mshv: Add the HVCALL_GET_PARTITION_PROPERTY_EX hypercall

This hypercall can be used to fetch extended properties of a
partition. Extended properties are properties with values larger than
a u64. Some of these also need additional input arguments.

Add helper function for using the hypercall in the mshv_root driver.

Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam <anirudh@anirudhrb.com>
Reviewed-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/mshv_root.h

@@ -303,6 +303,8 @@ int hv_call_unmap_stat_page(enum hv_stats_object_type type,
 int hv_call_modify_spa_host_access(u64 partition_id, struct page **pages,
 				   u64 page_struct_count, u32 host_access,
 				   u32 flags, u8 acquire);
+int hv_call_get_partition_property_ex(u64 partition_id, u64 property_code, u64 arg,
+				      void *property_value, size_t property_value_sz);
 
 extern struct mshv_root mshv_root;
 extern enum hv_scheduler_type hv_scheduler_type;

drivers/hv/mshv_root_hv_call.c

@@ -590,6 +590,37 @@ int hv_call_unmap_vp_state_page(u64 partition_id, u32 vp_index, u32 type,
 	return hv_result_to_errno(status);
 }
 
+int hv_call_get_partition_property_ex(u64 partition_id, u64 property_code,
+				      u64 arg, void *property_value,
+				      size_t property_value_sz)
+{
+	u64 status;
+	unsigned long flags;
+	struct hv_input_get_partition_property_ex *input;
+	struct hv_output_get_partition_property_ex *output;
+
+	local_irq_save(flags);
+	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
+
+	memset(input, 0, sizeof(*input));
+	input->partition_id = partition_id;
+	input->property_code = property_code;
+	input->arg = arg;
+	status = hv_do_hypercall(HVCALL_GET_PARTITION_PROPERTY_EX, input, output);
+
+	if (!hv_result_success(status)) {
+		local_irq_restore(flags);
+		hv_status_debug(status, "\n");
+		return hv_result_to_errno(status);
+	}
+	memcpy(property_value, &output->property_value, property_value_sz);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
 int
 hv_call_clear_virtual_interrupt(u64 partition_id)
 {

include/hyperv/hvgdk_mini.h

@@ -491,6 +491,7 @@ union hv_vp_assist_msr_contents {	 /* HV_REGISTER_VP_ASSIST_PAGE */
 #define HVCALL_GET_VP_STATE				0x00e3
 #define HVCALL_SET_VP_STATE				0x00e4
 #define HVCALL_GET_VP_CPUID_VALUES			0x00f4
+#define HVCALL_GET_PARTITION_PROPERTY_EX		0x0101
 #define HVCALL_MMIO_READ				0x0106
 #define HVCALL_MMIO_WRITE				0x0107
 

include/hyperv/hvhdk.h

@@ -376,6 +376,46 @@ struct hv_input_set_partition_property {
 	u64 property_value;
 } __packed;
 
+union hv_partition_property_arg {
+	u64 as_uint64;
+	struct {
+		union {
+			u32 arg;
+			u32 vp_index;
+		};
+		u16 reserved0;
+		u8 reserved1;
+		u8 object_type;
+	} __packed;
+};
+
+struct hv_input_get_partition_property_ex {
+	u64 partition_id;
+	u32 property_code; /* enum hv_partition_property_code */
+	u32 padding;
+	union {
+		union hv_partition_property_arg arg_data;
+		u64 arg;
+	};
+} __packed;
+
+/*
+ * NOTE: Should use hv_input_set_partition_property_ex_header to compute this
+ * size, but hv_input_get_partition_property_ex is identical so it suffices
+ */
+#define HV_PARTITION_PROPERTY_EX_MAX_VAR_SIZE \
+	(HV_HYP_PAGE_SIZE - sizeof(struct hv_input_get_partition_property_ex))
+
+union hv_partition_property_ex {
+	u8 buffer[HV_PARTITION_PROPERTY_EX_MAX_VAR_SIZE];
+	struct hv_partition_property_vmm_capabilities vmm_capabilities;
+	/* More fields to be filled in when needed */
+};
+
+struct hv_output_get_partition_property_ex {
+	union hv_partition_property_ex property_value;
+} __packed;
+
 enum hv_vp_state_page_type {
 	HV_VP_STATE_PAGE_REGISTERS = 0,
 	HV_VP_STATE_PAGE_INTERCEPT_MESSAGE = 1,

include/hyperv/hvhdk_mini.h

@@ -96,8 +96,34 @@ enum hv_partition_property_code {
 	HV_PARTITION_PROPERTY_XSAVE_STATES                      = 0x00060007,
 	HV_PARTITION_PROPERTY_MAX_XSAVE_DATA_SIZE		= 0x00060008,
 	HV_PARTITION_PROPERTY_PROCESSOR_CLOCK_FREQUENCY		= 0x00060009,
+
+	/* Extended properties with larger property values */
+	HV_PARTITION_PROPERTY_VMM_CAPABILITIES			= 0x00090007,
 };
 
+#define HV_PARTITION_VMM_CAPABILITIES_BANK_COUNT		1
+#define HV_PARTITION_VMM_CAPABILITIES_RESERVED_BITFIELD_COUNT	59
+
+struct hv_partition_property_vmm_capabilities {
+	u16 bank_count;
+	u16 reserved[3];
+	union {
+		u64 as_uint64[HV_PARTITION_VMM_CAPABILITIES_BANK_COUNT];
+		struct {
+			u64 map_gpa_preserve_adjustable: 1;
+			u64 vmm_can_provide_overlay_gpfn: 1;
+			u64 vp_affinity_property: 1;
+#if IS_ENABLED(CONFIG_ARM64)
+			u64 vmm_can_provide_gic_overlay_locations: 1;
+#else
+			u64 reservedbit3: 1;
+#endif
+			u64 assignable_synthetic_proc_features: 1;
+			u64 reserved0: HV_PARTITION_VMM_CAPABILITIES_RESERVED_BITFIELD_COUNT;
+		} __packed;
+	};
+} __packed;
+
 enum hv_snp_status {
 	HV_SNP_STATUS_NONE = 0,
 	HV_SNP_STATUS_AVAILABLE = 1,