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Re: [Qemu-devel] [PATCH 8/8] s390: Add new channel I/O based virtio tran
From: |
Cornelia Huck |
Subject: |
Re: [Qemu-devel] [PATCH 8/8] s390: Add new channel I/O based virtio transport. |
Date: |
Tue, 11 Dec 2012 14:03:58 +0100 |
On Tue, 11 Dec 2012 11:53:18 +0100
Alexander Graf <address@hidden> wrote:
>
> On 07.12.2012, at 13:50, Cornelia Huck wrote:
>
> > Add a new virtio transport that uses channel commands to perform
> > virtio operations.
> >
> > Add a new machine type s390-ccw that uses this virtio-ccw transport
> > and make it the default machine for s390.
> >
> > Signed-off-by: Cornelia Huck <address@hidden>
> > ---
> > hw/s390-virtio.c | 149 ++++++--
> > hw/s390x/Makefile.objs | 1 +
> > hw/s390x/virtio-ccw.c | 909
> > +++++++++++++++++++++++++++++++++++++++++++++++++
> > hw/s390x/virtio-ccw.h | 81 +++++
> > trace-events | 4 +
> > 5 files changed, 1124 insertions(+), 20 deletions(-)
> > create mode 100644 hw/s390x/virtio-ccw.c
> > create mode 100644 hw/s390x/virtio-ccw.h
> >
> > diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
> > index 9e1afb2..f29ff74 100644
> > --- a/hw/s390-virtio.c
> > +++ b/hw/s390-virtio.c
> > @@ -33,6 +33,8 @@
> >
> > #include "hw/s390-virtio-bus.h"
> > #include "hw/s390x/sclp.h"
> > +#include "hw/s390x/css.h"
> > +#include "hw/s390x/virtio-ccw.h"
> >
> > //#define DEBUG_S390
> >
> > @@ -47,6 +49,7 @@
> > #define KVM_S390_VIRTIO_NOTIFY 0
> > #define KVM_S390_VIRTIO_RESET 1
> > #define KVM_S390_VIRTIO_SET_STATUS 2
> > +#define KVM_S390_VIRTIO_CCW_NOTIFY 3
> >
> > #define KERN_IMAGE_START 0x010000UL
> > #define KERN_PARM_AREA 0x010480UL
> > @@ -63,6 +66,7 @@
> >
> > static VirtIOS390Bus *s390_bus;
> > static S390CPU **ipi_states;
> > +VirtioCcwBus *ccw_bus;
> >
> > S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> > {
> > @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> > int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t
> > hypercall)
> > {
> > int r = 0, i;
> > + int cssid, ssid, schid, m;
> > + SubchDev *sch;
> >
> > dprintf("KVM hypercall: %ld\n", hypercall);
> > switch (hypercall) {
> > case KVM_S390_VIRTIO_NOTIFY:
> > if (mem > ram_size) {
> > - VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> > - mem, &i);
> > - if (dev) {
> > - virtio_queue_notify(dev->vdev, i);
> > + if (s390_bus) {
> > + VirtIOS390Device *dev =
> > s390_virtio_bus_find_vring(s390_bus,
> > + mem,
> > &i);
> > + if (dev) {
> > + virtio_queue_notify(dev->vdev, i);
> > + } else {
> > + r = -EINVAL;
> > + }
>
> We really want to factor out the DIAG handling code similar to how spapr
> handles its hypercalls. That way the legacy s390-virtio machine can register
> a VIRTIO_NOTIFY hypercall that works for it here, while the s390-virtio-ccw
> machine doesn't.
>
> > } else {
> > r = -EINVAL;
> > }
> > @@ -93,28 +103,49 @@ int s390_virtio_hypercall(CPUS390XState *env, uint64_t
> > mem, uint64_t hypercall)
> > }
> > break;
> > case KVM_S390_VIRTIO_RESET:
> > - {
> > - VirtIOS390Device *dev;
> > -
> > - dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > - virtio_reset(dev->vdev);
> > - stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> > - s390_virtio_device_sync(dev);
> > - s390_virtio_reset_idx(dev);
> > + if (s390_bus) {
> > + VirtIOS390Device *dev;
> > +
> > + dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > + virtio_reset(dev->vdev);
> > + stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> > + s390_virtio_device_sync(dev);
> > + s390_virtio_reset_idx(dev);
> > + } else {
> > + r = -EINVAL;
> > + }
> > break;
> > - }
> > case KVM_S390_VIRTIO_SET_STATUS:
> > - {
> > - VirtIOS390Device *dev;
> > + if (s390_bus) {
> > + VirtIOS390Device *dev;
> >
> > - dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > - if (dev) {
> > - s390_virtio_device_update_status(dev);
> > + dev = s390_virtio_bus_find_mem(s390_bus, mem);
> > + if (dev) {
> > + s390_virtio_device_update_status(dev);
> > + } else {
> > + r = -EINVAL;
> > + }
> > } else {
> > r = -EINVAL;
> > }
> > break;
> > - }
> > + case KVM_S390_VIRTIO_CCW_NOTIFY:
> > + if (ccw_bus) {
> > + if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid,
> > &ssid,
> > + &schid)) {
> > + r = -EINVAL;
> > + } else {
> > + sch = css_find_subch(m, cssid, ssid, schid);
> > + if (sch && css_subch_visible(sch)) {
> > + virtio_queue_notify(virtio_ccw_get_vdev(sch),
> > env->regs[3]);
> > + } else {
> > + r = -EINVAL;
> > + }
> > + }
> > + } else {
> > + r = -EINVAL;
> > + }
> > + break;
> > default:
> > r = -EINVAL;
> > break;
> > @@ -370,7 +401,6 @@ static QEMUMachine s390_machine = {
> > .no_sdcard = 1,
> > .use_virtcon = 1,
> > .max_cpus = 255,
> > - .is_default = 1,
> > };
> >
> > static void s390_machine_init(void)
> > @@ -379,3 +409,82 @@ static void s390_machine_init(void)
> > }
> >
> > machine_init(s390_machine_init);
> > +
> > +static void ccw_init(QEMUMachineInitArgs *args)
>
> Do you think it'd be possible to move this into its own .c file?
Any particular reason why it should be moved? I saw this file as
'handle generic s390 virtio stuff'.
>
> > +{
> > + ram_addr_t my_ram_size = args->ram_size;
> > + ram_addr_t ram_size = args->ram_size;
> > + const char *cpu_model = args->cpu_model;
> > + const char *kernel_filename = args->kernel_filename;
> > + const char *kernel_cmdline = args->kernel_cmdline;
> > + const char *initrd_filename = args->initrd_filename;
> > + CPUS390XState *env = NULL;
> > + MemoryRegion *sysmem = get_system_memory();
> > + MemoryRegion *ram = g_new(MemoryRegion, 1);
> > + int shift = 0;
> > + uint8_t *storage_keys;
> > + int ret;
> > +
> > + /* s390x ram size detection needs a 16bit multiplier + an increment. So
> > + guests > 64GB can be specified in 2MB steps etc. */
> > + while ((my_ram_size >> (20 + shift)) > 65535) {
> > + shift++;
> > + }
> > + my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
> > +
> > + /* lets propagate the changed ram size into the global variable. */
> > + ram_size = my_ram_size;
> > +
> > + /* get a BUS */
> > + ccw_bus = virtio_ccw_bus_init();
> > + s390_sclp_init();
> > +
> > + /* allocate RAM */
> > + memory_region_init_ram(ram, "s390.ram", my_ram_size);
> > + vmstate_register_ram_global(ram);
> > + memory_region_add_subregion(sysmem, 0, ram);
> > +
> > + /* allocate storage keys */
> > + storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
> > +
> > + /* init CPUs */
> > + env = s390_init_cpus(cpu_model, storage_keys);
> > +
> > + kvm_s390_enable_css_support(env);
> > +
> > + /*
> > + * Create virtual css and set it as default so that non mcss-e
> > + * enabled guests only see virtio devices.
> > + */
> > + ret = css_create_css_image(VIRTUAL_CSSID, true);
> > + assert(ret == 0);
> > +
> > +
> > + s390_set_up_kernel(env, kernel_filename, kernel_cmdline,
> > initrd_filename);
> > +
> > + /* Create VirtIO network adapters */
> > + s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
> > +
> > +}
> > +
> > +static QEMUMachine ccw_machine = {
> > + .name = "s390-ccw-virtio",
> > + .alias = "s390-ccw",
> > + .desc = "VirtIO-ccw based S390 machine",
> > + .init = ccw_init,
> > + .no_cdrom = 1,
> > + .no_floppy = 1,
> > + .no_serial = 1,
> > + .no_parallel = 1,
> > + .no_sdcard = 1,
> > + .use_virtcon = 1,
> > + .max_cpus = 255,
> > + .is_default = 1,
> > +};
> > +
> > +static void ccw_machine_init(void)
> > +{
> > + qemu_register_machine(&ccw_machine);
> > +}
> > +
> > +machine_init(ccw_machine_init);
> > diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> > index 378b099..d408558 100644
> > --- a/hw/s390x/Makefile.objs
> > +++ b/hw/s390x/Makefile.objs
> > @@ -5,3 +5,4 @@ obj-y += sclp.o
> > obj-y += event-facility.o
> > obj-y += sclpquiesce.o sclpconsole.o
> > obj-y += css.o
> > +obj-y += virtio-ccw.o
> > diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> > new file mode 100644
> > index 0000000..b4624ab
> > --- /dev/null
> > +++ b/hw/s390x/virtio-ccw.c
> > @@ -0,0 +1,909 @@
> > +/*
> > + * virtio ccw target implementation
>
> Please extract this into a separate patch.
You mean first add the virtio-ccw backend and then introduce the new
machine?
> > +static int virtio_ccw_device_init(VirtioCcwData *dev, VirtIODevice *vdev)
> > +{
> > + unsigned int cssid = 0;
> > + unsigned int ssid = 0;
> > + unsigned int schid;
> > + unsigned int devno;
> > + bool have_devno = false;
> > + bool found = false;
> > + SubchDev *sch;
> > + int ret;
> > + int num;
> > +
> > + sch = g_malloc0(sizeof(SubchDev));
>
> Any reason to not just make sch part of dev?
If anything, we'd probably want the virtio-ccw stuff extending the
generic subchannel stuff (so that we can have a basic subchannel
structure which might later be extended in a different way if we want
real device passthrough).
I'll try to implement it in such a way that it can be easily refactored
and extended.
- [Qemu-devel] [PATCH 4/8] s390: Add channel I/O instructions., (continued)
[Qemu-devel] [PATCH 7/8] s390-virtio: Factor out some initialization code., Cornelia Huck, 2012/12/07
[Qemu-devel] [PATCH 8/8] s390: Add new channel I/O based virtio transport., Cornelia Huck, 2012/12/07
[Qemu-devel] [PATCH 5/8] s390: Virtual channel subsystem support., Cornelia Huck, 2012/12/07
[Qemu-devel] [PATCH 3/8] s390: I/O interrupt and machine check injection., Cornelia Huck, 2012/12/07
Re: [Qemu-devel] [RFC PATCH v4 0/8] s390: channel I/O support in qemu., Alexander Graf, 2012/12/10