From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:50596) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gzOZb-0002dq-E3 for qemu-devel@nongnu.org; Thu, 28 Feb 2019 11:30:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gzOZX-000116-FI for qemu-devel@nongnu.org; Thu, 28 Feb 2019 11:30:13 -0500 Date: Thu, 28 Feb 2019 17:29:38 +0100 From: Igor Mammedov Message-ID: <20190228172938.1993ed57@redhat.com> In-Reply-To: <20190228150324.25973-11-eric.auger@redhat.com> References: <20190228150324.25973-1-eric.auger@redhat.com> <20190228150324.25973-11-eric.auger@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v10 10/10] hw/arm/virt: Bump the 255GB initial RAM limit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Auger Cc: eric.auger.pro@gmail.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, shameerali.kolothum.thodi@huawei.com, david@redhat.com, dgilbert@redhat.com, david@gibson.dropbear.id.au, drjones@redhat.com, pbonzini@redhat.com On Thu, 28 Feb 2019 16:03:24 +0100 Eric Auger wrote: > 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 > > --- > 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 a3da75a5ae..a45f0fcf79 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -95,21 +95,8 @@ > > #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.) > - */ > #define RAMBASE GiB > +/* Legacy RAM limit in GB (< version 4.0) */ > #define LEGACY_RAMLIMIT_GB 255 > #define LEGACY_RAMLIMIT_BYTES (LEGACY_RAMLIMIT_GB * GiB) do we need to keep these couple around? it's used only in [VIRT_MEM] = { RAMBASE, LEGACY_RAMLIMIT_BYTES }, and doesn't have any effect whatsoever. I'd set initial VIRT_MEM.size to 0 and drop LEGACY_RAMLIMIT_* maybe add comment above entry that size is defined by ram_size > > @@ -1515,12 +1502,6 @@ 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");