
/* CONFIG_ARM_GICV3_TCG was set */
- vms->gic_version = VIRT_GIC_VERSION_3;
+ if (vms->virt) {
+ /* GICv4 only makes sense if CPU has EL2 */
+ vms->gic_version = VIRT_GIC_VERSION_4;
+ } else {
+ vms->gic_version = VIRT_GIC_VERSION_3;
+ }
} else {
vms->gic_version = VIRT_GIC_VERSION_2;
}
@@ -1876,6 +1891,12 @@
case VIRT_GIC_VERSION_HOST:
error_report("gic-version=host requires KVM");
exit(1);
+ case VIRT_GIC_VERSION_4:
+ if (!vms->virt) {
+ error_report("gic-version=4 requires virtualization enabled");
+ exit(1);
+ }
+ break;
case VIRT_GIC_VERSION_2:
case VIRT_GIC_VERSION_3:
break;
@@ -2043,14 +2064,16 @@
vms->psci_conduit = QEMU_PSCI_CONDUIT_HVC;
}
- /* The maximum number of CPUs depends on the GIC version, or on how
- * many redistributors we can fit into the memory map.
+ /*
+ * The maximum number of CPUs depends on the GIC version, or on how
+ * many redistributors we can fit into the memory map (which in turn
+ * depends on whether this is a GICv3 or v4).
*/
- if (vms->gic_version == VIRT_GIC_VERSION_3) {
+ if (vms->gic_version == VIRT_GIC_VERSION_2) {
+ virt_max_cpus = GIC_NCPU;
+ } else {
virt_max_cpus = virt_redist_capacity(vms, VIRT_GIC_REDIST) +
virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2);
- } else {
- virt_max_cpus = GIC_NCPU;
}
if (max_cpus > virt_max_cpus) {
@@ -2438,8 +2461,19 @@
static char *virt_get_gic_version(Object *obj, Error **errp)
{
VirtMachineState *vms = VIRT_MACHINE(obj);
- const char *val = vms->gic_version == VIRT_GIC_VERSION_3 ? "3" : "2";
+ const char *val;
+ switch (vms->gic_version) {
+ case VIRT_GIC_VERSION_4:
+ val = "4";
+ break;
+ case VIRT_GIC_VERSION_3:
+ val = "3";
+ break;
+ default:
+ val = "2";
+ break;
+ }
return g_strdup(val);
}
@@ -2447,7 +2481,9 @@
{
VirtMachineState *vms = VIRT_MACHINE(obj);
- if (!strcmp(value, "3")) {
+ if (!strcmp(value, "4")) {
+ vms->gic_version = VIRT_GIC_VERSION_4;
+ } else if (!strcmp(value, "3")) {
vms->gic_version = VIRT_GIC_VERSION_3;
} else if (!strcmp(value, "2")) {
vms->gic_version = VIRT_GIC_VERSION_2;
@@ -2905,7 +2941,7 @@
virt_set_gic_version);
object_class_property_set_description(oc, "gic-version",
"Set GIC version. "
- "Valid values are 2, 3, host and max");
+ "Valid values are 2, 3, 4, host and max");
object_class_property_add_str(oc, "iommu", virt_get_iommu, virt_set_iommu);
object_class_property_set_description(oc, "iommu",
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 360463e..15feaba 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -113,6 +113,7 @@
VIRT_GIC_VERSION_HOST,
VIRT_GIC_VERSION_2,
VIRT_GIC_VERSION_3,
+ VIRT_GIC_VERSION_4,
VIRT_GIC_VERSION_NOSEL,
} VirtGICType;
@@ -188,7 +189,14 @@
/* Return number of redistributors that fit in the specified region */
static uint32_t virt_redist_capacity(VirtMachineState *vms, int region)
{
- return vms->memmap[region].size / GICV3_REDIST_SIZE;
+ uint32_t redist_size;
+
+ if (vms->gic_version == VIRT_GIC_VERSION_3) {
+ redist_size = GICV3_REDIST_SIZE;
+ } else {
+ redist_size = GICV4_REDIST_SIZE;
+ }
+ return vms->memmap[region].size / redist_size;
}
/* Return the number of used redistributor regions */
@@ -196,7 +204,7 @@
{
uint32_t redist0_capacity = virt_redist_capacity(vms, VIRT_GIC_REDIST);
- assert(vms->gic_version == VIRT_GIC_VERSION_3);
+ assert(vms->gic_version != VIRT_GIC_VERSION_2);
return (MACHINE(vms)->smp.cpus > redist0_capacity &&
vms->highmem_redists) ? 2 : 1;
