linux-toradex.git/arch, branch v6.11-rc3 Linux kernel for Apalis and Colibri modules Merge tag 'x86-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2024-08-11T17:20:29+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-08-11T17:20:29+00:00 7006fe2f7f781fc96c8bab9df0c0417fd670a8e1 Pull x86 fixes from Thomas Gleixner: - Fix 32-bit PTI for real. pti_clone_entry_text() is called twice, once before initcalls so that initcalls can use the user-mode helper and then again after text is set read only. Setting read only on 32-bit might break up the PMD mapping, which makes the second invocation of pti_clone_entry_text() find the mappings out of sync and failing. Allow the second call to split the existing PMDs in the user mapping and synchronize with the kernel mapping. - Don't make acpi_mp_wake_mailbox read-only after init as the mail box must be writable in the case that CPU hotplug operations happen after boot. Otherwise the attempt to start a CPU crashes with a write to read only memory. - Add a missing sanity check in mtrr_save_state() to ensure that the fixed MTRR MSRs are supported. Otherwise mtrr_save_state() ends up in a #GP, which is fixed up, but the WARN_ON() can bring systems down when panic on warn is set. * tag 'x86-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mtrr: Check if fixed MTRRs exist before saving them x86/paravirt: Fix incorrect virt spinlock setting on bare metal x86/acpi: Remove __ro_after_init from acpi_mp_wake_mailbox x86/mm: Fix PTI for i386 some more 
Pull x86 fixes from Thomas Gleixner:

 - Fix 32-bit PTI for real.

   pti_clone_entry_text() is called twice, once before initcalls so that
   initcalls can use the user-mode helper and then again after text is
   set read only. Setting read only on 32-bit might break up the PMD
   mapping, which makes the second invocation of pti_clone_entry_text()
   find the mappings out of sync and failing.

   Allow the second call to split the existing PMDs in the user mapping
   and synchronize with the kernel mapping.

 - Don't make acpi_mp_wake_mailbox read-only after init as the mail box
   must be writable in the case that CPU hotplug operations happen after
   boot. Otherwise the attempt to start a CPU crashes with a write to
   read only memory.

 - Add a missing sanity check in mtrr_save_state() to ensure that the
   fixed MTRR MSRs are supported.

   Otherwise mtrr_save_state() ends up in a #GP, which is fixed up, but
   the WARN_ON() can bring systems down when panic on warn is set.

* tag 'x86-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mtrr: Check if fixed MTRRs exist before saving them
  x86/paravirt: Fix incorrect virt spinlock setting on bare metal
  x86/acpi: Remove __ro_after_init from acpi_mp_wake_mailbox
  x86/mm: Fix PTI for i386 some more
Merge tag 'arm-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc 2024-08-09T17:06:43+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-08-09T17:06:43+00:00 0f135d3e30c43be2034299c560272e18c6166d04 Pull ARM SoC fixes from Arnd Bergmann: "There are three sets of patches for the soc tree: - Marek Behún addresses multiple build time regressions caused by changes to the cznic turris-omnia support - Dmitry Torokhov fixes a regression in the legacy "gumstix" board code he cleaned up earlier - The TI K3 maintainers found multiple bugs in the in gpio, audio and pcie devicetree nodes" * tag 'arm-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: ARM: pxa/gumstix: fix attaching properties to vbus gpio device doc: platform: cznic: turris-omnia-mcu: Use double backticks for attribute value doc: platform: cznic: turris-omnia-mcu: Fix sphinx-build warning platform: cznic: turris-omnia-mcu: Make GPIO code optional platform: cznic: turris-omnia-mcu: Make poweroff and wakeup code optional platform: cznic: turris-omnia-mcu: Make TRNG code optional platform: cznic: turris-omnia-mcu: Make watchdog code optional arm64: dts: ti: k3-j784s4-main: Correct McASP DMAs arm64: dts: ti: k3-j722s: Fix gpio-range for main_pmx0 arm64: dts: ti: k3-am62p: Fix gpio-range for main_pmx0 arm64: dts: ti: k3-am62p: Add gpio-ranges for mcu_gpio0 arm64: dts: ti: k3-am62-verdin-dahlia: Keep CTRL_SLEEP_MOCI# regulator on arm64: dts: ti: k3-j784s4-evm: Consolidate serdes0 references arm64: dts: ti: k3-j784s4-evm: Assign only lanes 0 and 1 to PCIe1 
Pull ARM SoC fixes from Arnd Bergmann:
 "There are three sets of patches for the soc tree:

   - Marek Behún addresses multiple build time regressions caused by
     changes to the cznic turris-omnia support

   - Dmitry Torokhov fixes a regression in the legacy "gumstix" board
     code he cleaned up earlier

   - The TI K3 maintainers found multiple bugs in the in gpio, audio and
     pcie devicetree nodes"

* tag 'arm-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: pxa/gumstix: fix attaching properties to vbus gpio device
  doc: platform: cznic: turris-omnia-mcu: Use double backticks for attribute value
  doc: platform: cznic: turris-omnia-mcu: Fix sphinx-build warning
  platform: cznic: turris-omnia-mcu: Make GPIO code optional
  platform: cznic: turris-omnia-mcu: Make poweroff and wakeup code optional
  platform: cznic: turris-omnia-mcu: Make TRNG code optional
  platform: cznic: turris-omnia-mcu: Make watchdog code optional
  arm64: dts: ti: k3-j784s4-main: Correct McASP DMAs
  arm64: dts: ti: k3-j722s: Fix gpio-range for main_pmx0
  arm64: dts: ti: k3-am62p: Fix gpio-range for main_pmx0
  arm64: dts: ti: k3-am62p: Add gpio-ranges for mcu_gpio0
  arm64: dts: ti: k3-am62-verdin-dahlia: Keep CTRL_SLEEP_MOCI# regulator on
  arm64: dts: ti: k3-j784s4-evm: Consolidate serdes0 references
  arm64: dts: ti: k3-j784s4-evm: Assign only lanes 0 and 1 to PCIe1
x86/mtrr: Check if fixed MTRRs exist before saving them 2024-08-08T15:03:12+00:00 Andi Kleen ak@linux.intel.com 2024-08-08T00:02:44+00:00 919f18f961c03d6694aa726c514184f2311a4614 MTRRs have an obsolete fixed variant for fine grained caching control of the 640K-1MB region that uses separate MSRs. This fixed variant has a separate capability bit in the MTRR capability MSR. So far all x86 CPUs which support MTRR have this separate bit set, so it went unnoticed that mtrr_save_state() does not check the capability bit before accessing the fixed MTRR MSRs. Though on a CPU that does not support the fixed MTRR capability this results in a #GP. The #GP itself is harmless because the RDMSR fault is handled gracefully, but results in a WARN_ON(). Add the missing capability check to prevent this. Fixes: 2b1f6278d77c ("[PATCH] x86: Save the MTRRs of the BSP before booting an AP") Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240808000244.946864-1-ak@linux.intel.com 
MTRRs have an obsolete fixed variant for fine grained caching control
of the 640K-1MB region that uses separate MSRs. This fixed variant has
a separate capability bit in the MTRR capability MSR.

So far all x86 CPUs which support MTRR have this separate bit set, so it
went unnoticed that mtrr_save_state() does not check the capability bit
before accessing the fixed MTRR MSRs.

Though on a CPU that does not support the fixed MTRR capability this
results in a #GP.  The #GP itself is harmless because the RDMSR fault is
handled gracefully, but results in a WARN_ON().

Add the missing capability check to prevent this.

Fixes: 2b1f6278d77c ("[PATCH] x86: Save the MTRRs of the BSP before booting an AP")
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240808000244.946864-1-ak@linux.intel.com
x86/paravirt: Fix incorrect virt spinlock setting on bare metal 2024-08-07T18:04:38+00:00 Chen Yu yu.c.chen@intel.com 2024-08-06T11:22:07+00:00 e639222a51196c69c70b49b67098ce2f9919ed08 The kernel can change spinlock behavior when running as a guest. But this guest-friendly behavior causes performance problems on bare metal. The kernel uses a static key to switch between the two modes. In theory, the static key is enabled by default (run in guest mode) and should be disabled for bare metal (and in some guests that want native behavior or paravirt spinlock). A performance drop is reported when running encode/decode workload and BenchSEE cache sub-workload. Bisect points to commit ce0a1b608bfc ("x86/paravirt: Silence unused native_pv_lock_init() function warning"). When CONFIG_PARAVIRT_SPINLOCKS is disabled the virt_spin_lock_key is incorrectly set to true on bare metal. The qspinlock degenerates to test-and-set spinlock, which decreases the performance on bare metal. Set the default value of virt_spin_lock_key to false. If booting in a VM, enable this key. Later during the VM initialization, if other high-efficient spinlock is preferred (e.g. paravirt-spinlock), or the user wants the native qspinlock (via nopvspin boot commandline), the virt_spin_lock_key is disabled accordingly. This results in the following decision matrix: X86_FEATURE_HYPERVISOR Y Y Y N CONFIG_PARAVIRT_SPINLOCKS Y Y N Y/N PV spinlock Y N N Y/N virt_spin_lock_key N Y/N Y N Fixes: ce0a1b608bfc ("x86/paravirt: Silence unused native_pv_lock_init() function warning") Reported-by: Prem Nath Dey <prem.nath.dey@intel.com> Reported-by: Xiaoping Zhou <xiaoping.zhou@intel.com> Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> Suggested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Suggested-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240806112207.29792-1-yu.c.chen@intel.com 
The kernel can change spinlock behavior when running as a guest. But this
guest-friendly behavior causes performance problems on bare metal.

The kernel uses a static key to switch between the two modes.

In theory, the static key is enabled by default (run in guest mode) and
should be disabled for bare metal (and in some guests that want native
behavior or paravirt spinlock).

A performance drop is reported when running encode/decode workload and
BenchSEE cache sub-workload.

Bisect points to commit ce0a1b608bfc ("x86/paravirt: Silence unused
native_pv_lock_init() function warning"). When CONFIG_PARAVIRT_SPINLOCKS is
disabled the virt_spin_lock_key is incorrectly set to true on bare
metal. The qspinlock degenerates to test-and-set spinlock, which decreases
the performance on bare metal.

Set the default value of virt_spin_lock_key to false. If booting in a VM,
enable this key. Later during the VM initialization, if other
high-efficient spinlock is preferred (e.g. paravirt-spinlock), or the user
wants the native qspinlock (via nopvspin boot commandline), the
virt_spin_lock_key is disabled accordingly.

This results in the following decision matrix:

X86_FEATURE_HYPERVISOR         Y    Y       Y     N
CONFIG_PARAVIRT_SPINLOCKS      Y    Y       N     Y/N
PV spinlock                    Y    N       N     Y/N

virt_spin_lock_key             N    Y/N     Y     N

Fixes: ce0a1b608bfc ("x86/paravirt: Silence unused native_pv_lock_init() function warning")
Reported-by: Prem Nath Dey <prem.nath.dey@intel.com>
Reported-by: Xiaoping Zhou <xiaoping.zhou@intel.com>
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Suggested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Suggested-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240806112207.29792-1-yu.c.chen@intel.com
x86/acpi: Remove __ro_after_init from acpi_mp_wake_mailbox 2024-08-07T18:04:38+00:00 Zhiquan Li zhiquan1.li@intel.com 2024-08-05T10:35:31+00:00 ab84ba647f2c94ac4d0c3fc6951c49f08aa1fcf7 On a platform using the "Multiprocessor Wakeup Structure"[1] to startup secondary CPUs the control processor needs to memremap() the physical address of the MP Wakeup Structure mailbox to the variable acpi_mp_wake_mailbox, which holds the virtual address of mailbox. To wake up the AP the control processor writes the APIC ID of AP, the wakeup vector and the ACPI_MP_WAKE_COMMAND_WAKEUP command into the mailbox. Current implementation doesn't consider the case which restricts boot time CPU bringup to 1 with the kernel parameter "maxcpus=1" and brings other CPUs online later from user space as it sets acpi_mp_wake_mailbox to read-only after init. So when the first AP is tried to brought online after init, the attempt to update the variable results in a kernel panic. The memremap() call that initializes the variable cannot be moved into acpi_parse_mp_wake() because memremap() is not functional at that point in the boot process. Also as the APs might never be brought up, keep the memremap() call in acpi_wakeup_cpu() so that the operation only takes place when needed. Fixes: 24dd05da8c79 ("x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init") Signed-off-by: Zhiquan Li <zhiquan1.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lore.kernel.org/all/20240805103531.1230635-1-zhiquan1.li@intel.com 
On a platform using the "Multiprocessor Wakeup Structure"[1] to startup
secondary CPUs the control processor needs to memremap() the physical
address of the MP Wakeup Structure mailbox to the variable
acpi_mp_wake_mailbox, which holds the virtual address of mailbox.

To wake up the AP the control processor writes the APIC ID of AP, the
wakeup vector and the ACPI_MP_WAKE_COMMAND_WAKEUP command into the mailbox.

Current implementation doesn't consider the case which restricts boot time
CPU bringup to 1 with the kernel parameter "maxcpus=1" and brings other
CPUs online later from user space as it sets acpi_mp_wake_mailbox to
read-only after init.  So when the first AP is tried to brought online
after init, the attempt to update the variable results in a kernel panic.

The memremap() call that initializes the variable cannot be moved into
acpi_parse_mp_wake() because memremap() is not functional at that point in
the boot process. Also as the APs might never be brought up, keep the
memremap() call in acpi_wakeup_cpu() so that the operation only takes place
when needed.

Fixes: 24dd05da8c79 ("x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init")
Signed-off-by: Zhiquan Li <zhiquan1.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20240805103531.1230635-1-zhiquan1.li@intel.com
x86/mm: Fix PTI for i386 some more 2024-08-07T13:35:01+00:00 Thomas Gleixner tglx@linutronix.de 2024-08-06T18:48:43+00:00 c48b5a4cf3125adb679e28ef093f66ff81368d05 So it turns out that we have to do two passes of pti_clone_entry_text(), once before initcalls, such that device and late initcalls can use user-mode-helper / modprobe and once after free_initmem() / mark_readonly(). Now obviously mark_readonly() can cause PMD splits, and pti_clone_pgtable() doesn't like that much. Allow the late clone to split PMDs so that pagetables stay in sync. [peterz: Changelog and comments] Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lkml.kernel.org/r/20240806184843.GX37996@noisy.programming.kicks-ass.net 
So it turns out that we have to do two passes of
pti_clone_entry_text(), once before initcalls, such that device and
late initcalls can use user-mode-helper / modprobe and once after
free_initmem() / mark_readonly().

Now obviously mark_readonly() can cause PMD splits, and
pti_clone_pgtable() doesn't like that much.

Allow the late clone to split PMDs so that pagetables stay in sync.

[peterz: Changelog and comments]
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lkml.kernel.org/r/20240806184843.GX37996@noisy.programming.kicks-ass.net
Merge tag 'ti-k3-dt-fixes-for-v6.11' of https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux into arm/fixes 2024-08-07T12:45:45+00:00 Arnd Bergmann arnd@arndb.de 2024-08-07T12:45:45+00:00 6b1124c4526fb1648a3921a441515ea8a98b92e4 Devicetree fixes for TI K3 platforms for v6.11 Critical fixes for the following: * j784s4: Fix for McASP DMA map * J722s/AM62p: GPIO ranges fixes * k3-am62-verdin-dahlia: sleep-moci fixes for deep-sleep (revert) * tag 'ti-k3-dt-fixes-for-v6.11' of https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux: arm64: dts: ti: k3-j784s4-main: Correct McASP DMAs arm64: dts: ti: k3-j722s: Fix gpio-range for main_pmx0 arm64: dts: ti: k3-am62p: Fix gpio-range for main_pmx0 arm64: dts: ti: k3-am62p: Add gpio-ranges for mcu_gpio0 arm64: dts: ti: k3-am62-verdin-dahlia: Keep CTRL_SLEEP_MOCI# regulator on arm64: dts: ti: k3-j784s4-evm: Consolidate serdes0 references arm64: dts: ti: k3-j784s4-evm: Assign only lanes 0 and 1 to PCIe1 
Devicetree fixes for TI K3 platforms for v6.11

Critical fixes for the following:
* j784s4: Fix for McASP DMA map
* J722s/AM62p: GPIO ranges fixes
* k3-am62-verdin-dahlia: sleep-moci fixes for deep-sleep (revert)

* tag 'ti-k3-dt-fixes-for-v6.11' of https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux:
  arm64: dts: ti: k3-j784s4-main: Correct McASP DMAs
  arm64: dts: ti: k3-j722s: Fix gpio-range for main_pmx0
  arm64: dts: ti: k3-am62p: Fix gpio-range for main_pmx0
  arm64: dts: ti: k3-am62p: Add gpio-ranges for mcu_gpio0
  arm64: dts: ti: k3-am62-verdin-dahlia: Keep CTRL_SLEEP_MOCI# regulator on
  arm64: dts: ti: k3-j784s4-evm: Consolidate serdes0 references
  arm64: dts: ti: k3-j784s4-evm: Assign only lanes 0 and 1 to PCIe1
ARM: pxa/gumstix: fix attaching properties to vbus gpio device 2024-08-07T12:43:54+00:00 Dmitry Torokhov dmitry.torokhov@gmail.com 2024-08-06T16:12:58+00:00 cddaac0459c004c439510bd109929466b0d5908e Commit f1d6588af93b tried to convert GPIO lookup tables to software properties for the vbus gpio device, bit forgot the most important step: actually attaching the new properties to the device. Also fix up the name of the property array to reflect the board name, and add missing gpio/property.h and devices.h includes absence of which causes compile failures on some configurations. Switch "#ifdef CONFIG_USB_PXA25X" to "#if IS_ENABLED(CONFIG_USB_PXA25X)" because it should not matter if the driver is buolt in or a module, it still need vbus controls. Reported-by: Arnd Bergmann <arnd@arndb.de> Fixes: f1d6588af93b ("ARM: pxa/gumstix: convert vbus gpio to use software nodes") Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> 
Commit f1d6588af93b tried to convert GPIO lookup tables to software
properties for the vbus gpio device, bit forgot the most important
step: actually attaching the new properties to the device.

Also fix up the name of the property array to reflect the board name,
and add missing gpio/property.h and devices.h includes absence of which
causes compile failures on some configurations.

Switch "#ifdef CONFIG_USB_PXA25X" to "#if IS_ENABLED(CONFIG_USB_PXA25X)"
because it should not matter if the driver is buolt in or a module, it
still need vbus controls.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Fixes: f1d6588af93b ("ARM: pxa/gumstix: convert vbus gpio to use software nodes")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
LoongArch: KVM: Remove undefined a6 argument comment for kvm_hypercall() 2024-08-07T09:37:14+00:00 Dandan Zhang zhangdandan@uniontech.com 2024-08-07T09:37:14+00:00 494b0792d962e8efac72b3a5b6d9bcd4e6fa8cf0 The kvm_hypercall() set for LoongArch is limited to a1-a5. So the mention of a6 in the comment is undefined that needs to be rectified. Reviewed-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: Dandan Zhang <zhangdandan@uniontech.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
The kvm_hypercall() set for LoongArch is limited to a1-a5. So the
mention of a6 in the comment is undefined that needs to be rectified.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Dandan Zhang <zhangdandan@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
LoongArch: KVM: Remove unnecessary definition of KVM_PRIVATE_MEM_SLOTS 2024-08-07T09:37:14+00:00 Yuli Wang wangyuli@uniontech.com 2024-08-07T09:37:14+00:00 296b03ce389b4f7b3d7ea5664e53d432fb17e745 1. "KVM_PRIVATE_MEM_SLOTS" is renamed as "KVM_INTERNAL_MEM_SLOTS". 2. "KVM_INTERNAL_MEM_SLOTS" defaults to zero, so it is not necessary to define it in LoongArch's asm/kvm_host.h. Link: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bdd1c37a315bc50ab14066c4852bc8dcf070451e Link: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b075450868dbc0950f0942617f222eeb989cad10 Reviewed-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: Yuli Wang <wangyuli@uniontech.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
1. "KVM_PRIVATE_MEM_SLOTS" is renamed as "KVM_INTERNAL_MEM_SLOTS".

2. "KVM_INTERNAL_MEM_SLOTS" defaults to zero, so it is not necessary to
define it in LoongArch's asm/kvm_host.h.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bdd1c37a315bc50ab14066c4852bc8dcf070451e
Link: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b075450868dbc0950f0942617f222eeb989cad10
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>