1. 28 Nov, 2022 9 commits
    • Jiaxi Chen's avatar
      KVM: x86: Advertise AVX-VNNI-INT8 CPUID to user space · 24d74b9f
      Jiaxi Chen authored
      AVX-VNNI-INT8 is a new set of instructions in the latest Intel platform
      Sierra Forest, aims for the platform to have superior AI capabilities.
      This instruction multiplies the individual bytes of two unsigned or
      unsigned source operands, then adds and accumulates the results into the
      destination dword element size operand.
      
      The bit definition:
      CPUID.(EAX=7,ECX=1):EDX[bit 4]
      
      AVX-VNNI-INT8 is on a new and sparse CPUID leaf and all bits on this
      leaf have no truly kernel use case for now. Given that and to save space
      for kernel feature bits, move this new leaf to KVM-only subleaf and plus
      an x86_FEATURE definition for AVX-VNNI-INT8 to direct it to the KVM
      entry.
      
      Advertise AVX-VNNI-INT8 to KVM userspace. This is safe because there are
      no new VMX controls or additional host enabling required for guests to
      use this feature.
      Signed-off-by: default avatarJiaxi Chen <jiaxi.chen@linux.intel.com>
      Message-Id: <20221125125845.1182922-7-jiaxi.chen@linux.intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      24d74b9f
    • Jiaxi Chen's avatar
      x86: KVM: Advertise AVX-IFMA CPUID to user space · 5e85c4eb
      Jiaxi Chen authored
      AVX-IFMA is a new instruction in the latest Intel platform Sierra
      Forest. This instruction packed multiplies unsigned 52-bit integers and
      adds the low/high 52-bit products to Qword Accumulators.
      
      The bit definition:
      CPUID.(EAX=7,ECX=1):EAX[bit 23]
      
      AVX-IFMA is on an expected-dense CPUID leaf and some other bits on this
      leaf have kernel usages. Given that, define this feature bit like
      X86_FEATURE_<name> in kernel. Considering AVX-IFMA itself has no truly
      kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
      one in /proc/cpuinfo.
      
      Advertise AVX-IFMA to KVM userspace. This is safe because there are no
      new VMX controls or additional host enabling required for guests to use
      this feature.
      Signed-off-by: default avatarJiaxi Chen <jiaxi.chen@linux.intel.com>
      Acked-by: default avatarBorislav Petkov <bp@suse.de>
      Message-Id: <20221125125845.1182922-6-jiaxi.chen@linux.intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      5e85c4eb
    • Chang S. Bae's avatar
      x86: KVM: Advertise AMX-FP16 CPUID to user space · af2872f6
      Chang S. Bae authored
      Latest Intel platform Granite Rapids has introduced a new instruction -
      AMX-FP16, which performs dot-products of two FP16 tiles and accumulates
      the results into a packed single precision tile. AMX-FP16 adds FP16
      capability and also allows a FP16 GPU trained model to run faster
      without loss of accuracy or added SW overhead.
      
      The bit definition:
      CPUID.(EAX=7,ECX=1):EAX[bit 21]
      
      AMX-FP16 is on an expected-dense CPUID leaf and some other bits on this
      leaf have kernel usages. Given that, define this feature bit like
      X86_FEATURE_<name> in kernel. Considering AMX-FP16 itself has no truly
      kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
      one in /proc/cpuinfo.
      
      Advertise AMX-FP16 to KVM userspace. This is safe because there are no
      new VMX controls or additional host enabling required for guests to use
      this feature.
      Signed-off-by: default avatarChang S. Bae <chang.seok.bae@intel.com>
      Signed-off-by: default avatarJiaxi Chen <jiaxi.chen@linux.intel.com>
      Acked-by: default avatarBorislav Petkov <bp@suse.de>
      Message-Id: <20221125125845.1182922-5-jiaxi.chen@linux.intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      af2872f6
    • Jiaxi Chen's avatar
      x86: KVM: Advertise CMPccXADD CPUID to user space · 6a19d7aa
      Jiaxi Chen authored
      CMPccXADD is a new set of instructions in the latest Intel platform
      Sierra Forest. This new instruction set includes a semaphore operation
      that can compare and add the operands if condition is met, which can
      improve database performance.
      
      The bit definition:
      CPUID.(EAX=7,ECX=1):EAX[bit 7]
      
      CMPccXADD is on an expected-dense CPUID leaf and some other bits on this
      leaf have kernel usages. Given that, define this feature bit like
      X86_FEATURE_<name> in kernel. Considering CMPccXADD itself has no truly
      kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
      one in /proc/cpuinfo.
      
      Advertise CMPCCXADD to KVM userspace. This is safe because there are no
      new VMX controls or additional host enabling required for guests to use
      this feature.
      Signed-off-by: default avatarJiaxi Chen <jiaxi.chen@linux.intel.com>
      Acked-by: default avatarBorislav Petkov <bp@suse.de>
      Message-Id: <20221125125845.1182922-4-jiaxi.chen@linux.intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      6a19d7aa
    • Sean Christopherson's avatar
      KVM: x86: Update KVM-only leaf handling to allow for 100% KVM-only leafs · 047c7229
      Sean Christopherson authored
      Rename kvm_cpu_cap_init_scattered() to kvm_cpu_cap_init_kvm_defined() in
      anticipation of adding KVM-only CPUID leafs that aren't recognized by the
      kernel and thus not scattered, i.e. for leafs that are 100% KVM-defined.
      
      Adjust/add comments to kvm_only_cpuid_leafs and KVM_X86_FEATURE to
      document how to create new kvm_only_cpuid_leafs entries for scattered
      features as well as features that are entirely unknown to the kernel.
      
      No functional change intended.
      Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
      Message-Id: <20221125125845.1182922-3-jiaxi.chen@linux.intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      047c7229
    • Sean Christopherson's avatar
      KVM: x86: Add BUILD_BUG_ON() to detect bad usage of "scattered" flags · c4690d01
      Sean Christopherson authored
      Add a compile-time assert in the SF() macro to detect improper usage,
      i.e. to detect passing in an X86_FEATURE_* flag that isn't actually
      scattered by the kernel.  Upcoming feature flags will be 100% KVM-only
      and will have X86_FEATURE_* macros that point at a kvm_only_cpuid_leafs
      word, not a kernel-defined word.  Using SF() and thus boot_cpu_has() for
      such feature flags would access memory beyond x86_capability[NCAPINTS]
      and at best incorrectly hide a feature, and at worst leak kernel state to
      userspace.
      Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
      Message-Id: <20221125125845.1182922-2-jiaxi.chen@linux.intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      c4690d01
    • David Woodhouse's avatar
      MAINTAINERS: Add KVM x86/xen maintainer list · 7927e275
      David Woodhouse authored
      Adding Paul as co-maintainer of Xen support to help ensure that things
      don't fall through the cracks when I spend three months at a time
      travelling...
      Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
      Reviewed-by: default avatarPaul Durrant <paul@xen.org>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      7927e275
    • David Woodhouse's avatar
    • Paolo Bonzini's avatar
      KVM: always declare prototype for kvm_arch_irqchip_in_kernel · 3ca9d84e
      Paolo Bonzini authored
      Architecture code might want to use it even if CONFIG_HAVE_KVM_IRQ_ROUTING
      is false; for example PPC XICS has KVM_IRQ_LINE and wants to use
      kvm_arch_irqchip_in_kernel from there, but it does not have
      KVM_SET_GSI_ROUTING so the prototype was not provided.
      
      Fixes: d663b8a2 ("KVM: replace direct irq.h inclusion")
      Reported-by: default avatarkernel test robot <lkp@intel.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      3ca9d84e
  2. 24 Nov, 2022 1 commit
  3. 23 Nov, 2022 3 commits
  4. 21 Nov, 2022 12 commits
  5. 18 Nov, 2022 15 commits