From: Naman Jain <[email protected]> Sent: Thursday, October 8, 2026 9:39 PM > > On 10/9/2026 8:04 AM, Michael Kelley wrote: > > Support for running Linux guests on Windows Server 2012/2012 R2 Hyper-V > > hosts and Windows 8/8.1 hosts has been removed, which includes removing > > support for operating Hyper-V synthetic timers in other than Direct Mode. > > Update the documentation to reflect these removals. > > > > Signed-off-by: Michael Kelley <[email protected]> > > --- > > This patch reflects changes that are already in linux-next for merging > > into the 7.4 kernel. > > > > Documentation/virt/hyperv/clocks.rst | 8 ++------ > > Documentation/virt/hyperv/overview.rst | 6 +++--- > > 2 files changed, 5 insertions(+), 9 deletions(-) > > > > diff --git a/Documentation/virt/hyperv/clocks.rst > b/Documentation/virt/hyperv/clocks.rst > > index 176043265803..9527e6073654 100644 > > --- a/Documentation/virt/hyperv/clocks.rst > > +++ b/Documentation/virt/hyperv/clocks.rst > > @@ -64,12 +64,8 @@ applying the scale and offset to get the constant 10 MHz > > clock. > > > > Linux clockevents are based on Hyper-V synthetic timer 0 (stimer0). > > While Hyper-V offers 4 synthetic timers for each CPU, Linux only uses > > -timer 0. In older versions of Hyper-V, an interrupt from stimer0 > > -results in a VMBus control message that is demultiplexed by > > -vmbus_isr() as described in the Documentation/virt/hyperv/vmbus.rst > > -documentation. In newer versions of Hyper-V, stimer0 interrupts can > > -be mapped to an architectural interrupt, which is referred to as > > -"Direct Mode". Linux prefers to use Direct Mode when available. Since > > +timer 0. stimer0 is operated in what Hyper-V calls "Direct Mode" > > +where timer interrupts are mapped to an architectural interrupt. Since > > x86/x64 doesn't support per-CPU interrupts, Direct Mode statically > > allocates an x86 interrupt vector (HYPERV_STIMER0_VECTOR) across all CPUs > > and explicitly codes it to call the stimer0 interrupt handler. Hence > > diff --git a/Documentation/virt/hyperv/overview.rst > b/Documentation/virt/hyperv/overview.rst > > index 77408a89d1a4..c4c262b77aa3 100644 > > --- a/Documentation/virt/hyperv/overview.rst > > +++ b/Documentation/virt/hyperv/overview.rst > > @@ -157,9 +157,9 @@ when accessing data shared with Hyper-V. > > Versioning > > ---------- > > Current Linux kernels operate correctly with older versions of > > -Hyper-V back to Windows Server 2012 Hyper-V. Support for running > > -on the original Hyper-V release in Windows Server 2008/2008 R2 > > -has been removed. > > +Hyper-V back to Windows Server 2016 Hyper-V and Windows 10. Support for > > +running on Windows Server 2012/2012 R2, Windows Server 2008/2008 R2, > > +and Windows 8.1 and earlier has been removed. > > > > A Linux guest on Hyper-V outputs in dmesg the version of Hyper-V > > it is running on. This version is in the form of a Windows build > > Thanks Michael. Change LGTM, but while at it, please add a similar > change in > Documentation/networking/device_drivers/ethernet/microsoft/netvsc.rst as > well.
Indeed. I wasn't even aware the netvsc documentation existed. :-( I can update the supported Hyper-V versions. But this documentation has not had any significant content updates since early 2021. Haiyang should review it from an overall content standpoint and make appropriate updates. I don't have the knowledge to do that. Michael > > Reviewed-by: Naman Jain <[email protected]> > > Regards, > Naman
