| Message ID | 20230613172054.3959700-11-quic_eberman@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Drivers for Gunyah hypervisor | expand |
On Tue, Jun 13, 2023 at 10:20:38AM -0700, Elliot Berman wrote: > Gunyah resource manager provides API to manipulate stage 2 page tables. > Manipulations are represented as a memory parcel. Memory parcels > describe a list of memory regions (intermediate physical address--IPA--and > size), a list of new permissions for VMs, and the memory type (DDR or > MMIO). Each memory parcel is uniquely identified by a handle allocated by > Gunyah. There are a few types of memory parcel sharing which Gunyah > supports: > > - Sharing: the guest and host VM both have access > - Lending: only the guest has access; host VM loses access > - Donating: Permanently lent (not reclaimed even if guest shuts down) > > Memory parcels that have been shared or lent can be reclaimed by the > host via an additional call. The reclaim operation restores the original > access the host VM had to the memory parcel and removes the access to > other VM. > > One point to note that memory parcels don't describe where in the guest > VM the memory parcel should reside. The guest VM must accept the memory > parcel either explicitly via a "gh_rm_mem_accept" call (not introduced > here) or be configured to accept it automatically at boot. When the guest > VM accepts the memory parcel, it also mentions the IPA it wants to place > memory parcel. Although the region might be discontiguous on the host, > the memory parcel is place contiguously in the guest memory at the > specified IPA. > > Reviewed-by: Alex Elder <elder@linaro.org> > Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> > Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> > Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> > --- > drivers/virt/gunyah/rsc_mgr_rpc.c | 227 ++++++++++++++++++++++++++++++ > include/linux/gunyah_rsc_mgr.h | 48 +++++++ > 2 files changed, 275 insertions(+) > > diff --git a/drivers/virt/gunyah/rsc_mgr_rpc.c b/drivers/virt/gunyah/rsc_mgr_rpc.c > index a4a9f0ba4e1fc..25064123a31c3 100644 > --- a/drivers/virt/gunyah/rsc_mgr_rpc.c > +++ b/drivers/virt/gunyah/rsc_mgr_rpc.c > @@ -6,6 +6,12 @@ > #include <linux/gunyah_rsc_mgr.h> > #include "rsc_mgr.h" > > +/* Message IDs: Memory Management */ > +#define GH_RM_RPC_MEM_LEND 0x51000012 > +#define GH_RM_RPC_MEM_SHARE 0x51000013 > +#define GH_RM_RPC_MEM_RECLAIM 0x51000015 > +#define GH_RM_RPC_MEM_APPEND 0x51000018 > + > /* Message IDs: VM Management */ > #define GH_RM_RPC_VM_ALLOC_VMID 0x56000001 > #define GH_RM_RPC_VM_DEALLOC_VMID 0x56000002 > @@ -22,6 +28,46 @@ struct gh_rm_vm_common_vmid_req { > __le16 _padding; > } __packed; > > +/* Call: MEM_LEND, MEM_SHARE */ > +#define GH_MEM_SHARE_REQ_FLAGS_APPEND BIT(1) > + > +struct gh_rm_mem_share_req_header { > + u8 mem_type; > + u8 _padding0; > + u8 flags; > + u8 _padding1; > + __le32 label; > +} __packed; > + > +struct gh_rm_mem_share_req_acl_section { > + __le32 n_entries; > + struct gh_rm_mem_acl_entry entries[]; > +}; > + > +struct gh_rm_mem_share_req_mem_section { > + __le16 n_entries; > + __le16 _padding; > + struct gh_rm_mem_entry entries[]; > +}; Any reason why these two are not explicitly packed? > + > +/* Call: MEM_RELEASE */ > +struct gh_rm_mem_release_req { > + __le32 mem_handle; > + u8 flags; /* currently not used */ > + u8 _padding0; > + __le16 _padding1; > +} __packed; > + > +/* Call: MEM_APPEND */ > +#define GH_MEM_APPEND_REQ_FLAGS_END BIT(0) > + > +struct gh_rm_mem_append_req_header { > + __le32 mem_handle; > + u8 flags; > + u8 _padding0; > + __le16 _padding1; > +} __packed; > + > /* Call: VM_ALLOC */ > struct gh_rm_vm_alloc_vmid_resp { > __le16 vmid; > @@ -51,6 +97,8 @@ struct gh_rm_vm_config_image_req { > __le64 dtb_size; > } __packed; > > +#define GH_RM_MAX_MEM_ENTRIES 512 > + > /* > * Several RM calls take only a VMID as a parameter and give only standard > * response back. Deduplicate boilerplate code by using this common call. > @@ -64,6 +112,185 @@ static int gh_rm_common_vmid_call(struct gh_rm *rm, u32 message_id, u16 vmid) > return gh_rm_call(rm, message_id, &req_payload, sizeof(req_payload), NULL, NULL); > } > > +static int _gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle, bool end_append, > + struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries) > +{ > + struct gh_rm_mem_share_req_mem_section *mem_section; "sections" is sufficient. > + struct gh_rm_mem_append_req_header *req_header; > + size_t msg_size = 0; > + void *msg; > + int ret; > + > + msg_size += sizeof(struct gh_rm_mem_append_req_header); msg_size is sizeof(header) + sizeof(sections), but written this way you state that it's: msg_size is X + sizeof(header), and msg_size is also sizeof(sections) It's the same thing, but you're forcing the reader to look for the initial value of msg_size. > + msg_size += struct_size(mem_section, entries, n_mem_entries); > + > + msg = kzalloc(msg_size, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + req_header = msg; Can't you just make msg a strcut gh_rm_mem_append_req_header? > + mem_section = (void *)(req_header + 1); > + > + req_header->mem_handle = cpu_to_le32(mem_handle); > + if (end_append) > + req_header->flags |= GH_MEM_APPEND_REQ_FLAGS_END; > + > + mem_section->n_entries = cpu_to_le16(n_mem_entries); > + memcpy(mem_section->entries, mem_entries, sizeof(*mem_entries) * n_mem_entries); > + > + ret = gh_rm_call(rm, GH_RM_RPC_MEM_APPEND, msg, msg_size, NULL, NULL); > + kfree(msg); > + > + return ret; > +} > + > +static int gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle, > + struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries) You can name these arguments "entries" and "n_entries" (or num_entries) without loosing any infromation, but saving a whole bunch of characters that people have to read. > +{ > + bool end_append; Iiuc this means "is this the last entry", perhaps calling it "last" would make its purpose immediately obvious. > + int ret = 0; > + size_t n; > + > + while (n_mem_entries) { > + if (n_mem_entries > GH_RM_MAX_MEM_ENTRIES) { > + end_append = false; > + n = GH_RM_MAX_MEM_ENTRIES; > + } else { > + end_append = true; > + n = n_mem_entries; > + } > + > + ret = _gh_rm_mem_append(rm, mem_handle, end_append, mem_entries, n); Every loop here you kzallc() and kfree() the same chunk of scratch memory. If you inline _gh_rm_mem_append() here and do the allocation once based on GH_RM_MAX_MEM_ENTRIES this would be faster and seemingly easier to read/follow. > + if (ret) > + break; > + > + mem_entries += n; > + n_mem_entries -= n; > + } > + > + return ret; > +} > + > +static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_mem_parcel *p) > +{ > + size_t msg_size = 0, initial_mem_entries = p->n_mem_entries, resp_size; > + size_t acl_section_size, mem_section_size; You keep all other variables one per line, and in reverse x-mas style. Please do the same for this. Naming these acl_size and mem_size would be beneficial. > + struct gh_rm_mem_share_req_acl_section *acl_section; > + struct gh_rm_mem_share_req_mem_section *mem_section; Naming these acl and mem will make below easier to read. > + struct gh_rm_mem_share_req_header *req_header; > + u32 *attr_section; > + __le32 *resp; > + void *msg; > + int ret; > + > + if (!p->acl_entries || !p->n_acl_entries || !p->mem_entries || !p->n_mem_entries || > + p->n_acl_entries > U8_MAX || p->mem_handle != GH_MEM_HANDLE_INVAL) > + return -EINVAL; > + > + if (initial_mem_entries > GH_RM_MAX_MEM_ENTRIES) > + initial_mem_entries = GH_RM_MAX_MEM_ENTRIES; > + > + acl_section_size = struct_size(acl_section, entries, p->n_acl_entries); > + mem_section_size = struct_size(mem_section, entries, initial_mem_entries); An empty line here seems reasonable. > + /* The format of the message goes: > + * request header > + * ACL entries (which VMs get what kind of access to this memory parcel) > + * Memory entries (list of memory regions to share) > + * Memory attributes (currently unused, we'll hard-code the size to 0) > + */ > + msg_size += sizeof(struct gh_rm_mem_share_req_header); Hidden above is the confirmation that msg_size was initialized to 0, drop the '+' here to make it clear. > + msg_size += acl_section_size; > + msg_size += mem_section_size; > + msg_size += sizeof(u32); /* for memory attributes, currently unused */ > + > + msg = kzalloc(msg_size, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + req_header = msg; I don't think you need to keep req_header and msg separately. > + acl_section = (void *)req_header + sizeof(*req_header); > + mem_section = (void *)acl_section + acl_section_size; > + attr_section = (void *)mem_section + mem_section_size; > + > + req_header->mem_type = p->mem_type; > + if (initial_mem_entries != p->n_mem_entries) I think this will only happen if p->n_mem_entries > GH_RM_MAX_MEM_ENTRIES, for which you already have a condition earlier. Set the flag in that condition rather than spreading it over two (three) code paths. > + req_header->flags |= GH_MEM_SHARE_REQ_FLAGS_APPEND; > + req_header->label = cpu_to_le32(p->label); > + > + acl_section->n_entries = cpu_to_le32(p->n_acl_entries); > + memcpy(acl_section->entries, p->acl_entries, > + flex_array_size(acl_section, entries, p->n_acl_entries)); > + > + mem_section->n_entries = cpu_to_le16(initial_mem_entries); > + memcpy(mem_section->entries, p->mem_entries, > + flex_array_size(mem_section, entries, initial_mem_entries)); > + > + /* Set n_entries for memory attribute section to 0 */ > + *attr_section = 0; > + > + ret = gh_rm_call(rm, message_id, msg, msg_size, (void **)&resp, &resp_size); > + kfree(msg); > + > + if (ret) > + return ret; > + > + p->mem_handle = le32_to_cpu(*resp); > + kfree(resp); > + > + if (initial_mem_entries != p->n_mem_entries) { Another "we took that conditional path above", please make it obvious. Can you please also write a comment describing that this operation is split in a main one, followed by one of more appended operations as necessary. This took me too long time to realize... In particular I was wondering why "initial" didn't mean "the original value", but now I see that it probably means "the value relevant for the initial request". > + ret = gh_rm_mem_append(rm, p->mem_handle, > + &p->mem_entries[initial_mem_entries], > + p->n_mem_entries - initial_mem_entries); > + if (ret) { > + gh_rm_mem_reclaim(rm, p); > + p->mem_handle = GH_MEM_HANDLE_INVAL; What happens to the entries that was already lended or shared? Regards, Bjorn
diff --git a/drivers/virt/gunyah/rsc_mgr_rpc.c b/drivers/virt/gunyah/rsc_mgr_rpc.c index a4a9f0ba4e1fc..25064123a31c3 100644 --- a/drivers/virt/gunyah/rsc_mgr_rpc.c +++ b/drivers/virt/gunyah/rsc_mgr_rpc.c @@ -6,6 +6,12 @@ #include <linux/gunyah_rsc_mgr.h> #include "rsc_mgr.h" +/* Message IDs: Memory Management */ +#define GH_RM_RPC_MEM_LEND 0x51000012 +#define GH_RM_RPC_MEM_SHARE 0x51000013 +#define GH_RM_RPC_MEM_RECLAIM 0x51000015 +#define GH_RM_RPC_MEM_APPEND 0x51000018 + /* Message IDs: VM Management */ #define GH_RM_RPC_VM_ALLOC_VMID 0x56000001 #define GH_RM_RPC_VM_DEALLOC_VMID 0x56000002 @@ -22,6 +28,46 @@ struct gh_rm_vm_common_vmid_req { __le16 _padding; } __packed; +/* Call: MEM_LEND, MEM_SHARE */ +#define GH_MEM_SHARE_REQ_FLAGS_APPEND BIT(1) + +struct gh_rm_mem_share_req_header { + u8 mem_type; + u8 _padding0; + u8 flags; + u8 _padding1; + __le32 label; +} __packed; + +struct gh_rm_mem_share_req_acl_section { + __le32 n_entries; + struct gh_rm_mem_acl_entry entries[]; +}; + +struct gh_rm_mem_share_req_mem_section { + __le16 n_entries; + __le16 _padding; + struct gh_rm_mem_entry entries[]; +}; + +/* Call: MEM_RELEASE */ +struct gh_rm_mem_release_req { + __le32 mem_handle; + u8 flags; /* currently not used */ + u8 _padding0; + __le16 _padding1; +} __packed; + +/* Call: MEM_APPEND */ +#define GH_MEM_APPEND_REQ_FLAGS_END BIT(0) + +struct gh_rm_mem_append_req_header { + __le32 mem_handle; + u8 flags; + u8 _padding0; + __le16 _padding1; +} __packed; + /* Call: VM_ALLOC */ struct gh_rm_vm_alloc_vmid_resp { __le16 vmid; @@ -51,6 +97,8 @@ struct gh_rm_vm_config_image_req { __le64 dtb_size; } __packed; +#define GH_RM_MAX_MEM_ENTRIES 512 + /* * Several RM calls take only a VMID as a parameter and give only standard * response back. Deduplicate boilerplate code by using this common call. @@ -64,6 +112,185 @@ static int gh_rm_common_vmid_call(struct gh_rm *rm, u32 message_id, u16 vmid) return gh_rm_call(rm, message_id, &req_payload, sizeof(req_payload), NULL, NULL); } +static int _gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle, bool end_append, + struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries) +{ + struct gh_rm_mem_share_req_mem_section *mem_section; + struct gh_rm_mem_append_req_header *req_header; + size_t msg_size = 0; + void *msg; + int ret; + + msg_size += sizeof(struct gh_rm_mem_append_req_header); + msg_size += struct_size(mem_section, entries, n_mem_entries); + + msg = kzalloc(msg_size, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + req_header = msg; + mem_section = (void *)(req_header + 1); + + req_header->mem_handle = cpu_to_le32(mem_handle); + if (end_append) + req_header->flags |= GH_MEM_APPEND_REQ_FLAGS_END; + + mem_section->n_entries = cpu_to_le16(n_mem_entries); + memcpy(mem_section->entries, mem_entries, sizeof(*mem_entries) * n_mem_entries); + + ret = gh_rm_call(rm, GH_RM_RPC_MEM_APPEND, msg, msg_size, NULL, NULL); + kfree(msg); + + return ret; +} + +static int gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle, + struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries) +{ + bool end_append; + int ret = 0; + size_t n; + + while (n_mem_entries) { + if (n_mem_entries > GH_RM_MAX_MEM_ENTRIES) { + end_append = false; + n = GH_RM_MAX_MEM_ENTRIES; + } else { + end_append = true; + n = n_mem_entries; + } + + ret = _gh_rm_mem_append(rm, mem_handle, end_append, mem_entries, n); + if (ret) + break; + + mem_entries += n; + n_mem_entries -= n; + } + + return ret; +} + +static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_mem_parcel *p) +{ + size_t msg_size = 0, initial_mem_entries = p->n_mem_entries, resp_size; + size_t acl_section_size, mem_section_size; + struct gh_rm_mem_share_req_acl_section *acl_section; + struct gh_rm_mem_share_req_mem_section *mem_section; + struct gh_rm_mem_share_req_header *req_header; + u32 *attr_section; + __le32 *resp; + void *msg; + int ret; + + if (!p->acl_entries || !p->n_acl_entries || !p->mem_entries || !p->n_mem_entries || + p->n_acl_entries > U8_MAX || p->mem_handle != GH_MEM_HANDLE_INVAL) + return -EINVAL; + + if (initial_mem_entries > GH_RM_MAX_MEM_ENTRIES) + initial_mem_entries = GH_RM_MAX_MEM_ENTRIES; + + acl_section_size = struct_size(acl_section, entries, p->n_acl_entries); + mem_section_size = struct_size(mem_section, entries, initial_mem_entries); + /* The format of the message goes: + * request header + * ACL entries (which VMs get what kind of access to this memory parcel) + * Memory entries (list of memory regions to share) + * Memory attributes (currently unused, we'll hard-code the size to 0) + */ + msg_size += sizeof(struct gh_rm_mem_share_req_header); + msg_size += acl_section_size; + msg_size += mem_section_size; + msg_size += sizeof(u32); /* for memory attributes, currently unused */ + + msg = kzalloc(msg_size, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + req_header = msg; + acl_section = (void *)req_header + sizeof(*req_header); + mem_section = (void *)acl_section + acl_section_size; + attr_section = (void *)mem_section + mem_section_size; + + req_header->mem_type = p->mem_type; + if (initial_mem_entries != p->n_mem_entries) + req_header->flags |= GH_MEM_SHARE_REQ_FLAGS_APPEND; + req_header->label = cpu_to_le32(p->label); + + acl_section->n_entries = cpu_to_le32(p->n_acl_entries); + memcpy(acl_section->entries, p->acl_entries, + flex_array_size(acl_section, entries, p->n_acl_entries)); + + mem_section->n_entries = cpu_to_le16(initial_mem_entries); + memcpy(mem_section->entries, p->mem_entries, + flex_array_size(mem_section, entries, initial_mem_entries)); + + /* Set n_entries for memory attribute section to 0 */ + *attr_section = 0; + + ret = gh_rm_call(rm, message_id, msg, msg_size, (void **)&resp, &resp_size); + kfree(msg); + + if (ret) + return ret; + + p->mem_handle = le32_to_cpu(*resp); + kfree(resp); + + if (initial_mem_entries != p->n_mem_entries) { + ret = gh_rm_mem_append(rm, p->mem_handle, + &p->mem_entries[initial_mem_entries], + p->n_mem_entries - initial_mem_entries); + if (ret) { + gh_rm_mem_reclaim(rm, p); + p->mem_handle = GH_MEM_HANDLE_INVAL; + } + } + + return ret; +} + +/** + * gh_rm_mem_lend() - Lend memory to other virtual machines. + * @rm: Handle to a Gunyah resource manager + * @parcel: Information about the memory to be lent. + * + * Lending removes Linux's access to the memory while the memory parcel is lent. + */ +int gh_rm_mem_lend(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel) +{ + return gh_rm_mem_lend_common(rm, GH_RM_RPC_MEM_LEND, parcel); +} + + +/** + * gh_rm_mem_share() - Share memory with other virtual machines. + * @rm: Handle to a Gunyah resource manager + * @parcel: Information about the memory to be shared. + * + * Sharing keeps Linux's access to the memory while the memory parcel is shared. + */ +int gh_rm_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel) +{ + return gh_rm_mem_lend_common(rm, GH_RM_RPC_MEM_SHARE, parcel); +} + +/** + * gh_rm_mem_reclaim() - Reclaim a memory parcel + * @rm: Handle to a Gunyah resource manager + * @parcel: Information about the memory to be reclaimed. + * + * RM maps the associated memory back into the stage-2 page tables of the owner VM. + */ +int gh_rm_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel) +{ + struct gh_rm_mem_release_req req = { + .mem_handle = cpu_to_le32(parcel->mem_handle), + }; + + return gh_rm_call(rm, GH_RM_RPC_MEM_RECLAIM, &req, sizeof(req), NULL, NULL); +} + /** * gh_rm_alloc_vmid() - Allocate a new VM in Gunyah. Returns the VM identifier. * @rm: Handle to a Gunyah resource manager diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h index 1ac66d9004d2b..dfac088420bda 100644 --- a/include/linux/gunyah_rsc_mgr.h +++ b/include/linux/gunyah_rsc_mgr.h @@ -11,6 +11,7 @@ #include <linux/gunyah.h> #define GH_VMID_INVAL U16_MAX +#define GH_MEM_HANDLE_INVAL U32_MAX struct gh_rm; int gh_rm_notifier_register(struct gh_rm *rm, struct notifier_block *nb); @@ -51,7 +52,54 @@ struct gh_rm_vm_status_payload { #define GH_RM_NOTIFICATION_VM_STATUS 0x56100008 +#define GH_RM_ACL_X BIT(0) +#define GH_RM_ACL_W BIT(1) +#define GH_RM_ACL_R BIT(2) + +struct gh_rm_mem_acl_entry { + __le16 vmid; + u8 perms; + u8 reserved; +} __packed; + +struct gh_rm_mem_entry { + __le64 phys_addr; + __le64 size; +} __packed; + +enum gh_rm_mem_type { + GH_RM_MEM_TYPE_NORMAL = 0, + GH_RM_MEM_TYPE_IO = 1, +}; + +/* + * struct gh_rm_mem_parcel - Info about memory to be lent/shared/donated/reclaimed + * @mem_type: The type of memory: normal (DDR) or IO + * @label: An client-specified identifier which can be used by the other VMs to identify the purpose + * of the memory parcel. + * @n_acl_entries: Count of the number of entries in the @acl_entries array. + * @acl_entries: An array of access control entries. Each entry specifies a VM and what access + * is allowed for the memory parcel. + * @n_mem_entries: Count of the number of entries in the @mem_entries array. + * @mem_entries: An array of regions to be associated with the memory parcel. Addresses should be + * (intermediate) physical addresses from Linux's perspective. + * @mem_handle: On success, filled with memory handle that RM allocates for this memory parcel + */ +struct gh_rm_mem_parcel { + enum gh_rm_mem_type mem_type; + u32 label; + size_t n_acl_entries; + struct gh_rm_mem_acl_entry *acl_entries; + size_t n_mem_entries; + struct gh_rm_mem_entry *mem_entries; + u32 mem_handle; +}; + /* RPC Calls */ +int gh_rm_mem_lend(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel); +int gh_rm_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel); +int gh_rm_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel); + int gh_rm_alloc_vmid(struct gh_rm *rm, u16 vmid); int gh_rm_dealloc_vmid(struct gh_rm *rm, u16 vmid); int gh_rm_vm_reset(struct gh_rm *rm, u16 vmid);