| Message ID | 20210401010519.7225-1-vaibhav@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] ppc/spapr: Add support for implement support for H_SCM_HEALTH | expand |
On Thu, Apr 01, 2021 at 06:35:19AM +0530, Vaibhav Jain 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@linux.ibm.com/ > > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> As well as the handful of comments below, this will definitely need to wait for ppc-6.1 at this point. > --- > Changelog > > 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 ] > --- > hw/ppc/spapr_nvdimm.c | 38 ++++++++++++++++++++++++++++++++++++++ > include/hw/ppc/spapr.h | 3 ++- > 2 files changed, 40 insertions(+), 1 deletion(-) > > diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c > index b46c36917c..34096e4718 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. Taken from kernel's papr_scm.c */ > +/* SCM device is unable to persist memory contents */ > +#define PAPR_PMEM_UNARMED (1ULL << (63 - 0)) You can use PPC_BIT() for more clarity here. > +/* Bits status indicators for health bitmap indicating unarmed dimm */ > +#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED) I'm not sure why you want two equal #defines here. > + > bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm, > uint64_t size, Error **errp) > { > @@ -467,6 +474,36 @@ 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) { This will fail badly if !drc (given index is way out of bounds). I'm pretty sure you want if (!drc || spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { > + return H_PARAMETER; > + } > + > + /* Ensure that the dimm is plugged in */ > + if (!drc->dev) { > + return H_HARDWARE; H_HARDWARE doesn't seem right - it's the guest that has chosen to attempt this on an unplugged LMB, not the (virtual) hardware's fault. > + } > + > + nvdimm = NVDIMM(drc->dev); > + > + args[0] = 0; > + /* Check if the nvdimm is unarmed and send its status via health bitmaps */ > + if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) { > + args[0] |= PAPR_PMEM_UNARMED; > + } > + > + /* Update the health bitmap with the applicable mask */ > + args[1] = PAPR_PMEM_UNARMED_MASK; > + > + return H_SUCCESS; > +} > + > static void spapr_scm_register_types(void) > { > /* qemu/scm specific hcalls */ > @@ -475,6 +512,7 @@ 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.
On Thu, 1 Apr 2021 13:26:11 +1100 David Gibson <david@gibson.dropbear.id.au> wrote: > On Thu, Apr 01, 2021 at 06:35:19AM +0530, Vaibhav Jain 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@linux.ibm.com/ > > > > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> > > As well as the handful of comments below, this will definitely need to > wait for ppc-6.1 at this point. > > > --- > > Changelog > > > > 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 ] > > --- > > hw/ppc/spapr_nvdimm.c | 38 ++++++++++++++++++++++++++++++++++++++ > > include/hw/ppc/spapr.h | 3 ++- > > 2 files changed, 40 insertions(+), 1 deletion(-) > > > > diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c > > index b46c36917c..34096e4718 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. Taken from kernel's papr_scm.c */ > > +/* SCM device is unable to persist memory contents */ > > +#define PAPR_PMEM_UNARMED (1ULL << (63 - 0)) > > You can use PPC_BIT() for more clarity here. > I had already suggested PPC_BIT(0) but since this macro was copied from the kernel source, I've let Vaibhav decide whether to use PPC_BIT() or keep the macro and comment it comes from the kernel. I agree I prefer PPC_BIT(0) :-) > > +/* Bits status indicators for health bitmap indicating unarmed dimm */ > > +#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED) > > I'm not sure why you want two equal #defines here. > Especially, this define doesn't make sense for the hypervisor IMHO. It is _just_ the mask of bits for the "unarmed" state in the kernel. > > + > > bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm, > > uint64_t size, Error **errp) > > { > > @@ -467,6 +474,36 @@ 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) { > > This will fail badly if !drc (given index is way out of bounds). I'm > pretty sure you want > if (!drc || spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { > > > > + return H_PARAMETER; > > + } > > + > > + /* Ensure that the dimm is plugged in */ > > + if (!drc->dev) { > > + return H_HARDWARE; > > H_HARDWARE doesn't seem right - it's the guest that has chosen to > attempt this on an unplugged LMB, not the (virtual) hardware's fault. > Yes. As already suggested, simply do the same as in other hcall implementations in this file, e.g. from h_scm_bind_mem() : if (!drc || !drc->dev || spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { return H_PARAMETER; } > > + } > > + > > + nvdimm = NVDIMM(drc->dev); > > + > > + args[0] = 0; > > + /* Check if the nvdimm is unarmed and send its status via health bitmaps */ Not sure this comment is super useful. > > + if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) { > > + args[0] |= PAPR_PMEM_UNARMED; > > + } > > + > > + /* Update the health bitmap with the applicable mask */ > > + args[1] = PAPR_PMEM_UNARMED_MASK; I still think this is a misuse of PAPR_PMEM_UNARMED_MASK... The meaning of args[1] is "health-bit-valid-bitmap indicate which bits in health-bitmap are valid" according to the documentation. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/powerpc/papr_hcalls.rst#n228 Without any further detail, I tend to consider this as a hint to the guest on the bits supported by the hypervisor. Since we can only set PAPR_PMEM_UNARMED, for now, args[1] should be set to just that bit PAPR_PMEM_UNARMED. Other bits can be added later if QEMU supports more of them. > > + > > + return H_SUCCESS; > > +} > > + > > static void spapr_scm_register_types(void) > > { > > /* qemu/scm specific hcalls */ > > @@ -475,6 +512,7 @@ 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. >
Hi David, Thanks for looking into this patch David Gibson <david@gibson.dropbear.id.au> writes: > On Thu, Apr 01, 2021 at 06:35:19AM +0530, Vaibhav Jain 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@linux.ibm.com/ >> >> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> > > As well as the handful of comments below, this will definitely need to > wait for ppc-6.1 at this point. > Sure >> --- >> Changelog >> >> 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 ] >> --- >> hw/ppc/spapr_nvdimm.c | 38 ++++++++++++++++++++++++++++++++++++++ >> include/hw/ppc/spapr.h | 3 ++- >> 2 files changed, 40 insertions(+), 1 deletion(-) >> >> diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c >> index b46c36917c..34096e4718 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. Taken from kernel's papr_scm.c */ >> +/* SCM device is unable to persist memory contents */ >> +#define PAPR_PMEM_UNARMED (1ULL << (63 - 0)) > > You can use PPC_BIT() for more clarity here. > Sure, will address this in v3 >> +/* Bits status indicators for health bitmap indicating unarmed dimm */ >> +#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED) > > I'm not sure why you want two equal #defines here. > Will address this in v3. Switched to a single define. >> + >> bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm, >> uint64_t size, Error **errp) >> { >> @@ -467,6 +474,36 @@ 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) { > > This will fail badly if !drc (given index is way out of bounds). I'm > pretty sure you want > if (!drc || spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { > > Thanks for catching this. I have fixed this in v3 >> + return H_PARAMETER; >> + } >> + >> + /* Ensure that the dimm is plugged in */ >> + if (!drc->dev) { >> + return H_HARDWARE; > > H_HARDWARE doesn't seem right - it's the guest that has chosen to > attempt this on an unplugged LMB, not the (virtual) hardware's fault. > Agree, addressed this in v3 >> + } >> + >> + nvdimm = NVDIMM(drc->dev); >> + >> + args[0] = 0; >> + /* Check if the nvdimm is unarmed and send its status via health bitmaps */ >> + if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) { >> + args[0] |= PAPR_PMEM_UNARMED; >> + } >> + >> + /* Update the health bitmap with the applicable mask */ >> + args[1] = PAPR_PMEM_UNARMED_MASK; >> + >> + return H_SUCCESS; >> +} >> + >> static void spapr_scm_register_types(void) >> { >> /* qemu/scm specific hcalls */ >> @@ -475,6 +512,7 @@ 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. > > -- > 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
Hi Greg, Thanks for looking into this patch. Greg Kurz <groug@kaod.org> writes: > On Thu, 1 Apr 2021 13:26:11 +1100 > David Gibson <david@gibson.dropbear.id.au> wrote: > >> On Thu, Apr 01, 2021 at 06:35:19AM +0530, Vaibhav Jain 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@linux.ibm.com/ >> > >> > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> >> >> As well as the handful of comments below, this will definitely need to >> wait for ppc-6.1 at this point. >> >> > --- >> > Changelog >> > >> > 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 ] >> > --- >> > hw/ppc/spapr_nvdimm.c | 38 ++++++++++++++++++++++++++++++++++++++ >> > include/hw/ppc/spapr.h | 3 ++- >> > 2 files changed, 40 insertions(+), 1 deletion(-) >> > >> > diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c >> > index b46c36917c..34096e4718 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. Taken from kernel's papr_scm.c */ >> > +/* SCM device is unable to persist memory contents */ >> > +#define PAPR_PMEM_UNARMED (1ULL << (63 - 0)) >> >> You can use PPC_BIT() for more clarity here. >> > > I had already suggested PPC_BIT(0) but since this macro was copied > from the kernel source, I've let Vaibhav decide whether to use > PPC_BIT() or keep the macro and comment it comes from the kernel. > > I agree I prefer PPC_BIT(0) :-) > Have switched to PPC_BIT in v3 >> > +/* Bits status indicators for health bitmap indicating unarmed dimm */ >> > +#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED) >> >> I'm not sure why you want two equal #defines here. >> > > Especially, this define doesn't make sense for the hypervisor IMHO. > > It is _just_ the mask of bits for the "unarmed" state in the kernel. > Have gotten rid of this define in v3. We can revisit this In future when support for more bits is added. >> > + >> > bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm, >> > uint64_t size, Error **errp) >> > { >> > @@ -467,6 +474,36 @@ 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) { >> >> This will fail badly if !drc (given index is way out of bounds). I'm >> pretty sure you want >> if (!drc || spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { >> >> >> > + return H_PARAMETER; >> > + } >> > + >> > + /* Ensure that the dimm is plugged in */ >> > + if (!drc->dev) { >> > + return H_HARDWARE; >> >> H_HARDWARE doesn't seem right - it's the guest that has chosen to >> attempt this on an unplugged LMB, not the (virtual) hardware's fault. >> > > Yes. As already suggested, simply do the same as in other hcall > implementations in this file, e.g. from h_scm_bind_mem() : > > if (!drc || !drc->dev || > spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) { > return H_PARAMETER; > } > Yes, have used the same construct in the fixed v3 >> > + } >> > + >> > + nvdimm = NVDIMM(drc->dev); >> > + >> > + args[0] = 0; >> > + /* Check if the nvdimm is unarmed and send its status via health bitmaps */ > > Not sure this comment is super useful. > Have reworked this function in v3. >> > + if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) { >> > + args[0] |= PAPR_PMEM_UNARMED; >> > + } >> > + >> > + /* Update the health bitmap with the applicable mask */ >> > + args[1] = PAPR_PMEM_UNARMED_MASK; > > I still think this is a misuse of PAPR_PMEM_UNARMED_MASK... The > meaning of args[1] is "health-bit-valid-bitmap indicate which > bits in health-bitmap are valid" according to the documentation. > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/powerpc/papr_hcalls.rst#n228 > > Without any further detail, I tend to consider this as a hint > to the guest on the bits supported by the hypervisor. Since > we can only set PAPR_PMEM_UNARMED, for now, args[1] should > be set to just that bit PAPR_PMEM_UNARMED. Other bits can > be added later if QEMU supports more of them. > Agree and addressed in v3. >> > + >> > + return H_SUCCESS; >> > +} >> > + >> > static void spapr_scm_register_types(void) >> > { >> > /* qemu/scm specific hcalls */ >> > @@ -475,6 +512,7 @@ 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. >> >
diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c index b46c36917c..34096e4718 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. Taken from kernel's papr_scm.c */ +/* SCM device is unable to persist memory contents */ +#define PAPR_PMEM_UNARMED (1ULL << (63 - 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 +474,36 @@ 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; + } + + /* Ensure that the dimm is plugged in */ + if (!drc->dev) { + return H_HARDWARE; + } + + nvdimm = NVDIMM(drc->dev); + + args[0] = 0; + /* Check if the nvdimm is unarmed and send its status via health bitmaps */ + if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) { + args[0] |= PAPR_PMEM_UNARMED; + } + + /* Update the health bitmap with the applicable mask */ + args[1] = PAPR_PMEM_UNARMED_MASK; + + return H_SUCCESS; +} + static void spapr_scm_register_types(void) { /* qemu/scm specific hcalls */ @@ -475,6 +512,7 @@ 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.
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@linux.ibm.com/ Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> --- Changelog 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 ] --- hw/ppc/spapr_nvdimm.c | 38 ++++++++++++++++++++++++++++++++++++++ include/hw/ppc/spapr.h | 3 ++- 2 files changed, 40 insertions(+), 1 deletion(-)