linux.git/arch/x86/hyperv, branch v5.14

Drivers: hv: Move Hyper-V extended capability check to arch neutral code

2021-06-05T10:22:34+00:00

The extended capability query code is currently under arch/x86, but it
is architecture neutral, and is used by arch neutral code in the Hyper-V
balloon driver. Hence the balloon driver fails to build on other
architectures.

Fix by moving the ext cap code out from arch/x86.  Because it is also
called from built-in architecture specific code, it can't be in a module,
so the Makefile treats as built-in even when CONFIG_HYPERV is "m".  Also
drivers/Makefile is tweaked because this is the first occurrence of a
Hyper-V file that is built-in even when CONFIG_HYPERV is "m".

While here, update the hypercall status check to use the new helper
function instead of open coding. No functional change.

Signed-off-by: Michael Kelley 
Reviewed-by: Sunil Muthuswamy 
Link: https://lore.kernel.org/r/1622669804-2016-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu

Merge tag 'x86-mm-2021-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-04-29T18:41:43+00:00

Pull x86 tlb updates from Ingo Molnar:
 "The x86 MM changes in this cycle were:

   - Implement concurrent TLB flushes, which overlaps the local TLB
     flush with the remote TLB flush.

     In testing this improved sysbench performance measurably by a
     couple of percentage points, especially if TLB-heavy security
     mitigations are active.

   - Further micro-optimizations to improve the performance of TLB
     flushes"

* tag 'x86-mm-2021-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Micro-optimize smp_call_function_many_cond()
  smp: Inline on_each_cpu_cond() and on_each_cpu()
  x86/mm/tlb: Remove unnecessary uses of the inline keyword
  cpumask: Mark functions as pure
  x86/mm/tlb: Do not make is_lazy dirty for no reason
  x86/mm/tlb: Privatize cpu_tlbstate
  x86/mm/tlb: Flush remote and local TLBs concurrently
  x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy()
  x86/mm/tlb: Unify flush_tlb_func_local() and flush_tlb_func_remote()
  smp: Run functions concurrently in smp_call_function_many_cond()

Merge tag 'hyperv-next-signed-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2021-04-26T17:44:16+00:00

Pull Hyper-V updates from Wei Liu:

 - VMBus enhancement

 - Free page reporting support for Hyper-V balloon driver

 - Some patches for running Linux as Arm64 Hyper-V guest

 - A few misc clean-up patches

* tag 'hyperv-next-signed-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (30 commits)
  drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
  x86/hyperv: Move hv_do_rep_hypercall to asm-generic
  video: hyperv_fb: Add ratelimit on error message
  Drivers: hv: vmbus: Increase wait time for VMbus unload
  Drivers: hv: vmbus: Initialize unload_event statically
  Drivers: hv: vmbus: Check for pending channel interrupts before taking a CPU offline
  Drivers: hv: vmbus: Drivers: hv: vmbus: Introduce CHANNELMSG_MODIFYCHANNEL_RESPONSE
  Drivers: hv: vmbus: Introduce and negotiate VMBus protocol version 5.3
  Drivers: hv: vmbus: Use after free in __vmbus_open()
  Drivers: hv: vmbus: remove unused function
  Drivers: hv: vmbus: Remove unused linux/version.h header
  x86/hyperv: remove unused linux/version.h header
  x86/Hyper-V: Support for free page reporting
  x86/hyperv: Fix unused variable 'hi' warning in hv_apic_read
  x86/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_wait
  hv: hyperv.h: a few mundane typo fixes
  drivers: hv: Fix EXPORT_SYMBOL and tab spaces issue
  Drivers: hv: vmbus: Drop error message when 'No request id available'
  asm-generic/hyperv: Add missing function prototypes per -W1 warnings
  clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts
  ...

drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status

2021-04-21T09:49:19+00:00

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 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu

x86/hyperv: remove unused linux/version.h header

2021-04-02T22:07:26+00:00

That header is not needed in hv_proc.c.

Reported-by: Hulk Robot 
Signed-off-by: Yongjun Zheng 
Link: https://lore.kernel.org/r/20210326064942.3263776-1-zhengyongjun3@huawei.com
Signed-off-by: Wei Liu

x86/Hyper-V: Support for free page reporting

2021-03-24T11:35:24+00:00

Linux has support for free page reporting now (36e66c554b5c) 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 
Tested-by: Matheus Castello 
Reviewed-by: Michael Kelley 
Tested-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com
Signed-off-by: Wei Liu

x86/hyperv: Fix unused variable 'hi' warning in hv_apic_read

2021-03-24T11:32:56+00:00

Fixes the following W=1 kernel build warning(s):
arch/x86/hyperv/hv_apic.c:58:15: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable]

Compiled with CONFIG_HYPERV enabled:
make allmodconfig ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-
make W=1 arch/x86/hyperv/hv_apic.o ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu-

HV_X64_MSR_EOI occupies bit 31:0 and HV_X64_MSR_TPR occupies bit 7:0,
which means the higher 32 bits are not really used. Cast the variable hi
to void to silence this warning.

Reported-by: Hulk Robot 
Signed-off-by: Xu Yihang 
Link: https://lore.kernel.org/r/20210323025013.191533-1-xuyihang@huawei.com
Signed-off-by: Wei Liu

x86/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_wait

2021-03-24T11:31:04+00:00

Fixes the following W=1 kernel build warning(s):
arch/x86/hyperv/hv_spinlock.c:28:16: warning: variable ‘msr_val’ set but not used [-Wunused-but-set-variable]
  unsigned long msr_val;

As Hypervisor Top-Level Functional Specification states in chapter 7.5
Virtual Processor Idle Sleep State, "A partition which possesses the
AccessGuestIdleMsr privilege (refer to section 4.2.2) may trigger entry
into the virtual processor idle sleep state through a read to the
hypervisor-defined MSR HV_X64_MSR_GUEST_IDLE".

That means only a read of the MSR is necessary. The returned value
msr_val is not used. Cast it to void to silence this warning.

Reference:
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs

Reported-by: Hulk Robot 
Signed-off-by: Xu Yihang 
Link: https://lore.kernel.org/r/20210323024302.174434-1-xuyihang@huawei.com
Signed-off-by: Wei Liu

x86: Fix various typos in comments

2021-03-18T14:31:53+00:00

Fix ~144 single-word typos in arch/x86/ code comments.

Doing this in a single commit should reduce the churn.

Signed-off-by: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Paolo Bonzini 
Cc: Bjorn Helgaas 
Cc: linux-kernel@vger.kernel.org

clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts

2021-03-08T17:33:00+00:00

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 
Acked-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/1614721102-2241-11-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu