Hi Vaibhav, Great to see you around :-) On Mon, 29 Mar 2021 21:52:59 +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. > Any chance that you can provide the documentation of this new hcall ? > 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 > > [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> > --- > hw/ppc/spapr_nvdimm.c | 30 ++++++++++++++++++++++++++++++ > include/hw/ppc/spapr.h | 4 ++-- > 2 files changed, 32 insertions(+), 2 deletions(-) > > diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c > index b46c36917c..e38740036d 100644 > --- a/hw/ppc/spapr_nvdimm.c > +++ b/hw/ppc/spapr_nvdimm.c > @@ -31,6 +31,13 @@ > #include "qemu/range.h" > #include "hw/ppc/spapr_numa.h" > > +/* DIMM health bitmap bitmap indicators */ > +/* SCM device is unable to persist memory contents */ > +#define PAPR_PMEM_UNARMED (1ULL << (63 - 0)) This looks like PPC_BIT(0). > + > +/* Bits status indicators for health bitmap indicating unarmed dimm */ > +#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED) > + > bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm, > uint64_t size, Error **errp) > { > @@ -467,6 +474,28 @@ 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) > +{ > + uint32_t drc_index = args[0]; > + SpaprDrc *drc = spapr_drc_by_index(drc_index); > + NVDIMMDevice *nvdimm; > + > + if (drc && spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { > + return H_PARAMETER; > + } > + > + nvdimm = NVDIMM(drc->dev); Yeah as already suggested by Shiva, drc->dev should be checked like in h_scm_bind_mem(). > + > + /* Check if the nvdimm is unarmed and send its status via health bitmaps */ > + args[0] = nvdimm->unarmed ? PAPR_PMEM_UNARMED_MASK : 0; > + Shouldn't ^^ use PAPR_PMEM_UNARMED then ? > + /* health bitmap mask same as the health bitmap */ > + args[1] = args[0]; > + If so, it seems that PAPR_PMEM_UNARMED_MASK isn't even needed. Having access to the excerpts from the PAPR addendum that describes this hcall would _really_ help in reviewing. > + return H_SUCCESS; > +} > + > static void spapr_scm_register_types(void) > { > /* qemu/scm specific hcalls */ > @@ -475,6 +504,7 @@ 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..18859b9ab2 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -538,8 +538,8 @@ struct SpaprMachineState { > #define H_SCM_BIND_MEM 0x3EC > #define H_SCM_UNBIND_MEM 0x3F0 > #define H_SCM_UNBIND_ALL 0x3FC > - > -#define MAX_HCALL_OPCODE H_SCM_UNBIND_ALL > +#define H_SCM_HEALTH 0x400 > +#define MAX_HCALL_OPCODE H_SCM_HEALTH > > /* The hcalls above are standardized in PAPR and implemented by pHyp > * as well.
