Merge tag 'hyperv-fixes-signed-20250718' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Select use CONFIG_SYSFB only if EFI is enabled (Michael Kelley)

 - An assorted set of fixes to remove warnings for missing export.h
   header inclusion (Naman Jain)

 - An assorted set of fixes for when Linux run as the root partition
   for Microsoft Hypervisor (Mukesh Rathor, Nuno Das Neves, Stanislav
   Kinsburskii)

 - Fix the check for HYPERVISOR_CALLBACK_VECTOR (Naman Jain)

 - Fix fcopy tool to handle irregularities with size of ring buffer
   (Naman Jain)

 - Fix incorrect file path conversion in fcopy tool (Yasumasa Suenaga)

* tag 'hyperv-fixes-signed-20250718' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  tools/hv: fcopy: Fix irregularities with size of ring buffer
  PCI: hv: Use the correct hypercall for unmasking interrupts on nested
  x86/hyperv: Expose hv_map_msi_interrupt()
  Drivers: hv: Use nested hypercall for post message and signal event
  x86/hyperv: Clean up hv_map/unmap_interrupt() return values
  x86/hyperv: Fix usage of cpu_online_mask to get valid cpu
  PCI: hv: Don't load the driver for baremetal root partition
  net: mana: Fix warnings for missing export.h header inclusion
  PCI: hv: Fix warnings for missing export.h header inclusion
  clocksource: hyper-v: Fix warnings for missing export.h header inclusion
  x86/hyperv: Fix warnings for missing export.h header inclusion
  Drivers: hv: Fix warnings for missing export.h header inclusion
  Drivers: hv: Fix the check for HYPERVISOR_CALLBACK_VECTOR
  tools/hv: fcopy: Fix incorrect file path conversion
  Drivers: hv: Select CONFIG_SYSFB only if EFI is enabled

1 files changed, 19 insertions, 2 deletions

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index ef5d655a0052..13680363ff19 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -600,7 +600,7 @@ static unsigned int hv_msi_get_int_vector(struct irq_data *data)
 #define hv_msi_prepare		pci_msi_prepare
 
 /**
- * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current
+ * hv_irq_retarget_interrupt() - "Unmask" the IRQ by setting its current
  * affinity.
  * @data:	Describes the IRQ
  *
@@ -609,7 +609,7 @@ static unsigned int hv_msi_get_int_vector(struct irq_data *data)
  * is built out of this PCI bus's instance GUID and the function
  * number of the device.
  */
-static void hv_arch_irq_unmask(struct irq_data *data)
+static void hv_irq_retarget_interrupt(struct irq_data *data)
 {
 	struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
 	struct hv_retarget_device_interrupt *params;
@@ -714,6 +714,20 @@ out:
 		dev_err(&hbus->hdev->device,
 			"%s() failed: %#llx", __func__, res);
 }
+
+static void hv_arch_irq_unmask(struct irq_data *data)
+{
+	if (hv_root_partition())
+		/*
+		 * In case of the nested root partition, the nested hypervisor
+		 * is taking care of interrupt remapping and thus the
+		 * MAP_DEVICE_INTERRUPT hypercall is required instead of
+		 * RETARGET_INTERRUPT.
+		 */
+		(void)hv_map_msi_interrupt(data, NULL);
+	else
+		hv_irq_retarget_interrupt(data);
+}
 #elif defined(CONFIG_ARM64)
 /*
  * SPI vectors to use for vPCI; arch SPIs range is [32, 1019], but leaving a bit
@@ -4144,6 +4158,9 @@ static int __init init_hv_pci_drv(void)
 	if (!hv_is_hyperv_initialized())
 		return -ENODEV;
 
+	if (hv_root_partition() && !hv_nested)
+		return -ENODEV;
+
 	ret = hv_pci_irqchip_init();
 	if (ret)
 		return ret;