Commit Graph

16 Commits

Author SHA1 Message Date
Joseph Salisbury
753ed9c95c drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00
Joseph Salisbury
6523592cee x86/hyperv: Move hv_do_rep_hypercall to asm-generic
This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h

hv_do_rep_hypercall() is architecture independent, so it makes sense that it
should be in the architecture independent mshyperv.h, not in the x86-specific
mshyperv.h.

This is done in preperation for a follow up patch which creates a consistent
pattern for checking Hyper-V hypercall status.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-1-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00
Sunil Muthuswamy
6dc2a774cb x86/Hyper-V: Support for free page reporting
Linux has support for free page reporting now (36e66c554b) for
virtualized environment. On Hyper-V when virtually backed VMs are
configured, Hyper-V will advertise cold memory discard capability,
when supported. This patch adds the support to hook into the free
page reporting infrastructure and leverage the Hyper-V cold memory
discard hint hypercall to report/free these pages back to the host.

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Tested-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-24 11:35:24 +00:00
Michael Kelley
a620bbaa35 asm-generic/hyperv: Add missing function prototypes per -W1 warnings
Add two function prototypes for -W1 warnings generated by the
kernel test robot.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1615402069-39462-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-11 10:12:22 +00:00
Michael Kelley
ec866be6ec clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts
STIMER0 interrupts are most naturally modeled as per-cpu IRQs. But
because x86/x64 doesn't have per-cpu IRQs, the core STIMER0 interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used. Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception. Do this
by incorporating standard Linux per-cpu IRQ allocation into the main
SITMER0 driver code, and bypass it in the x86/x64 exception case. For
x86/x64, special case code is retained under arch/x86, but no STIMER0
interrupt handling code is needed under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1614721102-2241-11-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:33:00 +00:00
Michael Kelley
d608715d47 Drivers: hv: vmbus: Move handling of VMbus interrupts
VMbus interrupts are most naturally modelled as per-cpu IRQs.  But
because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used.  Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception.  Do this
by incorporating standard Linux per-cpu IRQ allocation into the main VMbus
driver, and bypassing it in the x86/x64 exception case. For x86/x64,
special case code is retained under arch/x86, but no VMbus interrupt
handling code is needed under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:33:00 +00:00
Michael Kelley
b548a77427 Drivers: hv: vmbus: Move hyperv_report_panic_msg to arch neutral code
With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be
architecture neutral, so move it out from under arch/x86 and merge into
hv_kmsg_dump(). This move also avoids needing a separate implementation
under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Michael Kelley
f3c5e63c36 Drivers: hv: Redo Hyper-V synthetic MSR get/set functions
Current code defines a separate get and set macro for each Hyper-V
synthetic MSR used by the VMbus driver. Furthermore, the get macro
can't be converted to a standard function because the second argument
is modified in place, which is somewhat bad form.

Redo this by providing a single get and a single set function that
take a parameter specifying the MSR to be operated on. Fixup usage
of the get function. Calling locations are no more complex than before,
but the code under arch/x86 and the upcoming code under arch/arm64
is significantly simplified.

Also standardize the names of Hyper-V synthetic MSRs that are
architecture neutral. But keep the old x86-specific names as aliases
that can be removed later when all references (particularly in KVM
code) have been cleaned up in a separate patch series.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Michael Kelley
ca48739e59 Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral code
The Hyper-V page allocator functions are implemented in an architecture
neutral way.  Move them into the architecture neutral VMbus module so
a separate implementation for ARM64 is not needed.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-2-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Andrea Parri (Microsoft)
a6c76bb08d x86/hyperv: Load/save the Isolation Configuration leaf
If bit 22 of Group B Features is set, the guest has access to the
Isolation Configuration CPUID leaf.  On x86, the first four bits
of EAX in this leaf provide the isolation type of the partition;
we entail three isolation types: 'SNP' (hardware-based isolation),
'VBS' (software-based isolation), and 'NONE' (no isolation).

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: x86@kernel.org
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20210201144814.2701-2-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11 08:47:05 +00:00
Michael Kelley
626b901f60 Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
On ARM64, Hyper-V now specifies the interrupt to be used by VMbus
in the ACPI DSDT.  This information is not used on x86 because the
interrupt vector must be hardcoded.  But update the generic
VMbus driver to do the parsing and pass the information to the
architecture specific code that sets up the Linux IRQ.  Update
consumers of the interrupt to get it from an architecture specific
function.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-14 19:14:51 +00:00
Michael Kelley
b9d8cf2eb3 x86/hyperv: Make hv_setup_sched_clock inline
Make hv_setup_sched_clock inline so the reference to pv_ops works
correctly with objtool updates to detect noinstr violations.
See https://lore.kernel.org/patchwork/patch/1283635/

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1597022991-24088-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-11 10:41:15 +00:00
Tianyu Lan
f3a99e761e x86/Hyper-V: Report crash data in die() when panic_on_oops is set
When oops happens with panic_on_oops unset, the oops
thread is killed by die() and system continues to run.
In such case, guest should not report crash register
data to host since system still runs. Check panic_on_oops
and return directly in hyperv_report_panic() when the function
is called in the die() and panic_on_oops is unset. Fix it.

Fixes: 7ed4325a44 ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11 17:19:07 +01:00
Dexuan Cui
b96f86534f x86/hyperv: Implement hv_is_hibernation_supported()
The API will be used by the hv_balloon and hv_vmbus drivers.

Balloon up/down and hot-add of memory must not be active if the user
wants the Linux VM to support hibernation, because they are incompatible
with hibernation according to Hyper-V team, e.g. upon suspend the
balloon VSP doesn't save any info about the ballooned-out pages (if any);
so, after Linux resumes, Linux balloon VSC expects that the VSP will
return the pages if Linux is under memory pressure, but the VSP will
never do that, since the VSP thinks it never stole the pages from the VM.

So, if the user wants Linux VM to support hibernation, Linux must forbid
balloon up/down and hot-add, and the only functionality of the balloon VSC
driver is reporting the VM's memory pressure to the host.

Ideally, when Linux detects that the user wants it to support hibernation,
the balloon VSC should tell the VSP that it does not support ballooning
and hot-add. However, the current version of the VSP requires the VSC
should support these capabilities, otherwise the capability negotiation
fails and the VSC can not load at all, so with the later changes to the
VSC driver, Linux VM still reports to the VSP that the VSC supports these
capabilities, but the VSC ignores the VSP's requests of balloon up/down
and hot add, and reports an error to the VSP, when applicable. BTW, in
the future the balloon VSP driver will allow the VSC to not support the
capabilities of balloon up/down and hot add.

The ACPI S4 state is not a must for hibernation to work, because Linux is
able to hibernate as long as the system can shut down. However in practice
we decide to artificially use the presence of the virtual ACPI S4 state as
an indicator of the user's intent of using hibernation, because Linux VM
must find a way to know if the user wants to use the hibernation feature
or not.

By default, Hyper-V does not enable the virtual ACPI S4 state; on recent
Hyper-V hosts (e.g. RS5, 19H1), the administrator is able to enable the
state for a VM by WMI commands.

Once all the vmbus and VSC patches for the hibernation feature are
accepted, an extra patch will be submitted to forbid hibernation if the
virtual ACPI S4 state is absent, i.e. hv_is_hibernation_supported() is
false.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Tianyu Lan
bd00cd52d5 clocksource/drivers/hyperv: Add Hyper-V specific sched clock function
Hyper-V guests use the default native_sched_clock() in
pv_ops.time.sched_clock on x86. But native_sched_clock() directly uses the
raw TSC value, which can be discontinuous in a Hyper-V VM.
    
Add the generic hv_setup_sched_clock() to set the sched clock function
appropriately. On x86, this sets pv_ops.time.sched_clock to read the
Hyper-V reference TSC value that is scaled and adjusted to be continuous.
    
Also move the Hyper-V reference TSC initialization much earlier in the boot
process so no discontinuity is observed when pv_ops.time.sched_clock
calculates its offset.

[ tglx: Folded build fix ]

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lkml.kernel.org/r/20190814123216.32245-3-Tianyu.Lan@microsoft.com
2019-08-23 16:59:54 +02:00
Michael Kelley
765e33f521 Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h
Break out parts of mshyperv.h that are ISA independent into a
separate file in include/asm-generic. This move facilitates
ARM64 code reusing these definitions and avoids code
duplication. No functionality or behavior is changed.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-08 19:06:27 -04:00