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authorLinus Torvalds <[email protected]>2023-11-03 10:07:39 -1000
committerLinus Torvalds <[email protected]>2023-11-03 10:07:39 -1000
commit707df298cbde200b939c70be2577b20775fe3345 (patch)
treeb29f663dac88ac45d4f1d1465133c85439febe6c /arch/powerpc/kvm/guest-state-buffer.c
parent6bdfe2d88b9ff8b0cce32ce87cd47c0e9d665f48 (diff)
parent303d77a6e1707498f09c9d8ee91b1dc07ca315a5 (diff)
Merge tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman: - Add support for KVM running as a nested hypervisor under development versions of PowerVM, using the new PAPR nested virtualisation API - Add support for the BPF prog pack allocator - A rework of the non-server MMU handling to support execute-only on all platforms - Some optimisations & cleanups for the powerpc qspinlock code - Various other small features and fixes Thanks to Aboorva Devarajan, Aditya Gupta, Amit Machhiwal, Benjamin Gray, Christophe Leroy, Dr. David Alan Gilbert, Gaurav Batra, Gautam Menghani, Geert Uytterhoeven, Haren Myneni, Hari Bathini, Joel Stanley, Jordan Niethe, Julia Lawall, Kautuk Consul, Kuan-Wei Chiu, Michael Neuling, Minjie Du, Muhammad Muzammil, Naveen N Rao, Nicholas Piggin, Nick Child, Nysal Jan K.A, Peter Lafreniere, Rob Herring, Sachin Sant, Sebastian Andrzej Siewior, Shrikanth Hegde, Srikar Dronamraju, Stanislav Kinsburskii, Vaibhav Jain, Wang Yufen, Yang Yingliang, and Yuan Tan. * tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (100 commits) powerpc/vmcore: Add MMU information to vmcoreinfo Revert "powerpc: add `cur_cpu_spec` symbol to vmcoreinfo" powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free] powerpc/bpf: rename powerpc64_jit_data to powerpc_jit_data powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack powerpc/bpf: implement bpf_arch_text_copy powerpc/code-patching: introduce patch_instructions() powerpc/32s: Implement local_flush_tlb_page_psize() powerpc/pseries: use kfree_sensitive() in plpks_gen_password() powerpc/code-patching: Perform hwsync in __patch_instruction() in case of failure powerpc/fsl_msi: Use device_get_match_data() powerpc: Remove cpm_dp...() macros powerpc/qspinlock: Rename yield_propagate_owner tunable powerpc/qspinlock: Propagate sleepy if previous waiter is preempted powerpc/qspinlock: don't propagate the not-sleepy state powerpc/qspinlock: propagate owner preemptedness rather than CPU number powerpc/qspinlock: stop queued waiters trying to set lock sleepy powerpc/perf: Fix disabling BHRB and instruction sampling powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API powerpc/tools: Pass -mabi=elfv2 to gcc-check-mprofile-kernel.sh ...
Diffstat (limited to 'arch/powerpc/kvm/guest-state-buffer.c')
-rw-r--r--arch/powerpc/kvm/guest-state-buffer.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
new file mode 100644
index 000000000000..b80dbc58621f
--- /dev/null
+++ b/arch/powerpc/kvm/guest-state-buffer.c
@@ -0,0 +1,621 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "asm/hvcall.h"
+#include <linux/log2.h>
+#include <asm/pgalloc.h>
+#include <asm/guest-state-buffer.h>
+
+static const u16 kvmppc_gse_iden_len[__KVMPPC_GSE_TYPE_MAX] = {
+ [KVMPPC_GSE_BE32] = sizeof(__be32),
+ [KVMPPC_GSE_BE64] = sizeof(__be64),
+ [KVMPPC_GSE_VEC128] = sizeof(vector128),
+ [KVMPPC_GSE_PARTITION_TABLE] = sizeof(struct kvmppc_gs_part_table),
+ [KVMPPC_GSE_PROCESS_TABLE] = sizeof(struct kvmppc_gs_proc_table),
+ [KVMPPC_GSE_BUFFER] = sizeof(struct kvmppc_gs_buff_info),
+};
+
+/**
+ * kvmppc_gsb_new() - create a new guest state buffer
+ * @size: total size of the guest state buffer (includes header)
+ * @guest_id: guest_id
+ * @vcpu_id: vcpu_id
+ * @flags: GFP flags
+ *
+ * Returns a guest state buffer.
+ */
+struct kvmppc_gs_buff *kvmppc_gsb_new(size_t size, unsigned long guest_id,
+ unsigned long vcpu_id, gfp_t flags)
+{
+ struct kvmppc_gs_buff *gsb;
+
+ gsb = kzalloc(sizeof(*gsb), flags);
+ if (!gsb)
+ return NULL;
+
+ size = roundup_pow_of_two(size);
+ gsb->hdr = kzalloc(size, GFP_KERNEL);
+ if (!gsb->hdr)
+ goto free;
+
+ gsb->capacity = size;
+ gsb->len = sizeof(struct kvmppc_gs_header);
+ gsb->vcpu_id = vcpu_id;
+ gsb->guest_id = guest_id;
+
+ gsb->hdr->nelems = cpu_to_be32(0);
+
+ return gsb;
+
+free:
+ kfree(gsb);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsb_new);
+
+/**
+ * kvmppc_gsb_free() - free a guest state buffer
+ * @gsb: guest state buffer
+ */
+void kvmppc_gsb_free(struct kvmppc_gs_buff *gsb)
+{
+ kfree(gsb->hdr);
+ kfree(gsb);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsb_free);
+
+/**
+ * kvmppc_gsb_put() - allocate space in a guest state buffer
+ * @gsb: buffer to allocate in
+ * @size: amount of space to allocate
+ *
+ * Returns a pointer to the amount of space requested within the buffer and
+ * increments the count of elements in the buffer.
+ *
+ * Does not check if there is enough space in the buffer.
+ */
+void *kvmppc_gsb_put(struct kvmppc_gs_buff *gsb, size_t size)
+{
+ u32 nelems = kvmppc_gsb_nelems(gsb);
+ void *p;
+
+ p = (void *)kvmppc_gsb_header(gsb) + kvmppc_gsb_len(gsb);
+ gsb->len += size;
+
+ kvmppc_gsb_header(gsb)->nelems = cpu_to_be32(nelems + 1);
+ return p;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsb_put);
+
+static int kvmppc_gsid_class(u16 iden)
+{
+ if ((iden >= KVMPPC_GSE_GUESTWIDE_START) &&
+ (iden <= KVMPPC_GSE_GUESTWIDE_END))
+ return KVMPPC_GS_CLASS_GUESTWIDE;
+
+ if ((iden >= KVMPPC_GSE_META_START) && (iden <= KVMPPC_GSE_META_END))
+ return KVMPPC_GS_CLASS_META;
+
+ if ((iden >= KVMPPC_GSE_DW_REGS_START) &&
+ (iden <= KVMPPC_GSE_DW_REGS_END))
+ return KVMPPC_GS_CLASS_DWORD_REG;
+
+ if ((iden >= KVMPPC_GSE_W_REGS_START) &&
+ (iden <= KVMPPC_GSE_W_REGS_END))
+ return KVMPPC_GS_CLASS_WORD_REG;
+
+ if ((iden >= KVMPPC_GSE_VSRS_START) && (iden <= KVMPPC_GSE_VSRS_END))
+ return KVMPPC_GS_CLASS_VECTOR;
+
+ if ((iden >= KVMPPC_GSE_INTR_REGS_START) &&
+ (iden <= KVMPPC_GSE_INTR_REGS_END))
+ return KVMPPC_GS_CLASS_INTR;
+
+ return -1;
+}
+
+static int kvmppc_gsid_type(u16 iden)
+{
+ int type = -1;
+
+ switch (kvmppc_gsid_class(iden)) {
+ case KVMPPC_GS_CLASS_GUESTWIDE:
+ switch (iden) {
+ case KVMPPC_GSID_HOST_STATE_SIZE:
+ case KVMPPC_GSID_RUN_OUTPUT_MIN_SIZE:
+ case KVMPPC_GSID_TB_OFFSET:
+ type = KVMPPC_GSE_BE64;
+ break;
+ case KVMPPC_GSID_PARTITION_TABLE:
+ type = KVMPPC_GSE_PARTITION_TABLE;
+ break;
+ case KVMPPC_GSID_PROCESS_TABLE:
+ type = KVMPPC_GSE_PROCESS_TABLE;
+ break;
+ case KVMPPC_GSID_LOGICAL_PVR:
+ type = KVMPPC_GSE_BE32;
+ break;
+ }
+ break;
+ case KVMPPC_GS_CLASS_META:
+ switch (iden) {
+ case KVMPPC_GSID_RUN_INPUT:
+ case KVMPPC_GSID_RUN_OUTPUT:
+ type = KVMPPC_GSE_BUFFER;
+ break;
+ case KVMPPC_GSID_VPA:
+ type = KVMPPC_GSE_BE64;
+ break;
+ }
+ break;
+ case KVMPPC_GS_CLASS_DWORD_REG:
+ type = KVMPPC_GSE_BE64;
+ break;
+ case KVMPPC_GS_CLASS_WORD_REG:
+ type = KVMPPC_GSE_BE32;
+ break;
+ case KVMPPC_GS_CLASS_VECTOR:
+ type = KVMPPC_GSE_VEC128;
+ break;
+ case KVMPPC_GS_CLASS_INTR:
+ switch (iden) {
+ case KVMPPC_GSID_HDAR:
+ case KVMPPC_GSID_ASDR:
+ case KVMPPC_GSID_HEIR:
+ type = KVMPPC_GSE_BE64;
+ break;
+ case KVMPPC_GSID_HDSISR:
+ type = KVMPPC_GSE_BE32;
+ break;
+ }
+ break;
+ }
+
+ return type;
+}
+
+/**
+ * kvmppc_gsid_flags() - the flags for a guest state ID
+ * @iden: guest state ID
+ *
+ * Returns any flags for the guest state ID.
+ */
+unsigned long kvmppc_gsid_flags(u16 iden)
+{
+ unsigned long flags = 0;
+
+ switch (kvmppc_gsid_class(iden)) {
+ case KVMPPC_GS_CLASS_GUESTWIDE:
+ flags = KVMPPC_GS_FLAGS_WIDE;
+ break;
+ case KVMPPC_GS_CLASS_META:
+ case KVMPPC_GS_CLASS_DWORD_REG:
+ case KVMPPC_GS_CLASS_WORD_REG:
+ case KVMPPC_GS_CLASS_VECTOR:
+ case KVMPPC_GS_CLASS_INTR:
+ break;
+ }
+
+ return flags;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsid_flags);
+
+/**
+ * kvmppc_gsid_size() - the size of a guest state ID
+ * @iden: guest state ID
+ *
+ * Returns the size of guest state ID.
+ */
+u16 kvmppc_gsid_size(u16 iden)
+{
+ int type;
+
+ type = kvmppc_gsid_type(iden);
+ if (type == -1)
+ return 0;
+
+ if (type >= __KVMPPC_GSE_TYPE_MAX)
+ return 0;
+
+ return kvmppc_gse_iden_len[type];
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsid_size);
+
+/**
+ * kvmppc_gsid_mask() - the settable bits of a guest state ID
+ * @iden: guest state ID
+ *
+ * Returns a mask of settable bits for a guest state ID.
+ */
+u64 kvmppc_gsid_mask(u16 iden)
+{
+ u64 mask = ~0ull;
+
+ switch (iden) {
+ case KVMPPC_GSID_LPCR:
+ mask = LPCR_DPFD | LPCR_ILE | LPCR_AIL | LPCR_LD | LPCR_MER |
+ LPCR_GTSE;
+ break;
+ case KVMPPC_GSID_MSR:
+ mask = ~(MSR_HV | MSR_S | MSR_ME);
+ break;
+ }
+
+ return mask;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsid_mask);
+
+/**
+ * __kvmppc_gse_put() - add a guest state element to a buffer
+ * @gsb: buffer to the element to
+ * @iden: guest state ID
+ * @size: length of data
+ * @data: pointer to data
+ */
+int __kvmppc_gse_put(struct kvmppc_gs_buff *gsb, u16 iden, u16 size,
+ const void *data)
+{
+ struct kvmppc_gs_elem *gse;
+ u16 total_size;
+
+ total_size = sizeof(*gse) + size;
+ if (total_size + kvmppc_gsb_len(gsb) > kvmppc_gsb_capacity(gsb))
+ return -ENOMEM;
+
+ if (kvmppc_gsid_size(iden) != size)
+ return -EINVAL;
+
+ gse = kvmppc_gsb_put(gsb, total_size);
+ gse->iden = cpu_to_be16(iden);
+ gse->len = cpu_to_be16(size);
+ memcpy(gse->data, data, size);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__kvmppc_gse_put);
+
+/**
+ * kvmppc_gse_parse() - create a parse map from a guest state buffer
+ * @gsp: guest state parser
+ * @gsb: guest state buffer
+ */
+int kvmppc_gse_parse(struct kvmppc_gs_parser *gsp, struct kvmppc_gs_buff *gsb)
+{
+ struct kvmppc_gs_elem *curr;
+ int rem, i;
+
+ kvmppc_gsb_for_each_elem(i, curr, gsb, rem) {
+ if (kvmppc_gse_len(curr) !=
+ kvmppc_gsid_size(kvmppc_gse_iden(curr)))
+ return -EINVAL;
+ kvmppc_gsp_insert(gsp, kvmppc_gse_iden(curr), curr);
+ }
+
+ if (kvmppc_gsb_nelems(gsb) != i)
+ return -EINVAL;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gse_parse);
+
+static inline int kvmppc_gse_flatten_iden(u16 iden)
+{
+ int bit = 0;
+ int class;
+
+ class = kvmppc_gsid_class(iden);
+
+ if (class == KVMPPC_GS_CLASS_GUESTWIDE) {
+ bit += iden - KVMPPC_GSE_GUESTWIDE_START;
+ return bit;
+ }
+
+ bit += KVMPPC_GSE_GUESTWIDE_COUNT;
+
+ if (class == KVMPPC_GS_CLASS_META) {
+ bit += iden - KVMPPC_GSE_META_START;
+ return bit;
+ }
+
+ bit += KVMPPC_GSE_META_COUNT;
+
+ if (class == KVMPPC_GS_CLASS_DWORD_REG) {
+ bit += iden - KVMPPC_GSE_DW_REGS_START;
+ return bit;
+ }
+
+ bit += KVMPPC_GSE_DW_REGS_COUNT;
+
+ if (class == KVMPPC_GS_CLASS_WORD_REG) {
+ bit += iden - KVMPPC_GSE_W_REGS_START;
+ return bit;
+ }
+
+ bit += KVMPPC_GSE_W_REGS_COUNT;
+
+ if (class == KVMPPC_GS_CLASS_VECTOR) {
+ bit += iden - KVMPPC_GSE_VSRS_START;
+ return bit;
+ }
+
+ bit += KVMPPC_GSE_VSRS_COUNT;
+
+ if (class == KVMPPC_GS_CLASS_INTR) {
+ bit += iden - KVMPPC_GSE_INTR_REGS_START;
+ return bit;
+ }
+
+ return 0;
+}
+
+static inline u16 kvmppc_gse_unflatten_iden(int bit)
+{
+ u16 iden;
+
+ if (bit < KVMPPC_GSE_GUESTWIDE_COUNT) {
+ iden = KVMPPC_GSE_GUESTWIDE_START + bit;
+ return iden;
+ }
+ bit -= KVMPPC_GSE_GUESTWIDE_COUNT;
+
+ if (bit < KVMPPC_GSE_META_COUNT) {
+ iden = KVMPPC_GSE_META_START + bit;
+ return iden;
+ }
+ bit -= KVMPPC_GSE_META_COUNT;
+
+ if (bit < KVMPPC_GSE_DW_REGS_COUNT) {
+ iden = KVMPPC_GSE_DW_REGS_START + bit;
+ return iden;
+ }
+ bit -= KVMPPC_GSE_DW_REGS_COUNT;
+
+ if (bit < KVMPPC_GSE_W_REGS_COUNT) {
+ iden = KVMPPC_GSE_W_REGS_START + bit;
+ return iden;
+ }
+ bit -= KVMPPC_GSE_W_REGS_COUNT;
+
+ if (bit < KVMPPC_GSE_VSRS_COUNT) {
+ iden = KVMPPC_GSE_VSRS_START + bit;
+ return iden;
+ }
+ bit -= KVMPPC_GSE_VSRS_COUNT;
+
+ if (bit < KVMPPC_GSE_IDEN_COUNT) {
+ iden = KVMPPC_GSE_INTR_REGS_START + bit;
+ return iden;
+ }
+
+ return 0;
+}
+
+/**
+ * kvmppc_gsp_insert() - add a mapping from an guest state ID to an element
+ * @gsp: guest state parser
+ * @iden: guest state id (key)
+ * @gse: guest state element (value)
+ */
+void kvmppc_gsp_insert(struct kvmppc_gs_parser *gsp, u16 iden,
+ struct kvmppc_gs_elem *gse)
+{
+ int i;
+
+ i = kvmppc_gse_flatten_iden(iden);
+ kvmppc_gsbm_set(&gsp->iterator, iden);
+ gsp->gses[i] = gse;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsp_insert);
+
+/**
+ * kvmppc_gsp_lookup() - lookup an element from a guest state ID
+ * @gsp: guest state parser
+ * @iden: guest state ID (key)
+ *
+ * Returns the guest state element if present.
+ */
+struct kvmppc_gs_elem *kvmppc_gsp_lookup(struct kvmppc_gs_parser *gsp, u16 iden)
+{
+ int i;
+
+ i = kvmppc_gse_flatten_iden(iden);
+ return gsp->gses[i];
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsp_lookup);
+
+/**
+ * kvmppc_gsbm_set() - set the guest state ID
+ * @gsbm: guest state bitmap
+ * @iden: guest state ID
+ */
+void kvmppc_gsbm_set(struct kvmppc_gs_bitmap *gsbm, u16 iden)
+{
+ set_bit(kvmppc_gse_flatten_iden(iden), gsbm->bitmap);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsbm_set);
+
+/**
+ * kvmppc_gsbm_clear() - clear the guest state ID
+ * @gsbm: guest state bitmap
+ * @iden: guest state ID
+ */
+void kvmppc_gsbm_clear(struct kvmppc_gs_bitmap *gsbm, u16 iden)
+{
+ clear_bit(kvmppc_gse_flatten_iden(iden), gsbm->bitmap);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsbm_clear);
+
+/**
+ * kvmppc_gsbm_test() - test the guest state ID
+ * @gsbm: guest state bitmap
+ * @iden: guest state ID
+ */
+bool kvmppc_gsbm_test(struct kvmppc_gs_bitmap *gsbm, u16 iden)
+{
+ return test_bit(kvmppc_gse_flatten_iden(iden), gsbm->bitmap);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsbm_test);
+
+/**
+ * kvmppc_gsbm_next() - return the next set guest state ID
+ * @gsbm: guest state bitmap
+ * @prev: last guest state ID
+ */
+u16 kvmppc_gsbm_next(struct kvmppc_gs_bitmap *gsbm, u16 prev)
+{
+ int bit, pbit;
+
+ pbit = prev ? kvmppc_gse_flatten_iden(prev) + 1 : 0;
+ bit = find_next_bit(gsbm->bitmap, KVMPPC_GSE_IDEN_COUNT, pbit);
+
+ if (bit < KVMPPC_GSE_IDEN_COUNT)
+ return kvmppc_gse_unflatten_iden(bit);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsbm_next);
+
+/**
+ * kvmppc_gsm_init() - initialize a guest state message
+ * @gsm: guest state message
+ * @ops: callbacks
+ * @data: private data
+ * @flags: guest wide or thread wide
+ */
+int kvmppc_gsm_init(struct kvmppc_gs_msg *gsm, struct kvmppc_gs_msg_ops *ops,
+ void *data, unsigned long flags)
+{
+ memset(gsm, 0, sizeof(*gsm));
+ gsm->ops = ops;
+ gsm->data = data;
+ gsm->flags = flags;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsm_init);
+
+/**
+ * kvmppc_gsm_new() - creates a new guest state message
+ * @ops: callbacks
+ * @data: private data
+ * @flags: guest wide or thread wide
+ * @gfp_flags: GFP allocation flags
+ *
+ * Returns an initialized guest state message.
+ */
+struct kvmppc_gs_msg *kvmppc_gsm_new(struct kvmppc_gs_msg_ops *ops, void *data,
+ unsigned long flags, gfp_t gfp_flags)
+{
+ struct kvmppc_gs_msg *gsm;
+
+ gsm = kzalloc(sizeof(*gsm), gfp_flags);
+ if (!gsm)
+ return NULL;
+
+ kvmppc_gsm_init(gsm, ops, data, flags);
+
+ return gsm;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsm_new);
+
+/**
+ * kvmppc_gsm_size() - creates a new guest state message
+ * @gsm: self
+ *
+ * Returns the size required for the message.
+ */
+size_t kvmppc_gsm_size(struct kvmppc_gs_msg *gsm)
+{
+ if (gsm->ops->get_size)
+ return gsm->ops->get_size(gsm);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsm_size);
+
+/**
+ * kvmppc_gsm_free() - free guest state message
+ * @gsm: guest state message
+ *
+ * Returns the size required for the message.
+ */
+void kvmppc_gsm_free(struct kvmppc_gs_msg *gsm)
+{
+ kfree(gsm);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsm_free);
+
+/**
+ * kvmppc_gsm_fill_info() - serialises message to guest state buffer format
+ * @gsm: self
+ * @gsb: buffer to serialise into
+ */
+int kvmppc_gsm_fill_info(struct kvmppc_gs_msg *gsm, struct kvmppc_gs_buff *gsb)
+{
+ if (!gsm->ops->fill_info)
+ return -EINVAL;
+
+ return gsm->ops->fill_info(gsb, gsm);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
+
+/**
+ * kvmppc_gsm_refresh_info() - deserialises from guest state buffer
+ * @gsm: self
+ * @gsb: buffer to serialise from
+ */
+int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
+ struct kvmppc_gs_buff *gsb)
+{
+ if (!gsm->ops->fill_info)
+ return -EINVAL;
+
+ return gsm->ops->refresh_info(gsm, gsb);
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsm_refresh_info);
+
+/**
+ * kvmppc_gsb_send - send all elements in the buffer to the hypervisor.
+ * @gsb: guest state buffer
+ * @flags: guest wide or thread wide
+ *
+ * Performs the H_GUEST_SET_STATE hcall for the guest state buffer.
+ */
+int kvmppc_gsb_send(struct kvmppc_gs_buff *gsb, unsigned long flags)
+{
+ unsigned long hflags = 0;
+ unsigned long i;
+ int rc;
+
+ if (kvmppc_gsb_nelems(gsb) == 0)
+ return 0;
+
+ if (flags & KVMPPC_GS_FLAGS_WIDE)
+ hflags |= H_GUEST_FLAGS_WIDE;
+
+ rc = plpar_guest_set_state(hflags, gsb->guest_id, gsb->vcpu_id,
+ __pa(gsb->hdr), gsb->capacity, &i);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsb_send);
+
+/**
+ * kvmppc_gsb_recv - request all elements in the buffer have their value
+ * updated.
+ * @gsb: guest state buffer
+ * @flags: guest wide or thread wide
+ *
+ * Performs the H_GUEST_GET_STATE hcall for the guest state buffer.
+ * After returning from the hcall the guest state elements that were
+ * present in the buffer will have updated values from the hypervisor.
+ */
+int kvmppc_gsb_recv(struct kvmppc_gs_buff *gsb, unsigned long flags)
+{
+ unsigned long hflags = 0;
+ unsigned long i;
+ int rc;
+
+ if (flags & KVMPPC_GS_FLAGS_WIDE)
+ hflags |= H_GUEST_FLAGS_WIDE;
+
+ rc = plpar_guest_get_state(hflags, gsb->guest_id, gsb->vcpu_id,
+ __pa(gsb->hdr), gsb->capacity, &i);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(kvmppc_gsb_recv);