[RFC PATCH 15/18] virt/mshv: get and set vp state ioctls

[Nuno Das Neves]

Introduce ioctls for getting and setting guest vcpu emulated LAPIC
state, and xsave data.

Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
---
 Documentation/virt/mshv/api.rst         |   8 +
 arch/x86/include/uapi/asm/hyperv-tlfs.h |  59 ++++++
 include/asm-generic/hyperv-tlfs.h       |  41 ++++
 include/uapi/asm-generic/hyperv-tlfs.h  |  28 +++
 include/uapi/linux/mshv.h               |  13 ++
 virt/mshv/mshv_main.c                   | 262 ++++++++++++++++++++++++
 6 files changed, 411 insertions(+)

diff --git a/Documentation/virt/mshv/api.rst b/Documentation/virt/mshv/api.rst
index 694f978131f9..7fd75f248eff 100644
--- a/Documentation/virt/mshv/api.rst
+++ b/Documentation/virt/mshv/api.rst
@@ -140,4 +140,12 @@ Assert interrupts in partitions that use Microsoft Hypervisor's internal
 emulated LAPIC. This must be enabled on partition creation with the flag:
 HV_PARTITION_CREATION_FLAG_LAPIC_ENABLED
 
+3.9 MSHV_GET_VP_STATE and MSHV_SET_VP_STATE
+--------------------------
+:Type: vp ioctl
+:Parameters: struct mshv_vp_state
+:Returns: 0 on success
+
+Get/set various vp state. Currently these can be used to get and set
+emulated LAPIC state, and xsave data.
 
diff --git a/arch/x86/include/uapi/asm/hyperv-tlfs.h b/arch/x86/include/uapi/asm/hyperv-tlfs.h
index 5478d4943bfc..78758aedf23e 100644
--- a/arch/x86/include/uapi/asm/hyperv-tlfs.h
+++ b/arch/x86/include/uapi/asm/hyperv-tlfs.h
@@ -1051,4 +1051,63 @@ union hv_interrupt_control {
 	__u64 as_uint64;
 };
 
+struct hv_local_interrupt_controller_state {
+	__u32 apic_id;
+	__u32 apic_version;
+	__u32 apic_ldr;
+	__u32 apic_dfr;
+	__u32 apic_spurious;
+	__u32 apic_isr[8];
+	__u32 apic_tmr[8];
+	__u32 apic_irr[8];
+	__u32 apic_esr;
+	__u32 apic_icr_high;
+	__u32 apic_icr_low;
+	__u32 apic_lvt_timer;
+	__u32 apic_lvt_thermal;
+	__u32 apic_lvt_perfmon;
+	__u32 apic_lvt_lint0;
+	__u32 apic_lvt_lint1;
+	__u32 apic_lvt_error;
+	__u32 apic_lvt_cmci;
+	__u32 apic_error_status;
+	__u32 apic_initial_count;
+	__u32 apic_counter_value;
+	__u32 apic_divide_configuration;
+	__u32 apic_remote_read;
+};
+
+#define HV_XSAVE_DATA_NO_XMM_REGISTERS 1
+
+union hv_x64_xsave_xfem_register {
+	__u64 as_uint64;
+	struct {
+		__u32 low_uint32;
+		__u32 high_uint32;
+	};
+	struct {
+		__u64 legacy_x87: 1;
+		__u64 legacy_sse: 1;
+		__u64 avx: 1;
+		__u64 mpx_bndreg: 1;
+		__u64 mpx_bndcsr: 1;
+		__u64 avx_512_op_mask: 1;
+		__u64 avx_512_zmmhi: 1;
+		__u64 avx_512_zmm16_31: 1;
+		__u64 rsvd8_9: 2;
+		__u64 pasid: 1;
+		__u64 cet_u: 1;
+		__u64 cet_s: 1;
+		__u64 rsvd13_16: 4;
+		__u64 xtile_cfg: 1;
+		__u64 xtile_data: 1;
+		__u64 rsvd19_63: 45;
+	};
+};
+
+struct hv_vp_state_data_xsave {
+	__u64 flags;
+	union hv_x64_xsave_xfem_register states;
+};
+
 #endif
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 2cd46241c545..4bc59a0344ce 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -167,6 +167,9 @@ struct ms_hyperv_tsc_page {
 #define HVCALL_ASSERT_VIRTUAL_INTERRUPT		0x0094
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
+#define HVCALL_MAP_VP_STATE_PAGE			0x00e1
+#define HVCALL_GET_VP_STATE				0x00e3
+#define HVCALL_SET_VP_STATE				0x00e4
 
 #define HV_FLUSH_ALL_PROCESSORS			BIT(0)
 #define HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES	BIT(1)
@@ -796,4 +799,42 @@ struct hv_assert_virtual_interrupt {
 	u16 rsvd_z1;
 };
 
+struct hv_vp_state_data {
+	enum hv_get_set_vp_state_type type;
+	u32 rsvd;
+	struct hv_vp_state_data_xsave xsave;
+
+};
+
+struct hv_get_vp_state_in {
+	u64 partition_id;
+	u32 vp_index;
+	u8 input_vtl;
+	u8 rsvd0;
+	u16 rsvd1;
+	struct hv_vp_state_data state_data;
+	u64 output_data_pfns[];
+};
+
+union hv_get_vp_state_out {
+	struct hv_local_interrupt_controller_state interrupt_controller_state;
+	/* Not supported yet */
+	/* struct hv_synthetic_timers_state synthetic_timers_state; */
+};
+
+union hv_input_set_vp_state_data {
+	u64 pfns;
+	u8 bytes;
+};
+
+struct hv_set_vp_state_in {
+	u64 partition_id;
+	u32 vp_index;
+	u8 input_vtl;
+	u8 rsvd0;
+	u16 rsvd1;
+	struct hv_vp_state_data state_data;
+	union hv_input_set_vp_state_data data[];
+};
+
 #endif
diff --git a/include/uapi/asm-generic/hyperv-tlfs.h b/include/uapi/asm-generic/hyperv-tlfs.h
index e87389054b68..b3c84c69b73f 100644
--- a/include/uapi/asm-generic/hyperv-tlfs.h
+++ b/include/uapi/asm-generic/hyperv-tlfs.h
@@ -64,4 +64,32 @@ struct hv_message {
 #define HV_MAP_GPA_EXECUTABLE           0xC
 #define HV_MAP_GPA_PERMISSIONS_MASK     0xF
 
+/*
+ * For getting and setting VP state, there are two options based on the state type:
+ *
+ *     1.) Data that is accessed by PFNs in the input hypercall page. This is used
+ *         for state which may not fit into the hypercall pages.
+ *     2.) Data that is accessed directly in the input\output hypercall pages.
+ *         This is used for state that will always fit into the hypercall pages.
+ *
+ * In the future this could be dynamic based on the size if needed.
+ *
+ * Note these hypercalls have an 8-byte aligned variable header size as per the tlfs
+ */
+
+#define HV_GET_SET_VP_STATE_TYPE_PFN	BIT(31)
+
+enum hv_get_set_vp_state_type {
+	HV_GET_SET_VP_STATE_LOCAL_INTERRUPT_CONTROLLER_STATE = 0,
+
+	HV_GET_SET_VP_STATE_XSAVE		= 1 | HV_GET_SET_VP_STATE_TYPE_PFN,
+	/* Synthetic message page */
+	HV_GET_SET_VP_STATE_SIM_PAGE		= 2 | HV_GET_SET_VP_STATE_TYPE_PFN,
+	/* Synthetic interrupt event flags page. */
+	HV_GET_SET_VP_STATE_SIEF_PAGE		= 3 | HV_GET_SET_VP_STATE_TYPE_PFN,
+
+	/* Synthetic timers. */
+	HV_GET_SET_VP_STATE_SYNTHETIC_TIMERS	= 4,
+};
+
 #endif
diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h
index faed9d065bb7..ae0bb64bbec3 100644
--- a/include/uapi/linux/mshv.h
+++ b/include/uapi/linux/mshv.h
@@ -53,6 +53,17 @@ struct mshv_assert_interrupt {
 	__u32 vector;
 };
 
+struct mshv_vp_state {
+	enum hv_get_set_vp_state_type type;
+	struct hv_vp_state_data_xsave xsave; /* only for xsave request */
+
+	__u64 buf_size; /* If xsave, must be page-aligned */
+	union {
+		struct hv_local_interrupt_controller_state *lapic;
+		__u8 *bytes; /* Xsave data. must be page-aligned */
+	} buf;
+};
+
 #define MSHV_IOCTL 0xB8
 
 /* mshv device */
@@ -70,5 +81,7 @@ struct mshv_assert_interrupt {
 #define MSHV_GET_VP_REGISTERS   _IOWR(MSHV_IOCTL, 0x05, struct mshv_vp_registers)
 #define MSHV_SET_VP_REGISTERS   _IOW(MSHV_IOCTL, 0x06, struct mshv_vp_registers)
 #define MSHV_RUN_VP		_IOR(MSHV_IOCTL, 0x07, struct hv_message)
+#define MSHV_GET_VP_STATE	_IOWR(MSHV_IOCTL, 0x0A, struct mshv_vp_state)
+#define MSHV_SET_VP_STATE	_IOWR(MSHV_IOCTL, 0x0B, struct mshv_vp_state)
 
 #endif
diff --git a/virt/mshv/mshv_main.c b/virt/mshv/mshv_main.c
index 9cf236ade50a..70172d9488de 100644
--- a/virt/mshv/mshv_main.c
+++ b/virt/mshv/mshv_main.c
@@ -864,6 +864,262 @@ mshv_vp_ioctl_set_regs(struct mshv_vp *vp, void __user *user_args)
 	return ret;
 }
 
+static int
+hv_call_get_vp_state(u32 vp_index,
+		     u64 partition_id,
+		     enum hv_get_set_vp_state_type type,
+		     struct hv_vp_state_data_xsave xsave,
+		    /* Choose between pages and ret_output */
+		     u64 page_count,
+		     struct page **pages,
+		     union hv_get_vp_state_out *ret_output)
+{
+	struct hv_get_vp_state_in *input;
+	union hv_get_vp_state_out *output;
+	int status;
+	int i;
+	u64 control;
+	unsigned long flags;
+	int ret = 0;
+
+	if (sizeof(*input) + (page_count * sizeof(u64)) > PAGE_SIZE)
+		return -EINVAL;
+
+	if (!page_count && !ret_output)
+		return -EINVAL;
+
+	do {
+		local_irq_save(flags);
+		input = (struct hv_get_vp_state_in *)
+				(*this_cpu_ptr(hyperv_pcpu_input_arg));
+		output = (union hv_get_vp_state_out *)
+				(*this_cpu_ptr(hyperv_pcpu_output_arg));
+		memset(input, 0, sizeof(*input));
+		memset(output, 0, sizeof(*output));
+
+		input->partition_id = partition_id;
+		input->vp_index = vp_index;
+		input->state_data.type = type;
+		memcpy(&input->state_data.xsave, &xsave, sizeof(xsave));
+		for (i = 0; i < page_count; i++)
+			input->output_data_pfns[i] =
+				page_to_pfn(pages[i]) & HV_MAP_GPA_MASK;
+
+		control = (HVCALL_GET_VP_STATE) |
+			  (page_count << HV_HYPERCALL_VARHEAD_OFFSET);
+
+		status = hv_do_hypercall(control, input, output) &
+			 HV_HYPERCALL_RESULT_MASK;
+
+		if (status != HV_STATUS_INSUFFICIENT_MEMORY) {
+			if (status != HV_STATUS_SUCCESS)
+				pr_err("%s: %s\n", __func__,
+				       hv_status_to_string(status));
+			else if (ret_output)
+				memcpy(ret_output, output, sizeof(*output));
+
+			local_irq_restore(flags);
+			ret = -hv_status_to_errno(status);
+			break;
+		}
+		local_irq_restore(flags);
+
+		ret = hv_call_deposit_pages(NUMA_NO_NODE,
+					    partition_id, 1);
+	} while (!ret);
+
+	return ret;
+}
+
+static int
+hv_call_set_vp_state(u32 vp_index,
+		     u64 partition_id,
+		     enum hv_get_set_vp_state_type type,
+		     struct hv_vp_state_data_xsave xsave,
+		    /* Choose between pages and bytes */
+		     u64 page_count,
+		     struct page **pages,
+		     u32 num_bytes,
+		     u8 *bytes)
+{
+	struct hv_set_vp_state_in *input;
+	int status;
+	int i;
+	u64 control;
+	unsigned long flags;
+	int ret = 0;
+	u16 varhead_sz;
+
+	if (sizeof(*input) + (page_count * sizeof(u64)) > PAGE_SIZE)
+		return -EINVAL;
+	if (sizeof(*input) + num_bytes > PAGE_SIZE)
+		return -EINVAL;
+
+	if (num_bytes)
+		/* round up to 8 and divide by 8 */
+		varhead_sz = (num_bytes + 7) >> 3;
+	else if (page_count)
+		varhead_sz =  page_count;
+	else
+		return -EINVAL;
+
+	do {
+		local_irq_save(flags);
+		input = (struct hv_set_vp_state_in *)
+				(*this_cpu_ptr(hyperv_pcpu_input_arg));
+		memset(input, 0, sizeof(*input));
+
+		input->partition_id = partition_id;
+		input->vp_index = vp_index;
+		input->state_data.type = type;
+		memcpy(&input->state_data.xsave, &xsave, sizeof(xsave));
+		if (num_bytes) {
+			memcpy((u8 *)input->data, bytes, num_bytes);
+		} else {
+			for (i = 0; i < page_count; i++)
+				input->data[i].pfns =
+					page_to_pfn(pages[i]) & HV_MAP_GPA_MASK;
+		}
+
+		control = (HVCALL_SET_VP_STATE) |
+			  (varhead_sz << HV_HYPERCALL_VARHEAD_OFFSET);
+
+		status = hv_do_hypercall(control, input, NULL) &
+			 HV_HYPERCALL_RESULT_MASK;
+
+		if (status != HV_STATUS_INSUFFICIENT_MEMORY) {
+			if (status != HV_STATUS_SUCCESS)
+				pr_err("%s: %s\n", __func__,
+				       hv_status_to_string(status));
+
+			local_irq_restore(flags);
+			ret = -hv_status_to_errno(status);
+			break;
+		}
+		local_irq_restore(flags);
+
+		ret = hv_call_deposit_pages(NUMA_NO_NODE,
+					    partition_id, 1);
+	} while (!ret);
+
+	return ret;
+}
+
+static long
+mshv_vp_ioctl_get_set_state_pfn(struct mshv_vp *vp,
+				struct mshv_vp_state *args,
+				bool is_set)
+{
+	u64 page_count, remaining;
+	int completed;
+	struct page **pages;
+	long ret;
+	unsigned long u_buf;
+
+	/* Buffer must be page aligned */
+	if (args->buf_size & (PAGE_SIZE - 1) ||
+	    (u64)args->buf.bytes & (PAGE_SIZE - 1))
+		return -EINVAL;
+
+	if (!access_ok(args->buf.bytes, args->buf_size))
+		return -EFAULT;
+
+	/* Pin user pages so hypervisor can copy directly to them */
+	page_count = args->buf_size >> PAGE_SHIFT;
+	pages = kcalloc(page_count, sizeof(struct page *), GFP_KERNEL);
+	if (!pages)
+		return -ENOMEM;
+
+	remaining = page_count;
+	u_buf = (unsigned long)args->buf.bytes;
+	while (remaining) {
+		completed = pin_user_pages_fast(
+				u_buf,
+				remaining,
+				FOLL_WRITE,
+				&pages[page_count - remaining]);
+		if (completed < 0) {
+			pr_err("%s: failed to pin user pages error %i\n",
+			       __func__, completed);
+			ret = completed;
+			goto unpin_pages;
+		}
+		remaining -= completed;
+		u_buf += completed * PAGE_SIZE;
+	}
+
+	if (is_set)
+		ret = hv_call_set_vp_state(vp->index,
+					   vp->partition->id,
+					   args->type, args->xsave,
+					   page_count, pages,
+					   0, NULL);
+	else
+		ret = hv_call_get_vp_state(vp->index,
+					   vp->partition->id,
+					   args->type, args->xsave,
+					   page_count, pages,
+					   NULL);
+
+unpin_pages:
+	unpin_user_pages(pages, page_count - remaining);
+	kfree(pages);
+	return ret;
+}
+
+static long
+mshv_vp_ioctl_get_set_state(struct mshv_vp *vp, void __user *user_args, bool is_set)
+{
+	struct mshv_vp_state args;
+	long ret = 0;
+	union hv_get_vp_state_out vp_state;
+
+	if (copy_from_user(&args, user_args, sizeof(args)))
+		return -EFAULT;
+
+	/* For now just support these */
+	if (args.type != HV_GET_SET_VP_STATE_LOCAL_INTERRUPT_CONTROLLER_STATE &&
+	    args.type != HV_GET_SET_VP_STATE_XSAVE)
+		return -EINVAL;
+
+	/* If we need to pin pfns, delegate to helper */
+	if (args.type & HV_GET_SET_VP_STATE_TYPE_PFN)
+		return mshv_vp_ioctl_get_set_state_pfn(vp, &args, is_set);
+
+	if (args.buf_size < sizeof(vp_state))
+		return -EINVAL;
+
+	if (is_set) {
+		if (copy_from_user(
+				&vp_state,
+				args.buf.lapic,
+				sizeof(vp_state)))
+			return -EFAULT;
+
+		return hv_call_set_vp_state(vp->index,
+					    vp->partition->id,
+					    args.type, args.xsave,
+					    0, NULL,
+					    sizeof(vp_state),
+					    (u8 *)&vp_state);
+	}
+
+	ret = hv_call_get_vp_state(vp->index,
+				   vp->partition->id,
+				   args.type, args.xsave,
+				   0, NULL,
+				   &vp_state);
+
+	if (ret)
+		return ret;
+
+	if (copy_to_user(args.buf.lapic,
+			 &vp_state.interrupt_controller_state,
+			 sizeof(vp_state.interrupt_controller_state)))
+		return -EFAULT;
+
+	return 0;
+}
 
 static long
 mshv_vp_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
@@ -884,6 +1140,12 @@ mshv_vp_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 	case MSHV_SET_VP_REGISTERS:
 		r = mshv_vp_ioctl_set_regs(vp, (void __user *)arg);
 		break;
+	case MSHV_GET_VP_STATE:
+		r = mshv_vp_ioctl_get_set_state(vp, (void __user *)arg, false);
+		break;
+	case MSHV_SET_VP_STATE:
+		r = mshv_vp_ioctl_get_set_state(vp, (void __user *)arg, true);
+		break;
 	default:
 		r = -ENOTTY;
 		break;
-- 
2.25.1