Commit graph

43 commits

Author SHA1 Message Date
Bibo Mao
46ecfb68dd LoongArch: KVM: Add stat information with kernel irqchip
Move stat information about kernel irqchip from VM to vCPU, since all
vm exiting events should be vCPU relative. And also add entry with
structure kvm_vcpu_stats_desc[], so that it can display with directory
/sys/kernel/debug/kvm.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-07-21 09:26:32 +08:00
Bibo Mao
5add0dbbeb LoongArch: KVM: Fix PMU pass-through issue if VM exits to host finally
In function kvm_pre_enter_guest(), it prepares to enter guest and check
whether there are pending signals or events. And it will not enter guest
if there are, PMU pass-through preparation for guest should be cancelled
and host should own PMU hardware.

Cc: stable@vger.kernel.org
Fixes: f4e40ea9f7 ("LoongArch: KVM: Add PMU support for guest")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-04-26 09:58:13 +08:00
Bibo Mao
9ea86232a5 LoongArch: KVM: Fully clear some CSRs when VM reboot
Some registers such as LOONGARCH_CSR_ESTAT and LOONGARCH_CSR_GINTC are
partly cleared with function _kvm_setcsr(). This comes from the hardware
specification, some bits are read only in VM mode, and however they can
be written in host mode. So they are partly cleared in VM mode, and can
be fully cleared in host mode.

These read only bits show pending interrupt or exception status. When VM
reset, the read-only bits should be cleared, otherwise vCPU will receive
unknown interrupts in boot stage.

Here registers LOONGARCH_CSR_ESTAT/LOONGARCH_CSR_GINTC are fully cleared
in ioctl KVM_REG_LOONGARCH_VCPU_RESET vCPU reset path.

Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-04-26 09:58:13 +08:00
Linus Torvalds
edb0e8f6e2 ARM:
* Nested virtualization support for VGICv3, giving the nested
 hypervisor control of the VGIC hardware when running an L2 VM
 
 * Removal of 'late' nested virtualization feature register masking,
   making the supported feature set directly visible to userspace
 
 * Support for emulating FEAT_PMUv3 on Apple silicon, taking advantage
   of an IMPLEMENTATION DEFINED trap that covers all PMUv3 registers
 
 * Paravirtual interface for discovering the set of CPU implementations
   where a VM may run, addressing a longstanding issue of guest CPU
   errata awareness in big-little systems and cross-implementation VM
   migration
 
 * Userspace control of the registers responsible for identifying a
   particular CPU implementation (MIDR_EL1, REVIDR_EL1, AIDR_EL1),
   allowing VMs to be migrated cross-implementation
 
 * pKVM updates, including support for tracking stage-2 page table
   allocations in the protected hypervisor in the 'SecPageTable' stat
 
 * Fixes to vPMU, ensuring that userspace updates to the vPMU after
   KVM_RUN are reflected into the backing perf events
 
 LoongArch:
 
 * Remove unnecessary header include path
 
 * Assume constant PGD during VM context switch
 
 * Add perf events support for guest VM
 
 RISC-V:
 
 * Disable the kernel perf counter during configure
 
 * KVM selftests improvements for PMU
 
 * Fix warning at the time of KVM module removal
 
 x86:
 
 * Add support for aging of SPTEs without holding mmu_lock.  Not taking mmu_lock
   allows multiple aging actions to run in parallel, and more importantly avoids
   stalling vCPUs.  This includes an implementation of per-rmap-entry locking;
   aging the gfn is done with only a per-rmap single-bin spinlock taken, whereas
   locking an rmap for write requires taking both the per-rmap spinlock and
   the mmu_lock.
 
   Note that this decreases slightly the accuracy of accessed-page information,
   because changes to the SPTE outside aging might not use atomic operations
   even if they could race against a clear of the Accessed bit.  This is
   deliberate because KVM and mm/ tolerate false positives/negatives for
   accessed information, and testing has shown that reducing the latency of
   aging is far more beneficial to overall system performance than providing
   "perfect" young/old information.
 
 * Defer runtime CPUID updates until KVM emulates a CPUID instruction, to
   coalesce updates when multiple pieces of vCPU state are changing, e.g. as
   part of a nested transition.
 
 * Fix a variety of nested emulation bugs, and add VMX support for synthesizing
   nested VM-Exit on interception (instead of injecting #UD into L2).
 
 * Drop "support" for async page faults for protected guests that do not set
   SEND_ALWAYS (i.e. that only want async page faults at CPL3)
 
 * Bring a bit of sanity to x86's VM teardown code, which has accumulated
   a lot of cruft over the years.  Particularly, destroy vCPUs before
   the MMU, despite the latter being a VM-wide operation.
 
 * Add common secure TSC infrastructure for use within SNP and in the
   future TDX
 
 * Block KVM_CAP_SYNC_REGS if guest state is protected.  It does not make
   sense to use the capability if the relevant registers are not
   available for reading or writing.
 
 * Don't take kvm->lock when iterating over vCPUs in the suspend notifier to
   fix a largely theoretical deadlock.
 
 * Use the vCPU's actual Xen PV clock information when starting the Xen timer,
   as the cached state in arch.hv_clock can be stale/bogus.
 
 * Fix a bug where KVM could bleed PVCLOCK_GUEST_STOPPED across different
   PV clocks; restrict PVCLOCK_GUEST_STOPPED to kvmclock, as KVM's suspend
   notifier only accounts for kvmclock, and there's no evidence that the
   flag is actually supported by Xen guests.
 
 * Clean up the per-vCPU "cache" of its reference pvclock, and instead only
   track the vCPU's TSC scaling (multipler+shift) metadata (which is moderately
   expensive to compute, and rarely changes for modern setups).
 
 * Don't write to the Xen hypercall page on MSR writes that are initiated by
   the host (userspace or KVM) to fix a class of bugs where KVM can write to
   guest memory at unexpected times, e.g. during vCPU creation if userspace has
   set the Xen hypercall MSR index to collide with an MSR that KVM emulates.
 
 * Restrict the Xen hypercall MSR index to the unofficial synthetic range to
   reduce the set of possible collisions with MSRs that are emulated by KVM
   (collisions can still happen as KVM emulates Hyper-V MSRs, which also reside
   in the synthetic range).
 
 * Clean up and optimize KVM's handling of Xen MSR writes and xen_hvm_config.
 
 * Update Xen TSC leaves during CPUID emulation instead of modifying the CPUID
   entries when updating PV clocks; there is no guarantee PV clocks will be
   updated between TSC frequency changes and CPUID emulation, and guest reads
   of the TSC leaves should be rare, i.e. are not a hot path.
 
 x86 (Intel):
 
 * Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and thus
   modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1.
 
 * Pass XFD_ERR as the payload when injecting #NM, as a preparatory step
   for upcoming FRED virtualization support.
 
 * Decouple the EPT entry RWX protection bit macros from the EPT Violation
   bits, both as a general cleanup and in anticipation of adding support for
   emulating Mode-Based Execution Control (MBEC).
 
 * Reject KVM_RUN if userspace manages to gain control and stuff invalid guest
   state while KVM is in the middle of emulating nested VM-Enter.
 
 * Add a macro to handle KVM's sanity checks on entry/exit VMCS control pairs
   in anticipation of adding sanity checks for secondary exit controls (the
   primary field is out of bits).
 
 x86 (AMD):
 
 * Ensure the PSP driver is initialized when both the PSP and KVM modules are
   built-in (the initcall framework doesn't handle dependencies).
 
 * Use long-term pins when registering encrypted memory regions, so that the
   pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and don't lead to
   excessive fragmentation.
 
 * Add macros and helpers for setting GHCB return/error codes.
 
 * Add support for Idle HLT interception, which elides interception if the vCPU
   has a pending, unmasked virtual IRQ when HLT is executed.
 
 * Fix a bug in INVPCID emulation where KVM fails to check for a non-canonical
   address.
 
 * Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is invalid, e.g.
   because the vCPU was "destroyed" via SNP's AP Creation hypercall.
 
 * Reject SNP AP Creation if the requested SEV features for the vCPU don't
   match the VM's configured set of features.
 
 Selftests:
 
 * Fix again the Intel PMU counters test; add a data load and do CLFLUSH{OPT} on the data
   instead of executing code.  The theory is that modern Intel CPUs have
   learned new code prefetching tricks that bypass the PMU counters.
 
 * Fix a flaw in the Intel PMU counters test where it asserts that an event is
   counting correctly without actually knowing what the event counts on the
   underlying hardware.
 
 * Fix a variety of flaws, bugs, and false failures/passes dirty_log_test, and
   improve its coverage by collecting all dirty entries on each iteration.
 
 * Fix a few minor bugs related to handling of stats FDs.
 
 * Add infrastructure to make vCPU and VM stats FDs available to tests by
   default (open the FDs during VM/vCPU creation).
 
 * Relax an assertion on the number of HLT exits in the xAPIC IPI test when
   running on a CPU that supports AMD's Idle HLT (which elides interception of
   HLT if a virtual IRQ is pending and unmasked).
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Nested virtualization support for VGICv3, giving the nested
     hypervisor control of the VGIC hardware when running an L2 VM

   - Removal of 'late' nested virtualization feature register masking,
     making the supported feature set directly visible to userspace

   - Support for emulating FEAT_PMUv3 on Apple silicon, taking advantage
     of an IMPLEMENTATION DEFINED trap that covers all PMUv3 registers

   - Paravirtual interface for discovering the set of CPU
     implementations where a VM may run, addressing a longstanding issue
     of guest CPU errata awareness in big-little systems and
     cross-implementation VM migration

   - Userspace control of the registers responsible for identifying a
     particular CPU implementation (MIDR_EL1, REVIDR_EL1, AIDR_EL1),
     allowing VMs to be migrated cross-implementation

   - pKVM updates, including support for tracking stage-2 page table
     allocations in the protected hypervisor in the 'SecPageTable' stat

   - Fixes to vPMU, ensuring that userspace updates to the vPMU after
     KVM_RUN are reflected into the backing perf events

  LoongArch:

   - Remove unnecessary header include path

   - Assume constant PGD during VM context switch

   - Add perf events support for guest VM

  RISC-V:

   - Disable the kernel perf counter during configure

   - KVM selftests improvements for PMU

   - Fix warning at the time of KVM module removal

  x86:

   - Add support for aging of SPTEs without holding mmu_lock.

     Not taking mmu_lock allows multiple aging actions to run in
     parallel, and more importantly avoids stalling vCPUs. This includes
     an implementation of per-rmap-entry locking; aging the gfn is done
     with only a per-rmap single-bin spinlock taken, whereas locking an
     rmap for write requires taking both the per-rmap spinlock and the
     mmu_lock.

     Note that this decreases slightly the accuracy of accessed-page
     information, because changes to the SPTE outside aging might not
     use atomic operations even if they could race against a clear of
     the Accessed bit.

     This is deliberate because KVM and mm/ tolerate false
     positives/negatives for accessed information, and testing has shown
     that reducing the latency of aging is far more beneficial to
     overall system performance than providing "perfect" young/old
     information.

   - Defer runtime CPUID updates until KVM emulates a CPUID instruction,
     to coalesce updates when multiple pieces of vCPU state are
     changing, e.g. as part of a nested transition

   - Fix a variety of nested emulation bugs, and add VMX support for
     synthesizing nested VM-Exit on interception (instead of injecting
     #UD into L2)

   - Drop "support" for async page faults for protected guests that do
     not set SEND_ALWAYS (i.e. that only want async page faults at CPL3)

   - Bring a bit of sanity to x86's VM teardown code, which has
     accumulated a lot of cruft over the years. Particularly, destroy
     vCPUs before the MMU, despite the latter being a VM-wide operation

   - Add common secure TSC infrastructure for use within SNP and in the
     future TDX

   - Block KVM_CAP_SYNC_REGS if guest state is protected. It does not
     make sense to use the capability if the relevant registers are not
     available for reading or writing

   - Don't take kvm->lock when iterating over vCPUs in the suspend
     notifier to fix a largely theoretical deadlock

   - Use the vCPU's actual Xen PV clock information when starting the
     Xen timer, as the cached state in arch.hv_clock can be stale/bogus

   - Fix a bug where KVM could bleed PVCLOCK_GUEST_STOPPED across
     different PV clocks; restrict PVCLOCK_GUEST_STOPPED to kvmclock, as
     KVM's suspend notifier only accounts for kvmclock, and there's no
     evidence that the flag is actually supported by Xen guests

   - Clean up the per-vCPU "cache" of its reference pvclock, and instead
     only track the vCPU's TSC scaling (multipler+shift) metadata (which
     is moderately expensive to compute, and rarely changes for modern
     setups)

   - Don't write to the Xen hypercall page on MSR writes that are
     initiated by the host (userspace or KVM) to fix a class of bugs
     where KVM can write to guest memory at unexpected times, e.g.
     during vCPU creation if userspace has set the Xen hypercall MSR
     index to collide with an MSR that KVM emulates

   - Restrict the Xen hypercall MSR index to the unofficial synthetic
     range to reduce the set of possible collisions with MSRs that are
     emulated by KVM (collisions can still happen as KVM emulates
     Hyper-V MSRs, which also reside in the synthetic range)

   - Clean up and optimize KVM's handling of Xen MSR writes and
     xen_hvm_config

   - Update Xen TSC leaves during CPUID emulation instead of modifying
     the CPUID entries when updating PV clocks; there is no guarantee PV
     clocks will be updated between TSC frequency changes and CPUID
     emulation, and guest reads of the TSC leaves should be rare, i.e.
     are not a hot path

  x86 (Intel):

   - Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and
     thus modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1

   - Pass XFD_ERR as the payload when injecting #NM, as a preparatory
     step for upcoming FRED virtualization support

   - Decouple the EPT entry RWX protection bit macros from the EPT
     Violation bits, both as a general cleanup and in anticipation of
     adding support for emulating Mode-Based Execution Control (MBEC)

   - Reject KVM_RUN if userspace manages to gain control and stuff
     invalid guest state while KVM is in the middle of emulating nested
     VM-Enter

   - Add a macro to handle KVM's sanity checks on entry/exit VMCS
     control pairs in anticipation of adding sanity checks for secondary
     exit controls (the primary field is out of bits)

  x86 (AMD):

   - Ensure the PSP driver is initialized when both the PSP and KVM
     modules are built-in (the initcall framework doesn't handle
     dependencies)

   - Use long-term pins when registering encrypted memory regions, so
     that the pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and
     don't lead to excessive fragmentation

   - Add macros and helpers for setting GHCB return/error codes

   - Add support for Idle HLT interception, which elides interception if
     the vCPU has a pending, unmasked virtual IRQ when HLT is executed

   - Fix a bug in INVPCID emulation where KVM fails to check for a
     non-canonical address

   - Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is
     invalid, e.g. because the vCPU was "destroyed" via SNP's AP
     Creation hypercall

   - Reject SNP AP Creation if the requested SEV features for the vCPU
     don't match the VM's configured set of features

  Selftests:

   - Fix again the Intel PMU counters test; add a data load and do
     CLFLUSH{OPT} on the data instead of executing code. The theory is
     that modern Intel CPUs have learned new code prefetching tricks
     that bypass the PMU counters

   - Fix a flaw in the Intel PMU counters test where it asserts that an
     event is counting correctly without actually knowing what the event
     counts on the underlying hardware

   - Fix a variety of flaws, bugs, and false failures/passes
     dirty_log_test, and improve its coverage by collecting all dirty
     entries on each iteration

   - Fix a few minor bugs related to handling of stats FDs

   - Add infrastructure to make vCPU and VM stats FDs available to tests
     by default (open the FDs during VM/vCPU creation)

   - Relax an assertion on the number of HLT exits in the xAPIC IPI test
     when running on a CPU that supports AMD's Idle HLT (which elides
     interception of HLT if a virtual IRQ is pending and unmasked)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (216 commits)
  RISC-V: KVM: Optimize comments in kvm_riscv_vcpu_isa_disable_allowed
  RISC-V: KVM: Teardown riscv specific bits after kvm_exit
  LoongArch: KVM: Register perf callbacks for guest
  LoongArch: KVM: Implement arch-specific functions for guest perf
  LoongArch: KVM: Add stub for kvm_arch_vcpu_preempted_in_kernel()
  LoongArch: KVM: Remove PGD saving during VM context switch
  LoongArch: KVM: Remove unnecessary header include path
  KVM: arm64: Tear down vGIC on failed vCPU creation
  KVM: arm64: PMU: Reload when resetting
  KVM: arm64: PMU: Reload when user modifies registers
  KVM: arm64: PMU: Fix SET_ONE_REG for vPMC regs
  KVM: arm64: PMU: Assume PMU presence in pmu-emul.c
  KVM: arm64: PMU: Set raw values from user to PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  KVM: arm64: Create each pKVM hyp vcpu after its corresponding host vcpu
  KVM: arm64: Factor out pKVM hyp vcpu creation to separate function
  KVM: arm64: Initialize HCRX_EL2 traps in pKVM
  KVM: arm64: Factor out setting HCRX_EL2 traps into separate function
  KVM: x86: block KVM_CAP_SYNC_REGS if guest state is protected
  KVM: x86: Add infrastructure for secure TSC
  KVM: x86: Push down setting vcpu.arch.user_set_tsc
  ...
2025-03-25 14:22:07 -07:00
Linus Torvalds
a50b4fe095 A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
   the callback pointer. This turned out to be suboptimal for the upcoming
   Rust integration and is obviously a silly implementation to begin with.
 
   This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
   with hrtimer_setup(T, cb);
 
   The conversion was done with Coccinelle and a few manual fixups.
 
   Once the conversion has completely landed in mainline, hrtimer_init()
   will be removed and the hrtimer::function becomes a private member.
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Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer cleanups from Thomas Gleixner:
 "A treewide hrtimer timer cleanup

  hrtimers are initialized with hrtimer_init() and a subsequent store to
  the callback pointer. This turned out to be suboptimal for the
  upcoming Rust integration and is obviously a silly implementation to
  begin with.

  This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
  with hrtimer_setup(T, cb);

  The conversion was done with Coccinelle and a few manual fixups.

  Once the conversion has completely landed in mainline, hrtimer_init()
  will be removed and the hrtimer::function becomes a private member"

* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  wifi: rt2x00: Switch to use hrtimer_update_function()
  io_uring: Use helper function hrtimer_update_function()
  serial: xilinx_uartps: Use helper function hrtimer_update_function()
  ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
  RDMA: Switch to use hrtimer_setup()
  virtio: mem: Switch to use hrtimer_setup()
  drm/vmwgfx: Switch to use hrtimer_setup()
  drm/xe/oa: Switch to use hrtimer_setup()
  drm/vkms: Switch to use hrtimer_setup()
  drm/msm: Switch to use hrtimer_setup()
  drm/i915/request: Switch to use hrtimer_setup()
  drm/i915/uncore: Switch to use hrtimer_setup()
  drm/i915/pmu: Switch to use hrtimer_setup()
  drm/i915/perf: Switch to use hrtimer_setup()
  drm/i915/gvt: Switch to use hrtimer_setup()
  drm/i915/huc: Switch to use hrtimer_setup()
  drm/amdgpu: Switch to use hrtimer_setup()
  stm class: heartbeat: Switch to use hrtimer_setup()
  i2c: Switch to use hrtimer_setup()
  iio: Switch to use hrtimer_setup()
  ...
2025-03-25 10:54:15 -07:00
Bibo Mao
2bf463d761 LoongArch: KVM: Implement arch-specific functions for guest perf
Three architecture specific functions are added for the guest perf
feature, they are kvm_arch_vcpu_in_kernel(), kvm_arch_vcpu_get_ip()
and kvm_arch_pmi_in_guest().

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-03-18 16:48:08 +08:00
Bibo Mao
6a16e448e5 LoongArch: KVM: Add stub for kvm_arch_vcpu_preempted_in_kernel()
Pause-Loop Exiting is not supported by LoongArch hardware, nor is pv
spinlock feature. So function kvm_vcpu_on_spin() is not used. Function
kvm_arch_vcpu_preempted_in_kernel() is defined as a stub function here
since it is only called by unused function kvm_vcpu_on_spin().

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-03-18 16:48:08 +08:00
Bibo Mao
062ac0cb83 LoongArch: KVM: Remove PGD saving during VM context switch
PGD table for primary mmu keeps unchanged once VM is created, it is not
necessary to save PGD table pointer during VM context switch. And it can
be acquired when VM is created.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-03-18 16:48:08 +08:00
Bibo Mao
6fb1867d5a LoongArch: KVM: Add interrupt checking for AVEC
There is a newly added macro INT_AVEC with CSR ESTAT register, which is
bit 14 used for LoongArch AVEC support. AVEC interrupt status bit 14 is
supported with macro CSR_ESTAT_IS, so here replace the hard-coded value
0x1fff with macro CSR_ESTAT_IS so that the AVEC interrupt status is also
supported by KVM.

Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-03-08 13:51:59 +08:00
Nam Cao
7d6f12520b LoongArch: KVM: Switch to use hrtimer_setup()
hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.

Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.

Patch was created by using Coccinelle.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/a5b1b53813a15a73afdfff6fbb4c9064fa582be1.1738746821.git.namcao@linutronix.de
2025-02-18 10:32:31 +01:00
Bibo Mao
d8cc4fee3f LoongArch: KVM: Remove duplicated cache attribute setting
Cache attribute comes from GPA->HPA secondary mmu page table and is
configured when kvm is enabled. It is the same for all VMs, so remove
duplicated cache attribute setting on vCPU context switch.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-02-13 12:02:56 +08:00
Bibo Mao
2737dee106 LoongArch: KVM: Add hypercall service support for usermode VMM
Some VMMs provides special hypercall service in usermode, KVM should not
handle the usermode hypercall service, thus pass it to usermode, let the
usermode VMM handle it.

Here a new code KVM_HCALL_CODE_USER_SERVICE is added for the user-mode
hypercall service, KVM lets all six registers visible to usermode VMM.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-01-13 21:37:17 +08:00
Huacai Chen
589e6cc759 LoongArch: KVM: Protect kvm_check_requests() with SRCU
When we enable lockdep we get such a warning:

 =============================
 WARNING: suspicious RCU usage
 6.12.0-rc7+ #1891 Tainted: G        W
 -----------------------------
 include/linux/kvm_host.h:1043 suspicious rcu_dereference_check() usage!
 other info that might help us debug this:
 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by qemu-system-loo/948:
  #0: 90000001184a00a8 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0xf4/0xe20 [kvm]
 stack backtrace:
 CPU: 0 UID: 0 PID: 948 Comm: qemu-system-loo Tainted: G        W          6.12.0-rc7+ #1891
 Tainted: [W]=WARN
 Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.0-prebeta9 10/21/2022
 Stack : 0000000000000089 9000000005a0db9c 90000000071519c8 900000012c578000
         900000012c57b920 0000000000000000 900000012c57b928 9000000007e53788
         900000000815bcc8 900000000815bcc0 900000012c57b790 0000000000000001
         0000000000000001 4b031894b9d6b725 0000000004dec000 90000001003299c0
         0000000000000414 0000000000000001 000000000000002d 0000000000000003
         0000000000000030 00000000000003b4 0000000004dec000 90000001184a0000
         900000000806d000 9000000007e53788 00000000000000b4 0000000000000004
         0000000000000004 0000000000000000 0000000000000000 9000000107baf600
         9000000008916000 9000000007e53788 9000000005924778 0000000010000044
         00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
         ...
 Call Trace:
 [<9000000005924778>] show_stack+0x38/0x180
 [<90000000071519c4>] dump_stack_lvl+0x94/0xe4
 [<90000000059eb754>] lockdep_rcu_suspicious+0x194/0x240
 [<ffff8000022143bc>] kvm_gfn_to_hva_cache_init+0xfc/0x120 [kvm]
 [<ffff80000222ade4>] kvm_pre_enter_guest+0x3a4/0x520 [kvm]
 [<ffff80000222b3dc>] kvm_handle_exit+0x23c/0x480 [kvm]

Fix it by protecting kvm_check_requests() with SRCU.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-12-02 16:42:10 +08:00
Xianglai Li
c532de5a67 LoongArch: KVM: Add IPI device support
Add device model for IPI interrupt controller, implement basic create &
destroy interfaces, and register device model to kvm device table.

Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-11-13 16:18:27 +08:00
Huacai Chen
73adbd92f3 LoongArch: KVM: Mark hrtimer to expire in hard interrupt context
Like commit 2c0d278f32 ("KVM: LAPIC: Mark hrtimer to expire in hard
interrupt context") and commit 9090825fa9 ("KVM: arm/arm64: Let the
timer expire in hardirq context on RT"), On PREEMPT_RT enabled kernels
unmarked hrtimers are moved into soft interrupt expiry mode by default.
Then the timers are canceled from an preempt-notifier which is invoked
with disabled preemption which is not allowed on PREEMPT_RT.

The timer callback is short so in could be invoked in hard-IRQ context.
So let the timer expire on hard-IRQ context even on -RT.

This fix a "scheduling while atomic" bug for PREEMPT_RT enabled kernels:

 BUG: scheduling while atomic: qemu-system-loo/1011/0x00000002
 Modules linked in: amdgpu rfkill nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat ns
 CPU: 1 UID: 0 PID: 1011 Comm: qemu-system-loo Tainted: G        W          6.12.0-rc2+ #1774
 Tainted: [W]=WARN
 Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.0-prebeta9 10/21/2022
 Stack : ffffffffffffffff 0000000000000000 9000000004e3ea38 9000000116744000
         90000001167475a0 0000000000000000 90000001167475a8 9000000005644830
         90000000058dc000 90000000058dbff8 9000000116747420 0000000000000001
         0000000000000001 6a613fc938313980 000000000790c000 90000001001c1140
         00000000000003fe 0000000000000001 000000000000000d 0000000000000003
         0000000000000030 00000000000003f3 000000000790c000 9000000116747830
         90000000057ef000 0000000000000000 9000000005644830 0000000000000004
         0000000000000000 90000000057f4b58 0000000000000001 9000000116747868
         900000000451b600 9000000005644830 9000000003a13998 0000000010000020
         00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
         ...
 Call Trace:
 [<9000000003a13998>] show_stack+0x38/0x180
 [<9000000004e3ea34>] dump_stack_lvl+0x84/0xc0
 [<9000000003a71708>] __schedule_bug+0x48/0x60
 [<9000000004e45734>] __schedule+0x1114/0x1660
 [<9000000004e46040>] schedule_rtlock+0x20/0x60
 [<9000000004e4e330>] rtlock_slowlock_locked+0x3f0/0x10a0
 [<9000000004e4f038>] rt_spin_lock+0x58/0x80
 [<9000000003b02d68>] hrtimer_cancel_wait_running+0x68/0xc0
 [<9000000003b02e30>] hrtimer_cancel+0x70/0x80
 [<ffff80000235eb70>] kvm_restore_timer+0x50/0x1a0 [kvm]
 [<ffff8000023616c8>] kvm_arch_vcpu_load+0x68/0x2a0 [kvm]
 [<ffff80000234c2d4>] kvm_sched_in+0x34/0x60 [kvm]
 [<9000000003a749a0>] finish_task_switch.isra.0+0x140/0x2e0
 [<9000000004e44a70>] __schedule+0x450/0x1660
 [<9000000004e45cb0>] schedule+0x30/0x180
 [<ffff800002354c70>] kvm_vcpu_block+0x70/0x120 [kvm]
 [<ffff800002354d80>] kvm_vcpu_halt+0x60/0x3e0 [kvm]
 [<ffff80000235b194>] kvm_handle_gspr+0x3f4/0x4e0 [kvm]
 [<ffff80000235f548>] kvm_handle_exit+0x1c8/0x260 [kvm]

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-10-23 22:15:44 +08:00
Bibo Mao
cdc118f802 LoongArch: KVM: Enable paravirt feature control from VMM
Export kernel paravirt features to user space, so that VMM can control
each single paravirt feature. By default paravirt features will be the
same with kvm supported features if VMM does not set it.

Also a new feature KVM_FEATURE_VIRT_EXTIOI is added which can be set
from user space. This feature indicates that the virt EIOINTC can route
interrupts to 256 vCPUs, rather than 4 vCPUs like with real HW.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-12 20:53:40 +08:00
Song Gao
f4e40ea9f7 LoongArch: KVM: Add PMU support for guest
On LoongArch, the host and guest have their own PMU CSRs registers and
they share PMU hardware resources. A set of PMU CSRs consists of a CTRL
register and a CNTR register. We can set which PMU CSRs are used by the
guest by writing to the GCFG register [24:26] bits.

On KVM side:
- Save the host PMU CSRs into structure kvm_context.
- If the host supports the PMU feature.
  - When entering guest mode, save the host PMU CSRs and restore the guest PMU CSRs.
  - When exiting guest mode, save the guest PMU CSRs and restore the host PMU CSRs.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-12 20:53:40 +08:00
Bibo Mao
acc7f20d54 LoongArch: KVM: Add vm migration support for LBT registers
Every vcpu has separate LBT registers. And there are four scr registers,
one flags and ftop register for LBT extension. When VM migrates, VMM
needs to get LBT registers for every vcpu.

Here macro KVM_REG_LOONGARCH_LBT is added for new vcpu lbt register type,
the following macro is added to get/put LBT registers.
  KVM_REG_LOONGARCH_LBT_SCR0
  KVM_REG_LOONGARCH_LBT_SCR1
  KVM_REG_LOONGARCH_LBT_SCR2
  KVM_REG_LOONGARCH_LBT_SCR3
  KVM_REG_LOONGARCH_LBT_EFLAGS
  KVM_REG_LOONGARCH_LBT_FTOP

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-11 23:26:32 +08:00
Bibo Mao
b67ee19a90 LoongArch: KVM: Add Binary Translation extension support
Loongson Binary Translation (LBT) is used to accelerate binary translation,
which contains 4 scratch registers (scr0 to scr3), x86/ARM eflags (eflags)
and x87 fpu stack pointer (ftop).

Like FPU extension, here a lazy enabling method is used for LBT. the LBT
context is saved/restored on the vcpu context switch path.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-11 23:26:32 +08:00
Bibo Mao
a53f48b632 LoongArch: KVM: Add VM feature detection function
Loongson SIMD Extension (LSX), Loongson Advanced SIMD Extension (LASX)
and Loongson Binary Translation (LBT) features are defined in register
CPUCFG2. Two kinds of LSX/LASX/LBT feature detection are added here, one
is VCPU feature, and the other is VM feature. VCPU feature dection can
only work with VCPU thread itself, and requires VCPU thread is created
already. So LSX/LASX/LBT feature detection for VM is added also, it can
be done even if VM is not created, and also can be done by any threads
besides VCPU threads.

Here ioctl command KVM_HAS_DEVICE_ATTR is added for VM, and macro
KVM_LOONGARCH_VM_FEAT_CTRL is added to check supported feature. And
five sub-features relative with LSX/LASX/LBT are added as following:
 KVM_LOONGARCH_VM_FEAT_LSX
 KVM_LOONGARCH_VM_FEAT_LASX
 KVM_LOONGARCH_VM_FEAT_X86BT
 KVM_LOONGARCH_VM_FEAT_ARMBT
 KVM_LOONGARCH_VM_FEAT_MIPSBT

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-11 23:26:32 +08:00
Bibo Mao
4956e07f05 LoongArch: KVM: Invalidate guest steal time address on vCPU reset
If ParaVirt steal time feature is enabled, there is a percpu gpa address
passed from guest vCPU and host modifies guest memory space with this gpa
address. When vCPU is reset normally, it will notify host and invalidate
gpa address.

However if VM is crashed and VMM reboots VM forcely, the vCPU reboot
notification callback will not be called in VM. Host needs invalidate
the gpa address, else host will modify guest memory during VM reboots.
Here it is invalidated from the vCPU KVM_REG_LOONGARCH_VCPU_RESET ioctl
interface.

Also funciton kvm_reset_timer() is removed at vCPU reset stage, since SW
emulated timer is only used in vCPU block state. When a vCPU is removed
from the block waiting queue, kvm_restore_timer() is called and SW timer
is cancelled. And the timer register is also cleared at VMM when a vCPU
is reset.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-08-26 23:11:32 +08:00
Paolo Bonzini
86014c1e20 KVM generic changes for 6.11
- Enable halt poll shrinking by default, as Intel found it to be a clear win.
 
  - Setup empty IRQ routing when creating a VM to avoid having to synchronize
    SRCU when creating a split IRQCHIP on x86.
 
  - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag
    that arch code can use for hooking both sched_in() and sched_out().
 
  - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid
    truncating a bogus value from userspace, e.g. to help userspace detect bugs.
 
  - Mark a vCPU as preempted if and only if it's scheduled out while in the
    KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest
    memory when retrieving guest state during live migration blackout.
 
  - A few minor cleanups
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Merge tag 'kvm-x86-generic-6.11' of https://github.com/kvm-x86/linux into HEAD

KVM generic changes for 6.11

 - Enable halt poll shrinking by default, as Intel found it to be a clear win.

 - Setup empty IRQ routing when creating a VM to avoid having to synchronize
   SRCU when creating a split IRQCHIP on x86.

 - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag
   that arch code can use for hooking both sched_in() and sched_out().

 - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid
   truncating a bogus value from userspace, e.g. to help userspace detect bugs.

 - Mark a vCPU as preempted if and only if it's scheduled out while in the
   KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest
   memory when retrieving guest state during live migration blackout.

 - A few minor cleanups
2024-07-16 09:51:36 -04:00
Bibo Mao
b4ba157044 LoongArch: KVM: Add PV steal time support in host side
Add ParaVirt steal time feature in host side, VM can search supported
features provided by KVM hypervisor, a feature KVM_FEATURE_STEAL_TIME
is added here. Like x86, steal time structure is saved in guest memory,
one hypercall function KVM_HCALL_FUNC_NOTIFY is added to notify KVM to
enable this feature.

One CPU attr ioctl command KVM_LOONGARCH_VCPU_PVTIME_CTRL is added to
save and restore the base address of steal time structure when a VM is
migrated.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-07-09 16:25:51 +08:00
Bibo Mao
b5d4e2325d LoongArch: KVM: Delay secondary mmu tlb flush until guest entry
With hardware assisted virtualization, there are two level HW mmu, one
is GVA to GPA mapping, the other is GPA to HPA mapping which is called
secondary mmu in generic. If there is page fault for secondary mmu,
there needs tlb flush operation indexed with fault GPA address and VMID.
VMID is stored at register CSR.GSTAT and will be reload or recalculated
before guest entry.

Currently CSR.GSTAT is not saved and restored during VCPU context
switch, instead it is recalculated during guest entry. So CSR.GSTAT is
effective only when a VCPU runs in guest mode, however it may not be
effective if the VCPU exits to host mode. Since register CSR.GSTAT may
be stale, it may records the VMID of the last schedule-out VCPU, rather
than the current VCPU.

Function kvm_flush_tlb_gpa() should be called with its real VMID, so
here move it to the guest entrance. Also an arch-specific request id
KVM_REQ_TLB_FLUSH_GPA is added to flush tlb for secondary mmu, and it
can be optimized if VMID is updated, since all guest tlb entries will
be invalid if VMID is updated.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-07-09 16:25:50 +08:00
Bibo Mao
e306e51490 LoongArch: KVM: Sync pending interrupt when getting ESTAT from user mode
Currently interrupts are posted and cleared with the asynchronous mode,
meanwhile they are saved in SW state vcpu::arch::irq_pending and vcpu::
arch::irq_clear. When vcpu is ready to run, pending interrupt is written
back to CSR.ESTAT register from SW state vcpu::arch::irq_pending at the
guest entrance.

During VM migration stage, vcpu is put into stopped state, however
pending interrupts are not synced to CSR.ESTAT register. So there will
be interrupt lost when VCPU is migrated to another host machines.

Here in this patch when ESTAT CSR register is read from VMM user mode,
pending interrupts are synchronized to ESTAT also. So that VMM can get
correct pending interrupts.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-07-09 16:25:50 +08:00
David Matlack
a6816314af KVM: Introduce vcpu->wants_to_run
Introduce vcpu->wants_to_run to indicate when a vCPU is in its core run
loop, i.e. when the vCPU is running the KVM_RUN ioctl and immediate_exit
was not set.

Replace all references to vcpu->run->immediate_exit with
!vcpu->wants_to_run to avoid TOCTOU races with userspace. For example, a
malicious userspace could invoked KVM_RUN with immediate_exit=true and
then after KVM reads it to set wants_to_run=false, flip it to false.
This would result in the vCPU running in KVM_RUN with
wants_to_run=false. This wouldn't cause any real bugs today but is a
dangerous landmine.

Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20240503181734.1467938-2-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-18 09:20:01 -07:00
Bibo Mao
163e9fc695 LoongArch: KVM: Add software breakpoint support
When VM runs in kvm mode, system will not exit to host mode when
executing a general software breakpoint instruction such as INSN_BREAK,
trap exception happens in guest mode rather than host mode. In order to
debug guest kernel on host side, one mechanism should be used to let VM
exit to host mode.

Here a hypercall instruction with a special code is used for software
breakpoint usage. VM exits to host mode and kvm hypervisor identifies
the special hypercall code and sets exit_reason with KVM_EXIT_DEBUG. And
then let qemu handle it.

Idea comes from ppc kvm, one api KVM_REG_LOONGARCH_DEBUG_INST is added
to get the hypercall code. VMM needs get sw breakpoint instruction with
this api and set the corresponding sw break point for guest kernel.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-05-06 22:00:47 +08:00
Bibo Mao
e33bda7ee5 LoongArch: KVM: Add PV IPI support on host side
On LoongArch system, IPI hw uses iocsr registers. There are one iocsr
register access on IPI sending, and two iocsr access on IPI receiving
for the IPI interrupt handler. In VM mode all iocsr accessing will cause
VM to trap into hypervisor. So with one IPI hw notification there will
be three times of trap.

In this patch PV IPI is added for VM, hypercall instruction is used for
IPI sender, and hypervisor will inject an SWI to the destination vcpu.
During the SWI interrupt handler, only CSR.ESTAT register is written to
clear irq. CSR.ESTAT register access will not trap into hypervisor, so
with PV IPI supported, there is one trap with IPI sender, and no trap
with IPI receiver, there is only one trap with IPI notification.

Also this patch adds IPI multicast support, the method is similar with
x86. With IPI multicast support, IPI notification can be sent to at
most 128 vcpus at one time. It greatly reduces the times of trapping
into hypervisor.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-05-06 22:00:47 +08:00
Bibo Mao
73516e9da5 LoongArch: KVM: Add vcpu mapping from physical cpuid
Physical CPUID is used for interrupt routing for irqchips such as ipi,
msgint and eiointc interrupt controllers. Physical CPUID is stored at
the CSR register LOONGARCH_CSR_CPUID, it can not be changed once vcpu
is created and the physical CPUIDs of two vcpus cannot be the same.

Different irqchips have different size declaration about physical CPUID,
the max CPUID value for CSR LOONGARCH_CSR_CPUID on Loongson-3A5000 is
512, the max CPUID supported by IPI hardware is 1024, while for eiointc
irqchip is 256, and for msgint irqchip is 65536.

The smallest value from all interrupt controllers is selected now, and
the max cpuid size is defines as 256 by KVM which comes from the eiointc
irqchip.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-05-06 22:00:47 +08:00
Bibo Mao
aebd3bd586 LoongArch: KVM: Set reserved bits as zero in CPUCFG
Supported CPUCFG information comes from function _kvm_get_cpucfg_mask().
A bit should be zero if it is reserved by HW or if it is not supported
by KVM.

Also LoongArch software page table walk feature defined in CPUCFG2_LSPW
is supported by KVM, it should be enabled by default.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-03-06 09:12:13 +08:00
WANG Xuerui
f0f5c4894f LoongArch: KVM: Streamline kvm_check_cpucfg() and improve comments
All the checks currently done in kvm_check_cpucfg can be realized with
early returns, so just do that to avoid extra cognitive burden related
to the return value handling.

While at it, clean up comments of _kvm_get_cpucfg_mask() and
kvm_check_cpucfg(), by removing comments that are merely restatement of
the code nearby, and paraphrasing the rest so they read more natural for
English speakers (that likely are not familiar with the actual Chinese-
influenced grammar).

No functional changes intended.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-02-23 14:36:31 +08:00
WANG Xuerui
ec83f39d2b LoongArch: KVM: Rename _kvm_get_cpucfg() to _kvm_get_cpucfg_mask()
The function is not actually a getter of guest CPUCFG, but rather
validation of the input CPUCFG ID plus information about the supported
bit flags of that CPUCFG leaf. So rename it to avoid confusion.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-02-23 14:36:31 +08:00
WANG Xuerui
179af5751a LoongArch: KVM: Fix input validation of _kvm_get_cpucfg() & kvm_check_cpucfg()
The range check for the CPUCFG ID is wrong (should have been a ||
instead of &&) and useless in effect, so fix the obvious mistake.

Furthermore, the juggling of the temp return value is unnecessary,
because it is semantically equivalent and more readable to just
return at every switch case's end. This is done too to avoid potential
bugs in the future related to the unwanted complexity.

Also, the return value of _kvm_get_cpucfg is meant to be checked, but
this was not done, so bad CPUCFG IDs wrongly fall back to the default
case and 0 is incorrectly returned; check the return value to fix the
UAPI behavior.

While at it, also remove the redundant range check in kvm_check_cpucfg,
because out-of-range CPUCFG IDs are already rejected by the -EINVAL
as returned by _kvm_get_cpucfg().

Fixes: db1ecca22e ("LoongArch: KVM: Add LSX (128bit SIMD) support")
Fixes: 118e10cd89 ("LoongArch: KVM: Add LASX (256bit SIMD) support")
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-02-23 14:36:31 +08:00
Tianrui Zhao
118e10cd89 LoongArch: KVM: Add LASX (256bit SIMD) support
This patch adds LASX (256bit SIMD) support for LoongArch KVM.

There will be LASX exception in KVM when guest use the LASX instructions.
KVM will enable LASX and restore the vector registers for guest and then
return to guest to continue running.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-12-19 10:48:28 +08:00
Tianrui Zhao
db1ecca22e LoongArch: KVM: Add LSX (128bit SIMD) support
This patch adds LSX (128bit SIMD) support for LoongArch KVM.

There will be LSX exception in KVM when guest use the LSX instructions.
KVM will enable LSX and restore the vector registers for guest and then
return to guest to continue running.

Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-12-19 10:48:28 +08:00
Bibo Mao
1ab9c60994 LoongArch: KVM: Remove kvm_acquire_timer() before entering guest
Timer emulation method in VM is switch to SW timer, there are two
places where timer emulation is needed. One is during vcpu thread
context switch, the other is halt-polling with idle instruction
emulation. SW timer switching is removed during halt-polling mode,
so it is not necessary to disable SW timer before entering to guest.

This patch removes SW timer handling before entering guest mode, and
put it in HW timer restoring flow when vcpu thread is sched-in. With
this patch, vm timer emulation is simpler, there is SW/HW timer
switch only in vcpu thread context switch scenario.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-12-19 10:48:28 +08:00
Bibo Mao
1612673201 LoongArch: KVM: Remove SW timer switch when vcpu is halt polling
With halt-polling supported, there is checking for pending events or
interrupts when vcpu executes idle instruction. Pending interrupts
include injected SW interrupts and passthrough HW interrupts, such as
HW timer interrupts, since HW timer works still even if vcpu exists from
VM mode.

Since HW timer pending interrupt can be set directly with CSR status
register, and pending HW timer interrupt checking is used in vcpu block
checking function, it is not necessary to switch to SW timer during
halt-polling. This patch adds preemption disabling in function
kvm_cpu_has_pending_timer(), and removes SW timer switching in idle
instruction emulation function.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-12-19 10:48:27 +08:00
Tianrui Zhao
93a9a197b6 LoongArch: KVM: Implement misc vcpu related interfaces
1, Implement LoongArch vcpu status description such as idle exits
counter, signal exits counter, cpucfg exits counter, etc.

2, Implement some misc vcpu relaterd interfaces, such as vcpu runnable,
vcpu should kick, vcpu dump regs, etc.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-10-02 10:01:28 +08:00
Tianrui Zhao
1f4c39b989 LoongArch: KVM: Implement vcpu load and vcpu put operations
Implement LoongArch vcpu load and vcpu put operations, including load
csr value into hardware and save csr value into vcpu structure.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-10-02 10:01:28 +08:00
Tianrui Zhao
f45ad5b8aa LoongArch: KVM: Implement vcpu interrupt operations
Implement vcpu interrupt operations such as vcpu set irq and vcpu
clear irq, using set_gcsr_estat() to set irq which is parsed by the
irq bitmap.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-10-02 10:01:28 +08:00
Tianrui Zhao
84be4212dc LoongArch: KVM: Implement fpu operations for vcpu
Implement LoongArch fpu related interface for vcpu, such as get fpu, set
fpu, own fpu and lose fpu, etc.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-10-02 10:01:28 +08:00
Tianrui Zhao
f6deff355b LoongArch: KVM: Implement basic vcpu ioctl interfaces
Implement basic vcpu ioctl interfaces, including:

1, vcpu KVM_ENABLE_CAP ioctl interface.

2, vcpu get registers and set registers operations, it is called when
user space use the ioctl interface to get or set regs.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-10-02 10:01:27 +08:00
Tianrui Zhao
2fc3bd86db LoongArch: KVM: Implement basic vcpu interfaces
Implement basic vcpu interfaces, including:

1, vcpu create and destroy interface, saving info into vcpu arch
structure such as vcpu exception entrance, vcpu enter guest pointer,
etc. Init vcpu timer and set address translation mode when vcpu create.

2, vcpu run interface, handling mmio, iocsr reading fault and deliver
interrupt, lose fpu before vcpu enter guest.

3, vcpu handle exit interface, getting the exit code by ESTAT register
and using kvm exception vector to handle it.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-10-02 10:01:27 +08:00