Merge tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Unify guest entry code for KVM and MSHV (Sean Christopherson)

 - Switch Hyper-V MSI domain to use msi_create_parent_irq_domain()
   (Nam Cao)

 - Add CONFIG_HYPERV_VMBUS and limit the semantics of CONFIG_HYPERV
   (Mukesh Rathor)

 - Add kexec/kdump support on Azure CVMs (Vitaly Kuznetsov)

 - Deprecate hyperv_fb in favor of Hyper-V DRM driver (Prasanna
   Kumar T S M)

 - Miscellaneous enhancements, fixes and cleanups (Abhishek Tiwari,
   Alok Tiwari, Nuno Das Neves, Wei Liu, Roman Kisel, Michael Kelley)

* tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hyperv: Remove the spurious null directive line
  MAINTAINERS: Mark hyperv_fb driver Obsolete
  fbdev/hyperv_fb: deprecate this in favor of Hyper-V DRM driver
  Drivers: hv: Make CONFIG_HYPERV bool
  Drivers: hv: Add CONFIG_HYPERV_VMBUS option
  Drivers: hv: vmbus: Fix typos in vmbus_drv.c
  Drivers: hv: vmbus: Fix sysfs output format for ring buffer index
  Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()
  x86/hyperv: Switch to msi_create_parent_irq_domain()
  mshv: Use common "entry virt" APIs to do work in root before running guest
  entry: Rename "kvm" entry code assets to "virt" to genericize APIs
  entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper
  mshv: Handle NEED_RESCHED_LAZY before transferring to guest
  x86/hyperv: Add kexec/kdump support on Azure CVMs
  Drivers: hv: Simplify data structures for VMBus channel close message
  Drivers: hv: util: Cosmetic changes for hv_utils_transport.c
  mshv: Add support for a new parent partition configuration
  clocksource: hyper-v: Skip unnecessary checks for the root partition
  hyperv: Add missing field to hv_output_map_device_interrupt

45 files changed, 449 insertions, 193 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index b45db73e55df..9b754d290f93 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10390,7 +10390,7 @@ L:	linux-kernel@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/entry
 F:	include/linux/entry-common.h
-F:	include/linux/entry-kvm.h
+F:	include/linux/entry-virt.h
 F:	include/linux/irq-entry-common.h
 F:	kernel/entry/
 
@@ -11604,7 +11604,6 @@ F:	drivers/pci/controller/pci-hyperv-intf.c
 F:	drivers/pci/controller/pci-hyperv.c
 F:	drivers/scsi/storvsc_drv.c
 F:	drivers/uio/uio_hv_generic.c
-F:	drivers/video/fbdev/hyperv_fb.c
 F:	include/asm-generic/mshyperv.h
 F:	include/clocksource/hyperv_timer.h
 F:	include/hyperv/hvgdk.h
@@ -11618,6 +11617,16 @@ F:	include/uapi/linux/hyperv.h
 F:	net/vmw_vsock/hyperv_transport.c
 F:	tools/hv/
 
+HYPER-V FRAMEBUFFER DRIVER
+M:	"K. Y. Srinivasan" <kys@microsoft.com>
+M:	Haiyang Zhang <haiyangz@microsoft.com>
+M:	Wei Liu <wei.liu@kernel.org>
+M:	Dexuan Cui <decui@microsoft.com>
+L:	linux-hyperv@vger.kernel.org
+S:	Obsolete
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git
+F:	drivers/video/fbdev/hyperv_fb.c
+
 HYPERBUS SUPPORT
 M:	Vignesh Raghavendra <vigneshr@ti.com>
 R:	Tudor Ambarus <tudor.ambarus@linaro.org>
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index bff62e75d681..4f803fd1c99a 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -25,7 +25,7 @@ menuconfig KVM
 	select HAVE_KVM_CPU_RELAX_INTERCEPT
 	select KVM_MMIO
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
-	select KVM_XFER_TO_GUEST_WORK
+	select VIRT_XFER_TO_GUEST_WORK
 	select KVM_VFIO
 	select HAVE_KVM_DIRTY_RING_ACQ_REL
 	select NEED_KVM_DIRTY_RING_WITH_BITMAP
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index fa79744290f3..f21d1b7f20f8 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -6,7 +6,6 @@
 
 #include <linux/bug.h>
 #include <linux/cpu_pm.h>
-#include <linux/entry-kvm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kvm_host.h>
@@ -1183,7 +1182,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		/*
 		 * Check conditions before entering the guest
 		 */
-		ret = xfer_to_guest_mode_handle_work(vcpu);
+		ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
 		if (!ret)
 			ret = 1;
 
diff --git a/arch/loongarch/kvm/Kconfig b/arch/loongarch/kvm/Kconfig
index 40eea6da7c25..ae64bbdf83a7 100644
--- a/arch/loongarch/kvm/Kconfig
+++ b/arch/loongarch/kvm/Kconfig
@@ -31,7 +31,7 @@ config KVM
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_GENERIC_MMU_NOTIFIER
 	select KVM_MMIO
-	select KVM_XFER_TO_GUEST_WORK
+	select VIRT_XFER_TO_GUEST_WORK
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
 	help
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 9c802f7103c6..30e3b089a596 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -4,7 +4,6 @@
  */
 
 #include <linux/kvm_host.h>
-#include <linux/entry-kvm.h>
 #include <asm/fpu.h>
 #include <asm/lbt.h>
 #include <asm/loongarch.h>
@@ -251,7 +250,7 @@ static int kvm_enter_guest_check(struct kvm_vcpu *vcpu)
 	/*
 	 * Check conditions before entering the guest
 	 */
-	ret = xfer_to_guest_mode_handle_work(vcpu);
+	ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
 	if (ret < 0)
 		return ret;
 
diff --git a/arch/riscv/kvm/Kconfig b/arch/riscv/kvm/Kconfig
index 5a62091b0809..c50328212917 100644
--- a/arch/riscv/kvm/Kconfig
+++ b/arch/riscv/kvm/Kconfig
@@ -30,7 +30,7 @@ config KVM
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_MMIO
-	select KVM_XFER_TO_GUEST_WORK
+	select VIRT_XFER_TO_GUEST_WORK
 	select KVM_GENERIC_MMU_NOTIFIER
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 47bcf190ccc5..bccb919ca615 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -7,7 +7,6 @@
  */
 
 #include <linux/bitops.h>
-#include <linux/entry-kvm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kdebug.h>
@@ -911,7 +910,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 	run->exit_reason = KVM_EXIT_UNKNOWN;
 	while (ret > 0) {
 		/* Check conditions before entering the guest */
-		ret = xfer_to_guest_mode_handle_work(vcpu);
+		ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
 		if (ret)
 			continue;
 		ret = 1;
diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c
index 090f5ac9f492..c3ba12b1bc07 100644
--- a/arch/x86/hyperv/irqdomain.c
+++ b/arch/x86/hyperv/irqdomain.c
@@ -11,6 +11,7 @@
 #include <linux/pci.h>
 #include <linux/irq.h>
 #include <linux/export.h>
+#include <linux/irqchip/irq-msi-lib.h>
 #include <asm/mshyperv.h>
 
 static int hv_map_interrupt(union hv_device_id device_id, bool level,
@@ -289,59 +290,99 @@ static void hv_teardown_msi_irq(struct pci_dev *dev, struct irq_data *irqd)
 	(void)hv_unmap_msi_interrupt(dev, &old_entry);
 }
 
-static void hv_msi_free_irq(struct irq_domain *domain,
-			    struct msi_domain_info *info, unsigned int virq)
-{
-	struct irq_data *irqd = irq_get_irq_data(virq);
-	struct msi_desc *desc;
-
-	if (!irqd)
-		return;
-
-	desc = irq_data_get_msi_desc(irqd);
-	if (!desc || !desc->irq || WARN_ON_ONCE(!dev_is_pci(desc->dev)))
-		return;
-
-	hv_teardown_msi_irq(to_pci_dev(desc->dev), irqd);
-}
-
 /*
  * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
  * which implement the MSI or MSI-X Capability Structure.
  */
 static struct irq_chip hv_pci_msi_controller = {
 	.name			= "HV-PCI-MSI",
-	.irq_unmask		= pci_msi_unmask_irq,
-	.irq_mask		= pci_msi_mask_irq,
 	.irq_ack		= irq_chip_ack_parent,
-	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_compose_msi_msg	= hv_irq_compose_msi_msg,
-	.irq_set_affinity	= msi_domain_set_affinity,
-	.flags			= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MOVE_DEFERRED,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
 };
 
-static struct msi_domain_ops pci_msi_domain_ops = {
-	.msi_free		= hv_msi_free_irq,
-	.msi_prepare		= pci_msi_prepare,
+static bool hv_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+				 struct irq_domain *real_parent, struct msi_domain_info *info)
+{
+	struct irq_chip *chip = info->chip;
+
+	if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))
+		return false;
+
+	chip->flags |= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MOVE_DEFERRED;
+
+	info->ops->msi_prepare = pci_msi_prepare;
+
+	return true;
+}
+
+#define HV_MSI_FLAGS_SUPPORTED	(MSI_GENERIC_FLAGS_MASK | MSI_FLAG_PCI_MSIX)
+#define HV_MSI_FLAGS_REQUIRED	(MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS)
+
+static struct msi_parent_ops hv_msi_parent_ops = {
+	.supported_flags	= HV_MSI_FLAGS_SUPPORTED,
+	.required_flags		= HV_MSI_FLAGS_REQUIRED,
+	.bus_select_token	= DOMAIN_BUS_NEXUS,
+	.bus_select_mask	= MATCH_PCI_MSI,
+	.chip_flags		= MSI_CHIP_FLAG_SET_ACK,
+	.prefix			= "HV-",
+	.init_dev_msi_info	= hv_init_dev_msi_info,
 };
 
-static struct msi_domain_info hv_pci_msi_domain_info = {
-	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
-			  MSI_FLAG_PCI_MSIX,
-	.ops		= &pci_msi_domain_ops,
-	.chip		= &hv_pci_msi_controller,
-	.handler	= handle_edge_irq,
-	.handler_name	= "edge",
+static int hv_msi_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,
+			       void *arg)
+{
+	/*
+	 * TODO: The allocation bits of hv_irq_compose_msi_msg(), i.e. everything except
+	 * entry_to_msi_msg() should be in here.
+	 */
+
+	int ret;
+
+	ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, arg);
+	if (ret)
+		return ret;
+
+	for (int i = 0; i < nr_irqs; ++i) {
+		irq_domain_set_info(d, virq + i, 0, &hv_pci_msi_controller, NULL,
+				    handle_edge_irq, NULL, "edge");
+	}
+	return 0;
+}
+
+static void hv_msi_domain_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs)
+{
+	for (int i = 0; i < nr_irqs; ++i) {
+		struct irq_data *irqd = irq_domain_get_irq_data(d, virq);
+		struct msi_desc *desc;
+
+		desc = irq_data_get_msi_desc(irqd);
+		if (!desc || !desc->irq || WARN_ON_ONCE(!dev_is_pci(desc->dev)))
+			continue;
+
+		hv_teardown_msi_irq(to_pci_dev(desc->dev), irqd);
+	}
+	irq_domain_free_irqs_top(d, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops hv_msi_domain_ops = {
+	.select	= msi_lib_irq_domain_select,
+	.alloc	= hv_msi_domain_alloc,
+	.free	= hv_msi_domain_free,
 };
 
 struct irq_domain * __init hv_create_pci_msi_domain(void)
 {
 	struct irq_domain *d = NULL;
-	struct fwnode_handle *fn;
 
-	fn = irq_domain_alloc_named_fwnode("HV-PCI-MSI");
-	if (fn)
-		d = pci_msi_create_irq_domain(fn, &hv_pci_msi_domain_info, x86_vector_domain);
+	struct irq_domain_info info = {
+		.fwnode		= irq_domain_alloc_named_fwnode("HV-PCI-MSI"),
+		.ops		= &hv_msi_domain_ops,
+		.parent		= x86_vector_domain,
+	};
+
+	if (info.fwnode)
+		d = msi_create_parent_irq_domain(&info, &hv_msi_parent_ops);
 
 	/* No point in going further if we can't get an irq domain */
 	BUG_ON(!d);
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index ade6c665c97e..a4615b889f3e 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -463,6 +463,195 @@ void hv_ivm_msr_read(u64 msr, u64 *value)
 }
 
 /*
+ * Keep track of the PFN regions which were shared with the host. The access
+ * must be revoked upon kexec/kdump (see hv_ivm_clear_host_access()).
+ */
+struct hv_enc_pfn_region {
+	struct list_head list;
+	u64 pfn;
+	int count;
+};
+
+static LIST_HEAD(hv_list_enc);
+static DEFINE_RAW_SPINLOCK(hv_list_enc_lock);
+
+static int hv_list_enc_add(const u64 *pfn_list, int count)
+{
+	struct hv_enc_pfn_region *ent;
+	unsigned long flags;
+	u64 pfn;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		pfn = pfn_list[i];
+
+		raw_spin_lock_irqsave(&hv_list_enc_lock, flags);
+		/* Check if the PFN already exists in some region first */
+		list_for_each_entry(ent, &hv_list_enc, list) {
+			if ((ent->pfn <= pfn) && (ent->pfn + ent->count - 1 >= pfn))
+				/* Nothing to do - pfn is already in the list */
+				goto unlock_done;
+		}
+
+		/*
+		 * Check if the PFN is adjacent to an existing region. Growing
+		 * a region can make it adjacent to another one but merging is
+		 * not (yet) implemented for simplicity. A PFN cannot be added
+		 * to two regions to keep the logic in hv_list_enc_remove()
+		 * correct.
+		 */
+		list_for_each_entry(ent, &hv_list_enc, list) {
+			if (ent->pfn + ent->count == pfn) {
+				/* Grow existing region up */
+				ent->count++;
+				goto unlock_done;
+			} else if (pfn + 1 == ent->pfn) {
+				/* Grow existing region down */
+				ent->pfn--;
+				ent->count++;
+				goto unlock_done;
+			}
+		}
+		raw_spin_unlock_irqrestore(&hv_list_enc_lock, flags);
+
+		/* No adjacent region found -- create a new one */
+		ent = kzalloc(sizeof(struct hv_enc_pfn_region), GFP_KERNEL);
+		if (!ent)
+			return -ENOMEM;
+
+		ent->pfn = pfn;
+		ent->count = 1;
+
+		raw_spin_lock_irqsave(&hv_list_enc_lock, flags);
+		list_add(&ent->list, &hv_list_enc);
+
+unlock_done:
+		raw_spin_unlock_irqrestore(&hv_list_enc_lock, flags);
+	}
+
+	return 0;
+}
+
+static int hv_list_enc_remove(const u64 *pfn_list, int count)
+{
+	struct hv_enc_pfn_region *ent, *t;
+	struct hv_enc_pfn_region new_region;
+	unsigned long flags;
+	u64 pfn;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		pfn = pfn_list[i];
+
+		raw_spin_lock_irqsave(&hv_list_enc_lock, flags);
+		list_for_each_entry_safe(ent, t, &hv_list_enc, list) {
+			if (pfn == ent->pfn + ent->count - 1) {
+				/* Removing tail pfn */
+				ent->count--;
+				if (!ent->count) {
+					list_del(&ent->list);
+					kfree(ent);
+				}
+				goto unlock_done;
+			} else if (pfn == ent->pfn) {
+				/* Removing head pfn */
+				ent->count--;
+				ent->pfn++;
+				if (!ent->count) {
+					list_del(&ent->list);
+					kfree(ent);
+				}
+				goto unlock_done;
+			} else if (pfn > ent->pfn && pfn < ent->pfn + ent->count - 1) {
+				/*
+				 * Removing a pfn in the middle. Cut off the tail
+				 * of the existing region and create a template for
+				 * the new one.
+				 */
+				new_region.pfn = pfn + 1;
+				new_region.count = ent->count - (pfn - ent->pfn + 1);
+				ent->count = pfn - ent->pfn;
+				goto unlock_split;
+			}
+
+		}
+unlock_done:
+		raw_spin_unlock_irqrestore(&hv_list_enc_lock, flags);
+		continue;
+
+unlock_split:
+		raw_spin_unlock_irqrestore(&hv_list_enc_lock, flags);
+
+		ent = kzalloc(sizeof(struct hv_enc_pfn_region), GFP_KERNEL);
+		if (!ent)
+			return -ENOMEM;
+
+		ent->pfn = new_region.pfn;
+		ent->count = new_region.count;
+
+		raw_spin_lock_irqsave(&hv_list_enc_lock, flags);
+		list_add(&ent->list, &hv_list_enc);
+		raw_spin_unlock_irqrestore(&hv_list_enc_lock, flags);
+	}
+
+	return 0;
+}
+
+/* Stop new private<->shared conversions */
+static void hv_vtom_kexec_begin(void)
+{
+	if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+		return;
+
+	/*
+	 * Crash kernel reaches here with interrupts disabled: can't wait for
+	 * conversions to finish.
+	 *
+	 * If race happened, just report and proceed.
+	 */
+	if (!set_memory_enc_stop_conversion())
+		pr_warn("Failed to stop shared<->private conversions\n");
+}
+
+static void hv_vtom_kexec_finish(void)
+{
+	struct hv_gpa_range_for_visibility *input;
+	struct hv_enc_pfn_region *ent;
+	unsigned long flags;
+	u64 hv_status;
+	int cur, i;
+
+	local_irq_save(flags);
+	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+
+	if (unlikely(!input))
+		goto out;
+
+	list_for_each_entry(ent, &hv_list_enc, list) {
+		for (i = 0, cur = 0; i < ent->count; i++) {
+			input->gpa_page_list[cur] = ent->pfn + i;
+			cur++;
+
+			if (cur == HV_MAX_MODIFY_GPA_REP_COUNT || i == ent->count - 1) {
+				input->partition_id = HV_PARTITION_ID_SELF;
+				input->host_visibility = VMBUS_PAGE_NOT_VISIBLE;
+				input->reserved0 = 0;
+				input->reserved1 = 0;
+				hv_status = hv_do_rep_hypercall(
+					HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY,
+					cur, 0, input, NULL);
+				WARN_ON_ONCE(!hv_result_success(hv_status));
+				cur = 0;
+			}
+		}
+
+	}
+
+out:
+	local_irq_restore(flags);
+}
+
+/*
  * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
  *
  * In Isolation VM, all guest memory is encrypted from host and guest
@@ -475,6 +664,7 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
 	struct hv_gpa_range_for_visibility *input;
 	u64 hv_status;
 	unsigned long flags;
+	int ret;
 
 	/* no-op if partition isolation is not enabled */
 	if (!hv_is_isolation_supported())
@@ -486,6 +676,13 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
 		return -EINVAL;
 	}
 
+	if (visibility == VMBUS_PAGE_NOT_VISIBLE)
+		ret = hv_list_enc_remove(pfn, count);
+	else
+		ret = hv_list_enc_add(pfn, count);
+	if (ret)
+		return ret;
+
 	local_irq_save(flags);
 	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
 
@@ -506,8 +703,18 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
 
 	if (hv_result_success(hv_status))
 		return 0;
+
+	if (visibility == VMBUS_PAGE_NOT_VISIBLE)
+		ret = hv_list_enc_add(pfn, count);
 	else
-		return -EFAULT;
+		ret = hv_list_enc_remove(pfn, count);
+	/*
+	 * There's no good way to recover from -ENOMEM here, the accounting is
+	 * wrong either way.
+	 */
+	WARN_ON_ONCE(ret);
+
+	return -EFAULT;
 }
 
 /*
@@ -669,6 +876,8 @@ void __init hv_vtom_init(void)
 	x86_platform.guest.enc_tlb_flush_required = hv_vtom_tlb_flush_required;
 	x86_platform.guest.enc_status_change_prepare = hv_vtom_clear_present;
 	x86_platform.guest.enc_status_change_finish = hv_vtom_set_host_visibility;
+	x86_platform.guest.enc_kexec_begin = hv_vtom_kexec_begin;
+	x86_platform.guest.enc_kexec_finish = hv_vtom_kexec_finish;
 
 	/* Set WB as the default cache mode. */
 	guest_force_mtrr_state(NULL, 0, MTRR_TYPE_WRBACK);
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index c78f860419d6..25773af116bc 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -565,6 +565,11 @@ static void __init ms_hyperv_init_platform(void)
 	machine_ops.crash_shutdown = hv_machine_crash_shutdown;
 #endif
 #endif
+	/*
+	 * HV_ACCESS_TSC_INVARIANT is always zero for the root partition. Root
+	 * partition doesn't need to write to synthetic MSR to enable invariant
+	 * TSC feature. It sees what the hardware provides.
+	 */
 	if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) {
 		/*
 		 * Writing to synthetic MSR 0x40000118 updates/changes the
@@ -636,8 +641,12 @@ static void __init ms_hyperv_init_platform(void)
 	 * TSC should be marked as unstable only after Hyper-V
 	 * clocksource has been initialized. This ensures that the
 	 * stability of the sched_clock is not altered.
+	 *
+	 * HV_ACCESS_TSC_INVARIANT is always zero for the root partition. No
+	 * need to check for it.
 	 */
-	if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
+	if (!hv_root_partition() &&
+	    !(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
 		mark_tsc_unstable("running on Hyper-V");
 
 	hardlockup_detector_disable();
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 4e43923656d0..67d4f23bab66 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -40,7 +40,7 @@ config KVM_X86
 	select HAVE_KVM_MSI
 	select HAVE_KVM_CPU_RELAX_INTERCEPT
 	select HAVE_KVM_NO_POLL
-	select KVM_XFER_TO_GUEST_WORK
+	select VIRT_XFER_TO_GUEST_WORK
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select KVM_VFIO
 	select HAVE_KVM_PM_NOTIFIER if PM
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 546272a5d34d..d7b258af63ea 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -28,7 +28,6 @@
 #include <linux/slab.h>
 #include <linux/tboot.h>
 #include <linux/trace_events.h>
-#include <linux/entry-kvm.h>
 
 #include <asm/apic.h>
 #include <asm/asm.h>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4b8138bd4857..42ecd093bb4c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -59,7 +59,6 @@
 #include <linux/sched/stat.h>
 #include <linux/sched/isolation.h>
 #include <linux/mem_encrypt.h>
-#include <linux/entry-kvm.h>
 #include <linux/suspend.h>
 #include <linux/smp.h>
 
@@ -11635,7 +11634,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 
 		if (__xfer_to_guest_mode_work_pending()) {
 			kvm_vcpu_srcu_read_unlock(vcpu);
-			r = xfer_to_guest_mode_handle_work(vcpu);
+			r = kvm_xfer_to_guest_mode_handle_work(vcpu);
 			kvm_vcpu_srcu_read_lock(vcpu);
 			if (r)
 				return r;
diff --git a/drivers/Makefile b/drivers/Makefile
index a104163b1353..8e1ffa4358d5 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -161,7 +161,7 @@ obj-$(CONFIG_SOUNDWIRE)		+= soundwire/
 
 # Virtualization drivers
 obj-$(CONFIG_VIRT_DRIVERS)	+= virt/
-obj-$(subst m,y,$(CONFIG_HYPERV))	+= hv/
+obj-$(CONFIG_HYPERV)		+= hv/
 
 obj-$(CONFIG_PM_DEVFREQ)	+= devfreq/
 obj-$(CONFIG_EXTCON)		+= extcon/
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 2edc13ca184e..10356d4ec55c 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -549,14 +549,22 @@ static void __init hv_init_tsc_clocksource(void)
 	union hv_reference_tsc_msr tsc_msr;
 
 	/*
+	 * When running as a guest partition:
+	 *
 	 * If Hyper-V offers TSC_INVARIANT, then the virtualized TSC correctly
 	 * handles frequency and offset changes due to live migration,
 	 * pause/resume, and other VM management operations.  So lower the
 	 * Hyper-V Reference TSC rating, causing the generic TSC to be used.
 	 * TSC_INVARIANT is not offered on ARM64, so the Hyper-V Reference
 	 * TSC will be preferred over the virtualized ARM64 arch counter.
+	 *
+	 * When running as the root partition:
+	 *
+	 * There is no HV_ACCESS_TSC_INVARIANT feature. Always lower the rating
+	 * of the Hyper-V Reference TSC.
 	 */
-	if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) {
+	if ((ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) ||
+	    hv_root_partition()) {
 		hyperv_cs_tsc.rating = 250;
 		hyperv_cs_msr.rating = 245;
 	}
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index fda170730468..7e6bc0b3a589 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -400,7 +400,7 @@ source "drivers/gpu/drm/tyr/Kconfig"
 
 config DRM_HYPERV
 	tristate "DRM Support for Hyper-V synthetic video device"
-	depends on DRM && PCI && HYPERV
+	depends on DRM && PCI && HYPERV_VMBUS
 	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_GEM_SHMEM_HELPER
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 7ff85c7200e5..5341aa79f387 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -1171,7 +1171,7 @@ config GREENASIA_FF
 
 config HID_HYPERV_MOUSE
 	tristate "Microsoft Hyper-V mouse driver"
-	depends on HYPERV
+	depends on HYPERV_VMBUS
 	help
 	Select this option to enable the Hyper-V mouse driver.
 
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 57623ca7f350..0b8c391a0342 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -3,13 +3,14 @@
 menu "Microsoft Hyper-V guest support"
 
 config HYPERV
-	tristate "Microsoft Hyper-V client drivers"
+	bool "Microsoft Hyper-V core hypervisor support"
 	depends on (X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \
 		|| (ARM64 && !CPU_BIG_ENDIAN)
 	select PARAVIRT
 	select X86_HV_CALLBACK_VECTOR if X86
 	select OF_EARLY_FLATTREE if OF
 	select SYSFB if EFI && !HYPERV_VTL_MODE
+	select IRQ_MSI_LIB if X86
 	help
 	  Select this option to run Linux as a Hyper-V client operating
 	  system.
@@ -44,18 +45,25 @@ config HYPERV_TIMER
 
 config HYPERV_UTILS
 	tristate "Microsoft Hyper-V Utilities driver"
-	depends on HYPERV && CONNECTOR && NLS
+	depends on HYPERV_VMBUS && CONNECTOR && NLS
 	depends on PTP_1588_CLOCK_OPTIONAL
 	help
 	  Select this option to enable the Hyper-V Utilities.
 
 config HYPERV_BALLOON
 	tristate "Microsoft Hyper-V Balloon driver"
-	depends on HYPERV
+	depends on HYPERV_VMBUS
 	select PAGE_REPORTING
 	help
 	  Select this option to enable Hyper-V Balloon driver.
 
+config HYPERV_VMBUS
+	tristate "Microsoft Hyper-V VMBus driver"
+	depends on HYPERV
+	default HYPERV
+	help
+	  Select this option to enable Hyper-V Vmbus driver.
+
 config MSHV_ROOT
 	tristate "Microsoft Hyper-V root partition support"
 	depends on HYPERV && (X86_64 || ARM64)
@@ -66,6 +74,7 @@ config MSHV_ROOT
 	# no particular order, making it impossible to reassemble larger pages
 	depends on PAGE_SIZE_4KB
 	select EVENTFD
+	select VIRT_XFER_TO_GUEST_WORK
 	default n
 	help
 	  Select this option to enable support for booting and running as root
diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
index 976189c725dc..1a1677bf4dac 100644
--- a/drivers/hv/Makefile
+++ b/drivers/hv/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_HYPERV)		+= hv_vmbus.o
+obj-$(CONFIG_HYPERV_VMBUS)	+= hv_vmbus.o
 obj-$(CONFIG_HYPERV_UTILS)	+= hv_utils.o
 obj-$(CONFIG_HYPERV_BALLOON)	+= hv_balloon.o
 obj-$(CONFIG_MSHV_ROOT)		+= mshv_root.o
@@ -16,5 +16,5 @@ mshv_root-y := mshv_root_main.o mshv_synic.o mshv_eventfd.o mshv_irq.o \
 	       mshv_root_hv_call.o mshv_portid_table.o
 
 # Code that must be built-in
-obj-$(subst m,y,$(CONFIG_HYPERV)) += hv_common.o
+obj-$(CONFIG_HYPERV) += hv_common.o
 obj-$(subst m,y,$(CONFIG_MSHV_ROOT)) += hv_proc.o mshv_common.o
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 7c7c66e0dc3f..162d6aeece7b 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -925,7 +925,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 
 	/* Send a closing message */
 
-	msg = &channel->close_msg.msg;
+	msg = &channel->close_msg;
 
 	msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 	msg->child_relid = channel->offermsg.child_relid;
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 49898d10faff..e109a620c83f 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -257,7 +257,7 @@ static void hv_kmsg_dump_register(void)
 
 static inline bool hv_output_page_exists(void)
 {
-	return hv_root_partition() || IS_ENABLED(CONFIG_HYPERV_VTL_MODE);
+	return hv_parent_partition() || IS_ENABLED(CONFIG_HYPERV_VTL_MODE);
 }
 
 void __init hv_get_partition_id(void)
@@ -377,7 +377,7 @@ int __init hv_common_init(void)
 		BUG_ON(!hyperv_pcpu_output_arg);
 	}
 
-	if (hv_root_partition()) {
+	if (hv_parent_partition()) {
 		hv_synic_eventring_tail = alloc_percpu(u8 *);
 		BUG_ON(!hv_synic_eventring_tail);
 	}
@@ -531,7 +531,7 @@ int hv_common_cpu_init(unsigned int cpu)
 	if (msr_vp_index > hv_max_vp_index)
 		hv_max_vp_index = msr_vp_index;
 
-	if (hv_root_partition()) {
+	if (hv_parent_partition()) {
 		synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail);
 		*synic_eventring_tail = kcalloc(HV_SYNIC_SINT_COUNT,
 						sizeof(u8), flags);
@@ -558,7 +558,7 @@ int hv_common_cpu_die(unsigned int cpu)
 	 * originally allocated memory is reused in hv_common_cpu_init().
 	 */
 
-	if (hv_root_partition()) {
+	if (hv_parent_partition()) {
 		synic_eventring_tail = this_cpu_ptr(hv_synic_eventring_tail);
 		kfree(*synic_eventring_tail);
 		*synic_eventring_tail = NULL;
@@ -729,13 +729,17 @@ void hv_identify_partition_type(void)
 	 * the root partition setting if also a Confidential VM.
 	 */
 	if ((ms_hyperv.priv_high & HV_CREATE_PARTITIONS) &&
-	    (ms_hyperv.priv_high & HV_CPU_MANAGEMENT) &&
 	    !(ms_hyperv.priv_high & HV_ISOLATION)) {
-		pr_info("Hyper-V: running as root partition\n");
-		if (IS_ENABLED(CONFIG_MSHV_ROOT))
-			hv_curr_partition_type = HV_PARTITION_TYPE_ROOT;
-		else
+
+		if (!IS_ENABLED(CONFIG_MSHV_ROOT)) {
 			pr_crit("Hyper-V: CONFIG_MSHV_ROOT not enabled!\n");
+		} else if (ms_hyperv.priv_high & HV_CPU_MANAGEMENT) {
+			pr_info("Hyper-V: running as root partition\n");
+			hv_curr_partition_type = HV_PARTITION_TYPE_ROOT;
+		} else {
+			pr_info("Hyper-V: running as L1VH partition\n");
+			hv_curr_partition_type = HV_PARTITION_TYPE_L1VH;
+		}
 	}
 }
 
diff --git a/drivers/hv/hv_utils_transport.c b/drivers/hv/hv_utils_transport.c
index 832885198643..b3de35ff6334 100644
--- a/drivers/hv/hv_utils_transport.c
+++ b/drivers/hv/hv_utils_transport.c
@@ -129,8 +129,7 @@ static int hvt_op_open(struct inode *inode, struct file *file)
 		 * device gets released.
 		 */
 		hvt->mode = HVUTIL_TRANSPORT_CHARDEV;
-	}
-	else if (hvt->mode == HVUTIL_TRANSPORT_NETLINK) {
+	} else if (hvt->mode == HVUTIL_TRANSPORT_NETLINK) {
 		/*
 		 * We're switching from netlink communication to using char
 		 * device. Issue the reset first.
@@ -195,7 +194,7 @@ static void hvt_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 	}
 	spin_unlock(&hvt_list_lock);
 	if (!hvt_found) {
-		pr_warn("hvt_cn_callback: spurious message received!\n");
+		pr_warn("%s: spurious message received!\n", __func__);
 		return;
 	}
 
@@ -210,7 +209,7 @@ static void hvt_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 	if (hvt->mode == HVUTIL_TRANSPORT_NETLINK)
 		hvt_found->on_msg(msg->data, msg->len);
 	else
-		pr_warn("hvt_cn_callback: unexpected netlink message!\n");
+		pr_warn("%s: unexpected netlink message!\n", __func__);
 	mutex_unlock(&hvt->lock);
 }
 
@@ -260,8 +259,9 @@ int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len,
 		hvt->outmsg_len = len;
 		hvt->on_read = on_read_cb;
 		wake_up_interruptible(&hvt->outmsg_q);
-	} else
+	} else {
 		ret = -ENOMEM;
+	}
 out_unlock:
 	mutex_unlock(&hvt->lock);
 	return ret;
diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h
index 0340a67acd0a..d4813df92b9c 100644
--- a/drivers/hv/mshv.h
+++ b/drivers/hv/mshv.h
@@ -25,6 +25,4 @@ int hv_call_set_vp_registers(u32 vp_index, u64 partition_id, u16 count,
 int hv_call_get_partition_property(u64 partition_id, u64 property_code,
 				   u64 *property_value);
 
-int mshv_do_pre_guest_mode_work(ulong th_flags);
-
 #endif /* _MSHV_H */
diff --git a/drivers/hv/mshv_common.c b/drivers/hv/mshv_common.c
index 6f227a8a5af7..aa2be51979fd 100644
--- a/drivers/hv/mshv_common.c
+++ b/drivers/hv/mshv_common.c
@@ -138,25 +138,3 @@ int hv_call_get_partition_property(u64 partition_id,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(hv_call_get_partition_property);
-
-/*
- * Handle any pre-processing before going into the guest mode on this cpu, most
- * notably call schedule(). Must be invoked with both preemption and
- * interrupts enabled.
- *
- * Returns: 0 on success, -errno on error.
- */
-int mshv_do_pre_guest_mode_work(ulong th_flags)
-{
-	if (th_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
-		return -EINTR;
-
-	if (th_flags & _TIF_NEED_RESCHED)
-		schedule();
-
-	if (th_flags & _TIF_NOTIFY_RESUME)
-		resume_user_mode_work(NULL);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(mshv_do_pre_guest_mode_work);
diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
index 72df774e410a..e3b2bd417c46 100644
--- a/drivers/hv/mshv_root_main.c
+++ b/drivers/hv/mshv_root_main.c
@@ -8,6 +8,7 @@
  * Authors: Microsoft Linux virtualization team
  */
 
+#include <linux/entry-virt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/fs.h>
@@ -37,12 +38,6 @@ MODULE_AUTHOR("Microsoft");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Microsoft Hyper-V root partition VMM interface /dev/mshv");
 
-/* TODO move this to mshyperv.h when needed outside driver */
-static inline bool hv_parent_partition(void)
-{
-	return hv_root_partition();
-}
-
 /* TODO move this to another file when debugfs code is added */
 enum hv_stats_vp_counters {			/* HV_THREAD_COUNTER */
 #if defined(CONFIG_X86)
@@ -487,28 +482,6 @@ mshv_vp_wait_for_hv_kick(struct mshv_vp *vp)
 	return 0;
 }
 
-static int mshv_pre_guest_mode_work(struct mshv_vp *vp)
-{
-	const ulong work_flags = _TIF_NOTIFY_SIGNAL | _TIF_SIGPENDING |
-				 _TIF_NEED_RESCHED  | _TIF_NOTIFY_RESUME;
-	ulong th_flags;
-
-	th_flags = read_thread_flags();
-	while (th_flags & work_flags) {
-		int ret;
-
-		/* nb: following will call schedule */
-		ret = mshv_do_pre_guest_mode_work(th_flags);
-
-		if (ret)
-			return ret;
-
-		th_flags = read_thread_flags();
-	}
-
-	return 0;
-}
-
 /* Must be called with interrupts enabled */
 static long mshv_run_vp_with_root_scheduler(struct mshv_vp *vp)
 {
@@ -529,9 +502,11 @@ static long mshv_run_vp_with_root_scheduler(struct mshv_vp *vp)
 		u32 flags = 0;
 		struct hv_output_dispatch_vp output;
 
-		ret = mshv_pre_guest_mode_work(vp);
-		if (ret)
-			break;
+		if (__xfer_to_guest_mode_work_pending()) {
+			ret = xfer_to_guest_mode_handle_work();
+			if (ret)
+				break;
+		}
 
 		if (vp->run.flags.intercept_suspend)
 			flags |= HV_DISPATCH_VP_FLAG_CLEAR_INTERCEPT_SUSPEND;
@@ -2074,9 +2049,13 @@ static int __init hv_retrieve_scheduler_type(enum hv_scheduler_type *out)
 /* Retrieve and stash the supported scheduler type */
 static int __init mshv_retrieve_scheduler_type(struct device *dev)
 {
-	int ret;
+	int ret = 0;
+
+	if (hv_l1vh_partition())
+		hv_scheduler_type = HV_SCHEDULER_TYPE_CORE_SMT;
+	else
+		ret = hv_retrieve_scheduler_type(&hv_scheduler_type);
 
-	ret = hv_retrieve_scheduler_type(&hv_scheduler_type);
 	if (ret)
 		return ret;
 
@@ -2203,9 +2182,6 @@ static int __init mshv_root_partition_init(struct device *dev)
 {
 	int err;
 
-	if (mshv_retrieve_scheduler_type(dev))
-		return -ENODEV;
-
 	err = root_scheduler_init(dev);
 	if (err)
 		return err;
@@ -2227,7 +2203,7 @@ static int __init mshv_parent_partition_init(void)
 	struct device *dev;
 	union hv_hypervisor_version_info version_info;
 
-	if (!hv_root_partition() || is_kdump_kernel())
+	if (!hv_parent_partition() || is_kdump_kernel())
 		return -ENODEV;
 
 	if (hv_get_hypervisor_version(&version_info))
@@ -2264,7 +2240,12 @@ static int __init mshv_parent_partition_init(void)
 
 	mshv_cpuhp_online = ret;
 
-	ret = mshv_root_partition_init(dev);
+	ret = mshv_retrieve_scheduler_type(dev);
+	if (ret)
+		goto remove_cpu_state;
+
+	if (hv_root_partition())
+		ret = mshv_root_partition_init(dev);
 	if (ret)
 		goto remove_cpu_state;
 
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 2ed5a1e89d69..69591dc7bad2 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -322,7 +322,7 @@ static ssize_t out_read_index_show(struct device *dev,
 					  &outbound);
 	if (ret < 0)
 		return ret;
-	return sysfs_emit(buf, "%d\n", outbound.current_read_index);
+	return sysfs_emit(buf, "%u\n", outbound.current_read_index);
 }
 static DEVICE_ATTR_RO(out_read_index);
 
@@ -341,7 +341,7 @@ static ssize_t out_write_index_show(struct device *dev,
 					  &outbound);
 	if (ret < 0)
 		return ret;
-	return sysfs_emit(buf, "%d\n", outbound.current_write_index);
+	return sysfs_emit(buf, "%u\n", outbound.current_write_index);
 }
 static DEVICE_ATTR_RO(out_write_index);
 
@@ -1742,7 +1742,7 @@ static ssize_t target_cpu_store(struct vmbus_channel *channel,
 	u32 target_cpu;
 	ssize_t ret;
 
-	if (sscanf(buf, "%uu", &target_cpu) != 1)
+	if (sscanf(buf, "%u", &target_cpu) != 1)
 		return -EIO;
 
 	cpus_read_lock();
@@ -1947,7 +1947,7 @@ static const struct kobj_type vmbus_chan_ktype = {
  * is running.
  * For example, HV_NIC device is used either by uio_hv_generic or hv_netvsc at any given point of
  * time, and "ring" sysfs is needed only when uio_hv_generic is bound to that device. To avoid
- * exposing the ring buffer by default, this function is reponsible to enable visibility of
+ * exposing the ring buffer by default, this function is responsible to enable visibility of
  * ring for userspace to use.
  * Note: Race conditions can happen with userspace and it is not encouraged to create new
  * use-cases for this. This was added to maintain backward compatibility, while solving
@@ -2110,7 +2110,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 	ret = vmbus_add_channel_kobj(child_device_obj,
 				     child_device_obj->channel);
 	if (ret) {
-		pr_err("Unable to register primary channeln");
+		pr_err("Unable to register primary channel\n");
 		goto err_kset_unregister;
 	}
 	hv_debug_add_dev_dir(child_device_obj);
diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index 17edc1597446..c7ef347a4dff 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -276,8 +276,8 @@ config SERIO_OLPC_APSP
 
 config HYPERV_KEYBOARD
 	tristate "Microsoft Synthetic Keyboard driver"
-	depends on HYPERV
-	default HYPERV
+	depends on HYPERV_VMBUS
+	default HYPERV_VMBUS
 	help
 	  Select this option to enable the Hyper-V Keyboard driver.
 
diff --git a/drivers/net/hyperv/Kconfig b/drivers/net/hyperv/Kconfig
index c8cbd85adcf9..982964c1a9fb 100644
--- a/drivers/net/hyperv/Kconfig
+++ b/drivers/net/hyperv/Kconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config HYPERV_NET
 	tristate "Microsoft Hyper-V virtual network driver"
-	depends on HYPERV
+	depends on HYPERV_VMBUS
 	select UCS2_STRING
 	select NLS
 	help
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 9a249c65aedc..7065a8e5f9b1 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -221,7 +221,7 @@ config PCI_LABEL
 
 config PCI_HYPERV
 	tristate "Hyper-V PCI Frontend"
-	depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS
+	depends on ((X86 && X86_64) || ARM64) && HYPERV_VMBUS && PCI_MSI && SYSFS
 	select PCI_HYPERV_INTERFACE
 	select IRQ_MSI_LIB
 	help
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 5522310bab8d..19d0884479a2 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -589,7 +589,7 @@ config XEN_SCSI_FRONTEND
 
 config HYPERV_STORAGE
 	tristate "Microsoft Hyper-V virtual storage driver"
-	depends on SCSI && HYPERV
+	depends on SCSI && HYPERV_VMBUS
 	depends on m || SCSI_FC_ATTRS != m
 	default HYPERV
 	help
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index b060dcd7c635..6f86a61231e6 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -140,7 +140,7 @@ config UIO_MF624
 
 config UIO_HV_GENERIC
 	tristate "Generic driver for Hyper-V VMBus"
-	depends on HYPERV
+	depends on HYPERV_VMBUS
 	help
 	  Generic driver that you can bind, dynamically, to any
 	  Hyper-V VMBus device. It is useful to provide direct access
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index c21484d15f0c..c3b9954df804 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -1773,13 +1773,16 @@ config FB_BROADSHEET
 	  a bridge adapter.
 
 config FB_HYPERV
-	tristate "Microsoft Hyper-V Synthetic Video support"
-	depends on FB && HYPERV
+	tristate "Microsoft Hyper-V Synthetic Video support (DEPRECATED)"
+	depends on FB && HYPERV_VMBUS
 	select DMA_CMA if HAVE_DMA_CONTIGUOUS && CMA
 	select FB_IOMEM_HELPERS_DEFERRED
 	help
 	  This framebuffer driver supports Microsoft Hyper-V Synthetic Video.
 
+	  This driver is deprecated, please use the Hyper-V DRM driver at
+	  drivers/gpu/drm/hyperv (CONFIG_DRM_HYPERV) instead.
+
 config FB_SIMPLE
 	tristate "Simple framebuffer support"
 	depends on FB
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index 75338ffc703f..c99e2ea4b3de 100644
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -1357,6 +1357,8 @@ static int __init hvfb_drv_init(void)
 {
 	int ret;
 
+	pr_warn("Deprecated: use Hyper-V DRM driver instead\n");
+
 	if (fb_modesetting_disabled("hyper_fb"))
 		return -ENODEV;
 
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index a729b77983fa..64ba6bc807d9 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -31,6 +31,7 @@
 enum hv_partition_type {
 	HV_PARTITION_TYPE_GUEST,
 	HV_PARTITION_TYPE_ROOT,
+	HV_PARTITION_TYPE_L1VH,
 };
 
 struct ms_hyperv_info {
@@ -162,6 +163,7 @@ static inline u64 hv_generate_guest_id(u64 kernel_version)
 	return guest_id;
 }
 
+#if IS_ENABLED(CONFIG_HYPERV_VMBUS)
 /* Free the message slot and signal end-of-message if required */
 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 {
@@ -197,6 +199,10 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 	}
 }
 
+extern int vmbus_interrupt;
+extern int vmbus_irq;
+#endif /* CONFIG_HYPERV_VMBUS */
+
 int hv_get_hypervisor_version(union hv_hypervisor_version_info *info);
 
 void hv_setup_vmbus_handler(void (*handler)(void));
@@ -210,9 +216,6 @@ void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 void hv_remove_crash_handler(void);
 void hv_setup_mshv_handler(void (*handler)(void));
 
-extern int vmbus_interrupt;
-extern int vmbus_irq;
-
 #if IS_ENABLED(CONFIG_HYPERV)
 /*
  * Hypervisor's notion of virtual processor ID is different from
@@ -354,12 +357,22 @@ static inline bool hv_root_partition(void)
 {
 	return hv_curr_partition_type == HV_PARTITION_TYPE_ROOT;
 }
+static inline bool hv_l1vh_partition(void)
+{
+	return hv_curr_partition_type == HV_PARTITION_TYPE_L1VH;
+}
+static inline bool hv_parent_partition(void)
+{
+	return hv_root_partition() || hv_l1vh_partition();
+}
 int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
 int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
 int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
 
 #else /* CONFIG_MSHV_ROOT */
 static inline bool hv_root_partition(void) { return false; }
+static inline bool hv_l1vh_partition(void) { return false; }
+static inline bool hv_parent_partition(void) { return false; }
 static inline int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
 {
 	return -EOPNOTSUPP;
diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
index 1be7f6a02304..77abddfc750e 100644
--- a/include/hyperv/hvgdk_mini.h
+++ b/include/hyperv/hvgdk_mini.h
@@ -597,8 +597,6 @@ struct ms_hyperv_tsc_page {	 /* HV_REFERENCE_TSC_PAGE */
 #define HV_SYNIC_SINT_AUTO_EOI		(1ULL << 17)
 #define HV_SYNIC_SINT_VECTOR_MASK	(0xFF)
 
-#
-
 /* Hyper-V defined statically assigned SINTs */
 #define HV_SYNIC_INTERCEPTION_SINT_INDEX 0x00000000
 #define HV_SYNIC_IOMMU_FAULT_SINT_INDEX  0x00000001
diff --git a/include/hyperv/hvhdk_mini.h b/include/hyperv/hvhdk_mini.h
index 42e7876455b5..858f6a3925b3 100644
--- a/include/hyperv/hvhdk_mini.h
+++ b/include/hyperv/hvhdk_mini.h
@@ -301,6 +301,7 @@ struct hv_input_map_device_interrupt {
 /* HV_OUTPUT_MAP_DEVICE_INTERRUPT */
 struct hv_output_map_device_interrupt {
 	struct hv_interrupt_entry interrupt_entry;
+	u64 ext_status_deprecated[5];
 } __packed;
 
 /* HV_INPUT_UNMAP_DEVICE_INTERRUPT */
diff --git a/include/linux/entry-kvm.h b/include/linux/entry-virt.h
index 16149f6625e4..42c89e3e5ca7 100644
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-virt.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_ENTRYKVM_H
-#define __LINUX_ENTRYKVM_H
+#ifndef __LINUX_ENTRYVIRT_H
+#define __LINUX_ENTRYVIRT_H
 
 #include <linux/static_call_types.h>
 #include <linux/resume_user_mode.h>
@@ -10,7 +10,7 @@
 #include <linux/tick.h>
 
 /* Transfer to guest mode work */
-#ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
+#ifdef CONFIG_VIRT_XFER_TO_GUEST_WORK
 
 #ifndef ARCH_XFER_TO_GUEST_MODE_WORK
 # define ARCH_XFER_TO_GUEST_MODE_WORK	(0)
@@ -21,8 +21,6 @@
 	 _TIF_NOTIFY_SIGNAL | _TIF_NOTIFY_RESUME |			\
 	 ARCH_XFER_TO_GUEST_MODE_WORK)
 
-struct kvm_vcpu;
-
 /**
  * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
  *					 mode work handling function.
@@ -32,12 +30,10 @@ struct kvm_vcpu;
  * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
  * replaced by architecture specific code.
  */
-static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
-						      unsigned long ti_work);
+static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work);
 
 #ifndef arch_xfer_to_guest_mode_work
-static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
-						      unsigned long ti_work)
+static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work)
 {
 	return 0;
 }
@@ -46,11 +42,10 @@ static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
 /**
  * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
  *				    to be handled before going to guest mode
- * @vcpu:	Pointer to current's VCPU data
  *
  * Returns: 0 or an error code
  */
-int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
+int xfer_to_guest_mode_handle_work(void);
 
 /**
  * xfer_to_guest_mode_prepare - Perform last minute preparation work that
@@ -95,6 +90,6 @@ static inline bool xfer_to_guest_mode_work_pending(void)
 	lockdep_assert_irqs_disabled();
 	return __xfer_to_guest_mode_work_pending();
 }
-#endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
+#endif /* CONFIG_VIRT_XFER_TO_GUEST_WORK */
 
 #endif
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index a59c5c3e95fb..59826c89171c 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -707,11 +707,6 @@ struct vmbus_channel_msginfo {
 	unsigned char msg[];
 };
 
-struct vmbus_close_msg {
-	struct vmbus_channel_msginfo info;
-	struct vmbus_channel_close_channel msg;
-};
-
 enum vmbus_device_type {
 	HV_IDE = 0,
 	HV_SCSI,
@@ -800,7 +795,7 @@ struct vmbus_channel {
 	struct hv_ring_buffer_info outbound;	/* send to parent */
 	struct hv_ring_buffer_info inbound;	/* receive from parent */
 
-	struct vmbus_close_msg close_msg;
+	struct vmbus_channel_close_channel close_msg;
 
 	/* Statistics */
 	u64	interrupts;	/* Host to Guest interrupts */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 19b8c4bebb9c..fa36e70df088 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2,7 +2,7 @@
 #ifndef __KVM_HOST_H
 #define __KVM_HOST_H
 
-
+#include <linux/entry-virt.h>
 #include <linux/types.h>
 #include <linux/hardirq.h>
 #include <linux/list.h>
@@ -2450,13 +2450,24 @@ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 }
 #endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
 
-#ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
+#ifdef CONFIG_VIRT_XFER_TO_GUEST_WORK
 static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
 {
 	vcpu->run->exit_reason = KVM_EXIT_INTR;
 	vcpu->stat.signal_exits++;
 }
-#endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
+
+static inline int kvm_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+{
+	int r = xfer_to_guest_mode_handle_work();
+
+	if (r) {
+		WARN_ON_ONCE(r != -EINTR);
+		kvm_handle_signal_exit(vcpu);
+	}
+	return r;
+}
+#endif /* CONFIG_VIRT_XFER_TO_GUEST_WORK */
 
 /*
  * If more than one page is being (un)accounted, @virt must be the address of
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 621b200d9b87..c5b30054cd01 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -129,7 +129,7 @@ static inline void rcu_sysrq_start(void) { }
 static inline void rcu_sysrq_end(void) { }
 #endif /* #else #ifdef CONFIG_RCU_STALL_COMMON */
 
-#if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK))
+#if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_VIRT_XFER_TO_GUEST_WORK))
 void rcu_irq_work_resched(void);
 #else
 static __always_inline void rcu_irq_work_resched(void) { }
diff --git a/kernel/entry/Makefile b/kernel/entry/Makefile
index 77fcd83dd663..2333d70802e4 100644
--- a/kernel/entry/Makefile
+++ b/kernel/entry/Makefile
@@ -14,4 +14,4 @@ CFLAGS_common.o		+= -fno-stack-protector
 
 obj-$(CONFIG_GENERIC_IRQ_ENTRY) 	+= common.o
 obj-$(CONFIG_GENERIC_SYSCALL) 		+= syscall-common.o syscall_user_dispatch.o
-obj-$(CONFIG_KVM_XFER_TO_GUEST_WORK)	+= kvm.o
+obj-$(CONFIG_VIRT_XFER_TO_GUEST_WORK)	+= virt.o
diff --git a/kernel/entry/kvm.c b/kernel/entry/virt.c
index 8485f63863af..c52f99249763 100644
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/virt.c
@@ -1,17 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0
 
-#include <linux/entry-kvm.h>
-#include <linux/kvm_host.h>
+#include <linux/entry-virt.h>
 
-static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
+static int xfer_to_guest_mode_work(unsigned long ti_work)
 {
 	do {
 		int ret;
 
-		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
-			kvm_handle_signal_exit(vcpu);
+		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
 			return -EINTR;
-		}
 
 		if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY))
 			schedule();
@@ -19,7 +16,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
 		if (ti_work & _TIF_NOTIFY_RESUME)
 			resume_user_mode_work(NULL);
 
-		ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
+		ret = arch_xfer_to_guest_mode_handle_work(ti_work);
 		if (ret)
 			return ret;
 
@@ -28,7 +25,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
 	return 0;
 }
 
-int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+int xfer_to_guest_mode_handle_work(void)
 {
 	unsigned long ti_work;
 
@@ -44,6 +41,6 @@ int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
 	if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
 		return 0;
 
-	return xfer_to_guest_mode_work(vcpu, ti_work);
+	return xfer_to_guest_mode_work(ti_work);
 }
 EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 31690ffa452a..8293bae1dec1 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -573,7 +573,7 @@ void rcutorture_format_gp_seqs(unsigned long long seqs, char *cp, size_t len)
 }
 EXPORT_SYMBOL_GPL(rcutorture_format_gp_seqs);
 
-#if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK))
+#if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_VIRT_XFER_TO_GUEST_WORK))
 /*
  * An empty function that will trigger a reschedule on
  * IRQ tail once IRQs get re-enabled on userspace/guest resume.
@@ -602,7 +602,7 @@ noinstr void rcu_irq_work_resched(void)
 	if (IS_ENABLED(CONFIG_GENERIC_ENTRY) && !(current->flags & PF_VCPU))
 		return;
 
-	if (IS_ENABLED(CONFIG_KVM_XFER_TO_GUEST_WORK) && (current->flags & PF_VCPU))
+	if (IS_ENABLED(CONFIG_VIRT_XFER_TO_GUEST_WORK) && (current->flags & PF_VCPU))
 		return;
 
 	instrumentation_begin();
@@ -611,7 +611,7 @@ noinstr void rcu_irq_work_resched(void)
 	}
 	instrumentation_end();
 }
-#endif /* #if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK)) */
+#endif /* #if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_VIRT_XFER_TO_GUEST_WORK)) */
 
 #ifdef CONFIG_PROVE_RCU
 /**
diff --git a/net/vmw_vsock/Kconfig b/net/vmw_vsock/Kconfig
index 56356d2980c8..8e803c4828c4 100644
--- a/net/vmw_vsock/Kconfig
+++ b/net/vmw_vsock/Kconfig
@@ -72,7 +72,7 @@ config VIRTIO_VSOCKETS_COMMON
 
 config HYPERV_VSOCKETS
 	tristate "Hyper-V transport for Virtual Sockets"
-	depends on VSOCKETS && HYPERV
+	depends on VSOCKETS && HYPERV_VMBUS
 	help
 	  This module implements a Hyper-V transport for Virtual Sockets.
 
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 1b7d5be0b6c4..0227e13cd8dd 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -87,7 +87,7 @@ config HAVE_KVM_VCPU_RUN_PID_CHANGE
 config HAVE_KVM_NO_POLL
        bool
 
-config KVM_XFER_TO_GUEST_WORK
+config VIRT_XFER_TO_GUEST_WORK
        bool
 
 config HAVE_KVM_PM_NOTIFIER