Re: [Qemu-ppc] [Qemu-devel] [PULL 02/29] ppc/spapr: Receive and store device tree blob from SLOF

[David Gibson]

On Sun, Mar 24, 2019 at 12:03:54AM -0400, Brad Smith wrote:
> Now that I am checking out 4.0.0 rc's I see this diff is broken and
> depends on a function libfdt does not expose. The breakage is
> hidden by the fallback check in the configure script.

Ah, bother.  That keeps happening, unfortunately.  I think it's
because so many people use libfdt embedded, rather than as a shared
library that we tend not to notice.

I guess we should figure out how to force the testsuite to link
against the shared library rather than static to test for this.  I'll
look into it if I have time (which is a big if).

> 
> On 1/8/2019 5:45 PM, David Gibson wrote:
> > From: Alexey Kardashevskiy <address@hidden>
> > 
> > SLOF receives a device tree and updates it with various properties
> > before switching to the guest kernel and QEMU is not aware of any changes
> > made by SLOF. Since there is no real RTAS (QEMU implements it), it makes
> > sense to pass the SLOF final device tree to QEMU to let it implement
> > RTAS related tasks better, such as PCI host bus adapter hotplug.
> > 
> > Specifially, now QEMU can find out the actual XICS phandle (for PHB
> > hotplug) and the RTAS linux,rtas-entry/base properties (for firmware
> > assisted NMI - FWNMI).
> > 
> > This stores the initial DT blob in the sPAPR machine and replaces it
> > in the KVMPPC_H_UPDATE_DT (new private hypercall) handler.
> > 
> > This adds an @update_dt_enabled machine property to allow backward
> > migration.
> > 
> > SLOF already has a hypercall since
> > https://github.com/aik/SLOF/commit/e6fc84652c9c0073f9183
> > 
> > This makes use of the new fdt_check_full() helper. In order to allow
> > the configure script to pick the correct DTC version, this adjusts
> > the DTC presense test.
> > 
> > Signed-off-by: Alexey Kardashevskiy <address@hidden>
> > Reviewed-by: Greg Kurz <address@hidden>
> > Signed-off-by: David Gibson <address@hidden>
> > Signed-off-by: Greg Kurz <address@hidden>
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> >   configure              |  2 +-
> >   hw/ppc/spapr.c         | 43 +++++++++++++++++++++++++++++++++++++++++-
> >   hw/ppc/spapr_hcall.c   | 42 +++++++++++++++++++++++++++++++++++++++++
> >   hw/ppc/trace-events    |  3 +++
> >   include/hw/ppc/spapr.h |  7 ++++++-
> >   5 files changed, 94 insertions(+), 3 deletions(-)
> > 
> > diff --git a/configure b/configure
> > index b9f34afc9e..8049b71eef 100755
> > --- a/configure
> > +++ b/configure
> > @@ -3939,7 +3939,7 @@ if test "$fdt" != "no" ; then
> >     cat > $TMPC << EOF
> >   #include <libfdt.h>
> >   #include <libfdt_env.h>
> > -int main(void) { fdt_first_subnode(0, 0); return 0; }
> > +int main(void) { fdt_check_full(NULL, 0); return 0; }
> >   EOF
> >     if compile_prog "" "$fdt_libs" ; then
> >       # system DTC is good - use it
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 5fba04e7b2..7e61f1e5ff 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -1669,7 +1669,10 @@ static void spapr_machine_reset(void)
> >       /* Load the fdt */
> >       qemu_fdt_dumpdtb(fdt, fdt_totalsize(fdt));
> >       cpu_physical_memory_write(fdt_addr, fdt, fdt_totalsize(fdt));
> > -    g_free(fdt);
> > +    g_free(spapr->fdt_blob);
> > +    spapr->fdt_size = fdt_totalsize(fdt);
> > +    spapr->fdt_initial_size = spapr->fdt_size;
> > +    spapr->fdt_blob = fdt;
> >       /* Set up the entry state */
> >       spapr_cpu_set_entry_state(first_ppc_cpu, SPAPR_ENTRY_POINT, fdt_addr);
> > @@ -1920,6 +1923,39 @@ static const VMStateDescription 
> > vmstate_spapr_irq_map = {
> >       },
> >   };
> > +static bool spapr_dtb_needed(void *opaque)
> > +{
> > +    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(opaque);
> > +
> > +    return smc->update_dt_enabled;
> > +}
> > +
> > +static int spapr_dtb_pre_load(void *opaque)
> > +{
> > +    sPAPRMachineState *spapr = (sPAPRMachineState *)opaque;
> > +
> > +    g_free(spapr->fdt_blob);
> > +    spapr->fdt_blob = NULL;
> > +    spapr->fdt_size = 0;
> > +
> > +    return 0;
> > +}
> > +
> > +static const VMStateDescription vmstate_spapr_dtb = {
> > +    .name = "spapr_dtb",
> > +    .version_id = 1,
> > +    .minimum_version_id = 1,
> > +    .needed = spapr_dtb_needed,
> > +    .pre_load = spapr_dtb_pre_load,
> > +    .fields = (VMStateField[]) {
> > +        VMSTATE_UINT32(fdt_initial_size, sPAPRMachineState),
> > +        VMSTATE_UINT32(fdt_size, sPAPRMachineState),
> > +        VMSTATE_VBUFFER_ALLOC_UINT32(fdt_blob, sPAPRMachineState, 0, NULL,
> > +                                     fdt_size),
> > +        VMSTATE_END_OF_LIST()
> > +    },
> > +};
> > +
> >   static const VMStateDescription vmstate_spapr = {
> >       .name = "spapr",
> >       .version_id = 3,
> > @@ -1949,6 +1985,7 @@ static const VMStateDescription vmstate_spapr = {
> >           &vmstate_spapr_cap_ibs,
> >           &vmstate_spapr_irq_map,
> >           &vmstate_spapr_cap_nested_kvm_hv,
> > +        &vmstate_spapr_dtb,
> >           NULL
> >       }
> >   };
> > @@ -3931,6 +3968,7 @@ static void spapr_machine_class_init(ObjectClass *oc, 
> > void *data)
> >       hc->unplug = spapr_machine_device_unplug;
> >       smc->dr_lmb_enabled = true;
> > +    smc->update_dt_enabled = true;
> >       mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power9_v2.0");
> >       mc->has_hotpluggable_cpus = true;
> >       smc->resize_hpt_default = SPAPR_RESIZE_HPT_ENABLED;
> > @@ -4023,9 +4061,12 @@ DEFINE_SPAPR_MACHINE(4_0, "4.0", true);
> >    */
> >   static void spapr_machine_3_1_class_options(MachineClass *mc)
> >   {
> > +    sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
> > +
> >       spapr_machine_4_0_class_options(mc);
> >       compat_props_add(mc->compat_props, hw_compat_3_1, hw_compat_3_1_len);
> >       mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power8_v2.0");
> > +    smc->update_dt_enabled = false;
> >   }
> >   DEFINE_SPAPR_MACHINE(3_1, "3.1", false);
> > diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> > index f131c7e04c..1ae3e6ff5e 100644
> > --- a/hw/ppc/spapr_hcall.c
> > +++ b/hw/ppc/spapr_hcall.c
> > @@ -1753,6 +1753,46 @@ static target_ulong 
> > h_get_cpu_characteristics(PowerPCCPU *cpu,
> >       args[0] = characteristics;
> >       args[1] = behaviour;
> > +    return H_SUCCESS;
> > +}
> > +
> > +static target_ulong h_update_dt(PowerPCCPU *cpu, sPAPRMachineState *spapr,
> > +                                target_ulong opcode, target_ulong *args)
> > +{
> > +    target_ulong dt = ppc64_phys_to_real(args[0]);
> > +    struct fdt_header hdr = { 0 };
> > +    unsigned cb;
> > +    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
> > +    void *fdt;
> > +
> > +    cpu_physical_memory_read(dt, &hdr, sizeof(hdr));
> > +    cb = fdt32_to_cpu(hdr.totalsize);
> > +
> > +    if (!smc->update_dt_enabled) {
> > +        return H_SUCCESS;
> > +    }
> > +
> > +    /* Check that the fdt did not grow out of proportion */
> > +    if (cb > spapr->fdt_initial_size * 2) {
> > +        trace_spapr_update_dt_failed_size(spapr->fdt_initial_size, cb,
> > +                                          fdt32_to_cpu(hdr.magic));
> > +        return H_PARAMETER;
> > +    }
> > +
> > +    fdt = g_malloc0(cb);
> > +    cpu_physical_memory_read(dt, fdt, cb);
> > +
> > +    /* Check the fdt consistency */
> > +    if (fdt_check_full(fdt, cb)) {
> > +        trace_spapr_update_dt_failed_check(spapr->fdt_initial_size, cb,
> > +                                           fdt32_to_cpu(hdr.magic));
> > +        return H_PARAMETER;
> > +    }
> > +
> > +    g_free(spapr->fdt_blob);
> > +    spapr->fdt_size = cb;
> > +    spapr->fdt_blob = fdt;
> > +    trace_spapr_update_dt(cb);
> >       return H_SUCCESS;
> >   }
> > @@ -1859,6 +1899,8 @@ static void hypercall_register_types(void)
> >       /* ibm,client-architecture-support support */
> >       spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
> > +    spapr_register_hypercall(KVMPPC_H_UPDATE_DT, h_update_dt);
> > +
> >       /* Virtual Processor Home Node */
> >       spapr_register_hypercall(H_HOME_NODE_ASSOCIATIVITY,
> >                                h_home_node_associativity);
> > diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events
> > index dc5e65aee9..0af155ed32 100644
> > --- a/hw/ppc/trace-events
> > +++ b/hw/ppc/trace-events
> > @@ -22,6 +22,9 @@ spapr_cas_pvr_try(uint32_t pvr) "0x%x"
> >   spapr_cas_pvr(uint32_t cur_pvr, bool explicit_match, uint32_t new_pvr) 
> > "current=0x%x, explicit_match=%u, new=0x%x"
> >   spapr_h_resize_hpt_prepare(uint64_t flags, uint64_t shift) 
> > "flags=0x%"PRIx64", shift=%"PRIu64
> >   spapr_h_resize_hpt_commit(uint64_t flags, uint64_t shift) 
> > "flags=0x%"PRIx64", shift=%"PRIu64
> > +spapr_update_dt(unsigned cb) "New blob %u bytes"
> > +spapr_update_dt_failed_size(unsigned cbold, unsigned cbnew, unsigned 
> > magic) "Old blob %u bytes, new blob %u bytes, magic 0x%x"
> > +spapr_update_dt_failed_check(unsigned cbold, unsigned cbnew, unsigned 
> > magic) "Old blob %u bytes, new blob %u bytes, magic 0x%x"
> >   # hw/ppc/spapr_iommu.c
> >   spapr_iommu_put(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t 
> > ret) "liobn=0x%"PRIx64" ioba=0x%"PRIx64" tce=0x%"PRIx64" ret=%"PRId64
> > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> > index eb04300d3b..fd24e91bd8 100644
> > --- a/include/hw/ppc/spapr.h
> > +++ b/include/hw/ppc/spapr.h
> > @@ -103,6 +103,7 @@ struct sPAPRMachineClass {
> >       /*< public >*/
> >       bool dr_lmb_enabled;       /* enable dynamic-reconfig/hotplug of LMBs 
> > */
> > +    bool update_dt_enabled;    /* enable KVMPPC_H_UPDATE_DT */
> >       bool use_ohci_by_default;  /* use USB-OHCI instead of XHCI */
> >       bool pre_2_10_has_unused_icps;
> >       bool legacy_irq_allocation;
> > @@ -139,6 +140,9 @@ struct sPAPRMachineState {
> >       int vrma_adjust;
> >       ssize_t rtas_size;
> >       void *rtas_blob;
> > +    uint32_t fdt_size;
> > +    uint32_t fdt_initial_size;
> > +    void *fdt_blob;
> >       long kernel_size;
> >       bool kernel_le;
> >       uint32_t initrd_base;
> > @@ -481,7 +485,8 @@ struct sPAPRMachineState {
> >   #define KVMPPC_H_LOGICAL_MEMOP  (KVMPPC_HCALL_BASE + 0x1)
> >   /* Client Architecture support */
> >   #define KVMPPC_H_CAS            (KVMPPC_HCALL_BASE + 0x2)
> > -#define KVMPPC_HCALL_MAX        KVMPPC_H_CAS
> > +#define KVMPPC_H_UPDATE_DT      (KVMPPC_HCALL_BASE + 0x3)
> > +#define KVMPPC_HCALL_MAX        KVMPPC_H_UPDATE_DT
> >   typedef struct sPAPRDeviceTreeUpdateHeader {
> >       uint32_t version_id;
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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