On Fri, 2 Apr 2021 15:51:28 +0530 Vaibhav Jain <vaibhav@xxxxxxxxxxxxx> wrote: > Add support for H_SCM_HEALTH hcall described at [1] for spapr > nvdimms. This enables guest to detect the 'unarmed' status of a > specific spapr nvdimm identified by its DRC and if its unarmed, mark > the region backed by the nvdimm as read-only. > > The patch adds h_scm_health() to handle the H_SCM_HEALTH hcall which > returns two 64-bit bitmaps (health bitmap, health bitmap mask) derived > from 'struct nvdimm->unarmed' member. > > Linux kernel side changes to enable handling of 'unarmed' nvdimms for > ppc64 are proposed at [2]. > > References: > [1] "Hypercall Op-codes (hcalls)" > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/powerpc/papr_hcalls.rst#n220 > [2] "powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe" > https://lore.kernel.org/linux-nvdimm/20210329113103.476760-1-vaibhav@xxxxxxxxxxxxx/ > > Signed-off-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxx> > --- > Changelog > > v3: > * Switched to PPC_BIT macro for definitions of the health bits. [ Greg, David ] > * Updated h_scm_health() to use a const uint64_t to denote supported > bits in 'hbitmap_mask'. > * Fixed an error check for drc->dev to return H_PARAMETER in case nvdimm > is not yet plugged in [ Greg ] > * Fixed an wrong error check for ensuring drc and drc-type are correct > [ Greg ] > > v2: > * Added a check for drc->dev to ensure that the dimm is plugged in > when servicing H_SCM_HEALTH. [ Shiva ] > * Instead of accessing the 'nvdimm->unarmed' member directly use the > object_property_get_bool accessor to fetch it. [ Shiva ] > * Update the usage of PAPR_PMEM_UNARMED* macros [ Greg ] > * Updated patch description reference#1 to point appropriate section > in the documentation. [ Greg ] > --- Reviewed-by: Greg Kurz <groug@xxxxxxxx> > hw/ppc/spapr_nvdimm.c | 36 ++++++++++++++++++++++++++++++++++++ > include/hw/ppc/spapr.h | 3 ++- > 2 files changed, 38 insertions(+), 1 deletion(-) > > diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c > index b46c36917c..252204e25f 100644 > --- a/hw/ppc/spapr_nvdimm.c > +++ b/hw/ppc/spapr_nvdimm.c > @@ -31,6 +31,10 @@ > #include "qemu/range.h" > #include "hw/ppc/spapr_numa.h" > > +/* DIMM health bitmap bitmap indicators. Taken from kernel's papr_scm.c */ > +/* SCM device is unable to persist memory contents */ > +#define PAPR_PMEM_UNARMED PPC_BIT(0) > + > bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm, > uint64_t size, Error **errp) > { > @@ -467,6 +471,37 @@ static target_ulong h_scm_unbind_all(PowerPCCPU *cpu, SpaprMachineState *spapr, > return H_SUCCESS; > } > > +static target_ulong h_scm_health(PowerPCCPU *cpu, SpaprMachineState *spapr, > + target_ulong opcode, target_ulong *args) > +{ > + > + NVDIMMDevice *nvdimm; > + uint64_t hbitmap = 0; > + uint32_t drc_index = args[0]; > + SpaprDrc *drc = spapr_drc_by_index(drc_index); > + const uint64_t hbitmap_mask = PAPR_PMEM_UNARMED; > + > + > + /* Ensure that the drc is valid & is valid PMEM dimm and is plugged in */ > + if (!drc || !drc->dev || > + spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { > + return H_PARAMETER; > + } > + > + nvdimm = NVDIMM(drc->dev); > + > + /* Update if the nvdimm is unarmed and send its status via health bitmaps */ > + if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) { > + hbitmap |= PAPR_PMEM_UNARMED; > + } > + > + /* Update the out args with health bitmap/mask */ > + args[0] = hbitmap; > + args[1] = hbitmap_mask; > + > + return H_SUCCESS; > +} > + > static void spapr_scm_register_types(void) > { > /* qemu/scm specific hcalls */ > @@ -475,6 +510,7 @@ static void spapr_scm_register_types(void) > spapr_register_hypercall(H_SCM_BIND_MEM, h_scm_bind_mem); > spapr_register_hypercall(H_SCM_UNBIND_MEM, h_scm_unbind_mem); > spapr_register_hypercall(H_SCM_UNBIND_ALL, h_scm_unbind_all); > + spapr_register_hypercall(H_SCM_HEALTH, h_scm_health); > } > > type_init(spapr_scm_register_types) > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index 47cebaf3ac..6e1eafb05d 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -538,8 +538,9 @@ struct SpaprMachineState { > #define H_SCM_BIND_MEM 0x3EC > #define H_SCM_UNBIND_MEM 0x3F0 > #define H_SCM_UNBIND_ALL 0x3FC > +#define H_SCM_HEALTH 0x400 > > -#define MAX_HCALL_OPCODE H_SCM_UNBIND_ALL > +#define MAX_HCALL_OPCODE H_SCM_HEALTH > > /* The hcalls above are standardized in PAPR and implemented by pHyp > * as well.
