hv: provide vm_config information in get_platform_info hypercall

Hypervisor reports VM configuration information to SOS which can be used to
dynamically allocate VCPU affinity.

Servise OS can get the vm_configs in this order:

1. call platform_info HC (set vm_configs_addr with 0) to get max_vms and
   vm_config_entry_size.
2. allocate memory for acrn_vm_config array based on the number of VMs
   and entry size that just got in step 1.
3. call platform_info HC again to collect VM configurations.

Tracked-On: #4616
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: ZideChen0

hypervisor/common/hypercall.c

@@ -108,13 +108,31 @@ int32_t hcall_get_api_version(struct acrn_vm *vm, uint64_t param)
  */
 int32_t hcall_get_platform_info(struct acrn_vm *vm, uint64_t param)
 {
-	struct hc_platform_info platform_info;
+	struct hc_platform_info pi = { 0 };
+	uint32_t entry_size = sizeof(struct acrn_vm_config);
+	int32_t ret;
+
+	/* to get the vm_config_info pointer */
+	ret = copy_from_gpa(vm, &pi, param, sizeof(pi));
+	if (ret == 0) {
+		pi.cpu_num = get_pcpu_nums();
+		pi.version = 0x100;  /* version 1.0; byte[1:0] = major:minor version */
+		pi.max_vcpus_per_vm = MAX_VCPUS_PER_VM;
+		pi.max_kata_containers = CONFIG_MAX_KATA_VM_NUM;
+		pi.max_vms = CONFIG_MAX_VM_NUM;
+		pi.vm_config_entry_size = entry_size;
+
+		/* If it wants to get the vm_configs info */
+		if (pi.vm_configs_addr != 0UL) {
+			ret = copy_to_gpa(vm, (void *)get_vm_config(0U), pi.vm_configs_addr, entry_size * pi.max_vms);
+		}
 
-	platform_info.cpu_num = get_pcpu_nums();
-	platform_info.max_vcpus_per_vm = MAX_VCPUS_PER_VM;
-	platform_info.max_kata_containers = CONFIG_MAX_KATA_VM_NUM;
+		if (ret == 0) {
+			ret = copy_to_gpa(vm, &pi, param, sizeof(pi));
+		}
+	}
 
-	return copy_to_gpa(vm, &platform_info, param, sizeof(platform_info));
+	return ret;
 }
 
 /**

hypervisor/include/public/acrn_hv_defs.h

@@ -318,8 +318,11 @@ struct hc_platform_info {
 	/** Physical CPU number */
 	uint16_t cpu_num;
 
+	/** version of this structure */
+	uint16_t version;
+
 	/** Align the size of version & hardware info to 128Bytes. */
-	uint8_t reserved0[126];
+	uint8_t reserved0[124];
 
 	/** Configuration Information */
 	/** Maximum vCPU number for one VM. */
@@ -328,8 +331,30 @@ struct hc_platform_info {
 	/** Maximum Kata container number in SOS VM */
 	uint8_t max_kata_containers;
 
+	uint8_t reserved1[7];
+
+	/** Number of configured VMs */
+	uint16_t max_vms;
+
+	/**
+	 * The size of acrn_vm_config is various on different platforms.
+	 * This is the size of this struct which is used by the caller
+	 * to parse the vm_configs array.
+	 */
+	uint32_t vm_config_entry_size;
+
+	/**
+	 * Address to an array of struct acrn_vm_config, containing all
+	 * the configurations of all VMs. VHM treats it as an opague data
+	 * structure.
+	 *
+	 * The size of one array element is vm_config_entry_size while
+	 * the number of elements is max_vms.
+	 */
+	uint64_t vm_configs_addr;
+
 	/** Align the size of Configuration info to 128Bytes. */
-	uint8_t reserved1[125];
+	uint8_t reserved2[104];
 } __aligned(8);
 
 /**