Merge tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Wei Liu:

 - VMBus hardening patches from Andrea Parri and Andres Beltran.

 - Patches to make Linux boot as the root partition on Microsoft
   Hypervisor from Wei Liu.

 - One patch to add a new sysfs interface to support hibernation on
   Hyper-V from Dexuan Cui.

 - Two miscellaneous clean-up patches from Colin and Gustavo.

* tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (31 commits)
  Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"
  iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partition
  x86/hyperv: implement an MSI domain for root partition
  asm-generic/hyperv: import data structures for mapping device interrupts
  asm-generic/hyperv: introduce hv_device_id and auxiliary structures
  asm-generic/hyperv: update hv_interrupt_entry
  asm-generic/hyperv: update hv_msi_entry
  x86/hyperv: implement and use hv_smp_prepare_cpus
  x86/hyperv: provide a bunch of helper functions
  ACPI / NUMA: add a stub function for node_to_pxm()
  x86/hyperv: handling hypercall page setup for root
  x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary
  x86/hyperv: allocate output arg pages if required
  clocksource/hyperv: use MSR-based access if running as root
  Drivers: hv: vmbus: skip VMBus initialization if Linux is root
  x86/hyperv: detect if Linux is the root partition
  asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT
  hv: hyperv.h: Replace one-element array with flexible-array in struct icmsg_negotiate
  hv_netvsc: Restrict configurations on isolated guests
  Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guests
  ...

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index ba04cb381cd3..269a691bd2c4 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -426,6 +426,9 @@ static bool __init hv_init_tsc_clocksource(void)
 	if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
 		return false;
 
+	if (hv_root_partition)
+		return false;
+
 	hv_read_reference_counter = read_hv_clock_tsc;
 	phys_addr = virt_to_phys(hv_get_tsc_page());