On Mon, Jun 16, 2014 at 02:29:08PM +0800, Hu Tao wrote:
> On Sun, Jun 15, 2014 at 01:00:56PM +0300, Michael S. Tsirkin wrote:
> > On Sat, Jun 14, 2014 at 12:48:55PM +0800, Hu Tao wrote:
> > > Michael,
> > >
> > > This is fixes for your pci tree.
> > >
> > > patch 1 remove signed range as requested.
> >
> > This also fixes make check failures so I applied this.
> >
> > Others don't look like regressions to me -
> > this is error handling in new functionality, correct?
>
> Yes.
>
>
> BTW, thre are two more problems:
>
> 1. if numa node number doesn't start from 0 then qemu will core dump.
>
> cmd line:
>
> ./x86_64-softmmu/qemu-system-x86_64 -hda
> /home/data/libvirt-images/f18.img -m 128M,maxmem=2G,slots=3 -qmp
> unix:/tmp/m,server,nowait -monitor stdio -enable-kvm -object
> memory-backend-ram,id=m1,size=128M -numa node,nodeid=1,cpus=1,memdev=m1
>
> This problem can be fixed by:
>
> diff --git a/numa.c b/numa.c
> index ce9382d..b00c5cf 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -270,10 +270,13 @@ void memory_region_allocate_system_memory(MemoryRegion
> *mr, Obj
> }
>
> memory_region_init(mr, owner, name, ram_size);
> - for (i = 0; i < nb_numa_nodes; i++) {
> + for (i = 0; i < MAX_NODES; i++) {
> Error *local_err = NULL;
> uint64_t size = numa_info[i].node_mem;
> HostMemoryBackend *backend = numa_info[i].node_memdev;
> + if (!backend) {
> + continue;
> + }
> MemoryRegion *seg = host_memory_backend_get_memory(backend,
> &local_err);
> if (local_err) {
> qerror_report_err(local_err);
>
> 2. your current pci tree doesn't compile because patch 'qmp: add
> query-memdev' is dropped
> while commit 5b517e74ed7825(hmp: add info memdev) depends on it.
Hmm it builds for me.
Does it only build if some library is present?
> but patch 'qmp: add query-memdev' itself has a problem: if memory-backend-ram
> is on the command
> line but no numa, info memdev returns nothing:
>
> ./x86_64-softmmu/qemu-system-x86_64 -hda /home/data/libvirt-images/f18.img
> -m 128M,maxmem=2G,slots=3 -qmp unix:/tmp/m,server,nowait -monitor stdio
> -enable-kvm -object memory-backend-ram,id=m1,size=128M
> QEMU 2.0.50 monitor - type 'help' for more information
> (qemu) info memdev
> (nothing returned)
>
> even worse, if with -numa mem=size then qemu will core dump:
>
> ./x86_64-softmmu/qemu-system-x86_64 -hda /home/data/libvirt-images/f18.img
> -m 128M,maxmem=2G,slots=3 -qmp unix:/tmp/m,server,nowait -monitor stdio
> -enable-kvm -object memory-backend-ram,id=m1,size=128M -numa
> node,nodeid=0,cpus=0,mem=128M
> (qemu) info memdev
> Segmentation fault (core dumped)
>
> this is because query_memdev searchs for memdev information in
> numa_info[].node_memdev,
> which don't have value if there is no numa or numa isn't used with
> memory-backend-ram.
>
> the solution can be gather memdevs in a list. Or query at /objects?
query QOM seems nicer.
> > Thus I'll wait for comments on these to be resolved,
> > and hopefully for some acks.
> >
> > > There are 3 problems in current pci tree, as follows:
> > >
> > > 1. pc-dimm specified on command line but only -m size (aka not -m
> > > size,maxmem,slots)
> > >
> > > ./x86_64-softmmu/qemu-system-x86_64 -hda
> > > /home/data/libvirt-images/f18.img -smp 2 -object
> > > memory-backend-ram,size=512M,id=ram-node0,prealloc=y,policy=bind,host-nodes=0
> > > -device pc-dimm,id=d0,memdev=ram-node0 -m 640M -qmp
> > > unix:/tmp/m,server,nowait -monitor stdio -enable-kvm
> > >
> > > result:
> > >
> > > qemu/hw/mem/pc-dimm.c:110: pc_dimm_get_free_addr: Assertion
> > > `address_space_end > address_space_size' failed.
> > > Aborted (core dumped)
> > >
> > > patch 2 fixes this.
> > >
> > > 2. using qemu monitor command object-add to add a memory-backend-ram
> > > object whose's size is too big
> > >
> > > ./x86_64-softmmu/qemu-system-x86_64 -hda
> > > /home/data/libvirt-images/f18.img -smp 2 -m 512M -qmp
> > > unix:/tmp/m,server,nowait -monitor stdio -enable-kvm
> > >
> > > in monitor:
> > > (qemu)object_add memory-backend-ram,size=40960G,id=mem0
> > >
> > > result:
> > >
> > > qemu just exits with message: Cannot set up guest memory 'mem0': Cannot
> > > allocate memory
> > >
> > > patch 3 fixes this.
> > >
> > > 3. specifying a non-existing directory for memory-backend-file
> > >
> > > ./x86_64-softmmu/qemu-system-x86_64 -hda
> > > /home/data/libvirt-images/f18.img -smp 2 -m 512M,maxmem=1000G,slots=100
> > > -qmp unix:/tmp/m,server,nowait -monitor stdio -enable-kvm -object
> > > memory-backend-file,size=512M,id=mem0,mem-path=/nonexistingdir -device
> > > pc-dimm,id=d0,memdev=mem0
> > >
> > > result:
> > >
> > > /nonexistingdir: No such file or directory
> > > Bad ram offset fffffffffffff000
> > > Aborted (core dumped)
> > >
> > > patch 4 fixes this.
> > >
> > >
> > > please review. Thanks!
> > >
> > >
> > > Hu Tao (4):
> > > get rid of signed range
> > > check if we have space left for hotplugged memory
> > > exec: don't exit unconditionally if failed to allocate memory
> > > memory-backend-file: error out if failed to allocate memory
> > >
> > > backends/hostmem-file.c | 3 +
> > > backends/hostmem-ram.c | 3 +
> > > exec.c | 6 +-
> > > hw/mem/pc-dimm.c | 7 +-
> > > include/qemu/range.h | 144
> > > ++++++++++++-------------------------
> > > qapi/string-input-visitor.c | 116 +++++++++++++++++-------------
> > > qapi/string-output-visitor.c | 97 +++++++++++++------------
> > > tests/test-string-input-visitor.c | 4 +-
> > > tests/test-string-output-visitor.c | 8 +--
> > > 9 files changed, 182 insertions(+), 206 deletions(-)
> > >
> > > --
> > > 1.9.3
