On Mon, 12 Nov 2018 15:12:26 +1100 Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> On 12/11/2018 05:10, Greg Kurz wrote: > > Hi Alexey, > > > > Just a few remarks. See below. > > > > On Thu, 8 Nov 2018 12:44:06 +1100 > > Alexey Kardashevskiy <a...@ozlabs.ru> wrote: > > > >> 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 > >> > >> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > >> --- > >> include/hw/ppc/spapr.h | 7 ++++++- > >> hw/ppc/spapr.c | 29 ++++++++++++++++++++++++++++- > >> hw/ppc/spapr_hcall.c | 32 ++++++++++++++++++++++++++++++++ > >> hw/ppc/trace-events | 2 ++ > >> 4 files changed, 68 insertions(+), 2 deletions(-) > >> > >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > >> index ad4d7cfd97..f5dcaf44cb 100644 > >> --- a/include/hw/ppc/spapr.h > >> +++ b/include/hw/ppc/spapr.h > >> @@ -100,6 +100,7 @@ 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; > >> @@ -136,6 +137,9 @@ struct sPAPRMachineState { > >> int vrma_adjust; > >> ssize_t rtas_size; > >> void *rtas_blob; > >> + uint32_t fdt_size; > >> + uint32_t fdt_initial_size; > > > > I don't quite see the purpose of fdt_initial_size... it seems to be only > > used to print a trace. > > > Ah, lost in rebase. The purpose was to test if the new device tree has > not grown too much. > Ok, makes sense during development. > > > > > >> + void *fdt_blob; > >> long kernel_size; > >> bool kernel_le; > >> uint32_t initrd_base; > >> @@ -462,7 +466,8 @@ 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; > >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > >> index c08130facb..5e2d4d211c 100644 > >> --- a/hw/ppc/spapr.c > >> +++ b/hw/ppc/spapr.c > >> @@ -1633,7 +1633,10 @@ 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; > > > > Hmm... It looks weird to store state in a reset handler. I'd rather zeroe > > both fdt_blob and fdt_size here. > > > The device tree is built from the reset handler and the idea is that we > want to always have some tree in the machine. > Yes of course, I forgot that we need to keep the fdt to be kept somewhere so that we can use it :). My remark has more to do with migration actually: the fdt built at reset time is supposed to derive from the command line and hot-(un)plugged devices, ie, identical in source and destination. This isn't state we should migrate IIUC. Maybe add a boolean field that tells that the fdt was updated, use it in spapr_dtb_needed() and reset it in spapr_machine_reset() ? > > > > > >> > >> /* Set up the entry state */ > >> spapr_cpu_set_entry_state(first_ppc_cpu, SPAPR_ENTRY_POINT, fdt_addr); > >> @@ -1887,6 +1890,27 @@ 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; > > > > This means we always migrate the fdt, even if migration occurs before > > SLOF could call KVMPPC_H_UPDATE_DT. > > > > With spapr->fdt_blob set to NULL on reset, a better check would be: > > > > sPAPRMachineState *spapr = SPAPR_MACHINE(opaque); > > > > return smc->update_dt_enabled && spapr->fdt_blob; > > > >> +} > >> + > >> +static const VMStateDescription vmstate_spapr_dtb = { > >> + .name = "spapr_dtb", > >> + .version_id = 1, > >> + .minimum_version_id = 1, > >> + .needed = spapr_dtb_needed, > >> + .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, > >> @@ -1915,6 +1939,7 @@ static const VMStateDescription vmstate_spapr = { > >> &vmstate_spapr_cap_sbbc, > >> &vmstate_spapr_cap_ibs, > >> &vmstate_spapr_irq_map, > >> + &vmstate_spapr_dtb, > > > > This needs to be rebased. > > > > <<<<<<< > > &vmstate_spapr_cap_nested_kvm_hv, > > ======= > > &vmstate_spapr_dtb, > >>>>>>>> > > > > > > I'll try to find some time to respin the PHB hotplug series and I'll happily > > give a try to this patch. > > > Good :) > > > > > >> NULL > >> } > >> }; > >> @@ -3849,6 +3874,7 @@ 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("power8_v2.0"); > >> mc->has_hotpluggable_cpus = true; > >> smc->resize_hpt_default = SPAPR_RESIZE_HPT_ENABLED; > >> @@ -3965,6 +3991,7 @@ static void > >> spapr_machine_3_0_class_options(MachineClass *mc) > >> > >> smc->legacy_irq_allocation = true; > >> smc->irq = &spapr_irq_xics_legacy; > >> + smc->update_dt_enabled = false; > >> } > >> > >> DEFINE_SPAPR_MACHINE(3_0, "3.0", false); > >> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c > >> index ae913d070f..d5833f3f8d 100644 > >> --- a/hw/ppc/spapr_hcall.c > >> +++ b/hw/ppc/spapr_hcall.c > >> @@ -1717,6 +1717,36 @@ 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); > >> + > >> + cpu_physical_memory_read(dt, &hdr, sizeof(hdr)); > >> + cb = fdt32_to_cpu(hdr.totalsize); > >> + > >> + if (fdt_check_full(spapr->fdt_blob, cb)) { > >> + trace_spapr_update_dt_failed(spapr->fdt_initial_size, cb, > >> + fdt32_to_cpu(hdr.magic)); > >> + return H_PARAMETER; > >> + } > >> + > >> + if (!smc->update_dt_enabled) { > >> + return H_SUCCESS; > >> + } > >> + > >> + g_free(spapr->fdt_blob); > >> + spapr->fdt_size = cb; > >> + spapr->fdt_blob = g_malloc0(cb); > >> + cpu_physical_memory_read(dt, spapr->fdt_blob, cb); > >> + > >> + trace_spapr_update_dt(cb); > >> > >> return H_SUCCESS; > >> } > >> @@ -1822,6 +1852,8 @@ 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); > >> } > >> > >> type_init(hypercall_register_types) > >> diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events > >> index dc5e65aee9..4432a5ce74 100644 > >> --- a/hw/ppc/trace-events > >> +++ b/hw/ppc/trace-events > >> @@ -22,6 +22,8 @@ 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(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 > > >