The highmem attribute is nothing but another way to express the
PA range of a VM. To support HW that has a smaller PA range then
what QEMU assumes, pass this PA range to the virt_set_memmap()
function, allowing it to correctly exclude highmem devices
if they are outside of the PA range.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
hw/arm/virt.c | 53 ++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 46 insertions(+), 7 deletions(-)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 57c55e8a37..db4b0636e1 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1660,7 +1660,7 @@ 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)
+static void virt_set_memmap(VirtMachineState *vms, int pa_bits)
{
MachineState *ms = MACHINE(vms);
hwaddr base, device_memory_base, device_memory_size, memtop;
@@ -1678,6 +1678,13 @@ static void virt_set_memmap(VirtMachineState *vms)
exit(EXIT_FAILURE);
}
+ /*
+ * !highmem is exactly the same as limiting the PA space to 32bit,
+ * irrespective of the underlying capabilities of the HW.
+ */
+ if (!vms->highmem)
+ pa_bits = 32;
+
/*
* We compute the base of the high IO region depending on the
* amount of initial and device memory. The device memory start/size
@@ -1691,8 +1698,9 @@ static void virt_set_memmap(VirtMachineState *vms)
/* Base address of the high IO region */
memtop = base = device_memory_base + ROUND_UP(device_memory_size, GiB);
- if (!vms->highmem && memtop > 4 * GiB) {
- error_report("highmem=off, but memory crosses the 4GiB limit\n");
+ if (memtop > BIT_ULL(pa_bits)) {
+ error_report("Addressing limited to %d bits, but memory exceeds it by %llu bytes\n",
+ pa_bits, memtop - BIT_ULL(pa_bits));
exit(EXIT_FAILURE);
}
if (base < device_memory_base) {
@@ -1711,7 +1719,13 @@ static void virt_set_memmap(VirtMachineState *vms)
vms->memmap[i].size = size;
base += size;
}
- vms->highest_gpa = (vms->highmem ? base : memtop) - 1;
+
+ /*
+ * If base fits within pa_bits, all good. If it doesn't, limit it
+ * to the end of RAM, which is guaranteed to fit within pa_bits.
+ */
+ vms->highest_gpa = (base <= BIT_ULL(pa_bits) ? base : memtop) - 1;
+
if (device_memory_size > 0) {
ms->device_memory = g_malloc0(sizeof(*ms->device_memory));
ms->device_memory->base = device_memory_base;
@@ -1902,12 +1916,38 @@ static void machvirt_init(MachineState *machine)
unsigned int smp_cpus = machine->smp.cpus;
unsigned int max_cpus = machine->smp.max_cpus;
+ possible_cpus = mc->possible_cpu_arch_ids(machine);
+
/*
* In accelerated mode, the memory map is computed earlier in kvm_type()
* to create a VM with the right number of IPA bits.
*/
if (!vms->memmap) {
- virt_set_memmap(vms);
+ Object *cpuobj;
+ ARMCPU *armcpu;
+ int pa_bits;
+
+ /*
+ * Instanciate a temporary CPU object to find out about what
+ * we are about to deal with. Once this is done, get rid of
+ * the object.
+ */
+ cpuobj = object_new(possible_cpus->cpus[0].type);
+ armcpu = ARM_CPU(cpuobj);
+
+ if (object_property_get_bool(cpuobj, "aarch64", NULL)) {
+ pa_bits = arm_pamax(armcpu);
+ } else if (arm_feature(&armcpu->env, ARM_FEATURE_LPAE)) {
+ /* v7 with LPAE */
+ pa_bits = 40;
+ } else {
+ /* Anything else */
+ pa_bits = 32;
+ }
+
+ object_unref(cpuobj);
+
+ virt_set_memmap(vms, pa_bits);
}
/* We can probe only here because during property set
@@ -1989,7 +2029,6 @@ static void machvirt_init(MachineState *machine)
create_fdt(vms);
- possible_cpus = mc->possible_cpu_arch_ids(machine);
assert(possible_cpus->len == max_cpus);
for (n = 0; n < possible_cpus->len; n++) {
Object *cpuobj;
@@ -2646,7 +2685,7 @@ static int virt_kvm_type(MachineState *ms, const char *type_str)
max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms, &fixed_ipa);
/* we freeze the memory map to compute the highest gpa */
- virt_set_memmap(vms);
+ virt_set_memmap(vms, max_vm_pa_size);
requested_pa_size = 64 - clz64(vms->highest_gpa);
--
2.30.2
