Merge tag 'hyperv-next-signed-20230220' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - allow Linux to run as the nested root partition for Microsoft
   Hypervisor (Jinank Jain and Nuno Das Neves)

 - clean up the return type of callback functions (Dawei Li)

* tag 'hyperv-next-signed-20230220' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Fix hv_get/set_register for nested bringup
  Drivers: hv: Make remove callback of hyperv driver void returned
  Drivers: hv: Enable vmbus driver for nested root partition
  x86/hyperv: Add an interface to do nested hypercalls
  Drivers: hv: Setup synic registers in case of nested root partition
  x86/hyperv: Add support for detecting nested hypervisor

13 files changed, 31 insertions, 45 deletions

diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
index 427c20ba3404..f830d62a5ce6 100644
--- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
+++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
@@ -165,7 +165,7 @@ err_hv_set_drv_data:
 	return ret;
 }
 
-static int hyperv_vmbus_remove(struct hv_device *hdev)
+static void hyperv_vmbus_remove(struct hv_device *hdev)
 {
 	struct drm_device *dev = hv_get_drvdata(hdev);
 	struct hyperv_drm_device *hv = to_hv(dev);
@@ -176,8 +176,6 @@ static int hyperv_vmbus_remove(struct hv_device *hdev)
 	hv_set_drvdata(hdev, NULL);
 
 	vmbus_free_mmio(hv->mem->start, hv->fb_size);
-
-	return 0;
 }
 
 static int hyperv_vmbus_suspend(struct hv_device *hdev)
diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
index cf12f17e6533..2a0aabd50a45 100644
--- a/drivers/hid/hid-hyperv.c
+++ b/drivers/hid/hid-hyperv.c
@@ -524,7 +524,7 @@ probe_err0:
 }
 
 
-static int mousevsc_remove(struct hv_device *dev)
+static void mousevsc_remove(struct hv_device *dev)
 {
 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 
@@ -533,8 +533,6 @@ static int mousevsc_remove(struct hv_device *dev)
 	hid_hw_stop(input_dev->hid_device);
 	hid_destroy_device(input_dev->hid_device);
 	mousevsc_free_device(input_dev);
-
-	return 0;
 }
 
 static int mousevsc_suspend(struct hv_device *dev)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 4d6480d57546..8b0dd8e5244d 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -147,7 +147,7 @@ int hv_synic_alloc(void)
 		 * Synic message and event pages are allocated by paravisor.
 		 * Skip these pages allocation here.
 		 */
-		if (!hv_isolation_type_snp()) {
+		if (!hv_isolation_type_snp() && !hv_root_partition) {
 			hv_cpu->synic_message_page =
 				(void *)get_zeroed_page(GFP_ATOMIC);
 			if (hv_cpu->synic_message_page == NULL) {
@@ -216,7 +216,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
 	simp.simp_enabled = 1;
 
-	if (hv_isolation_type_snp()) {
+	if (hv_isolation_type_snp() || hv_root_partition) {
 		hv_cpu->synic_message_page
 			= memremap(simp.base_simp_gpa << HV_HYP_PAGE_SHIFT,
 				   HV_HYP_PAGE_SIZE, MEMREMAP_WB);
@@ -233,7 +233,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
 	siefp.siefp_enabled = 1;
 
-	if (hv_isolation_type_snp()) {
+	if (hv_isolation_type_snp() || hv_root_partition) {
 		hv_cpu->synic_event_page =
 			memremap(siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT,
 				 HV_HYP_PAGE_SIZE, MEMREMAP_WB);
@@ -315,20 +315,24 @@ void hv_synic_disable_regs(unsigned int cpu)
 	 * addresses.
 	 */
 	simp.simp_enabled = 0;
-	if (hv_isolation_type_snp())
+	if (hv_isolation_type_snp() || hv_root_partition) {
 		memunmap(hv_cpu->synic_message_page);
-	else
+		hv_cpu->synic_message_page = NULL;
+	} else {
 		simp.base_simp_gpa = 0;
+	}
 
 	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
 
 	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
 	siefp.siefp_enabled = 0;
 
-	if (hv_isolation_type_snp())
+	if (hv_isolation_type_snp() || hv_root_partition) {
 		memunmap(hv_cpu->synic_event_page);
-	else
+		hv_cpu->synic_event_page = NULL;
+	} else {
 		siefp.base_siefp_gpa = 0;
+	}
 
 	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
 
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 64ac5bdee3a6..dffcc894f117 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -2042,7 +2042,7 @@ connect_error:
 	return ret;
 }
 
-static int balloon_remove(struct hv_device *dev)
+static void balloon_remove(struct hv_device *dev)
 {
 	struct hv_dynmem_device *dm = hv_get_drvdata(dev);
 	struct hv_hotadd_state *has, *tmp;
@@ -2083,8 +2083,6 @@ static int balloon_remove(struct hv_device *dev)
 		kfree(has);
 	}
 	spin_unlock_irqrestore(&dm_device.ha_lock, flags);
-
-	return 0;
 }
 
 static int balloon_suspend(struct hv_device *hv_dev)
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index ae68298c0dca..52a6f89ccdbd 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -25,17 +25,20 @@
 #include <asm/mshyperv.h>
 
 /*
- * hv_root_partition and ms_hyperv are defined here with other Hyper-V
- * specific globals so they are shared across all architectures and are
+ * hv_root_partition, ms_hyperv and hv_nested are defined here with other
+ * Hyper-V specific globals so they are shared across all architectures and are
  * built only when CONFIG_HYPERV is defined.  But on x86,
  * ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not
- * defined, and it uses these two variables.  So mark them as __weak
+ * defined, and it uses these three variables.  So mark them as __weak
  * here, allowing for an overriding definition in the module containing
  * ms_hyperv_init_platform().
  */
 bool __weak hv_root_partition;
 EXPORT_SYMBOL_GPL(hv_root_partition);
 
+bool __weak hv_nested;
+EXPORT_SYMBOL_GPL(hv_nested);
+
 struct ms_hyperv_info __weak ms_hyperv;
 EXPORT_SYMBOL_GPL(ms_hyperv);
 
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index d776074b49cb..42aec2c5606a 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -602,7 +602,7 @@ error1:
 	return ret;
 }
 
-static int util_remove(struct hv_device *dev)
+static void util_remove(struct hv_device *dev)
 {
 	struct hv_util_service *srv = hv_get_drvdata(dev);
 
@@ -610,8 +610,6 @@ static int util_remove(struct hv_device *dev)
 		srv->util_deinit();
 	vmbus_close(dev->channel);
 	kfree(srv->recv_buffer);
-
-	return 0;
 }
 
 /*
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 3146710d4ac6..1901556efe79 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2744,7 +2744,7 @@ static int __init hv_acpi_init(void)
 	if (!hv_is_hyperv_initialized())
 		return -ENODEV;
 
-	if (hv_root_partition)
+	if (hv_root_partition && !hv_nested)
 		return 0;
 
 	/*
diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index d62aefb2e245..31def6ce5157 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -369,7 +369,7 @@ err_free_mem:
 	return error;
 }
 
-static int hv_kbd_remove(struct hv_device *hv_dev)
+static void hv_kbd_remove(struct hv_device *hv_dev)
 {
 	struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
 
@@ -378,8 +378,6 @@ static int hv_kbd_remove(struct hv_device *hv_dev)
 	kfree(kbd_dev);
 
 	hv_set_drvdata(hv_dev, NULL);
-
-	return 0;
 }
 
 static int hv_kbd_suspend(struct hv_device *hv_dev)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index f9b219e6cd58..42162167b5b4 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2594,7 +2594,7 @@ no_net:
 	return ret;
 }
 
-static int netvsc_remove(struct hv_device *dev)
+static void netvsc_remove(struct hv_device *dev)
 {
 	struct net_device_context *ndev_ctx;
 	struct net_device *vf_netdev, *net;
@@ -2603,7 +2603,7 @@ static int netvsc_remove(struct hv_device *dev)
 	net = hv_get_drvdata(dev);
 	if (net == NULL) {
 		dev_err(&dev->device, "No net device to remove\n");
-		return 0;
+		return;
 	}
 
 	ndev_ctx = netdev_priv(net);
@@ -2637,7 +2637,6 @@ static int netvsc_remove(struct hv_device *dev)
 
 	free_percpu(ndev_ctx->vf_stats);
 	free_netdev(net);
-	return 0;
 }
 
 static int netvsc_suspend(struct hv_device *dev)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 084f5313895c..f33370b75628 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -3800,13 +3800,10 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
 /**
  * hv_pci_remove() - Remove routine for this VMBus channel
  * @hdev:	VMBus's tracking struct for this root PCI bus
- *
- * Return: 0 on success, -errno on failure
  */
-static int hv_pci_remove(struct hv_device *hdev)
+static void hv_pci_remove(struct hv_device *hdev)
 {
 	struct hv_pcibus_device *hbus;
-	int ret;
 
 	hbus = hv_get_drvdata(hdev);
 	if (hbus->state == hv_pcibus_installed) {
@@ -3829,7 +3826,7 @@ static int hv_pci_remove(struct hv_device *hdev)
 		pci_unlock_rescan_remove();
 	}
 
-	ret = hv_pci_bus_exit(hdev, false);
+	hv_pci_bus_exit(hdev, false);
 
 	vmbus_close(hdev->channel);
 
@@ -3842,7 +3839,6 @@ static int hv_pci_remove(struct hv_device *hdev)
 	hv_put_dom_num(hbus->bridge->domain_nr);
 
 	kfree(hbus);
-	return ret;
 }
 
 static int hv_pci_suspend(struct hv_device *hdev)
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 22705eb781b0..33f568b7f54d 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -2095,7 +2095,7 @@ static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
 	return scsi_change_queue_depth(sdev, queue_depth);
 }
 
-static int storvsc_remove(struct hv_device *dev)
+static void storvsc_remove(struct hv_device *dev)
 {
 	struct storvsc_device *stor_device = hv_get_drvdata(dev);
 	struct Scsi_Host *host = stor_device->host;
@@ -2111,8 +2111,6 @@ static int storvsc_remove(struct hv_device *dev)
 	scsi_remove_host(host);
 	storvsc_dev_remove(dev);
 	scsi_host_put(host);
-
-	return 0;
 }
 
 static int storvsc_suspend(struct hv_device *hv_dev)
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index c08a6cfd119f..20d9762331bd 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -355,20 +355,19 @@ fail_free_ring:
 	return ret;
 }
 
-static int
+static void
 hv_uio_remove(struct hv_device *dev)
 {
 	struct hv_uio_private_data *pdata = hv_get_drvdata(dev);
 
 	if (!pdata)
-		return 0;
+		return;
 
 	sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr);
 	uio_unregister_device(&pdata->info);
 	hv_uio_cleanup(dev, pdata);
 
 	vmbus_free_ring(dev->channel);
-	return 0;
 }
 
 static struct hv_driver hv_uio_drv = {
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index fdbf02b42723..a7f79f51f40c 100644
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -1239,8 +1239,7 @@ error1:
 	return ret;
 }
 
-
-static int hvfb_remove(struct hv_device *hdev)
+static void hvfb_remove(struct hv_device *hdev)
 {
 	struct fb_info *info = hv_get_drvdata(hdev);
 	struct hvfb_par *par = info->par;
@@ -1261,8 +1260,6 @@ static int hvfb_remove(struct hv_device *hdev)
 
 	hvfb_putmem(hdev, info);
 	framebuffer_release(info);
-
-	return 0;
 }
 
 static int hvfb_suspend(struct hv_device *hdev)