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Re: [Qemu-ppc] [RFC PATCH 4/4] spapr: Add Hcalls to support PAPR NVDIMM
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From: |
David Gibson |
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Subject: |
Re: [Qemu-ppc] [RFC PATCH 4/4] spapr: Add Hcalls to support PAPR NVDIMM device |
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Date: |
Tue, 12 Feb 2019 13:28:16 +1100 |
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User-agent: |
Mutt/1.10.1 (2018-07-13) |
On Tue, Feb 05, 2019 at 11:26:41PM -0600, Shivaprasad G Bhat wrote:
> This patch implements few of the necessary hcalls for the nvdimm support.
>
> PAPR semantics is such that each NVDIMM device is comprising of multiple
> SCM(Storage Class Memory) blocks. The guest requests the hypervisor to bind
> each of the SCM blocks of the NVDIMM device using hcalls. There can be
> SCM block unbind requests in case of driver errors or unplug(not supported
> now)
> use cases. The NVDIMM label read/writes are done through hcalls.
>
> Since each virtual NVDIMM device is divided into multiple SCM blocks, the
> bind,
> unbind, and queries using hcalls on those blocks can come independently. This
> doesn't fit well into the qemu device semantics, where the map/unmap are done
> at the (whole)device/object level granularity. The patch doesnt actually
> bind/unbind on hcalls but let it happen at the object_add/del phase itself
> instead.
>
> The guest kernel makes bind/unbind requests for the virtual NVDIMM device at
> the
> region level granularity. Without interleaving, each virtual NVDIMM device is
> presented as separate region. There is no way to configure the virtual NVDIMM
> interleaving for the guests today. So, there is no way a partial bind/unbind
> request can come for the vNVDIMM in a hcall for a subset of SCM blocks of a
> virtual NVDIMM. Hence it is safe to do bind/unbind everything during the
> object_add/del.
Hrm. I don't entirely follow the above, but implementing something
that doesn't really match the PAPR model seems like it could lead to
problems.
>
> The kernel today is not using the hcalls - h_scm_mem_query, h_scm_mem_clear,
> h_scm_query_logical_mem_binding and h_scm_query_block_mem_binding. They are
> just
> stubs in this patch.
>
> Signed-off-by: Shivaprasad G Bhat <address@hidden>
> ---
> hw/ppc/spapr_hcall.c | 230
> ++++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/ppc/spapr.h | 12 ++-
> 2 files changed, 240 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 17bcaa3822..40553e80d6 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -3,11 +3,13 @@
> #include "sysemu/hw_accel.h"
> #include "sysemu/sysemu.h"
> #include "qemu/log.h"
> +#include "qemu/range.h"
> #include "qemu/error-report.h"
> #include "cpu.h"
> #include "exec/exec-all.h"
> #include "helper_regs.h"
> #include "hw/ppc/spapr.h"
> +#include "hw/ppc/spapr_drc.h"
> #include "hw/ppc/spapr_cpu_core.h"
> #include "mmu-hash64.h"
> #include "cpu-models.h"
> @@ -16,6 +18,7 @@
> #include "hw/ppc/spapr_ovec.h"
> #include "mmu-book3s-v3.h"
> #include "hw/mem/memory-device.h"
> +#include "hw/mem/nvdimm.h"
>
> struct LPCRSyncState {
> target_ulong value;
> @@ -1808,6 +1811,222 @@ static target_ulong h_update_dt(PowerPCCPU *cpu,
> sPAPRMachineState *spapr,
> return H_SUCCESS;
> }
>
> +static target_ulong h_scm_read_metadata(PowerPCCPU *cpu,
> + sPAPRMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + uint32_t drc_index = args[0];
> + uint64_t offset = args[1];
> + uint8_t numBytesToRead = args[2];
This will truncate the argument to 8 bits _before_ you validate it,
which doesn't seem like what you want.
> + sPAPRDRConnector *drc = spapr_drc_by_index(drc_index);
> + NVDIMMDevice *nvdimm = NULL;
> + NVDIMMClass *ddc = NULL;
> +
> + if (numBytesToRead != 1 && numBytesToRead != 2 &&
> + numBytesToRead != 4 && numBytesToRead != 8) {
> + return H_P3;
> + }
> +
> + if (offset & (numBytesToRead - 1)) {
> + return H_P2;
> + }
> +
> + if (drc && spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) {
> + return H_PARAMETER;
> + }
> +
> + nvdimm = NVDIMM(drc->dev);
> + ddc = NVDIMM_GET_CLASS(nvdimm);
> +
> + ddc->read_label_data(nvdimm, &args[0], numBytesToRead, offset);
Hm. Is this the only way to access the label data, or is it also
mapped into the guest visible address space? I ask because some of
the calculations you made about size+label_size in an earlier patch
seemed to suggest it was part of the address space.
> + return H_SUCCESS;
> +}
> +
> +
> +static target_ulong h_scm_write_metadata(PowerPCCPU *cpu,
> + sPAPRMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + uint32_t drc_index = args[0];
> + uint64_t offset = args[1];
> + uint64_t data = args[2];
> + int8_t numBytesToWrite = args[3];
> + sPAPRDRConnector *drc = spapr_drc_by_index(drc_index);
> + NVDIMMDevice *nvdimm = NULL;
> + DeviceState *dev = NULL;
> + NVDIMMClass *ddc = NULL;
> +
> + if (numBytesToWrite != 1 && numBytesToWrite != 2 &&
> + numBytesToWrite != 4 && numBytesToWrite != 8) {
> + return H_P4;
> + }
> +
> + if (offset & (numBytesToWrite - 1)) {
> + return H_P2;
> + }
> +
> + if (drc && spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) {
> + return H_PARAMETER;
> + }
> +
> + dev = drc->dev;
> + nvdimm = NVDIMM(dev);
> + if (offset >= nvdimm->label_size) {
> + return H_P3;
> + }
> +
> + ddc = NVDIMM_GET_CLASS(nvdimm);
> +
> + ddc->write_label_data(nvdimm, &data, numBytesToWrite, offset);
> +
> + return H_SUCCESS;
> +}
> +
> +static target_ulong h_scm_bind_mem(PowerPCCPU *cpu, sPAPRMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + uint32_t drc_index = args[0];
> + uint64_t starting_index = args[1];
> + uint64_t no_of_scm_blocks_to_bind = args[2];
> + uint64_t target_logical_mem_addr = args[3];
> + uint64_t continue_token = args[4];
> + uint64_t size;
> + uint64_t total_no_of_scm_blocks;
> +
> + sPAPRDRConnector *drc = spapr_drc_by_index(drc_index);
> + hwaddr addr;
> + DeviceState *dev = NULL;
> + PCDIMMDevice *dimm = NULL;
> + Error *local_err = NULL;
> +
> + if (drc && spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) {
> + return H_PARAMETER;
> + }
> +
> + dev = drc->dev;
> + dimm = PC_DIMM(dev);
> +
> + size = object_property_get_uint(OBJECT(dimm),
> + PC_DIMM_SIZE_PROP, &local_err);
> + if (local_err) {
> + error_report_err(local_err);
> + return H_PARAMETER;
This should probably be H_HARDWARE, no? The error isn't caused by one
of the parameters.
> + }
> +
> + total_no_of_scm_blocks = size / SPAPR_MINIMUM_SCM_BLOCK_SIZE;
> +
> + if (starting_index > total_no_of_scm_blocks) {
> + return H_P2;
> + }
> +
> + if ((starting_index + no_of_scm_blocks_to_bind) >
> total_no_of_scm_blocks) {
You should probably have a check for integer overflow here as well,
just to be thorough.
> + return H_P3;
> + }
> +
> + /* Currently qemu assigns the address. */
> + if (target_logical_mem_addr != 0xffffffffffffffff) {
> + return H_OVERLAP;
> + }
> +
> + /*
> + * Currently continue token should be zero qemu has already bound
> + * everything and this hcall doesnt return H_BUSY.
> + */
> + if (continue_token > 0) {
> + return H_P5;
> + }
> +
> + /* NB : Already bound, Return target logical address in R4 */
> + addr = object_property_get_uint(OBJECT(dimm),
> + PC_DIMM_ADDR_PROP, &local_err);
> + if (local_err) {
> + error_report_err(local_err);
> + return H_PARAMETER;
> + }
> +
> + args[1] = addr;
> +
> + return H_SUCCESS;
> +}
> +
> +static target_ulong h_scm_unbind_mem(PowerPCCPU *cpu, sPAPRMachineState
> *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + uint64_t starting_scm_logical_addr = args[0];
> + uint64_t no_of_scm_blocks_to_unbind = args[1];
> + uint64_t size_to_unbind;
> + uint64_t continue_token = args[2];
> + Range as = range_empty;
> + GSList *dimms = NULL;
> + bool valid = false;
> +
> + size_to_unbind = no_of_scm_blocks_to_unbind *
> SPAPR_MINIMUM_SCM_BLOCK_SIZE;
> +
> + /* Check if starting_scm_logical_addr is block aligned */
> + if (!QEMU_IS_ALIGNED(starting_scm_logical_addr,
> + SPAPR_MINIMUM_SCM_BLOCK_SIZE)) {
> + return H_PARAMETER;
> + }
> +
> + range_init_nofail(&as, starting_scm_logical_addr, size_to_unbind);
> +
> + dimms = nvdimm_get_device_list();
> + for (; dimms; dimms = dimms->next) {
> + NVDIMMDevice *nvdimm = dimms->data;
> + Range tmp;
> + int size = object_property_get_int(OBJECT(nvdimm), PC_DIMM_SIZE_PROP,
> + NULL);
> + int addr = object_property_get_int(OBJECT(nvdimm), PC_DIMM_ADDR_PROP,
> + NULL);
> + range_init_nofail(&tmp, addr, size);
> +
> + if (range_contains_range(&tmp, &as)) {
> + valid = true;
> + break;
> + }
> + }
> +
> + if (!valid) {
> + return H_P2;
> + }
> +
> + if (continue_token > 0) {
> + return H_P3;
> + }
> +
> + /*NB : dont do anything, let object_del take care of this for now. */
> +
> + return H_SUCCESS;
> +}
> +
> +static target_ulong h_scm_query_block_mem_binding(PowerPCCPU *cpu,
> + sPAPRMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + return H_SUCCESS;
> +}
> +
> +static target_ulong h_scm_query_logical_mem_binding(PowerPCCPU *cpu,
> + sPAPRMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + return H_SUCCESS;
> +}
> +
> +static target_ulong h_scm_mem_query(PowerPCCPU *cpu, sPAPRMachineState
> *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + return H_SUCCESS;
> +}
> +
> static spapr_hcall_fn papr_hypercall_table[(MAX_HCALL_OPCODE / 4) + 1];
> static spapr_hcall_fn kvmppc_hypercall_table[KVMPPC_HCALL_MAX -
> KVMPPC_HCALL_BASE + 1];
>
> @@ -1907,6 +2126,17 @@ static void hypercall_register_types(void)
> /* qemu/KVM-PPC specific hcalls */
> spapr_register_hypercall(KVMPPC_H_RTAS, h_rtas);
>
> + /* qemu/scm specific hcalls */
> + spapr_register_hypercall(H_SCM_READ_METADATA, h_scm_read_metadata);
> + spapr_register_hypercall(H_SCM_WRITE_METADATA, h_scm_write_metadata);
> + 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_QUERY_BLOCK_MEM_BINDING,
> + h_scm_query_block_mem_binding);
> + spapr_register_hypercall(H_SCM_QUERY_LOGICAL_MEM_BINDING,
> + h_scm_query_logical_mem_binding);
> + spapr_register_hypercall(H_SCM_MEM_QUERY, h_scm_mem_query);
> +
> /* ibm,client-architecture-support support */
> spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
>
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 21a9709afe..28249567f4 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -268,6 +268,7 @@ struct sPAPRMachineState {
> #define H_P7 -60
> #define H_P8 -61
> #define H_P9 -62
> +#define H_OVERLAP -68
> #define H_UNSUPPORTED_FLAG -256
> #define H_MULTI_THREADS_ACTIVE -9005
>
> @@ -473,8 +474,15 @@ struct sPAPRMachineState {
> #define H_INT_ESB 0x3C8
> #define H_INT_SYNC 0x3CC
> #define H_INT_RESET 0x3D0
> -
> -#define MAX_HCALL_OPCODE H_INT_RESET
> +#define H_SCM_READ_METADATA 0x3E4
> +#define H_SCM_WRITE_METADATA 0x3E8
> +#define H_SCM_BIND_MEM 0x3EC
> +#define H_SCM_UNBIND_MEM 0x3F0
> +#define H_SCM_QUERY_BLOCK_MEM_BINDING 0x3F4
> +#define H_SCM_QUERY_LOGICAL_MEM_BINDING 0x3F8
> +#define H_SCM_MEM_QUERY 0x3FC
> +
> +#define MAX_HCALL_OPCODE H_SCM_MEM_QUERY
>
> /* 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
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