Commit graph

59 commits

Author SHA1 Message Date
Quan Zhou
eded6754f3 riscv: KVM: add basic support for host vs guest profiling
For the information collected on the host side, we need to
identify which data originates from the guest and record
these events separately, this can be achieved by having
KVM register perf callbacks.

Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/00342d535311eb0629b9ba4f1e457a48e2abee33.1728957131.git.zhouquan@iscas.ac.cn
Signed-off-by: Anup Patel <anup@brainfault.org>
2024-10-28 16:41:14 +05:30
Linus Torvalds
2c9b351240 ARM:
* Initial infrastructure for shadow stage-2 MMUs, as part of nested
   virtualization enablement
 
 * Support for userspace changes to the guest CTR_EL0 value, enabling
   (in part) migration of VMs between heterogenous hardware
 
 * Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1 of
   the protocol
 
 * FPSIMD/SVE support for nested, including merged trap configuration
   and exception routing
 
 * New command-line parameter to control the WFx trap behavior under KVM
 
 * Introduce kCFI hardening in the EL2 hypervisor
 
 * Fixes + cleanups for handling presence/absence of FEAT_TCRX
 
 * Miscellaneous fixes + documentation updates
 
 LoongArch:
 
 * Add paravirt steal time support.
 
 * Add support for KVM_DIRTY_LOG_INITIALLY_SET.
 
 * Add perf kvm-stat support for loongarch.
 
 RISC-V:
 
 * Redirect AMO load/store access fault traps to guest
 
 * perf kvm stat support
 
 * Use guest files for IMSIC virtualization, when available
 
 ONE_REG support for the Zimop, Zcmop, Zca, Zcf, Zcd, Zcb and Zawrs ISA
 extensions is coming through the RISC-V tree.
 
 s390:
 
 * Assortment of tiny fixes which are not time critical
 
 x86:
 
 * Fixes for Xen emulation.
 
 * Add a global struct to consolidate tracking of host values, e.g. EFER
 
 * Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the effective APIC
   bus frequency, because TDX.
 
 * Print the name of the APICv/AVIC inhibits in the relevant tracepoint.
 
 * Clean up KVM's handling of vendor specific emulation to consistently act on
   "compatible with Intel/AMD", versus checking for a specific vendor.
 
 * Drop MTRR virtualization, and instead always honor guest PAT on CPUs
   that support self-snoop.
 
 * Update to the newfangled Intel CPU FMS infrastructure.
 
 * Don't advertise IA32_PERF_GLOBAL_OVF_CTRL as an MSR-to-be-saved, as it reads
   '0' and writes from userspace are ignored.
 
 * Misc cleanups
 
 x86 - MMU:
 
 * Small cleanups, renames and refactoring extracted from the upcoming
   Intel TDX support.
 
 * Don't allocate kvm_mmu_page.shadowed_translation for shadow pages that can't
   hold leafs SPTEs.
 
 * Unconditionally drop mmu_lock when allocating TDP MMU page tables for eager
   page splitting, to avoid stalling vCPUs when splitting huge pages.
 
 * Bug the VM instead of simply warning if KVM tries to split a SPTE that is
   non-present or not-huge.  KVM is guaranteed to end up in a broken state
   because the callers fully expect a valid SPTE, it's all but dangerous
   to let more MMU changes happen afterwards.
 
 x86 - AMD:
 
 * Make per-CPU save_area allocations NUMA-aware.
 
 * Force sev_es_host_save_area() to be inlined to avoid calling into an
   instrumentable function from noinstr code.
 
 * Base support for running SEV-SNP guests.  API-wise, this includes
   a new KVM_X86_SNP_VM type, encrypting/measure the initial image into
   guest memory, and finalizing it before launching it.  Internally,
   there are some gmem/mmu hooks needed to prepare gmem-allocated pages
   before mapping them into guest private memory ranges.
 
   This includes basic support for attestation guest requests, enough to
   say that KVM supports the GHCB 2.0 specification.
 
   There is no support yet for loading into the firmware those signing
   keys to be used for attestation requests, and therefore no need yet
   for the host to provide certificate data for those keys.  To support
   fetching certificate data from userspace, a new KVM exit type will be
   needed to handle fetching the certificate from userspace. An attempt to
   define a new KVM_EXIT_COCO/KVM_EXIT_COCO_REQ_CERTS exit type to handle
   this was introduced in v1 of this patchset, but is still being discussed
   by community, so for now this patchset only implements a stub version
   of SNP Extended Guest Requests that does not provide certificate data.
 
 x86 - Intel:
 
 * Remove an unnecessary EPT TLB flush when enabling hardware.
 
 * Fix a series of bugs that cause KVM to fail to detect nested pending posted
   interrupts as valid wake eents for a vCPU executing HLT in L2 (with
   HLT-exiting disable by L1).
 
 * KVM: x86: Suppress MMIO that is triggered during task switch emulation
 
   Explicitly suppress userspace emulated MMIO exits that are triggered when
   emulating a task switch as KVM doesn't support userspace MMIO during
   complex (multi-step) emulation.  Silently ignoring the exit request can
   result in the WARN_ON_ONCE(vcpu->mmio_needed) firing if KVM exits to
   userspace for some other reason prior to purging mmio_needed.
 
   See commit 0dc902267c ("KVM: x86: Suppress pending MMIO write exits if
   emulator detects exception") for more details on KVM's limitations with
   respect to emulated MMIO during complex emulator flows.
 
 Generic:
 
 * Rename the AS_UNMOVABLE flag that was introduced for KVM to AS_INACCESSIBLE,
   because the special casing needed by these pages is not due to just
   unmovability (and in fact they are only unmovable because the CPU cannot
   access them).
 
 * New ioctl to populate the KVM page tables in advance, which is useful to
   mitigate KVM page faults during guest boot or after live migration.
   The code will also be used by TDX, but (probably) not through the ioctl.
 
 * 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.
 
 Selftests:
 
 * Remove dead code in the memslot modification stress test.
 
 * Treat "branch instructions retired" as supported on all AMD Family 17h+ CPUs.
 
 * Print the guest pseudo-RNG seed only when it changes, to avoid spamming the
   log for tests that create lots of VMs.
 
 * Make the PMU counters test less flaky when counting LLC cache misses by
   doing CLFLUSH{OPT} in every loop iteration.
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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:

   - Initial infrastructure for shadow stage-2 MMUs, as part of nested
     virtualization enablement

   - Support for userspace changes to the guest CTR_EL0 value, enabling
     (in part) migration of VMs between heterogenous hardware

   - Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1
     of the protocol

   - FPSIMD/SVE support for nested, including merged trap configuration
     and exception routing

   - New command-line parameter to control the WFx trap behavior under
     KVM

   - Introduce kCFI hardening in the EL2 hypervisor

   - Fixes + cleanups for handling presence/absence of FEAT_TCRX

   - Miscellaneous fixes + documentation updates

  LoongArch:

   - Add paravirt steal time support

   - Add support for KVM_DIRTY_LOG_INITIALLY_SET

   - Add perf kvm-stat support for loongarch

  RISC-V:

   - Redirect AMO load/store access fault traps to guest

   - perf kvm stat support

   - Use guest files for IMSIC virtualization, when available

  s390:

   - Assortment of tiny fixes which are not time critical

  x86:

   - Fixes for Xen emulation

   - Add a global struct to consolidate tracking of host values, e.g.
     EFER

   - Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the
     effective APIC bus frequency, because TDX

   - Print the name of the APICv/AVIC inhibits in the relevant
     tracepoint

   - Clean up KVM's handling of vendor specific emulation to
     consistently act on "compatible with Intel/AMD", versus checking
     for a specific vendor

   - Drop MTRR virtualization, and instead always honor guest PAT on
     CPUs that support self-snoop

   - Update to the newfangled Intel CPU FMS infrastructure

   - Don't advertise IA32_PERF_GLOBAL_OVF_CTRL as an MSR-to-be-saved, as
     it reads '0' and writes from userspace are ignored

   - Misc cleanups

  x86 - MMU:

   - Small cleanups, renames and refactoring extracted from the upcoming
     Intel TDX support

   - Don't allocate kvm_mmu_page.shadowed_translation for shadow pages
     that can't hold leafs SPTEs

   - Unconditionally drop mmu_lock when allocating TDP MMU page tables
     for eager page splitting, to avoid stalling vCPUs when splitting
     huge pages

   - Bug the VM instead of simply warning if KVM tries to split a SPTE
     that is non-present or not-huge. KVM is guaranteed to end up in a
     broken state because the callers fully expect a valid SPTE, it's
     all but dangerous to let more MMU changes happen afterwards

  x86 - AMD:

   - Make per-CPU save_area allocations NUMA-aware

   - Force sev_es_host_save_area() to be inlined to avoid calling into
     an instrumentable function from noinstr code

   - Base support for running SEV-SNP guests. API-wise, this includes a
     new KVM_X86_SNP_VM type, encrypting/measure the initial image into
     guest memory, and finalizing it before launching it. Internally,
     there are some gmem/mmu hooks needed to prepare gmem-allocated
     pages before mapping them into guest private memory ranges

     This includes basic support for attestation guest requests, enough
     to say that KVM supports the GHCB 2.0 specification

     There is no support yet for loading into the firmware those signing
     keys to be used for attestation requests, and therefore no need yet
     for the host to provide certificate data for those keys.

     To support fetching certificate data from userspace, a new KVM exit
     type will be needed to handle fetching the certificate from
     userspace.

     An attempt to define a new KVM_EXIT_COCO / KVM_EXIT_COCO_REQ_CERTS
     exit type to handle this was introduced in v1 of this patchset, but
     is still being discussed by community, so for now this patchset
     only implements a stub version of SNP Extended Guest Requests that
     does not provide certificate data

  x86 - Intel:

   - Remove an unnecessary EPT TLB flush when enabling hardware

   - Fix a series of bugs that cause KVM to fail to detect nested
     pending posted interrupts as valid wake eents for a vCPU executing
     HLT in L2 (with HLT-exiting disable by L1)

   - KVM: x86: Suppress MMIO that is triggered during task switch
     emulation

     Explicitly suppress userspace emulated MMIO exits that are
     triggered when emulating a task switch as KVM doesn't support
     userspace MMIO during complex (multi-step) emulation

     Silently ignoring the exit request can result in the
     WARN_ON_ONCE(vcpu->mmio_needed) firing if KVM exits to userspace
     for some other reason prior to purging mmio_needed

     See commit 0dc902267c ("KVM: x86: Suppress pending MMIO write
     exits if emulator detects exception") for more details on KVM's
     limitations with respect to emulated MMIO during complex emulator
     flows

  Generic:

   - Rename the AS_UNMOVABLE flag that was introduced for KVM to
     AS_INACCESSIBLE, because the special casing needed by these pages
     is not due to just unmovability (and in fact they are only
     unmovable because the CPU cannot access them)

   - New ioctl to populate the KVM page tables in advance, which is
     useful to mitigate KVM page faults during guest boot or after live
     migration. The code will also be used by TDX, but (probably) not
     through the ioctl

   - 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

  Selftests:

   - Remove dead code in the memslot modification stress test

   - Treat "branch instructions retired" as supported on all AMD Family
     17h+ CPUs

   - Print the guest pseudo-RNG seed only when it changes, to avoid
     spamming the log for tests that create lots of VMs

   - Make the PMU counters test less flaky when counting LLC cache
     misses by doing CLFLUSH{OPT} in every loop iteration"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  crypto: ccp: Add the SNP_VLEK_LOAD command
  KVM: x86/pmu: Add kvm_pmu_call() to simplify static calls of kvm_pmu_ops
  KVM: x86: Introduce kvm_x86_call() to simplify static calls of kvm_x86_ops
  KVM: x86: Replace static_call_cond() with static_call()
  KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event
  x86/sev: Move sev_guest.h into common SEV header
  KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event
  KVM: x86: Suppress MMIO that is triggered during task switch emulation
  KVM: x86/mmu: Clean up make_huge_page_split_spte() definition and intro
  KVM: x86/mmu: Bug the VM if KVM tries to split a !hugepage SPTE
  KVM: selftests: x86: Add test for KVM_PRE_FAULT_MEMORY
  KVM: x86: Implement kvm_arch_vcpu_pre_fault_memory()
  KVM: x86/mmu: Make kvm_mmu_do_page_fault() return mapped level
  KVM: x86/mmu: Account pf_{fixed,emulate,spurious} in callers of "do page fault"
  KVM: x86/mmu: Bump pf_taken stat only in the "real" page fault handler
  KVM: Add KVM_PRE_FAULT_MEMORY vcpu ioctl to pre-populate guest memory
  KVM: Document KVM_PRE_FAULT_MEMORY ioctl
  mm, virt: merge AS_UNMOVABLE and AS_INACCESSIBLE
  perf kvm: Add kvm-stat for loongarch64
  LoongArch: KVM: Add PV steal time support in guest side
  ...
2024-07-20 12:41:03 -07:00
Palmer Dabbelt
5ee121a393
Merge patch series "riscv: Apply Zawrs when available"
Andrew Jones <ajones@ventanamicro.com> says:

Zawrs provides two instructions (wrs.nto and wrs.sto), where both are
meant to allow the hart to enter a low-power state while waiting on a
store to a memory location. The instructions also both wait an
implementation-defined "short" duration (unless the implementation
terminates the stall for another reason). The difference is that while
wrs.sto will terminate when the duration elapses, wrs.nto, depending on
configuration, will either just keep waiting or an ILL exception will be
raised. Linux will use wrs.nto, so if platforms have an implementation
which falls in the "just keep waiting" category (which is not expected),
then it should _not_ advertise Zawrs in the hardware description.

Like wfi (and with the same {m,h}status bits to configure it), when
wrs.nto is configured to raise exceptions it's expected that the higher
privilege level will see the instruction was a wait instruction, do
something, and then resume execution following the instruction. For
example, KVM does configure exceptions for wfi (hstatus.VTW=1) and
therefore also for wrs.nto. KVM does this for wfi since it's better to
allow other tasks to be scheduled while a VCPU waits for an interrupt.
For waits such as those where wrs.nto/sto would be used, which are
typically locks, it is also a good idea for KVM to be involved, as it
can attempt to schedule the lock holding VCPU.

This series starts with Christoph's addition of the riscv
smp_cond_load_relaxed function which applies wrs.sto when available.
That patch has been reworked to use wrs.nto and to use the same approach
as Arm for the wait loop, since we can't have arbitrary C code between
the load-reserved and the wrs. Then, hwprobe support is added (since the
instructions are also usable from usermode), and finally KVM is
taught about wrs.nto, allowing guests to see and use the Zawrs
extension.

We still don't have test results from hardware, and it's not possible to
prove that using Zawrs is a win when testing on QEMU, not even when
oversubscribing VCPUs to guests. However, it is possible to use KVM
selftests to force a scenario where we can prove Zawrs does its job and
does it well. [4] is a test which does this and, on my machine, without
Zawrs it takes 16 seconds to complete and with Zawrs it takes 0.25
seconds.

This series is also available here [1]. In order to use QEMU for testing
a build with [2] is needed. In order to enable guests to use Zawrs with
KVM using kvmtool, the branch at [3] may be used.

[1] https://github.com/jones-drew/linux/commits/riscv/zawrs-v3/
[2] https://lore.kernel.org/all/20240312152901.512001-2-ajones@ventanamicro.com/
[3] https://github.com/jones-drew/kvmtool/commits/riscv/zawrs/
[4] cb2beccebc

Link: https://lore.kernel.org/r/20240426100820.14762-8-ajones@ventanamicro.com

* b4-shazam-merge:
  KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
  KVM: riscv: Support guest wrs.nto
  riscv: hwprobe: export Zawrs ISA extension
  riscv: Add Zawrs support for spinlocks
  dt-bindings: riscv: Add Zawrs ISA extension description
  riscv: Provide a definition for 'pause'

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-12 08:55:29 -07:00
Andrew Jones
86d6a86e59
KVM: riscv: Support guest wrs.nto
When a guest traps on wrs.nto, call kvm_vcpu_on_spin() to attempt
to yield to the lock holding VCPU. Also extend the KVM ISA extension
ONE_REG interface to allow KVM userspace to detect and enable the
Zawrs extension for the Guest/VM.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240426100820.14762-13-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-12 08:54:51 -07:00
Sean Christopherson
2a27c43140 KVM: Delete the now unused kvm_arch_sched_in()
Delete kvm_arch_sched_in() now that all implementations are nops.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20240522014013.1672962-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-11 14:18:45 -07:00
Yong-Xuan Wang
9752fed8f6 RISCV: KVM: Introduce vcpu->reset_cntx_lock
Originally, the use of kvm->lock in SBI_EXT_HSM_HART_START also avoids
the simultaneous updates to the reset context of target VCPU. Since this
lock has been replace with vcpu->mp_state_lock, and this new lock also
protects the vcpu->mp_state. We have to add a separate lock for
vcpu->reset_cntx.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240417074528.16506-3-yongxuan.wang@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
2024-04-22 10:39:03 +05:30
Yong-Xuan Wang
2121cadec4 RISCV: KVM: Introduce mp_state_lock to avoid lock inversion
Documentation/virt/kvm/locking.rst advises that kvm->lock should be
acquired outside vcpu->mutex and kvm->srcu. However, when KVM/RISC-V
handling SBI_EXT_HSM_HART_START, the lock ordering is vcpu->mutex,
kvm->srcu then kvm->lock.

Although the lockdep checking no longer complains about this after commit
f0f44752f5 ("rcu: Annotate SRCU's update-side lockdep dependencies"),
it's necessary to replace kvm->lock with a new dedicated lock to ensure
only one hart can execute the SBI_EXT_HSM_HART_START call for the target
hart simultaneously.

Additionally, this patch also rename "power_off" to "mp_state" with two
possible values. The vcpu->mp_state_lock also protects the access of
vcpu->mp_state.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240417074528.16506-2-yongxuan.wang@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
2024-04-22 10:37:11 +05:30
Chao Du
edcbe90f12 RISC-V: KVM: Implement kvm_arch_vcpu_ioctl_set_guest_debug()
kvm_vm_ioctl_check_extension(): Return 1 if KVM_CAP_SET_GUEST_DEBUG is
been checked.

kvm_arch_vcpu_ioctl_set_guest_debug(): Update the guest_debug flags
from userspace accordingly. Route the breakpoint exceptions to HS mode
if the VCPU is being debugged by userspace, by clearing the
corresponding bit in hedeleg.

Initialize the hedeleg configuration in kvm_riscv_vcpu_setup_config().
Write the actual CSR in kvm_arch_vcpu_load().

Signed-off-by: Chao Du <duchao@eswincomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240402062628.5425-2-duchao@eswincomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>
2024-04-08 14:06:27 +05:30
Paolo Bonzini
9cc52627c7 KVM/riscv changes for 6.8 part #1
- KVM_GET_REG_LIST improvement for vector registers
 - Generate ISA extension reg_list using macros in get-reg-list selftest
 - Steal time account support along with selftest
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Merge tag 'kvm-riscv-6.8-1' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv changes for 6.8 part #1

- KVM_GET_REG_LIST improvement for vector registers
- Generate ISA extension reg_list using macros in get-reg-list selftest
- Steal time account support along with selftest
2024-01-02 13:19:40 -05:00
Andrew Jones
38b3390ee4 RISC-V: KVM: Add SBI STA info to vcpu_arch
KVM's implementation of SBI STA needs to track the address of each
VCPU's steal-time shared memory region as well as the amount of
stolen time. Add a structure to vcpu_arch to contain this state
and make sure that the address is always set to INVALID_GPA on
vcpu reset. And, of course, ensure KVM won't try to update steal-
time when the shared memory address is invalid.

Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-30 11:26:26 +05:30
Andrew Jones
2a1f6bf079 RISC-V: KVM: Add steal-update vcpu request
Add a new vcpu request to inform a vcpu that it should record its
steal-time information. The request is made each time it has been
detected that the vcpu task was not assigned a cpu for some time,
which is easy to do by making the request from vcpu-load. The record
function is just a stub for now and will be filled in with the rest
of the steal-time support functions in following patches.

Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-30 11:26:22 +05:30
Sean Christopherson
f128cf8cfb KVM: Convert KVM_ARCH_WANT_MMU_NOTIFIER to CONFIG_KVM_GENERIC_MMU_NOTIFIER
Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where
appropriate to effectively maintain existing behavior.  Using a proper
Kconfig will simplify building more functionality on top of KVM's
mmu_notifier infrastructure.

Add a forward declaration of kvm_gfn_range to kvm_types.h so that
including arch/powerpc/include/asm/kvm_ppc.h's with CONFIG_KVM=n doesn't
generate warnings due to kvm_gfn_range being undeclared.  PPC defines
hooks for PR vs. HV without guarding them via #ifdeffery, e.g.

  bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range);
  bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
  bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
  bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);

Alternatively, PPC could forward declare kvm_gfn_range, but there's no
good reason not to define it in common KVM.

Acked-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-11-13 05:29:09 -05:00
Mayuresh Chitale
81f0f314fe RISCV: KVM: Add sstateen0 context save/restore
Define sstateen0 and add sstateen0 save/restore for guest VCPUs.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12 18:44:11 +05:30
Mayuresh Chitale
db3c01c7a3 RISCV: KVM: Add senvcfg context save/restore
Add senvcfg context save/restore for guest VCPUs and also add it to the
ONE_REG interface to allow its access from user space.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12 18:44:09 +05:30
Mayuresh Chitale
d21b5d342f RISC-V: KVM: Enable Smstateen accesses
Configure hstateen0 register so that the AIA state and envcfg are
accessible to the vcpus. This includes registers such as siselect,
sireg, siph, sieh and all the IMISC registers.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12 18:44:07 +05:30
Mayuresh Chitale
fe0bab701e RISC-V: KVM: Add kvm_vcpu_config
Add a placeholder for all registers such as henvcfg, hstateen etc
which have 'static' configurations depending on extensions supported by
the guest. The values are derived once and are then subsequently written
to the corresponding CSRs while switching to the vcpu.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12 18:44:02 +05:30
Haibo Xu
031f9efafc KVM: riscv: Add KVM_GET_REG_LIST API support
KVM_GET_REG_LIST API will return all registers that are available to
KVM_GET/SET_ONE_REG APIs. It's very useful to identify some platform
regression issue during VM migration.

Since this API was already supported on arm64, it is straightforward
to enable it on riscv with similar code structure.

Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-09 12:15:25 +05:30
Anup Patel
e98b1085be RISC-V: KVM: Factor-out ONE_REG related code to its own source file
The VCPU ONE_REG interface has grown over time and it will continue
to grow with new ISA extensions and other features. Let us move all
ONE_REG related code to its own source file so that vcpu.c only
focuses only on high-level VCPU functions.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:25:29 +05:30
Linus Torvalds
e8069f5a8e ARM64:
* Eager page splitting optimization for dirty logging, optionally
   allowing for a VM to avoid the cost of hugepage splitting in the stage-2
   fault path.
 
 * Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with
   services that live in the Secure world. pKVM intervenes on FF-A calls
   to guarantee the host doesn't misuse memory donated to the hyp or a
   pKVM guest.
 
 * Support for running the split hypervisor with VHE enabled, known as
   'hVHE' mode. This is extremely useful for testing the split
   hypervisor on VHE-only systems, and paves the way for new use cases
   that depend on having two TTBRs available at EL2.
 
 * Generalized framework for configurable ID registers from userspace.
   KVM/arm64 currently prevents arbitrary CPU feature set configuration
   from userspace, but the intent is to relax this limitation and allow
   userspace to select a feature set consistent with the CPU.
 
 * Enable the use of Branch Target Identification (FEAT_BTI) in the
   hypervisor.
 
 * Use a separate set of pointer authentication keys for the hypervisor
   when running in protected mode, as the host is untrusted at runtime.
 
 * Ensure timer IRQs are consistently released in the init failure
   paths.
 
 * Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps
   (FEAT_EVT), as it is a register commonly read from userspace.
 
 * Erratum workaround for the upcoming AmpereOne part, which has broken
   hardware A/D state management.
 
 RISC-V:
 
 * Redirect AMO load/store misaligned traps to KVM guest
 
 * Trap-n-emulate AIA in-kernel irqchip for KVM guest
 
 * Svnapot support for KVM Guest
 
 s390:
 
 * New uvdevice secret API
 
 * CMM selftest and fixes
 
 * fix racy access to target CPU for diag 9c
 
 x86:
 
 * Fix missing/incorrect #GP checks on ENCLS
 
 * Use standard mmu_notifier hooks for handling APIC access page
 
 * Drop now unnecessary TR/TSS load after VM-Exit on AMD
 
 * Print more descriptive information about the status of SEV and SEV-ES during
   module load
 
 * Add a test for splitting and reconstituting hugepages during and after
   dirty logging
 
 * Add support for CPU pinning in demand paging test
 
 * Add support for AMD PerfMonV2, with a variety of cleanups and minor fixes
   included along the way
 
 * Add a "nx_huge_pages=never" option to effectively avoid creating NX hugepage
   recovery threads (because nx_huge_pages=off can be toggled at runtime)
 
 * Move handling of PAT out of MTRR code and dedup SVM+VMX code
 
 * Fix output of PIC poll command emulation when there's an interrupt
 
 * Add a maintainer's handbook to document KVM x86 processes, preferred coding
   style, testing expectations, etc.
 
 * Misc cleanups, fixes and comments
 
 Generic:
 
 * Miscellaneous bugfixes and cleanups
 
 Selftests:
 
 * Generate dependency files so that partial rebuilds work as expected
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Eager page splitting optimization for dirty logging, optionally
     allowing for a VM to avoid the cost of hugepage splitting in the
     stage-2 fault path.

   - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact
     with services that live in the Secure world. pKVM intervenes on
     FF-A calls to guarantee the host doesn't misuse memory donated to
     the hyp or a pKVM guest.

   - Support for running the split hypervisor with VHE enabled, known as
     'hVHE' mode. This is extremely useful for testing the split
     hypervisor on VHE-only systems, and paves the way for new use cases
     that depend on having two TTBRs available at EL2.

   - Generalized framework for configurable ID registers from userspace.
     KVM/arm64 currently prevents arbitrary CPU feature set
     configuration from userspace, but the intent is to relax this
     limitation and allow userspace to select a feature set consistent
     with the CPU.

   - Enable the use of Branch Target Identification (FEAT_BTI) in the
     hypervisor.

   - Use a separate set of pointer authentication keys for the
     hypervisor when running in protected mode, as the host is untrusted
     at runtime.

   - Ensure timer IRQs are consistently released in the init failure
     paths.

   - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization
     Traps (FEAT_EVT), as it is a register commonly read from userspace.

   - Erratum workaround for the upcoming AmpereOne part, which has
     broken hardware A/D state management.

  RISC-V:

   - Redirect AMO load/store misaligned traps to KVM guest

   - Trap-n-emulate AIA in-kernel irqchip for KVM guest

   - Svnapot support for KVM Guest

  s390:

   - New uvdevice secret API

   - CMM selftest and fixes

   - fix racy access to target CPU for diag 9c

  x86:

   - Fix missing/incorrect #GP checks on ENCLS

   - Use standard mmu_notifier hooks for handling APIC access page

   - Drop now unnecessary TR/TSS load after VM-Exit on AMD

   - Print more descriptive information about the status of SEV and
     SEV-ES during module load

   - Add a test for splitting and reconstituting hugepages during and
     after dirty logging

   - Add support for CPU pinning in demand paging test

   - Add support for AMD PerfMonV2, with a variety of cleanups and minor
     fixes included along the way

   - Add a "nx_huge_pages=never" option to effectively avoid creating NX
     hugepage recovery threads (because nx_huge_pages=off can be toggled
     at runtime)

   - Move handling of PAT out of MTRR code and dedup SVM+VMX code

   - Fix output of PIC poll command emulation when there's an interrupt

   - Add a maintainer's handbook to document KVM x86 processes,
     preferred coding style, testing expectations, etc.

   - Misc cleanups, fixes and comments

  Generic:

   - Miscellaneous bugfixes and cleanups

  Selftests:

   - Generate dependency files so that partial rebuilds work as
     expected"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (153 commits)
  Documentation/process: Add a maintainer handbook for KVM x86
  Documentation/process: Add a label for the tip tree handbook's coding style
  KVM: arm64: Fix misuse of KVM_ARM_VCPU_POWER_OFF bit index
  RISC-V: KVM: Remove unneeded semicolon
  RISC-V: KVM: Allow Svnapot extension for Guest/VM
  riscv: kvm: define vcpu_sbi_ext_pmu in header
  RISC-V: KVM: Expose IMSIC registers as attributes of AIA irqchip
  RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC
  RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip
  RISC-V: KVM: Add in-kernel emulation of AIA APLIC
  RISC-V: KVM: Implement device interface for AIA irqchip
  RISC-V: KVM: Skeletal in-kernel AIA irqchip support
  RISC-V: KVM: Set kvm_riscv_aia_nr_hgei to zero
  RISC-V: KVM: Add APLIC related defines
  RISC-V: KVM: Add IMSIC related defines
  RISC-V: KVM: Implement guest external interrupt line management
  KVM: x86: Remove PRIx* definitions as they are solely for user space
  s390/uv: Update query for secret-UVCs
  s390/uv: replace scnprintf with sysfs_emit
  s390/uvdevice: Add 'Lock Secret Store' UVC
  ...
2023-07-03 15:32:22 -07:00
Anup Patel
00f918f61c RISC-V: KVM: Skeletal in-kernel AIA irqchip support
To incrementally implement in-kernel AIA irqchip support, we first
add minimal skeletal support which only compiles but does not provide
any functionality.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-06-18 21:24:40 +05:30
Vincent Chen
0f4b825797
riscv: KVM: Add vector lazy save/restore support
This patch adds vector context save/restore for guest VCPUs. To reduce the
impact on KVM performance, the implementation imitates the FP context
switch mechanism to lazily store and restore the vector context only when
the kernel enters/exits the in-kernel run loop and not during the KVM
world switch.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230605110724.21391-20-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08 07:16:51 -07:00
Anup Patel
6b1e8ba4ba RISC-V: KVM: Use bitmap for irqs_pending and irqs_pending_mask
To support 64 VCPU local interrupts on RV32 host, we should use
bitmap for irqs_pending and irqs_pending_mask in struct kvm_vcpu_arch.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-04-21 17:45:58 +05:30
Anup Patel
54e43320c2 RISC-V: KVM: Initial skeletal support for AIA
To incrementally implement AIA support, we first add minimal skeletal
support which only compiles and detects AIA hardware support at the
boot-time but does not provide any functionality.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-04-21 17:45:48 +05:30
Paolo Bonzini
33436335e9 KVM/riscv changes for 6.3
- Fix wrong usage of PGDIR_SIZE to check page sizes
 - Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect()
 - Redirect illegal instruction traps to guest
 - SBI PMU support for guest
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Merge tag 'kvm-riscv-6.3-1' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv changes for 6.3

- Fix wrong usage of PGDIR_SIZE to check page sizes
- Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect()
- Redirect illegal instruction traps to guest
- SBI PMU support for guest
2023-02-15 12:33:28 -05:00
Atish Patra
8f0153ecd3 RISC-V: KVM: Add skeleton support for perf
This patch only adds barebone structure of perf implementation. Most
of the function returns zero at this point and will be implemented
fully in the future.

Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-02-07 20:35:51 +05:30
Sean Christopherson
45b66dc139 KVM: RISC-V: Tag init functions and data with __init, __ro_after_init
Now that KVM setup is handled directly in riscv_kvm_init(), tag functions
and data that are used/set only during init with __init/__ro_after_init.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Anup Patel <anup@brainfault.org>
Message-Id: <20221130230934.1014142-26-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29 15:41:18 -05:00
Sean Christopherson
63a1bd8ad1 KVM: Drop arch hardware (un)setup hooks
Drop kvm_arch_hardware_setup() and kvm_arch_hardware_unsetup() now that
all implementations are nops.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>	# s390
Acked-by: Anup Patel <anup@brainfault.org>
Message-Id: <20221130230934.1014142-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29 15:40:54 -05:00
Anup Patel
52ec4b695d RISC-V: KVM: Save mvendorid, marchid, and mimpid when creating VCPU
We should save VCPU mvendorid, marchid, and mimpid at the time
of creating VCPU so that we don't have to do host SBI call every
time Guest/VM ask for these details.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-12-07 09:17:43 +05:30
Anup Patel
23fe562e45 RISC-V: KVM: Move sbi related struct and functions to kvm_vcpu_sbi.h
Just like asm/kvm_vcpu_timer.h, we should have all sbi related struct
and functions in asm/kvm_vcpu_sbi.h.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-12-07 09:17:27 +05:30
Anup Patel
1343c61a70 RISC-V: KVM: Remove redundant includes of asm/csr.h
We should include asm/csr.h only where required so let us remove
redundant includes of this header.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-12-07 09:17:12 +05:30
Jisheng Zhang
54ce3f7ff3 RISC-V: KVM: Record number of signal exits as a vCPU stat
Record a statistic indicating the number of times a vCPU has exited
due to a pending signal.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org
2022-10-02 10:19:16 +05:30
Anup Patel
c9d57373fc RISC-V: KVM: Add G-stage ioremap() and iounmap() functions
The in-kernel AIA IMSIC support requires on-demand mapping / unmapping
of Guest IMSIC address to Host IMSIC guest files. To help achieve this,
we add kvm_riscv_stage2_ioremap() and kvm_riscv_stage2_iounmap() functions.
These new functions for updating G-stage page table mappings will be called
in atomic context so we have special "in_atomic" parameter for this purpose.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29 17:15:06 +05:30
Anup Patel
8a061562e2 RISC-V: KVM: Add extensible CSR emulation framework
We add an extensible CSR emulation framework which is based upon the
existing system instruction emulation. This will be useful to upcoming
AIA, PMU, Nested and other virtualization features.

The CSR emulation framework also has provision to emulate CSR in user
space but this will be used only in very specific cases such as AIA
IMSIC CSR emulation in user space or vendor specific CSR emulation
in user space.

By default, all CSRs not handled by KVM RISC-V will be redirected back
to Guest VCPU as illegal instruction trap.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29 17:14:53 +05:30
Anup Patel
b91f0e4cb8 RISC-V: KVM: Factor-out instruction emulation into separate sources
The instruction and CSR emulation for VCPU is going to grow over time
due to upcoming AIA, PMU, Nested and other virtualization features.

Let us factor-out VCPU instruction emulation from vcpu_exit.c to a
separate source dedicated for this purpose.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29 17:14:40 +05:30
Atish Patra
9bfd900bee RISC-V: KVM: Improve ISA extension by using a bitmap
Currently, the every vcpu only stores the ISA extensions in a unsigned long
which is not scalable as number of extensions will continue to grow.
Using a bitmap allows the ISA extension to support any number of
extensions. The CONFIG one reg interface implementation is modified to
support the bitmap as well. But it is meant only for base extensions.
Thus, the first element of the bitmap array is sufficient for that
interface.

In the future, all the new multi-letter extensions must use the
ISA_EXT one reg interface that allows enabling/disabling any extension
now.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29 17:14:11 +05:30
Anup Patel
92e450507d RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
On RISC-V platforms with hardware VMID support, we share same
VMID for all VCPUs of a particular Guest/VM. This means we might
have stale G-stage TLB entries on the current Host CPU due to
some other VCPU of the same Guest which ran previously on the
current Host CPU.

To cleanup stale TLB entries, we simply flush all G-stage TLB
entries by VMID whenever underlying Host CPU changes for a VCPU.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:18 +05:30
Anup Patel
13acfec2db RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
The generic KVM has support for VCPU requests which can be used
to do arch-specific work in the run-loop. We introduce remote
HFENCE functions which will internally use VCPU requests instead
of host SBI calls.

Advantages of doing remote HFENCEs as VCPU requests are:
1) Multiple VCPUs of a Guest may be running on different Host CPUs
   so it is not always possible to determine the Host CPU mask for
   doing Host SBI call. For example, when VCPU X wants to do HFENCE
   on VCPU Y, it is possible that VCPU Y is blocked or in user-space
   (i.e. vcpu->cpu < 0).
2) To support nested virtualization, we will be having a separate
   shadow G-stage for each VCPU and a common host G-stage for the
   entire Guest/VM. The VCPU requests based remote HFENCEs helps
   us easily synchronize the common host G-stage and shadow G-stage
   of each VCPU without any additional IPI calls.

This is also a preparatory patch for upcoming nested virtualization
support where we will be having a shadow G-stage page table for
each Guest VCPU.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:15 +05:30
Anup Patel
486a384294 RISC-V: KVM: Reduce KVM_MAX_VCPUS value
Currently, the KVM_MAX_VCPUS value is 16384 for RV64 and 128
for RV32.

The KVM_MAX_VCPUS value is too high for RV64 and too low for
RV32 compared to other architectures (e.g. x86 sets it to 1024
and ARM64 sets it to 512). The too high value of KVM_MAX_VCPUS
on RV64 also leads to VCPU mask on stack consuming 2KB.

We set KVM_MAX_VCPUS to 1024 for both RV64 and RV32 to be
aligned other architectures.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:12 +05:30
Anup Patel
2415e46e3a RISC-V: KVM: Introduce range based local HFENCE functions
Various  __kvm_riscv_hfence_xyz() functions implemented in the
kvm/tlb.S are equivalent to corresponding HFENCE.GVMA instructions
and we don't have range based local HFENCE functions.

This patch provides complete set of local HFENCE functions which
supports range based TLB invalidation and supports HFENCE.VVMA
based functions. This is also a preparatory patch for upcoming
Svinval support in KVM RISC-V.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:09 +05:30
Anup Patel
26708234eb RISC-V: KVM: Use G-stage name for hypervisor page table
The two-stage address translation defined by the RISC-V privileged
specification defines: VS-stage (guest virtual address to guest
physical address) programmed by the Guest OS  and G-stage (guest
physical addree to host physical address) programmed by the
hypervisor.

To align with above terminology, we replace "stage2" with "gstage"
and "Stage2" with "G-stage" name everywhere in KVM RISC-V sources.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:01 +05:30
Sean Christopherson
fdd6f6ac2e KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copy
Use the generic kvm_vcpu's srcu_idx instead of using an indentical field
in RISC-V's version of kvm_vcpu_arch.  Generic KVM very intentionally
does not touch vcpu->srcu_idx, i.e. there's zero chance of running afoul
of common code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220415004343.2203171-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21 13:16:10 -04:00
Anup Patel
c9d3b5bd26 RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
The wait for interrupt (WFI) instruction emulation can share the VCPU
halt logic with SBI HSM suspend emulation so this patch adds a common
kvm_riscv_vcpu_wfi() function for this purpose.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:37 +05:30
Anup Patel
a457fd5660 RISC-V: KVM: Add VM capability to allow userspace get GPA bits
The number of GPA bits supported for a RISC-V Guest/VM is based on the
MMU mode used by the G-stage translation. The KVM RISC-V will detect and
use the best possible MMU mode for the G-stage in kvm_arch_init().

We add a generic VM capability KVM_CAP_VM_GPA_BITS which can be used by
the KVM userspace to get the number of GPA (guest physical address) bits
supported for a Guest/VM.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-and-tested-by: Atish Patra <atishp@rivosinc.com>
2022-01-06 15:16:58 +05:30
Sean Christopherson
cc4f602bc4 KVM: RISC-V: Use common KVM implementation of MMU memory caches
Use common KVM's implementation of the MMU memory caches, which for all
intents and purposes is semantically identical to RISC-V's version, the
only difference being that the common implementation will fall back to an
atomic allocation if there's a KVM bug that triggers a cache underflow.

RISC-V appears to have based its MMU code on arm64 before the conversion
to the common caches in commit c1a33aebe9 ("KVM: arm64: Use common KVM
implementation of MMU memory caches"), despite having also copy-pasted
the definition of KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE in kvm_types.h.

Opportunistically drop the superfluous wrapper
kvm_riscv_stage2_flush_cache(), whose name is very, very confusing as
"cache flush" in the context of MMU code almost always refers to flushing
hardware caches, not freeing unused software objects.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:38:50 +05:30
Sean Christopherson
005467e06b KVM: Drop obsolete kvm_arch_vcpu_block_finish()
Drop kvm_arch_vcpu_block_finish() now that all arch implementations are
nops.

No functional change intended.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:50 -05:00
Anup Patel
74c2e97b01 RISC-V: KVM: Fix incorrect KVM_MAX_VCPUS value
The KVM_MAX_VCPUS value is supposed to be aligned with number of
VMID bits in the hgatp CSR but the current KVM_MAX_VCPUS value
is aligned with number of ASID bits in the satp CSR.

Fixes: 99cdc6c18c ("RISC-V: Add initial skeletal KVM support")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
2021-11-22 10:36:19 +05:30
Anup Patel
7c8de080d4 RISC-V: KVM: Fix GPA passed to __kvm_riscv_hfence_gvma_xyz() functions
The parameter passed to HFENCE.GVMA instruction in rs1 register
is guest physical address right shifted by 2 (i.e. divided by 4).

Unfortunately, we overlooked the semantics of rs1 registers for
HFENCE.GVMA instruction and never right shifted guest physical
address by 2. This issue did not manifest for hypervisors till
now because:
  1) Currently, only __kvm_riscv_hfence_gvma_all() and SBI
     HFENCE calls are used to invalidate TLB.
  2) All H-extension implementations (such as QEMU, Spike,
     Rocket Core FPGA, etc) that we tried till now were
     conservatively flushing everything upon any HFENCE.GVMA
     instruction.

This patch fixes GPA passed to __kvm_riscv_hfence_gvma_vmid_gpa()
and __kvm_riscv_hfence_gvma_gpa() functions.

Fixes: fd7bb4a251 ("RISC-V: KVM: Implement VMID allocator")
Reported-by: Ian Huang <ihuang@ventanamicro.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211026170136.2147619-4-anup.patel@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-31 02:45:43 -04:00
Anup Patel
0a86512dc1 RISC-V: KVM: Factor-out FP virtualization into separate sources
The timer and SBI virtualization is already in separate sources.
In future, we will have vector and AIA virtualization also added
as separate sources.

To align with above described modularity, we factor-out FP
virtualization into separate sources.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211026170136.2147619-3-anup.patel@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-31 02:45:43 -04:00
Atish Patra
dea8ee31a0 RISC-V: KVM: Add SBI v0.1 support
The KVM host kernel is running in HS-mode needs so we need to handle
the SBI calls coming from guest kernel running in VS-mode.

This patch adds SBI v0.1 support in KVM RISC-V. Almost all SBI v0.1
calls are implemented in KVM kernel module except GETCHAR and PUTCHART
calls which are forwarded to user space because these calls cannot be
implemented in kernel space. In future, when we implement SBI v0.2 for
Guest, we will forward SBI v0.2 experimental and vendor extension calls
to user space.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:11:30 +05:30
Atish Patra
5de52d4a23 RISC-V: KVM: FP lazy save/restore
This patch adds floating point (F and D extension) context save/restore
for guest VCPUs. The FP context is saved and restored lazily only when
kernel enter/exits the in-kernel run loop and not during the KVM world
switch. This way FP save/restore has minimal impact on KVM performance.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:08:23 +05:30