Commit graph

238 commits

Author SHA1 Message Date
Linus Torvalds
09d1c6a80f Generic:
- Use memdup_array_user() to harden against overflow.
 
 - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all architectures.
 
 - Clean up Kconfigs that all KVM architectures were selecting
 
 - New functionality around "guest_memfd", a new userspace API that
   creates an anonymous file and returns a file descriptor that refers
   to it.  guest_memfd files are bound to their owning virtual machine,
   cannot be mapped, read, or written by userspace, and cannot be resized.
   guest_memfd files do however support PUNCH_HOLE, which can be used to
   switch a memory area between guest_memfd and regular anonymous memory.
 
 - New ioctl KVM_SET_MEMORY_ATTRIBUTES allowing userspace to specify
   per-page attributes for a given page of guest memory; right now the
   only attribute is whether the guest expects to access memory via
   guest_memfd or not, which in Confidential SVMs backed by SEV-SNP,
   TDX or ARM64 pKVM is checked by firmware or hypervisor that guarantees
   confidentiality (AMD PSP, Intel TDX module, or EL2 in the case of pKVM).
 
 x86:
 
 - Support for "software-protected VMs" that can use the new guest_memfd
   and page attributes infrastructure.  This is mostly useful for testing,
   since there is no pKVM-like infrastructure to provide a meaningfully
   reduced TCB.
 
 - Fix a relatively benign off-by-one error when splitting huge pages during
   CLEAR_DIRTY_LOG.
 
 - Fix a bug where KVM could incorrectly test-and-clear dirty bits in non-leaf
   TDP MMU SPTEs if a racing thread replaces a huge SPTE with a non-huge SPTE.
 
 - Use more generic lockdep assertions in paths that don't actually care
   about whether the caller is a reader or a writer.
 
 - let Xen guests opt out of having PV clock reported as "based on a stable TSC",
   because some of them don't expect the "TSC stable" bit (added to the pvclock
   ABI by KVM, but never set by Xen) to be set.
 
 - Revert a bogus, made-up nested SVM consistency check for TLB_CONTROL.
 
 - Advertise flush-by-ASID support for nSVM unconditionally, as KVM always
   flushes on nested transitions, i.e. always satisfies flush requests.  This
   allows running bleeding edge versions of VMware Workstation on top of KVM.
 
 - Sanity check that the CPU supports flush-by-ASID when enabling SEV support.
 
 - On AMD machines with vNMI, always rely on hardware instead of intercepting
   IRET in some cases to detect unmasking of NMIs
 
 - Support for virtualizing Linear Address Masking (LAM)
 
 - Fix a variety of vPMU bugs where KVM fail to stop/reset counters and other state
   prior to refreshing the vPMU model.
 
 - Fix a double-overflow PMU bug by tracking emulated counter events using a
   dedicated field instead of snapshotting the "previous" counter.  If the
   hardware PMC count triggers overflow that is recognized in the same VM-Exit
   that KVM manually bumps an event count, KVM would pend PMIs for both the
   hardware-triggered overflow and for KVM-triggered overflow.
 
 - Turn off KVM_WERROR by default for all configs so that it's not
   inadvertantly enabled by non-KVM developers, which can be problematic for
   subsystems that require no regressions for W=1 builds.
 
 - Advertise all of the host-supported CPUID bits that enumerate IA32_SPEC_CTRL
   "features".
 
 - Don't force a masterclock update when a vCPU synchronizes to the current TSC
   generation, as updating the masterclock can cause kvmclock's time to "jump"
   unexpectedly, e.g. when userspace hotplugs a pre-created vCPU.
 
 - Use RIP-relative address to read kvm_rebooting in the VM-Enter fault paths,
   partly as a super minor optimization, but mostly to make KVM play nice with
   position independent executable builds.
 
 - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on
   CONFIG_HYPERV as a minor optimization, and to self-document the code.
 
 - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV "emulation"
   at build time.
 
 ARM64:
 
 - LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB
   base granule sizes. Branch shared with the arm64 tree.
 
 - Large Fine-Grained Trap rework, bringing some sanity to the
   feature, although there is more to come. This comes with
   a prefix branch shared with the arm64 tree.
 
 - Some additional Nested Virtualization groundwork, mostly
   introducing the NV2 VNCR support and retargetting the NV
   support to that version of the architecture.
 
 - A small set of vgic fixes and associated cleanups.
 
 Loongarch:
 
 - Optimization for memslot hugepage checking
 
 - Cleanup and fix some HW/SW timer issues
 
 - Add LSX/LASX (128bit/256bit SIMD) support
 
 RISC-V:
 
 - KVM_GET_REG_LIST improvement for vector registers
 
 - Generate ISA extension reg_list using macros in get-reg-list selftest
 
 - Support for reporting steal time along with selftest
 
 s390:
 
 - Bugfixes
 
 Selftests:
 
 - Fix an annoying goof where the NX hugepage test prints out garbage
   instead of the magic token needed to run the test.
 
 - Fix build errors when a header is delete/moved due to a missing flag
   in the Makefile.
 
 - Detect if KVM bugged/killed a selftest's VM and print out a helpful
   message instead of complaining that a random ioctl() failed.
 
 - Annotate the guest printf/assert helpers with __printf(), and fix the
   various bugs that were lurking due to lack of said annotation.
 
 There are two non-KVM patches buried in the middle of guest_memfd support:
 
   fs: Rename anon_inode_getfile_secure() and anon_inode_getfd_secure()
   mm: Add AS_UNMOVABLE to mark mapping as completely unmovable
 
 The first is small and mostly suggested-by Christian Brauner; the second
 a bit less so but it was written by an mm person (Vlastimil Babka).
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmWcMWkUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroO15gf/WLmmg3SET6Uzw9iEq2xo28831ZA+
 6kpILfIDGKozV5safDmMvcInlc/PTnqOFrsKyyN4kDZ+rIJiafJdg/loE0kPXBML
 wdR+2ix5kYI1FucCDaGTahskBDz8Lb/xTpwGg9BFLYFNmuUeHc74o6GoNvr1uliE
 4kLZL2K6w0cSMPybUD+HqGaET80ZqPwecv+s1JL+Ia0kYZJONJifoHnvOUJ7DpEi
 rgudVdgzt3EPjG0y1z6MjvDBXTCOLDjXajErlYuZD3Ej8N8s59Dh2TxOiDNTLdP4
 a4zjRvDmgyr6H6sz+upvwc7f4M4p+DBvf+TkWF54mbeObHUYliStqURIoA==
 =66Ws
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "Generic:

   - Use memdup_array_user() to harden against overflow.

   - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all
     architectures.

   - Clean up Kconfigs that all KVM architectures were selecting

   - New functionality around "guest_memfd", a new userspace API that
     creates an anonymous file and returns a file descriptor that refers
     to it. guest_memfd files are bound to their owning virtual machine,
     cannot be mapped, read, or written by userspace, and cannot be
     resized. guest_memfd files do however support PUNCH_HOLE, which can
     be used to switch a memory area between guest_memfd and regular
     anonymous memory.

   - New ioctl KVM_SET_MEMORY_ATTRIBUTES allowing userspace to specify
     per-page attributes for a given page of guest memory; right now the
     only attribute is whether the guest expects to access memory via
     guest_memfd or not, which in Confidential SVMs backed by SEV-SNP,
     TDX or ARM64 pKVM is checked by firmware or hypervisor that
     guarantees confidentiality (AMD PSP, Intel TDX module, or EL2 in
     the case of pKVM).

  x86:

   - Support for "software-protected VMs" that can use the new
     guest_memfd and page attributes infrastructure. This is mostly
     useful for testing, since there is no pKVM-like infrastructure to
     provide a meaningfully reduced TCB.

   - Fix a relatively benign off-by-one error when splitting huge pages
     during CLEAR_DIRTY_LOG.

   - Fix a bug where KVM could incorrectly test-and-clear dirty bits in
     non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with
     a non-huge SPTE.

   - Use more generic lockdep assertions in paths that don't actually
     care about whether the caller is a reader or a writer.

   - let Xen guests opt out of having PV clock reported as "based on a
     stable TSC", because some of them don't expect the "TSC stable" bit
     (added to the pvclock ABI by KVM, but never set by Xen) to be set.

   - Revert a bogus, made-up nested SVM consistency check for
     TLB_CONTROL.

   - Advertise flush-by-ASID support for nSVM unconditionally, as KVM
     always flushes on nested transitions, i.e. always satisfies flush
     requests. This allows running bleeding edge versions of VMware
     Workstation on top of KVM.

   - Sanity check that the CPU supports flush-by-ASID when enabling SEV
     support.

   - On AMD machines with vNMI, always rely on hardware instead of
     intercepting IRET in some cases to detect unmasking of NMIs

   - Support for virtualizing Linear Address Masking (LAM)

   - Fix a variety of vPMU bugs where KVM fail to stop/reset counters
     and other state prior to refreshing the vPMU model.

   - Fix a double-overflow PMU bug by tracking emulated counter events
     using a dedicated field instead of snapshotting the "previous"
     counter. If the hardware PMC count triggers overflow that is
     recognized in the same VM-Exit that KVM manually bumps an event
     count, KVM would pend PMIs for both the hardware-triggered overflow
     and for KVM-triggered overflow.

   - Turn off KVM_WERROR by default for all configs so that it's not
     inadvertantly enabled by non-KVM developers, which can be
     problematic for subsystems that require no regressions for W=1
     builds.

   - Advertise all of the host-supported CPUID bits that enumerate
     IA32_SPEC_CTRL "features".

   - Don't force a masterclock update when a vCPU synchronizes to the
     current TSC generation, as updating the masterclock can cause
     kvmclock's time to "jump" unexpectedly, e.g. when userspace
     hotplugs a pre-created vCPU.

   - Use RIP-relative address to read kvm_rebooting in the VM-Enter
     fault paths, partly as a super minor optimization, but mostly to
     make KVM play nice with position independent executable builds.

   - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on
     CONFIG_HYPERV as a minor optimization, and to self-document the
     code.

   - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV
     "emulation" at build time.

  ARM64:

   - LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB base
     granule sizes. Branch shared with the arm64 tree.

   - Large Fine-Grained Trap rework, bringing some sanity to the
     feature, although there is more to come. This comes with a prefix
     branch shared with the arm64 tree.

   - Some additional Nested Virtualization groundwork, mostly
     introducing the NV2 VNCR support and retargetting the NV support to
     that version of the architecture.

   - A small set of vgic fixes and associated cleanups.

  Loongarch:

   - Optimization for memslot hugepage checking

   - Cleanup and fix some HW/SW timer issues

   - Add LSX/LASX (128bit/256bit SIMD) support

  RISC-V:

   - KVM_GET_REG_LIST improvement for vector registers

   - Generate ISA extension reg_list using macros in get-reg-list
     selftest

   - Support for reporting steal time along with selftest

  s390:

   - Bugfixes

  Selftests:

   - Fix an annoying goof where the NX hugepage test prints out garbage
     instead of the magic token needed to run the test.

   - Fix build errors when a header is delete/moved due to a missing
     flag in the Makefile.

   - Detect if KVM bugged/killed a selftest's VM and print out a helpful
     message instead of complaining that a random ioctl() failed.

   - Annotate the guest printf/assert helpers with __printf(), and fix
     the various bugs that were lurking due to lack of said annotation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (185 commits)
  x86/kvm: Do not try to disable kvmclock if it was not enabled
  KVM: x86: add missing "depends on KVM"
  KVM: fix direction of dependency on MMU notifiers
  KVM: introduce CONFIG_KVM_COMMON
  KVM: arm64: Add missing memory barriers when switching to pKVM's hyp pgd
  KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache
  RISC-V: KVM: selftests: Add get-reg-list test for STA registers
  RISC-V: KVM: selftests: Add steal_time test support
  RISC-V: KVM: selftests: Add guest_sbi_probe_extension
  RISC-V: KVM: selftests: Move sbi_ecall to processor.c
  RISC-V: KVM: Implement SBI STA extension
  RISC-V: KVM: Add support for SBI STA registers
  RISC-V: KVM: Add support for SBI extension registers
  RISC-V: KVM: Add SBI STA info to vcpu_arch
  RISC-V: KVM: Add steal-update vcpu request
  RISC-V: KVM: Add SBI STA extension skeleton
  RISC-V: paravirt: Implement steal-time support
  RISC-V: Add SBI STA extension definitions
  RISC-V: paravirt: Add skeleton for pv-time support
  RISC-V: KVM: Fix indentation in kvm_riscv_vcpu_set_reg_csr()
  ...
2024-01-17 13:03:37 -08:00
Linus Torvalds
4331f07026 RISC-V Patches for the 6.8 Merge Window, Part 1
* Support for many new extensions in hwprobe, along with a handful of
   cleanups.
 * Various cleanups to our page table handling code, so we alwayse use
   {READ,WRITE}_ONCE.
 * Support for the which-cpus flavor of hwprobe.
 * Support for XIP kernels has been resurrected.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEKzw3R0RoQ7JKlDp6LhMZ81+7GIkFAmWhb+sTHHBhbG1lckBk
 YWJiZWx0LmNvbQAKCRAuExnzX7sYiWyJEADH/l2PND3AE2sfhtkDceMR8k+MOrjn
 3T0+EIow28tBEpcu7Bdu7aw65ZQDgV9aEDuo8HYlwtimPUfvTQ01QiwDRVZoxPGT
 4Br2X7n5lczQOvp6r5+8p34viQVNXaBXApgZc+iMbelj0W7AnNJNdr8/d1pMw/hA
 y6v8rq6BBgFKZKmU0va+T2AaXQN3nj/fme1l8Rn6Wf8JpaBtTnlNWGOepRfJdFbv
 ZewTEqu4CVmCE6ij8c+Gatk8k71KXLjH3mSjZ2F0FIreI0I5pdD9OKQJk+hiRCEA
 wnEneWyl+rHPUTRXpZEeLVPD4gBTbKt20awImpNG+eN+l68s4ESNWP2EZM4n5utF
 NWJAscxMA1c8NlWhnQfAKK2eAmi2sp0/9O3pTfpvZ7yWAp/GpkZGEuAaQe4R80X+
 0lLKrS8P8T2ZSA5UVfszN5vLXU/Ae3GpAQCJkzoYXjDes8sxw4fjHcg/AWn/ZmrO
 FoqPA1ka/2i0b5be+p3Emt5kfTK8WeDnV2rV1ZLYEJYBkXdTLAM8jR+mhXJ7z59P
 shfOSpZ7icvX7Q3t/eFKApryM93JE3w6WZBOYuY4D7FPoPSxJG7VgL2U42wiTZjj
 xr1ta4vdfEqWgRpAOvGaP569MQ9awzA6JZHJQOVLx9FOWox2gMWsTB8xQ33y5k/n
 eNd7JjUOu4K3jQ==
 =fLgG
 -----END PGP SIGNATURE-----

Merge tag 'riscv-for-linus-6.8-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for many new extensions in hwprobe, along with a handful of
   cleanups

 - Various cleanups to our page table handling code, so we alwayse use
   {READ,WRITE}_ONCE

 - Support for the which-cpus flavor of hwprobe

 - Support for XIP kernels has been resurrected

* tag 'riscv-for-linus-6.8-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (52 commits)
  riscv: hwprobe: export Zicond extension
  riscv: hwprobe: export Zacas ISA extension
  riscv: add ISA extension parsing for Zacas
  dt-bindings: riscv: add Zacas ISA extension description
  riscv: hwprobe: export Ztso ISA extension
  riscv: add ISA extension parsing for Ztso
  use linux/export.h rather than asm-generic/export.h
  riscv: Remove SHADOW_OVERFLOW_STACK_SIZE macro
  riscv; fix __user annotation in save_v_state()
  riscv: fix __user annotation in traps_misaligned.c
  riscv: Select ARCH_WANTS_NO_INSTR
  riscv: Remove obsolete rv32_defconfig file
  riscv: Allow disabling of BUILTIN_DTB for XIP
  riscv: Fixed wrong register in XIP_FIXUP_FLASH_OFFSET macro
  riscv: Make XIP bootable again
  riscv: Fix set_direct_map_default_noflush() to reset _PAGE_EXEC
  riscv: Fix module_alloc() that did not reset the linear mapping permissions
  riscv: Fix wrong usage of lm_alias() when splitting a huge linear mapping
  riscv: Check if the code to patch lies in the exit section
  riscv: Use the same CPU operations for all CPUs
  ...
2024-01-17 10:50:46 -08:00
Paolo Bonzini
fb872da8e7 Common KVM changes for 6.8:
- Use memdup_array_user() to harden against overflow.
 
  - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all architectures.
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCgAwFiEEMHr+pfEFOIzK+KY1YJEiAU0MEvkFAmWW8F4SHHNlYW5qY0Bn
 b29nbGUuY29tAAoJEGCRIgFNDBL5urcP/Rex6Too26aHJXelUVHlFOGw3hfOnvbq
 Wr/P3kPqB/1Mncx3aiYTpEvUxFjVTvIkMB5dWba39Eq/G1BbOT2CAHCunlvKJrXy
 L83YgOl17QtZZJS1KmLTRCj1umfl4Z0c+GEIH+P1FOuOmllNXlLJ1+GWmolP6LLf
 u4DF2/tyVZf8JXXeJWYITHsU0YQQ0MhHgYL8/aMYJK8epNFpR3wKIqT3428ASxV3
 Ru4WH7jpYkFF7PaKbvjKdepr+1wyVt4PXJDDpciCScz45/8eebgfylLJbMglpsR1
 JSUTzd6KdCbekgzp51NnRdoIxP+MXgKA3dIuzXKyIDzm2Xq6tna87ve/aWDGw8JC
 nUMkP/vAuaKT+/QTOwskGAvK2GYDQD1UwVcFNLi12Iis50H0qPwcxsUionQuZgUC
 ykCmY4N31rSX4DhPg1WLiqsvC/EeDhfXprYrfSd4HQq08NgD45orRJw0Kov+shcS
 xijIlE1e3aVJMRrbfoSWyc4m79AcooxjYwojQC1Ayqsq0ZTTzzIpd6rqjmY+LbLL
 aP/wNz8hCfMhFekUV7dDk9rMdZY+bBnTiolyKAN66E6EnPYfl2EdrDEGnZOCPXF4
 L/O/kMCXHE90cszzrmiR40yNHLkPelij8sK+ligE4JpqteQ7ia/knh8YAiPBxDw6
 XcIfftXMm5XG
 =wpT4
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-generic-6.8' of https://github.com/kvm-x86/linux into HEAD

Common KVM changes for 6.8:

 - Use memdup_array_user() to harden against overflow.

 - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all architectures.
2024-01-08 08:09:57 -05:00
Paolo Bonzini
caadf876bb KVM: introduce CONFIG_KVM_COMMON
CONFIG_HAVE_KVM is currently used by some architectures to either
enabled the KVM config proper, or to enable host-side code that is
not part of the KVM module.  However, CONFIG_KVM's "select" statement
in virt/kvm/Kconfig corresponds to a third meaning, namely to
enable common Kconfigs required by all architectures that support
KVM.

These three meanings can be replaced respectively by an
architecture-specific Kconfig, by IS_ENABLED(CONFIG_KVM), or by
a new Kconfig symbol that is in turn selected by the
architecture-specific "config KVM".

Start by introducing such a new Kconfig symbol, CONFIG_KVM_COMMON.
Unlike CONFIG_HAVE_KVM, it is selected by CONFIG_KVM, not by
architecture code, and it brings in all dependencies of common
KVM code.  In particular, INTERVAL_TREE was missing in loongarch
and riscv, so that is another thing that is fixed.

Fixes: 8132d887a7 ("KVM: remove CONFIG_HAVE_KVM_EVENTFD", 2023-12-08)
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/all/44907c6b-c5bd-4e4a-a921-e4d3825539d8@infradead.org/
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-01-08 08:09:38 -05:00
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
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEZdn75s5e6LHDQ+f/rUjsVaLHLAcFAmWQ+cgACgkQrUjsVaLH
 LAckBA//R4X9L5ugfPdDunp3ntjZXmNtBS5pM2jD+UvaoFn2kOA1o5kOD5mXluuh
 0imNjVuzlrX7XoAATQ4BoeoXg0whDbnv/8TE13KqSl1PfNziH2p5YD2DuHXPST3B
 V2VHrGACZ4wN074Whztl0oYI72obGnmpcsiglifkeCvRPerghHuDu40eUaWvCmgD
 DPwT+bjBgxkDZ4IheyytUrPql6reALh1Qo1vfj0FsJAgj+MAqQeD8n6rixSPnOdE
 9XXa4jdu7ycDp675VX/DVEWsNBQGPrsRK/uCiMksO36td+wLCKpAkvX95mE0w/L8
 qFJ+dN1c+1ZkjooHdVLfq2MjxaIRwmIowk7SeJbpvGIf/zG3r7eany7eXJT0+NjO
 22j5FY2z1NqcSG6Fazx76Qp2vVBVbxHShP9h7d6VTZYS7XENjmV6IWHpTSuSF8+n
 puj8Nf5C7WuqbySirSgQndDuKawn9myqfXXEoAuSiZ+kVyYEl8QnXm2gAIcxRDHX
 x+NDPMv0DpMBRO9qa/tXeqgNue/XOTJwgbmXzAlCNff3U7hPIHJ/5aZiJ/Re5TeE
 DxiU9AmIsNN2Bh0csS/wQbdScIqkOdOiDYEwT1DXOJWpmhiyCW7vR8ltaIuMJ4vP
 DtlfuUlSe4aml957nAiqqyjQAY/7gqmpoaGwu+lmrOX1K7fdtF0=
 =FeiG
 -----END PGP SIGNATURE-----

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
e9f12b5fff RISC-V: KVM: Implement SBI STA extension
Add a select SCHED_INFO to the KVM config in order to get run_delay
info. Then implement SBI STA's set-steal-time-shmem function and
kvm_riscv_vcpu_record_steal_time() to provide the steal-time info
to guests.

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 11:26:38 +05:30
Andrew Jones
f61ce890b1 RISC-V: KVM: Add support for SBI STA registers
KVM userspace needs to be able to save and restore the steal-time
shared memory address. Provide the address through the get/set-one-reg
interface with two ulong-sized SBI STA extension registers (lo and hi).
64-bit KVM userspace must not set the hi register to anything other
than zero and is allowed to completely neglect saving/restoring it.

Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-30 11:26:35 +05:30
Andrew Jones
5b9e41321b RISC-V: KVM: Add support for SBI extension registers
Some SBI extensions have state that needs to be saved / restored
when migrating the VM. Provide a get/set-one-reg register type
for SBI extension registers. Each SBI extension that uses this type
will have its own subtype. There are currently no subtypes defined.
The next patch introduces the first one.

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 11:26:33 +05:30
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
Andrew Jones
5fed84a800 RISC-V: KVM: Add SBI STA extension skeleton
Add the files and functions needed to support the SBI STA
(steal-time accounting) extension. In the next patches we'll
complete the functions to fully enable SBI STA support.

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 11:26:20 +05:30
Anup Patel
4c460eb369 RISC-V: KVM: Fix indentation in kvm_riscv_vcpu_set_reg_csr()
The indentation of "break" in kvm_riscv_vcpu_set_reg_csr() is
inconsistent hence let us fix it.

Fixes: c04913f2b5 ("RISCV: KVM: Add sstateen0 to ONE_REG")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312190719.kBuYl6oJ-lkp@intel.com/
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:58 +05:30
Daniel Henrique Barboza
3975525e55 RISC-V: KVM: add vector registers and CSRs in KVM_GET_REG_LIST
Add all vector registers and CSRs (vstart, vl, vtype, vcsr, vlenb) in
get-reg-list.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:56 +05:30
Daniel Henrique Barboza
2fa290372d RISC-V: KVM: add 'vlenb' Vector CSR
Userspace requires 'vlenb' to be able to encode it in reg ID. Otherwise
it is not possible to retrieve any vector reg since we're returning
EINVAL if reg_size isn't vlenb (see kvm_riscv_vcpu_vreg_addr()).

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:54 +05:30
Daniel Henrique Barboza
197bd237b6 RISC-V: KVM: set 'vlenb' in kvm_riscv_vcpu_alloc_vector_context()
'vlenb', added to riscv_v_ext_state by commit c35f3aa345 ("RISC-V:
vector: export VLENB csr in __sc_riscv_v_state"), isn't being
initialized in guest_context. If we export 'vlenb' as a KVM CSR,
something we want to do in the next patch, it'll always return 0.

Set 'vlenb' to riscv_v_size/32.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:53 +05:30
Andrew Jones
23e1dc4502 RISC-V: KVM: Make SBI uapi consistent with ISA uapi
When an SBI extension cannot be enabled, that's a distinct state vs.
enabled and disabled. Modify enum kvm_riscv_sbi_ext_status to
accommodate it, which allows KVM userspace to tell the difference
in state too, as the SBI extension register will disappear when it
cannot be enabled, i.e. accesses to it return ENOENT. get-reg-list is
updated as well to only add SBI extension registers to the list which
may be enabled. Returning ENOENT for SBI extension registers which
cannot be enabled makes them consistent with ISA extension registers.
Any SBI extensions which were enabled by default are still enabled by
default, if they can be enabled at all.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:44 +05:30
Andrew Jones
7f58de96aa RISC-V: KVM: Don't add SBI multi regs in get-reg-list
The multi regs are derived from the single registers. Only list the
single registers in get-reg-list. This also makes the SBI extension
register listing consistent with the ISA extension register listing.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:40 +05:30
Chao Du
bcd08e9bae RISC-V: KVM: remove a redundant condition in kvm_arch_vcpu_ioctl_run()
The latest ret value is updated by kvm_riscv_vcpu_aia_update(),
the loop will continue if the ret is less than or equal to zero.
So the later condition will never hit. Thus remove it.

Signed-off-by: Chao Du <duchao@eswincomputing.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:36 +05:30
Clément Léger
e5ff012743 riscv: kvm: use ".L" local labels in assembly when applicable
For the sake of coherency, use local labels in assembly when
applicable. This also avoid kprobes being confused when applying a
kprobe since the size of function is computed by checking where the
next visible symbol is located. This might end up in computing some
function size to be way shorter than expected and thus failing to apply
kprobes to the specified offset.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:33 +05:30
Clément Léger
683c5bbbf6 riscv: kvm: Use SYM_*() assembly macros instead of deprecated ones
ENTRY()/END()/WEAK() macros are deprecated and we should make use of the
new SYM_*() macros [1] for better annotation of symbols. Replace the
deprecated ones with the new ones and fix wrong usage of END()/ENDPROC()
to correctly describe the symbols.

[1] https://docs.kernel.org/core-api/asm-annotations.html

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-29 12:31:31 +05:30
Alexandre Ghiti
edf9556472
riscv: Use accessors to page table entries instead of direct dereference
As very well explained in commit 20a004e7b0 ("arm64: mm: Use
READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose
page table walker can modify the PTE in parallel must use
READ_ONCE()/WRITE_ONCE() macro to avoid any compiler transformation.

So apply that to riscv which is such architecture.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20231213203001.179237-5-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-20 10:48:15 -08:00
Yong-Xuan Wang
4ad9843e1e RISCV: KVM: update external interrupt atomically for IMSIC swfile
The emulated IMSIC update the external interrupt pending depending on
the value of eidelivery and topei. It might lose an interrupt when it
is interrupted before setting the new value to the pending status.

For example, when VCPU0 sends an IPI to VCPU1 via IMSIC:

VCPU0                           VCPU1

                                CSRSWAP topei = 0
                                The VCPU1 has claimed all the external
                                interrupt in its interrupt handler.

                                topei of VCPU1's IMSIC = 0

set pending in VCPU1's IMSIC

topei of VCPU1' IMSIC = 1

set the external interrupt
pending of VCPU1

                                clear the external interrupt pending
                                of VCPU1

When the VCPU1 switches back to VS mode, it exits the interrupt handler
because the result of CSRSWAP topei is 0. If there are no other external
interrupts injected into the VCPU1's IMSIC, VCPU1 will never know this
pending interrupt unless it initiative read the topei.

If the interruption occurs between updating interrupt pending in IMSIC
and updating external interrupt pending of VCPU, it will not cause a
problem. Suppose that the VCPU1 clears the IPI pending in IMSIC right
after VCPU0 sets the pending, the external interrupt pending of VCPU1
will not be set because the topei is 0. But when the VCPU1 goes back to
VS mode, the pending IPI will be reported by the CSRSWAP topei, it will
not lose this interrupt.

So we only need to make the external interrupt updating procedure as a
critical section to avoid the problem.

Fixes: db8b7e97d6 ("RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC")
Tested-by: Roy Lin <roy.lin@sifive.com>
Tested-by: Wayling Chen <wayling.chen@sifive.com>
Co-developed-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-12-13 11:59:52 +05:30
Paolo Bonzini
c5b31cc237 KVM: remove CONFIG_HAVE_KVM_IRQFD
All platforms with a kernel irqchip have support for irqfd.  Unify the
two configuration items so that userspace can expect to use irqfd to
inject interrupts into the irqchip.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-12-08 15:43:33 -05:00
Paolo Bonzini
8132d887a7 KVM: remove CONFIG_HAVE_KVM_EVENTFD
virt/kvm/eventfd.c is compiled unconditionally, meaning that the ioeventfds
member of struct kvm is accessed unconditionally.  CONFIG_HAVE_KVM_EVENTFD
therefore must be defined for KVM common code to compile successfully,
remove it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-12-08 15:43:33 -05:00
Wei Wang
63912245c1 KVM: move KVM_CAP_DEVICE_CTRL to the generic check
KVM_CAP_DEVICE_CTRL allows userspace to check if the kvm_device
framework (e.g. KVM_CREATE_DEVICE) is supported by KVM. Move
KVM_CAP_DEVICE_CTRL to the generic check for the two reasons:
1) it already supports arch agnostic usages (i.e. KVM_DEV_TYPE_VFIO).
For example, userspace VFIO implementation may needs to create
KVM_DEV_TYPE_VFIO on x86, riscv, or arm etc. It is simpler to have it
checked at the generic code than at each arch's code.
2) KVM_CREATE_DEVICE has been added to the generic code.

Link: https://lore.kernel.org/all/20221215115207.14784-1-wei.w.wang@intel.com
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Acked-by: Anup Patel <anup@brainfault.org> (riscv)
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://lore.kernel.org/r/20230315101606.10636-1-wei.w.wang@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-11-30 13:09:43 -08:00
Paolo Bonzini
6c370dc653 Merge branch 'kvm-guestmemfd' into HEAD
Introduce several new KVM uAPIs to ultimately create a guest-first memory
subsystem within KVM, a.k.a. guest_memfd.  Guest-first memory allows KVM
to provide features, enhancements, and optimizations that are kludgly
or outright impossible to implement in a generic memory subsystem.

The core KVM ioctl() for guest_memfd is KVM_CREATE_GUEST_MEMFD, which
similar to the generic memfd_create(), creates an anonymous file and
returns a file descriptor that refers to it.  Again like "regular"
memfd files, guest_memfd files live in RAM, have volatile storage,
and are automatically released when the last reference is dropped.
The key differences between memfd files (and every other memory subystem)
is that guest_memfd files are bound to their owning virtual machine,
cannot be mapped, read, or written by userspace, and cannot be resized.
guest_memfd files do however support PUNCH_HOLE, which can be used to
convert a guest memory area between the shared and guest-private states.

A second KVM ioctl(), KVM_SET_MEMORY_ATTRIBUTES, allows userspace to
specify attributes for a given page of guest memory.  In the long term,
it will likely be extended to allow userspace to specify per-gfn RWX
protections, including allowing memory to be writable in the guest
without it also being writable in host userspace.

The immediate and driving use case for guest_memfd are Confidential
(CoCo) VMs, specifically AMD's SEV-SNP, Intel's TDX, and KVM's own pKVM.
For such use cases, being able to map memory into KVM guests without
requiring said memory to be mapped into the host is a hard requirement.
While SEV+ and TDX prevent untrusted software from reading guest private
data by encrypting guest memory, pKVM provides confidentiality and
integrity *without* relying on memory encryption.  In addition, with
SEV-SNP and especially TDX, accessing guest private memory can be fatal
to the host, i.e. KVM must be prevent host userspace from accessing
guest memory irrespective of hardware behavior.

Long term, guest_memfd may be useful for use cases beyond CoCo VMs,
for example hardening userspace against unintentional accesses to guest
memory.  As mentioned earlier, KVM's ABI uses userspace VMA protections to
define the allow guest protection (with an exception granted to mapping
guest memory executable), and similarly KVM currently requires the guest
mapping size to be a strict subset of the host userspace mapping size.
Decoupling the mappings sizes would allow userspace to precisely map
only what is needed and with the required permissions, without impacting
guest performance.

A guest-first memory subsystem also provides clearer line of sight to
things like a dedicated memory pool (for slice-of-hardware VMs) and
elimination of "struct page" (for offload setups where userspace _never_
needs to DMA from or into guest memory).

guest_memfd is the result of 3+ years of development and exploration;
taking on memory management responsibilities in KVM was not the first,
second, or even third choice for supporting CoCo VMs.  But after many
failed attempts to avoid KVM-specific backing memory, and looking at
where things ended up, it is quite clear that of all approaches tried,
guest_memfd is the simplest, most robust, and most extensible, and the
right thing to do for KVM and the kernel at-large.

The "development cycle" for this version is going to be very short;
ideally, next week I will merge it as is in kvm/next, taking this through
the KVM tree for 6.8 immediately after the end of the merge window.
The series is still based on 6.6 (plus KVM changes for 6.7) so it
will require a small fixup for changes to get_file_rcu() introduced in
6.7 by commit 0ede61d858 ("file: convert to SLAB_TYPESAFE_BY_RCU").
The fixup will be done as part of the merge commit, and most of the text
above will become the commit message for the merge.

Pending post-merge work includes:
- hugepage support
- looking into using the restrictedmem framework for guest memory
- introducing a testing mechanism to poison memory, possibly using
  the same memory attributes introduced here
- SNP and TDX support

There are two non-KVM patches buried in the middle of this series:

  fs: Rename anon_inode_getfile_secure() and anon_inode_getfd_secure()
  mm: Add AS_UNMOVABLE to mark mapping as completely unmovable

The first is small and mostly suggested-by Christian Brauner; the second
a bit less so but it was written by an mm person (Vlastimil Babka).
2023-11-14 08:31:31 -05:00
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
Linus Torvalds
56d428ae1c RISC-V Patches for the 6.7 Merge Window, Part 2
* Support for handling misaligned accesses in S-mode.
 * Probing for misaligned access support is now properly cached and
   handled in parallel.
 * PTDUMP now reflects the SW reserved bits, as well as the PBMT and
   NAPOT extensions.
 * Performance improvements for TLB flushing.
 * Support for many new relocations in the module loader.
 * Various bug fixes and cleanups.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEKzw3R0RoQ7JKlDp6LhMZ81+7GIkFAmVOUCcTHHBhbG1lckBk
 YWJiZWx0LmNvbQAKCRAuExnzX7sYicJ2D/9S+9dnHYHVGTeJfr9Zf2T4r+qHBPyx
 LXbTAbgHN6139MgcRLMRlcUaQ04RVxuBCWhxewJ6mQiHiYNlullgKmJO8oYMS4uZ
 2yQGHKhzKEVluXxe+qT6VW+zsP0cY6pDQ+e59AqZgyWzvATxMU4VtFfCDdjFG03I
 k/8Y3MUKSHAKzIHUsGHiMW5J2YRiM/iVehv2gZfanreulWlK6lyiV4AZ4KChu8Sa
 gix9QkFJw+9+7RHnouHvczt4xTqLPJQcdecLJsbisEI4VaaPtTVzkvXx/kwbMwX0
 qkQnZ7I60fPHrCb9ccuedjDMa1Z0lrfwRldBGz9f9QaW37Eppirn6LA5JiZ1cA47
 wKTwba6gZJCTRXELFTJLcv+Cwdy003E0y3iL5UK2rkbLqcxfvLdq1WAJU2t05Lmh
 aRQN10BtM2DZG+SNPlLoBpXPDw0Q3KOc20zGtuhmk010+X4yOK7WXlu8zNGLLE0+
 yHamiZqAbpIUIEzwDdGbb95jywR1sUhNTbScuhj4Rc79ZqLtPxty1PUhnfqFat1R
 i3ngQtCbeUUYFS2YV9tKkXjLf/xkQNRbt7kQBowuvFuvfksl9UwMdRAWcE/h0M9P
 7uz7cBFhuG0v/XblB7bUhYLkKITvP+ltSMyxaGlfpGqCLAH2KIztdZ2PLWLRdKeU
 +9dtZSQR6oBLqQ==
 =NhdR
 -----END PGP SIGNATURE-----

Merge tag 'riscv-for-linus-6.7-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:

 - Support for handling misaligned accesses in S-mode

 - Probing for misaligned access support is now properly cached and
   handled in parallel

 - PTDUMP now reflects the SW reserved bits, as well as the PBMT and
   NAPOT extensions

 - Performance improvements for TLB flushing

 - Support for many new relocations in the module loader

 - Various bug fixes and cleanups

* tag 'riscv-for-linus-6.7-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits)
  riscv: Optimize bitops with Zbb extension
  riscv: Rearrange hwcap.h and cpufeature.h
  drivers: perf: Do not broadcast to other cpus when starting a counter
  drivers: perf: Check find_first_bit() return value
  of: property: Add fw_devlink support for msi-parent
  RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs
  riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings
  riscv: Don't use PGD entries for the linear mapping
  RISC-V: Probe misaligned access speed in parallel
  RISC-V: Remove __init on unaligned_emulation_finish()
  RISC-V: Show accurate per-hart isa in /proc/cpuinfo
  RISC-V: Don't rely on positional structure initialization
  riscv: Add tests for riscv module loading
  riscv: Add remaining module relocations
  riscv: Avoid unaligned access when relocating modules
  riscv: split cache ops out of dma-noncoherent.c
  riscv: Improve flush_tlb_kernel_range()
  riscv: Make __flush_tlb_range() loop over pte instead of flushing the whole tlb
  riscv: Improve flush_tlb_range() for hugetlb pages
  riscv: Improve tlb_flush()
  ...
2023-11-10 09:23:17 -08:00
Xiao Wang
e72c4333d2
riscv: Rearrange hwcap.h and cpufeature.h
Now hwcap.h and cpufeature.h are mutually including each other, and most of
the variable/API declarations in hwcap.h are implemented in cpufeature.c,
so, it's better to move them into cpufeature.h and leave only macros for
ISA extension logical IDs in hwcap.h.

BTW, the riscv_isa_extension_mask macro is not used now, so this patch
removes it.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231031064553.2319688-2-xiao.w.wang@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-09 10:15:51 -08:00
Anup Patel
c667ad229d RISC-V: KVM: Forward SBI DBCN extension to user-space
The frozen SBI v2.0 specification defines the SBI debug console
(DBCN) extension which replaces the legacy SBI v0.1 console
functions namely sbi_console_getchar() and sbi_console_putchar().

The SBI DBCN extension needs to be emulated in the KVM user-space
(i.e. QEMU-KVM or KVMTOOL) so we forward SBI DBCN calls from KVM
guest to the KVM user-space which can then redirect the console
input/output to wherever it wants (e.g. telnet, file, stdio, etc).

The SBI debug console is simply a early console available to KVM
guest for early prints and it does not intend to replace the proper
console devices such as 8250, VirtIO console, etc.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-20 16:50:36 +05:30
Anup Patel
56d8a385b6 RISC-V: KVM: Allow some SBI extensions to be disabled by default
Currently, all SBI extensions are enabled by default which is
problematic for SBI extensions (such as DBCN) which are forwarded
to the KVM user-space because we might have an older KVM user-space
which is not aware/ready to handle newer SBI extensions. Ideally,
the SBI extensions forwarded to the KVM user-space must be
disabled by default.

To address above, we allow certain SBI extensions to be disabled
by default so that KVM user-space must explicitly enable such
SBI extensions to receive forwarded calls from Guest VCPU.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-20 16:50:33 +05:30
Anup Patel
df68f4d8cb RISC-V: KVM: Allow Zicond extension for Guest/VM
We extend the KVM ISA extension ONE_REG interface to allow KVM
user space to detect and enable Zicond extension for Guest/VM.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12 18:44:23 +05:30
Mayuresh Chitale
c04913f2b5 RISCV: KVM: Add sstateen0 to ONE_REG
Add support for sstateen0 CSR 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 18:44:13 +05:30
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
Anup Patel
17f71a2a34 RISC-V: KVM: Fix riscv_vcpu_get_isa_ext_single() for missing extensions
The riscv_vcpu_get_isa_ext_single() should fail with -ENOENT error
when corresponding ISA extension is not available on the host.

Fixes: e98b1085be ("RISC-V: KVM: Factor-out ONE_REG related code to its own source file")
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>
2023-09-21 15:04:01 +05:30
Anup Patel
ef4d483685 RISC-V: KVM: Fix KVM_GET_REG_LIST API for ISA_EXT registers
The ISA_EXT registers to enabled/disable ISA extensions for VCPU
are always available when underlying host has the corresponding
ISA extension. The copy_isa_ext_reg_indices() called by the
KVM_GET_REG_LIST API does not align with this expectation so
let's fix it.

Fixes: 031f9efafc ("KVM: riscv: Add KVM_GET_REG_LIST API support")
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>
2023-09-21 15:03:59 +05:30
Paolo Bonzini
e43ae8b689 KVM/riscv changes for 6.6
- Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for Guest/VM
 - Added ONE_REG interface for SATP mode
 - Added ONE_REG interface to enable/disable multiple ISA extensions
 - Improved error codes returned by ONE_REG interfaces
 - Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V
 - Added get-reg-list selftest for KVM RISC-V
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEZdn75s5e6LHDQ+f/rUjsVaLHLAcFAmTlo4gACgkQrUjsVaLH
 LAfuxA/+KzZJ4o6dM5c/VltYNdYwb3y17QJa/FE5abl+mBsGApv+fmefXOKeoj21
 W72XCkGBhpHoaEAIyN63eP0IIs4LvaJOfyGkkINeIR1we9Ws++x8PBaCf/oiclHA
 xwTSOHLj0OYMyR/zeusTqz1moHBwKFQ5Zx3EsBk+HPVThgoejbyQS37+8dG3paRU
 UYaHKz1SJg120G7Xbl/WUpM7e8wQzFZTx/cGuNIWad3U8TM9chYcg2q/HTgEq8pz
 tIwV04g+8bYT9Y/kb1LdqUprHPQgdrYphOnIyf/916goYwIhHkf2PVO2BajzmWjU
 12gZAAOSD5JSS2Rel47dmM2AYAT5nii9E5x9/56YeqHdYG6LqtYdLDAkXvrsIDIh
 EnZdNj7svoWpe5IQ9CqZRgy6uNhXx1u6JlUA6Euuhd0vEvQWRNj9BaPaF7pjFu7E
 6KyRxBhpmueJQ1exBQsnOMV97UB00SYH+8HiQE5kma0yBqKHFTgZbhPDI+VEMfrG
 sqbNJ49Xpm+2Ac1+H00WB+8xtyxGab0z+8PCA2nrkgtquGeGzkwuWQvF3wGctDds
 PXxgS6qaXSXCa3j5KlCShwLgi4wpKiwZ9Nz70NI4TQWWiQBMbxJ+Y2R+5BE5ugk5
 8tFKWO0jLDanNINgg+uJmxa7oQSsZMBJ0+CLqPYc76rC0ivKbKI=
 =ZNgs
 -----END PGP SIGNATURE-----

Merge tag 'kvm-riscv-6.6-1' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv changes for 6.6

- Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for Guest/VM
- Added ONE_REG interface for SATP mode
- Added ONE_REG interface to enable/disable multiple ISA extensions
- Improved error codes returned by ONE_REG interfaces
- Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V
- Added get-reg-list selftest for KVM RISC-V
2023-08-31 13:25:55 -04:00
Paolo Bonzini
0d15bf966d Common KVM changes for 6.6:
- Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier events to pass
    action specific data without needing to constantly update the main handlers.
 
  - Drop unused function declarations
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCgAwFiEEMHr+pfEFOIzK+KY1YJEiAU0MEvkFAmTudpYSHHNlYW5qY0Bn
 b29nbGUuY29tAAoJEGCRIgFNDBL5xJUQAKnMVEV+7gRtfV5KCJFRTNAMxo4zSIt/
 K6QX+x/SwUriXj4nTAlvAtju1xz4nwTYBABKj3bXEaLpVjIUIbnEzEGuTKKK6XY9
 UyJKVgafwLuKLWPYN/5Zv5SCO7DmVC9W3lVMtchgt7gFcRxtZhmEn53boHhrhan0
 /2L5XD6N9rd81Zmd/rQkJNRND7XY3HkvDSnfmsRI/rfFUglCUHBDp4c2Wkmz+Dnb
 ux7N37si5OTbRVp18VzbLg1jalstDEm36ZQ7tLkvIbNbZV6pV93/ZmcTmsOruTeN
 gHVr6/RXmKKwgO3wtZ9DKL6oMcoh20yoT+vqhbaihVssLPGPusk7S2cCQ7529u8/
 Oda+w67MMdbE46N9CmB56fkpwNvn9nLCoQFhMhXBWhPJVNmorpiR6drHKqLy5zCq
 lrsWGqXU/DXA2PwdsztfIIMVeALawzExHu9ayppcKwb4S8TLJhLma7dT+EvwUxuV
 hoswaIT7Tq2ptZ34Fo5/vEz+90u2wi7LynHrNdTs7NLsW+WI/jab7KxKc+mf5WYh
 KuMzqmmPXmWRFupFeDa61YY5PCvMddDeac/jCYL/2cr73RA8bUItivwt5mEg5nOW
 9NEU+cLbl1s8g2KfxwhvodVkbhiNGf8MkVpE5skHHh9OX8HYzZUa/s6uUZO1O0eh
 XOk+fa9KWabt
 =n819
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-generic-6.6' of https://github.com/kvm-x86/linux into HEAD

Common KVM changes for 6.6:

 - Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier events to pass
   action specific data without needing to constantly update the main handlers.

 - Drop unused function declarations
2023-08-31 13:19:55 -04:00
Sean Christopherson
3e1efe2b67 KVM: Wrap kvm_{gfn,hva}_range.pte in a per-action union
Wrap kvm_{gfn,hva}_range.pte in a union so that future notifier events can
pass event specific information up and down the stack without needing to
constantly expand and churn the APIs.  Lockless aging of SPTEs will pass
around a bitmap, and support for memory attributes will pass around the
new attributes for the range.

Add a "KVM_NO_ARG" placeholder to simplify handling events without an
argument (creating a dummy union variable is midly annoying).

Opportunstically drop explicit zero-initialization of the "pte" field, as
omitting the field (now a union) has the same effect.

Cc: Yu Zhao <yuzhao@google.com>
Link: https://lore.kernel.org/all/CAOUHufagkd2Jk3_HrVoFFptRXM=hX2CV8f+M-dka-hJU4bP8kw@mail.gmail.com
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Yu Zhao <yuzhao@google.com>
Link: https://lore.kernel.org/r/20230729004144.1054885-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-08-17 11:26:53 -07:00
David Matlack
619b507244 KVM: Move kvm_arch_flush_remote_tlbs_memslot() to common code
Move kvm_arch_flush_remote_tlbs_memslot() to common code and drop
"arch_" from the name. kvm_arch_flush_remote_tlbs_memslot() is just a
range-based TLB invalidation where the range is defined by the memslot.
Now that kvm_flush_remote_tlbs_range() can be called from common code we
can just use that and drop a bunch of duplicate code from the arch
directories.

Note this adds a lockdep assertion for slots_lock being held when
calling kvm_flush_remote_tlbs_memslot(), which was previously only
asserted on x86. MIPS has calls to kvm_flush_remote_tlbs_memslot(),
but they all hold the slots_lock, so the lockdep assertion continues to
hold true.

Also drop the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT ifdef gating
kvm_flush_remote_tlbs_memslot(), since it is no longer necessary.

Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Acked-by: Anup Patel <anup@brainfault.org>
Acked-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230811045127.3308641-7-rananta@google.com
2023-08-17 09:40:35 +01:00
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
Andrew Jones
630b4cee9c RISC-V: KVM: Improve vector save/restore functions
Make two nonfunctional changes to the vector get/set vector reg
functions and their supporting function for simplification and
readability. The first is to not pass KVM_REG_RISCV_VECTOR, but
rather integrate it directly into the masking. The second is to
rename reg_val to reg_addr where and address is used instead of
a value.

Also opportunistically touch up some of the code formatting for
a third nonfunctional change.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:26:05 +05:30
Andrew Jones
1deaf754f5 RISC-V: KVM: Improve vector save/restore errors
kvm_riscv_vcpu_(get/set)_reg_vector() now returns ENOENT if V is not
available, EINVAL if reg type is not of VECTOR type, and any error that
might be thrown by kvm_riscv_vcpu_vreg_addr().

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:26:00 +05:30
Daniel Henrique Barboza
1099c80906 RISC-V: KVM: avoid EBUSY when writing the same isa_ext val
riscv_vcpu_set_isa_ext_single() will prevent any write of isa_ext regs
if the vcpu already started spinning.

But if there's no extension state (enabled/disabled) made by the
userspace, there's no need to -EBUSY out - we can treat the operation as
a no-op.

zicbom/zicboz_block_size, ISA config reg and mvendorid/march/mimpid
already works in a more permissive manner w.r.t userspace writes being a
no-op, so let's do the same with isa_ext writes.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:25:58 +05:30
Daniel Henrique Barboza
63bd660657 RISC-V: KVM: avoid EBUSY when writing the same machine ID val
Right now we do not allow any write in mvendorid/marchid/mimpid if the
vcpu already started, preventing these regs to be changed.

However, if userspace doesn't change them, an alternative is to consider
the reg write a no-op and avoid erroring out altogether. Userpace can
then be oblivious about KVM internals if no changes were intended in the
first place.

Allow the same form of 'lazy writing' that registers such as
zicbom/zicboz_block_size supports: avoid erroring out if userspace makes
no changes in mvendorid/marchid/mimpid during reg write.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:25:55 +05:30
Daniel Henrique Barboza
bea8d23713 RISC-V: KVM: avoid EBUSY when writing same ISA val
kvm_riscv_vcpu_set_reg_config() will return -EBUSY if the ISA config reg
is being written after the VCPU ran at least once.

The same restriction isn't placed in kvm_riscv_vcpu_get_reg_config(), so
there's a chance that we'll -EBUSY out on an ISA config reg write even
if the userspace intended no changes to it.

We'll allow the same form of 'lazy writing' that registers such as
zicbom/zicboz_block_size supports: avoid erroring out if userspace made
no changes to the ISA config reg.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:25:53 +05:30
Daniel Henrique Barboza
d57304bbfb RISC-V: KVM: use EBUSY when !vcpu->arch.ran_atleast_once
vcpu_set_reg_config() and vcpu_set_reg_isa_ext() is throwing an
EOPNOTSUPP error when !vcpu->arch.ran_atleast_once. In similar cases
we're throwing an EBUSY error, like in mvendorid/marchid/mimpid
set_reg().

EOPNOTSUPP has a conotation of finality. EBUSY is more adequate in this
case since its a condition/error related to the vcpu lifecycle.

Change these EOPNOTSUPP instances to EBUSY.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08 17:25:51 +05:30