On Wed, Oct 13, 2021 at 22:41 PM Bin Meng <[email protected]> wrote: > > On Tue, Oct 12, 2021 at 9:46 AM MingWang Li <[email protected]> wrote: > > > > From: Mingwang Li <[email protected]> > > > > When I start the VM with the following command: > > $ ./qemu-system-riscv64 -M virt,accel=kvm -m 4096M -cpu host -nographic \ > > -name guest=riscv-guset \ > > -smp 2 \ > > -bios none \ > > -kernel ./Image \ > > -drive file=./guest.img,format=raw,id=hd0 \ > > -device virtio-blk-device,drive=hd0 \ > > -append "root=/dev/vda rw console=ttyS0 earlycon=sbi" \ > > -object > memory-backend-file,id=mem,size=4096M,mem-path=/dev/hugepages,share=on \ > > -numa node,memdev=mem -mem-prealloc \ > > -chardev socket,id=char0,path=/mnt/vhost-net0 \ > > -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \ > > -device > > virtio-net-pci,mac=52:54:00:00:00:01,netdev=mynet1,mrg_rxbuf=on,csum=o > > n,guest_csum=on,guest_ecn=on \ > > > > Then, QEMU displays the following error information: > > qemu-system-riscv64: Failed initializing vhost-user memory map, > > consider using -object memory-backend-file share=on > > I see your command line parameters already contain "-object > memory-backend-file > share=on", so this error message is not accurate.
QEMU uses this command to alloc fd in the "memory_region_init_ram_from_file" function and assigns the value of fd to mr->ram_block-fd. If the QEMU uses the default memory to initialize the system, the QEMU cannot obtain the fd in the "vhost_user_mem_section_filter" function when initializing the vhost-user. As a result, an error is reported in the "vhost_user_fill_set_mem_table_msg" function. Because of the above bug, even if "-object memory-backend-file share=on" is added to the command line, the QEMU still reports an error. This patch can solve this bug. > Should this message be altered to mention things like what this patch does? Thanks, I will rewrite the message in next version. > > > qemu-system-riscv64: vhost_set_mem_table failed: Interrupted system > > call (4) > > qemu-system-riscv64: unable to start vhost net: 4: falling back on > > userspace virtio > > > > Note that, before starting the kvm-acceled QEMU VM, following > > temporarily unaccepted QEMU patches should be used: > > https://lists.gnu.org/archive/html/qemu-devel/2021-08/msg02516.html > > > > This error was made bacause default main_mem is used to be registered > > typo: because > Thanks. > > as the system memory, other memory cannot be initialized. Therefore, > > the system memory should be initialized to the machine->ram, which > > consists of the default main_mem and other possible memory required by > > applications, such as shared hugepage memory in DPDK. > > Also, the mc->defaul_ram_id should be set to the default main_mem, > > such as "riscv_virt_board.ram" for the virt machine. > > > > How about changing the commit title to: "Use machine->ram as the system > memory" ?? > I think it is just a bugfix. > > Signed-off-by: Mingwang Li <[email protected]> > > Signed-off-by: Yifei Jiang <[email protected]> > > Reviewed-by: Alistair Francis <[email protected]> > > --- > > hw/riscv/virt.c | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > > > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c index > > ec0cb69b8c..b3b431c847 100644 > > --- a/hw/riscv/virt.c > > +++ b/hw/riscv/virt.c > > @@ -771,7 +771,6 @@ static void virt_machine_init(MachineState *machine) > > const MemMapEntry *memmap = virt_memmap; > > RISCVVirtState *s = RISCV_VIRT_MACHINE(machine); > > MemoryRegion *system_memory = get_system_memory(); > > - MemoryRegion *main_mem = g_new(MemoryRegion, 1); > > MemoryRegion *mask_rom = g_new(MemoryRegion, 1); > > char *plic_hart_config, *soc_name; > > target_ulong start_addr = memmap[VIRT_DRAM].base; @@ -890,10 > > +889,8 @@ static void virt_machine_init(MachineState *machine) > > } > > > > /* register system main memory (actual RAM) */ > > - memory_region_init_ram(main_mem, NULL, "riscv_virt_board.ram", > > - machine->ram_size, &error_fatal); > > memory_region_add_subregion(system_memory, > memmap[VIRT_DRAM].base, > > - main_mem); > > + machine->ram); > > > > /* create device tree */ > > create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline, > > @@ -1032,6 +1029,7 @@ static void virt_machine_class_init(ObjectClass *oc, > void *data) > > mc->cpu_index_to_instance_props = riscv_numa_cpu_index_to_props; > > mc->get_default_cpu_node_id = riscv_numa_get_default_cpu_node_id; > > mc->numa_mem_supported = true; > > + mc->default_ram_id = "riscv_virt_board.ram"; > > > > machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE); > > > > Regards, > Bin
