On Fri, 22 Feb 2019 15:01:25 +0100 Auger Eric <eric.au...@redhat.com> wrote:
> Hi Igor, > > On 2/22/19 1:45 PM, Igor Mammedov wrote: > > On Wed, 20 Feb 2019 23:39:54 +0100 > > Eric Auger <eric.au...@redhat.com> wrote: > > > >> This patch implements the machine class kvm_type() callback. > >> It returns the number of bits requested to implement the whole GPA > >> range including the RAM and IO regions located beyond. > >> The returned value in passed though the KVM_CREATE_VM ioctl and > >> this allows KVM to set the stage2 tables dynamically. > >> > >> Signed-off-by: Eric Auger <eric.au...@redhat.com> > >> > >> --- > >> > >> v6 -> v7: > >> - Introduce RAMBASE and rename add LEGACY_ prefix in that patch > >> - use local variables with explicit names in virt_set_memmap: > >> device_memory_base, device_memory_size > >> - add an extended_memmap field in the class > >> > >> v5 -> v6: > >> - add some comments > >> - high IO region cannot start before 256GiB > >> --- > >> hw/arm/virt.c | 50 ++++++++++++++++++++++++++++++++++++++++++- > >> include/hw/arm/virt.h | 2 ++ > >> 2 files changed, 51 insertions(+), 1 deletion(-) > >> > >> diff --git a/hw/arm/virt.c b/hw/arm/virt.c > >> index 9db602457b..ad3a0ad73d 100644 > >> --- a/hw/arm/virt.c > >> +++ b/hw/arm/virt.c > >> @@ -1437,7 +1437,14 @@ static void machvirt_init(MachineState *machine) > >> bool firmware_loaded = bios_name || drive_get(IF_PFLASH, 0, 0); > >> bool aarch64 = true; > >> > >> - virt_set_memmap(vms); > >> + /* > >> + * In accelerated mode, the memory map is computed in kvm_type(), > >> + * if set, to create a VM with the right number of IPA bits. > >> + */ > >> + > >> + if (!mc->kvm_type || !kvm_enabled()) { > >> + virt_set_memmap(vms); > >> + } > >> > >> /* We can probe only here because during property set > >> * KVM is not available yet > >> @@ -1814,6 +1821,36 @@ static HotplugHandler > >> *virt_machine_get_hotplug_handler(MachineState *machine, > >> return NULL; > >> } > >> > >> +/* > >> + * for arm64 kvm_type [7-0] encodes the requested number of bits > >> + * in the IPA address space > >> + */ > >> +static int virt_kvm_type(MachineState *ms, const char *type_str) > >> +{ > >> + VirtMachineState *vms = VIRT_MACHINE(ms); > >> + int max_vm_pa_size = kvm_arm_get_max_vm_ipa_size(ms); > >> + int requested_pa_size; > >> + > >> + /* we freeze the memory map to compute the highest gpa */ > >> + virt_set_memmap(vms); > >> + > >> + requested_pa_size = 64 - clz64(vms->highest_gpa); > >> + > >> + if (requested_pa_size > max_vm_pa_size) { > >> + error_report("-m and ,maxmem option values " > >> + "require an IPA range (%d bits) larger than " > >> + "the one supported by the host (%d bits)", > >> + requested_pa_size, max_vm_pa_size); > >> + exit(1); > >> + } > >> + /* > >> + * By default we return 0 which corresponds to an implicit legacy > >> + * 40b IPA setting. Otherwise we return the actual requested PA > >> + * logsize > >> + */ > >> + return requested_pa_size > 40 ? requested_pa_size : 0; > >> +} > >> + > >> static void virt_machine_class_init(ObjectClass *oc, void *data) > >> { > >> MachineClass *mc = MACHINE_CLASS(oc); > >> @@ -1838,6 +1875,7 @@ static void virt_machine_class_init(ObjectClass *oc, > >> void *data) > >> mc->cpu_index_to_instance_props = virt_cpu_index_to_props; > >> mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15"); > >> mc->get_default_cpu_node_id = virt_get_default_cpu_node_id; > >> + mc->kvm_type = virt_kvm_type; > >> assert(!mc->get_hotplug_handler); > >> mc->get_hotplug_handler = virt_machine_get_hotplug_handler; > >> hc->plug = virt_machine_device_plug_cb; > >> @@ -1909,6 +1947,12 @@ static void virt_instance_init(Object *obj) > >> "Valid values are none and smmuv3", > >> NULL); > >> > >> + if (vmc->no_extended_memmap) { > >> + vms->extended_memmap = false; > >> + } else { > >> + vms->extended_memmap = true; > >> + } > >> + > >> vms->irqmap = a15irqmap; > >> } > >> > >> @@ -1939,8 +1983,12 @@ DEFINE_VIRT_MACHINE_AS_LATEST(4, 0) > >> > >> static void virt_machine_3_1_options(MachineClass *mc) > >> { > >> + VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc)); > >> virt_machine_4_0_options(mc); > >> compat_props_add(mc->compat_props, hw_compat_3_1, hw_compat_3_1_len); > >> + > >> + /* extended memory map is enabled from 4.0 onwards */ > >> + vmc->no_extended_memmap = true; > > That's probably was asked in v6, > > do we really need this knob? > Yes the point was raised by Peter and I replied by another question ;-) " > But don't we want to forbid any pre-4.0 machvirt to run with more than > 255GiB RAM? > " > without this knob: > - pre-4.0 machines will gain the capability to support more than 255GB > initial RAM if the kernel supports dynamic IPA setting should be fine, you shouldn't be able to start old QEMU with more than 255Gb > - pre-4.0 machines will gain PCDIMM/NVDIMM support ditto > - another concern, maxmem and slots were not checked previously. If for > some reason - without instantiating the actual slots -, the user > specified it this was previously ignored. Now this is not anymore as > both parameters allow to compute the requested IPA range. So this may > fail now. well that's in category of a broken setup even if QEMU didn't complain about it before. User should fix it instead of QEMU supporting madness. (I think that such invariant doesn't even deserve deprecation process) > So I thought this was clearer to disable all the above for pre-4.0 > machines. However if both of you agree, I will remove it. > > thanks > > Eric > > > >> } > >> DEFINE_VIRT_MACHINE(3, 1) > >> > >> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h > >> index acad0400d8..7798462cb0 100644 > >> --- a/include/hw/arm/virt.h > >> +++ b/include/hw/arm/virt.h > >> @@ -106,6 +106,7 @@ typedef struct { > >> bool claim_edge_triggered_timers; > >> bool smbios_old_sys_ver; > >> bool no_highmem_ecam; > >> + bool no_extended_memmap; > >> } VirtMachineClass; > >> > >> typedef struct { > >> @@ -135,6 +136,7 @@ typedef struct { > >> hwaddr highest_gpa; > >> hwaddr device_memory_base; > >> hwaddr device_memory_size; > >> + bool extended_memmap; > >> } VirtMachineState; > >> > >> #define VIRT_ECAM_ID(high) (high ? VIRT_HIGH_PCIE_ECAM : VIRT_PCIE_ECAM) > > >