On Fri Mar 8, 2024 at 9:19 PM AEST, Harsh Prateek Bora wrote:
> Introduce the nested PAPR hcalls:
> - H_GUEST_GET_STATE which is used to get state of a nested guest or
> a guest VCPU. The value field for each element in the request is
> destination to be updated to reflect current state on success.
> - H_GUEST_SET_STATE which is used to modify the state of a guest or
> a guest VCPU. On success, guest (or its VCPU) state shall be
> updated as per the value field for the requested element(s).
>
> Signed-off-by: Michael Neuling <mi...@neuling.org>
> Signed-off-by: Harsh Prateek Bora <hars...@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npig...@gmail.com>
> ---
> include/hw/ppc/spapr.h | 3 +
> include/hw/ppc/spapr_nested.h | 23 +++
> hw/ppc/spapr_nested.c | 268 ++++++++++++++++++++++++++++++++++
> 3 files changed, 294 insertions(+)
>
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 070135793a..6223873641 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -366,6 +366,7 @@ struct SpaprMachineState {
> #define H_OVERLAP -68
> #define H_STATE -75
> #define H_IN_USE -77
> +#define H_INVALID_ELEMENT_VALUE -81
> #define H_UNSUPPORTED_FLAG -256
> #define H_MULTI_THREADS_ACTIVE -9005
>
> @@ -589,6 +590,8 @@ struct SpaprMachineState {
> #define H_GUEST_SET_CAPABILITIES 0x464
> #define H_GUEST_CREATE 0x470
> #define H_GUEST_CREATE_VCPU 0x474
> +#define H_GUEST_GET_STATE 0x478
> +#define H_GUEST_SET_STATE 0x47C
> #define H_GUEST_DELETE 0x488
>
> #define MAX_HCALL_OPCODE H_GUEST_DELETE
> diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h
> index 433d93c480..bd43c6b6ef 100644
> --- a/include/hw/ppc/spapr_nested.h
> +++ b/include/hw/ppc/spapr_nested.h
> @@ -224,6 +224,10 @@ typedef struct SpaprMachineStateNestedGuest {
> #define HVMASK_MSR 0xEBFFFFFFFFBFEFFF
> #define HVMASK_HDEXCR 0x00000000FFFFFFFF
> #define HVMASK_TB_OFFSET 0x000000FFFFFFFFFF
> +#define GSB_MAX_BUF_SIZE (1024 * 1024)
> +#define H_GUEST_GETSET_STATE_FLAG_GUEST_WIDE 0x8000000000000000
> +#define GUEST_STATE_REQUEST_GUEST_WIDE 0x1
> +#define GUEST_STATE_REQUEST_SET 0x2
>
> /* As per ISA v3.1B, following bits are reserved:
> * 0:2
> @@ -321,6 +325,25 @@ typedef struct SpaprMachineStateNestedGuest {
> #define GSE_ENV_DWM(i, f, m) \
> GUEST_STATE_ELEMENT_MSK(i, 8, f, copy_state_8to8, m)
>
> +struct guest_state_element {
> + uint16_t id;
> + uint16_t size;
> + uint8_t value[];
> +} QEMU_PACKED;
> +
> +struct guest_state_buffer {
> + uint32_t num_elements;
> + struct guest_state_element elements[];
> +} QEMU_PACKED;
> +
> +/* Actual buffer plus some metadata about the request */
> +struct guest_state_request {
> + struct guest_state_buffer *gsb;
> + int64_t buf;
> + int64_t len;
> + uint16_t flags;
> +};
> +
> /*
> * Register state for entering a nested guest with H_ENTER_NESTED.
> * New member must be added at the end.
> diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c
> index 07dc294c5a..ca99805ce8 100644
> --- a/hw/ppc/spapr_nested.c
> +++ b/hw/ppc/spapr_nested.c
> @@ -1028,6 +1028,140 @@ void spapr_nested_gsb_init(void)
> }
> }
>
> +static struct guest_state_element *guest_state_element_next(
> + struct guest_state_element *element,
> + int64_t *len,
> + int64_t *num_elements)
> +{
> + uint16_t size;
> +
> + /* size is of element->value[] only. Not whole guest_state_element */
> + size = be16_to_cpu(element->size);
> +
> + if (len) {
> + *len -= size + offsetof(struct guest_state_element, value);
> + }
> +
> + if (num_elements) {
> + *num_elements -= 1;
> + }
> +
> + return (struct guest_state_element *)(element->value + size);
> +}
> +
> +static
> +struct guest_state_element_type *guest_state_element_type_find(uint16_t id)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(guest_state_element_types); i++)
> + if (id == guest_state_element_types[i].id) {
> + return &guest_state_element_types[i];
> + }
> +
> + return NULL;
> +}
> +
> +static void log_element(struct guest_state_element *element,
> + struct guest_state_request *gsr)
> +{
> + qemu_log_mask(LOG_GUEST_ERROR, "h_guest_%s_state id:0x%04x size:0x%04x",
> + gsr->flags & GUEST_STATE_REQUEST_SET ? "set" : "get",
> + be16_to_cpu(element->id), be16_to_cpu(element->size));
> + qemu_log_mask(LOG_GUEST_ERROR, "buf:0x%016lx ...\n",
> + be64_to_cpu(*(uint64_t *)element->value));
> +}
> +
> +static bool guest_state_request_check(struct guest_state_request *gsr)
> +{
> + int64_t num_elements, len = gsr->len;
> + struct guest_state_buffer *gsb = gsr->gsb;
> + struct guest_state_element *element;
> + struct guest_state_element_type *type;
> + uint16_t id, size;
> +
> + /* gsb->num_elements = 0 == 32 bits long */
> + assert(len >= 4);
> +
> + num_elements = be32_to_cpu(gsb->num_elements);
> + element = gsb->elements;
> + len -= sizeof(gsb->num_elements);
> +
> + /* Walk the buffer to validate the length */
> + while (num_elements) {
> +
> + id = be16_to_cpu(element->id);
> + size = be16_to_cpu(element->size);
> +
> + if (false) {
> + log_element(element, gsr);
> + }
> + /* buffer size too small */
> + if (len < 0) {
> + return false;
> + }
> +
> + type = guest_state_element_type_find(id);
> + if (!type) {
> + qemu_log_mask(LOG_GUEST_ERROR,"Element ID %04x unknown\n", id);
> + log_element(element, gsr);
> + return false;
> + }
> +
> + if (id == GSB_HV_VCPU_IGNORED_ID) {
> + goto next_element;
> + }
> +
> + if (size != type->size) {
> + qemu_log_mask(LOG_GUEST_ERROR,"Size mismatch. Element ID:%04x."
> + "Size Exp:%i Got:%i\n", id, type->size, size);
> + log_element(element, gsr);
> + return false;
> + }
> +
> + if ((type->flags & GUEST_STATE_ELEMENT_TYPE_FLAG_READ_ONLY) &&
> + (gsr->flags & GUEST_STATE_REQUEST_SET)) {
> + qemu_log_mask(LOG_GUEST_ERROR,"trying to set a read-only Element
> "
> + "ID:%04x.\n", id);
> + return false;
> + }
> +
> + if (type->flags & GUEST_STATE_ELEMENT_TYPE_FLAG_GUEST_WIDE) {
> + /* guest wide element type */
> + if (!(gsr->flags & GUEST_STATE_REQUEST_GUEST_WIDE)) {
> + qemu_log_mask(LOG_GUEST_ERROR, "trying to set a guest wide "
> + "Element ID:%04x.\n", id);
> + return false;
> + }
> + } else {
> + /* thread wide element type */
> + if (gsr->flags & GUEST_STATE_REQUEST_GUEST_WIDE) {
> + qemu_log_mask(LOG_GUEST_ERROR, "trying to set a thread wide "
> + "Element ID:%04x.\n", id);
> + return false;
> + }
> + }
> +next_element:
> + element = guest_state_element_next(element, &len, &num_elements);
> +
> + }
> + return true;
> +}
> +
> +static bool is_gsr_invalid(struct guest_state_request *gsr,
> + struct guest_state_element *element,
> + struct guest_state_element_type *type)
> +{
> + if ((gsr->flags & GUEST_STATE_REQUEST_SET) &&
> + (*(uint64_t *)(element->value) & ~(type->mask))) {
> + log_element(element, gsr);
> + qemu_log_mask(LOG_GUEST_ERROR, "L1 can't set reserved bits i"
> + "(allowed mask: 0x%08lx)\n", type->mask);
> + return true;
> + }
> + return false;
> +}
> +
> static target_ulong h_guest_get_capabilities(PowerPCCPU *cpu,
> SpaprMachineState *spapr,
> target_ulong opcode,
> @@ -1261,6 +1395,136 @@ static target_ulong h_guest_create_vcpu(PowerPCCPU
> *cpu,
> return H_SUCCESS;
> }
>
> +static target_ulong getset_state(SpaprMachineStateNestedGuest *guest,
> + uint64_t vcpuid,
> + struct guest_state_request *gsr)
> +{
> + void *ptr;
> + uint16_t id;
> + struct guest_state_element *element;
> + struct guest_state_element_type *type;
> + int64_t lenleft, num_elements;
> +
> + lenleft = gsr->len;
> +
> + if (!guest_state_request_check(gsr)) {
> + return H_P3;
> + }
> +
> + num_elements = be32_to_cpu(gsr->gsb->num_elements);
> + element = gsr->gsb->elements;
> + /* Process the elements */
> + while (num_elements) {
> + type = NULL;
> + /* log_element(element, gsr); */
> +
> + id = be16_to_cpu(element->id);
> + if (id == GSB_HV_VCPU_IGNORED_ID) {
> + goto next_element;
> + }
> +
> + type = guest_state_element_type_find(id);
> + assert(type);
> +
> + /* Get pointer to guest data to get/set */
> + if (type->location && type->copy) {
> + ptr = type->location(guest, vcpuid);
> + assert(ptr);
> + if (!~(type->mask) && is_gsr_invalid(gsr, element, type)) {
> + return H_INVALID_ELEMENT_VALUE;
> + }
> + type->copy(ptr + type->offset, element->value,
> + gsr->flags & GUEST_STATE_REQUEST_SET ? true : false);
> + }
> +
> +next_element:
> + element = guest_state_element_next(element, &lenleft, &num_elements);
> + }
> +
> + return H_SUCCESS;
> +}
> +
> +static target_ulong map_and_getset_state(PowerPCCPU *cpu,
> + SpaprMachineStateNestedGuest *guest,
> + uint64_t vcpuid,
> + struct guest_state_request *gsr)
> +{
> + target_ulong rc;
> + int64_t len;
> + bool is_write;
> +
> + len = gsr->len;
> + /* only get_state would require write access to the provided buffer */
> + is_write = (gsr->flags & GUEST_STATE_REQUEST_SET) ? false : true;
> + gsr->gsb = address_space_map(CPU(cpu)->as, gsr->buf, (uint64_t *)&len,
> + is_write, MEMTXATTRS_UNSPECIFIED);
> + if (!gsr->gsb) {
> + rc = H_P3;
> + goto out1;
> + }
> +
> + if (len != gsr->len) {
> + rc = H_P3;
> + goto out1;
> + }
> +
> + rc = getset_state(guest, vcpuid, gsr);
> +
> +out1:
> + address_space_unmap(CPU(cpu)->as, gsr->gsb, len, is_write, len);
> + return rc;
> +}
> +
> +static target_ulong h_guest_getset_state(PowerPCCPU *cpu,
> + SpaprMachineState *spapr,
> + target_ulong *args,
> + bool set)
> +{
> + target_ulong flags = args[0];
> + target_ulong lpid = args[1];
> + target_ulong vcpuid = args[2];
> + target_ulong buf = args[3];
> + target_ulong buflen = args[4];
> + struct guest_state_request gsr;
> + SpaprMachineStateNestedGuest *guest;
> +
> + guest = spapr_get_nested_guest(spapr, lpid);
> + if (!guest) {
> + return H_P2;
> + }
> + gsr.buf = buf;
> + assert(buflen <= GSB_MAX_BUF_SIZE);
> + gsr.len = buflen;
> + gsr.flags = 0;
> + if (flags & H_GUEST_GETSET_STATE_FLAG_GUEST_WIDE) {
> + gsr.flags |= GUEST_STATE_REQUEST_GUEST_WIDE;
> + }
> + if (flags & !H_GUEST_GETSET_STATE_FLAG_GUEST_WIDE) {
> + return H_PARAMETER; /* flag not supported yet */
> + }
> +
> + if (set) {
> + gsr.flags |= GUEST_STATE_REQUEST_SET;
> + }
> + return map_and_getset_state(cpu, guest, vcpuid, &gsr);
> +}
> +
> +static target_ulong h_guest_set_state(PowerPCCPU *cpu,
> + SpaprMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + return h_guest_getset_state(cpu, spapr, args, true);
> +}
> +
> +static target_ulong h_guest_get_state(PowerPCCPU *cpu,
> + SpaprMachineState *spapr,
> + target_ulong opcode,
> + target_ulong *args)
> +{
> + return h_guest_getset_state(cpu, spapr, args, false);
> +}
> +
> void spapr_register_nested_hv(void)
> {
> spapr_register_hypercall(KVMPPC_H_SET_PARTITION_TABLE, h_set_ptbl);
> @@ -1284,6 +1548,8 @@ void spapr_register_nested_papr(void)
> spapr_register_hypercall(H_GUEST_CREATE , h_guest_create);
> spapr_register_hypercall(H_GUEST_DELETE , h_guest_delete);
> spapr_register_hypercall(H_GUEST_CREATE_VCPU , h_guest_create_vcpu);
> + spapr_register_hypercall(H_GUEST_SET_STATE , h_guest_set_state);
> + spapr_register_hypercall(H_GUEST_GET_STATE , h_guest_get_state);
> }
>
> void spapr_unregister_nested_papr(void)
> @@ -1293,6 +1559,8 @@ void spapr_unregister_nested_papr(void)
> spapr_unregister_hypercall(H_GUEST_CREATE);
> spapr_unregister_hypercall(H_GUEST_DELETE);
> spapr_unregister_hypercall(H_GUEST_CREATE_VCPU);
> + spapr_unregister_hypercall(H_GUEST_SET_STATE);
> + spapr_unregister_hypercall(H_GUEST_GET_STATE);
> }
>
> #else
