On Wed, 12 Dec 2018 10:57:20 +1100 Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> On 12/12/2018 03:35, Greg Kurz wrote: > > On Tue, 11 Dec 2018 16:49:25 +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 | 31 ++++++++++++++++++++++++++++++- > >> hw/ppc/spapr_hcall.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > >> hw/ppc/trace-events | 3 +++ > >> 4 files changed, 81 insertions(+), 2 deletions(-) > >> > >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > >> index 1987640..86c90df 100644 > >> --- a/include/hw/ppc/spapr.h > >> +++ b/include/hw/ppc/spapr.h > >> @@ -102,6 +102,7 @@ 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; > >> @@ -138,6 +139,9 @@ 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; > >> @@ -464,7 +468,8 @@ 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 8a18250..984bf32 100644 > >> --- a/hw/ppc/spapr.c > >> +++ b/hw/ppc/spapr.c > >> @@ -1654,7 +1654,10 @@ 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); > >> @@ -1908,6 +1911,27 @@ 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; > >> +} > >> + > >> +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), > > > > Unless I'm missing something, it looks like the initial spapr->fdt_blob in > > the > > destination might be leaked... > > ah true. > > > > > >> + VMSTATE_END_OF_LIST() > >> + }, > >> +}; > >> + > >> static const VMStateDescription vmstate_spapr = { > >> .name = "spapr", > >> .version_id = 3, > >> @@ -1937,6 +1961,7 @@ static const VMStateDescription vmstate_spapr = { > >> &vmstate_spapr_cap_ibs, > >> &vmstate_spapr_irq_map, > >> &vmstate_spapr_cap_nested_kvm_hv, > >> + &vmstate_spapr_dtb, > >> NULL > >> } > >> }; > >> @@ -3871,6 +3896,7 @@ 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; > >> @@ -3981,8 +4007,11 @@ static void > >> spapr_machine_3_1_instance_options(MachineState *machine) > >> > >> static void spapr_machine_3_1_class_options(MachineClass *mc) > >> { > >> + sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc); > >> + > >> spapr_machine_4_0_class_options(mc); > >> SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_3_1); > >> + 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 ae913d0..dfd3cf3 100644 > >> --- a/hw/ppc/spapr_hcall.c > >> +++ b/hw/ppc/spapr_hcall.c > >> @@ -1717,6 +1717,46 @@ 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) { > > > > Ok, so this caps the new fdt tree to 2 megs, which seems reasonable. > > Why _megs_? It is 2 _times_. We do not expect big growth, it should be The initial or cas fdt is capped to 1 meg (FDT_MAX_SIZE), isn't it ? So this check would allow the new fdt to be theoretically up to 2 meg. > phandles and some slof nodes (packages, options,...), pretty much. Right > now it is 10% bigger than the initial fdt. > Expecting up to 100% may seem overkill then but even with a big initial/cas fdt, it would _only_ be 2 megs, which is a reasonable limit for a guest triggered allocation I guess. > > > BTW, why 2 and not some other growth factor ? > > > >> + 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 consostency */ > >> + 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; > >> } > >> @@ -1822,6 +1862,8 @@ 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 dc5e65a..0af155e 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 > > >
