[Qemu-devel] [PATCH v11 10/10] hw/arm/virt: Bump the 255GB initial RAM limit

[Eric Auger]

Now we have the extended memory map (high IO regions beyond the
scalable RAM) and dynamic IPA range support at KVM/ARM level
we can bump the legacy 255GB initial RAM limit. The actual maximum
RAM size now depends on the physical CPU and host kernel, in
accelerated mode. In TCG mode, it depends on the VCPU
AA64MMFR0.PARANGE.

Signed-off-by: Eric Auger <address@hidden>

---
v7 -> v8:
- TCG PAMAX check moved in a separate patch

v6 -> v7
- handle TCG case
- set_memmap modifications moved to previous patches
---
 hw/arm/virt.c | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index ab70e4a657..aa06570050 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -95,20 +95,7 @@
 
 #define PLATFORM_BUS_NUM_IRQS 64
 
-/* RAM limit in GB. Since VIRT_MEM starts at the 1GB mark, this means
- * RAM can go up to the 256GB mark, leaving 256GB of the physical
- * address space unallocated and free for future use between 256G and 512G.
- * If we need to provide more RAM to VMs in the future then we need to:
- *  * allocate a second bank of RAM starting at 2TB and working up
- *  * fix the DT and ACPI table generation code in QEMU to correctly
- *    report two split lumps of RAM to the guest
- *  * fix KVM in the host kernel to allow guests with >40 bit address spaces
- * (We don't want to fill all the way up to 512GB with RAM because
- * we might want it for non-RAM purposes later. Conversely it seems
- * reasonable to assume that anybody configuring a VM with a quarter
- * of a terabyte of RAM will be doing it on a host with more than a
- * terabyte of physical address space.)
- */
+/* Legacy RAM limit in GB (< version 4.0) */
 #define LEGACY_RAMLIMIT_GB 255
 #define LEGACY_RAMLIMIT_BYTES (LEGACY_RAMLIMIT_GB * GiB)
 
@@ -1516,12 +1503,6 @@ static void machvirt_init(MachineState *machine)
 
     vms->smp_cpus = smp_cpus;
 
-    if (machine->ram_size > vms->memmap[VIRT_MEM].size) {
-        error_report("mach-virt: cannot model more than %dGB RAM",
-                     LEGACY_RAMLIMIT_GB);
-        exit(1);
-    }
-
     if (vms->virt && kvm_enabled()) {
         error_report("mach-virt: KVM does not support providing "
                      "Virtualization extensions to the guest CPU");
-- 
2.20.1