1. 10 4月, 2015 1 次提交
  2. 31 3月, 2015 1 次提交
  3. 17 12月, 2014 1 次提交
    • P
      KVM: PPC: Book3S HV: Remove code for PPC970 processors · c17b98cf
      Paul Mackerras 提交于
      This removes the code that was added to enable HV KVM to work
      on PPC970 processors.  The PPC970 is an old CPU that doesn't
      support virtualizing guest memory.  Removing PPC970 support also
      lets us remove the code for allocating and managing contiguous
      real-mode areas, the code for the !kvm->arch.using_mmu_notifiers
      case, the code for pinning pages of guest memory when first
      accessed and keeping track of which pages have been pinned, and
      the code for handling H_ENTER hypercalls in virtual mode.
      
      Book3S HV KVM is now supported only on POWER7 and POWER8 processors.
      The KVM_CAP_PPC_RMA capability now always returns 0.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      c17b98cf
  4. 15 12月, 2014 1 次提交
    • P
      KVM: PPC: Book3S HV: Fix computation of tlbie operand · d506735b
      Paul Mackerras 提交于
      The B (segment size) field in the RB operand for the tlbie
      instruction is two bits, which we get from the top two bits of
      the first doubleword of the HPT entry to be invalidated.  These
      bits go in bits 8 and 9 of the RB operand (bits 54 and 55 in IBM
      bit numbering).
      
      The compute_tlbie_rb() function gets these bits as v >> (62 - 8),
      which is not correct as it will bring in the top 10 bits, not
      just the top two.  These extra bits could corrupt the AP, AVAL
      and L fields in the RB value.  To fix this we shift right 62 bits
      and then shift left 8 bits, so we only get the two bits of the
      B field.
      
      The first doubleword of the HPT entry is under the control of the
      guest kernel.  In fact, Linux guests will always put zeroes in bits
      54 -- 61 (IBM bits 2 -- 9), but we should not rely on guests doing
      this.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      d506735b
  5. 28 7月, 2014 3 次提交
  6. 25 6月, 2014 1 次提交
  7. 30 5月, 2014 1 次提交
    • A
      KVM: PPC: BOOK3S: HV: Add mixed page-size support for guest · 1f365bb0
      Aneesh Kumar K.V 提交于
      On recent IBM Power CPUs, while the hashed page table is looked up using
      the page size from the segmentation hardware (i.e. the SLB), it is
      possible to have the HPT entry indicate a larger page size.  Thus for
      example it is possible to put a 16MB page in a 64kB segment, but since
      the hash lookup is done using a 64kB page size, it may be necessary to
      put multiple entries in the HPT for a single 16MB page.  This
      capability is called mixed page-size segment (MPSS).  With MPSS,
      there are two relevant page sizes: the base page size, which is the
      size used in searching the HPT, and the actual page size, which is the
      size indicated in the HPT entry. [ Note that the actual page size is
      always >= base page size ].
      
      We use "ibm,segment-page-sizes" device tree node to advertise
      the MPSS support to PAPR guest. The penc encoding indicates whether
      we support a specific combination of base page size and actual
      page size in the same segment. We also use the penc value in the
      LP encoding of HPTE entry.
      
      This patch exposes MPSS support to KVM guest by advertising the
      feature via "ibm,segment-page-sizes". It also adds the necessary changes
      to decode the base page size and the actual page size correctly from the
      HPTE entry.
      Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      1f365bb0
  8. 29 3月, 2014 1 次提交
    • P
      KVM: PPC: Book3S HV: Don't use kvm_memslots() in real mode · 797f9c07
      Paul Mackerras 提交于
      With HV KVM, some high-frequency hypercalls such as H_ENTER are handled
      in real mode, and need to access the memslots array for the guest.
      Accessing the memslots array is safe, because we hold the SRCU read
      lock for the whole time that a guest vcpu is running.  However, the
      checks that kvm_memslots() does when lockdep is enabled are potentially
      unsafe in real mode, when only the linear mapping is available.
      Furthermore, kvm_memslots() can be called from a secondary CPU thread,
      which is an offline CPU from the point of view of the host kernel,
      and is not running the task which holds the SRCU read lock.
      
      To avoid false positives in the checks in kvm_memslots(), and to avoid
      possible side effects from doing the checks in real mode, this replaces
      kvm_memslots() with kvm_memslots_raw() in all the places that execute
      in real mode.  kvm_memslots_raw() is a new function that is like
      kvm_memslots() but uses rcu_dereference_raw_notrace() instead of
      kvm_dereference_check().
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Acked-by: NScott Wood <scottwood@freescale.com>
      797f9c07
  9. 17 10月, 2013 2 次提交
  10. 10 7月, 2013 1 次提交
    • P
      KVM: PPC: Book3S HV: Correct tlbie usage · 54480501
      Paul Mackerras 提交于
      This corrects the usage of the tlbie (TLB invalidate entry) instruction
      in HV KVM.  The tlbie instruction changed between PPC970 and POWER7.
      On the PPC970, the bit to select large vs. small page is in the instruction,
      not in the RB register value.  This changes the code to use the correct
      form on PPC970.
      
      On POWER7 we were calculating the AVAL (Abbreviated Virtual Address, Lower)
      field of the RB value incorrectly for 64k pages.  This fixes it.
      
      Since we now have several cases to handle for the tlbie instruction, this
      factors out the code to do a sequence of tlbies into a new function,
      do_tlbies(), and calls that from the various places where the code was
      doing tlbie instructions inline.  It also makes kvmppc_h_bulk_remove()
      use the same global_invalidates() function for determining whether to do
      local or global TLB invalidations as is used in other places, for
      consistency, and also to make sure that kvm->arch.need_tlb_flush gets
      updated properly.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      54480501
  11. 08 7月, 2013 2 次提交
  12. 21 6月, 2013 1 次提交
  13. 27 4月, 2013 1 次提交
    • P
      KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes · a1b4a0f6
      Paul Mackerras 提交于
      At present, the code that determines whether a HPT entry has changed,
      and thus needs to be sent to userspace when it is copying the HPT,
      doesn't consider a hardware update to the reference and change bits
      (R and C) in the HPT entries to constitute a change that needs to
      be sent to userspace.  This adds code to check for changes in R and C
      when we are scanning the HPT to find changed entries, and adds code
      to set the changed flag for the HPTE when we update the R and C bits
      in the guest view of the HPTE.
      
      Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c
      as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification()
      function into kvm_book3s_64.h.
      
      Current Linux guest kernels don't use the hardware updates of R and C
      in the HPT, so this change won't affect them.  Linux (or other) kernels
      might in future want to use the R and C bits and have them correctly
      transferred across when a guest is migrated, so it is better to correct
      this deficiency.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      a1b4a0f6
  14. 06 12月, 2012 2 次提交
    • P
      KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT · a2932923
      Paul Mackerras 提交于
      A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor.  Reads on
      this fd return the contents of the HPT (hashed page table), writes
      create and/or remove entries in the HPT.  There is a new capability,
      KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl.  The ioctl
      takes an argument structure with the index of the first HPT entry to
      read out and a set of flags.  The flags indicate whether the user is
      intending to read or write the HPT, and whether to return all entries
      or only the "bolted" entries (those with the bolted bit, 0x10, set in
      the first doubleword).
      
      This is intended for use in implementing qemu's savevm/loadvm and for
      live migration.  Therefore, on reads, the first pass returns information
      about all HPTEs (or all bolted HPTEs).  When the first pass reaches the
      end of the HPT, it returns from the read.  Subsequent reads only return
      information about HPTEs that have changed since they were last read.
      A read that finds no changed HPTEs in the HPT following where the last
      read finished will return 0 bytes.
      
      The format of the data provides a simple run-length compression of the
      invalid entries.  Each block of data starts with a header that indicates
      the index (position in the HPT, which is just an array), the number of
      valid entries starting at that index (may be zero), and the number of
      invalid entries following those valid entries.  The valid entries, 16
      bytes each, follow the header.  The invalid entries are not explicitly
      represented.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      [agraf: fix documentation]
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      a2932923
    • P
      KVM: PPC: Book3S HV: Add a mechanism for recording modified HPTEs · 44e5f6be
      Paul Mackerras 提交于
      This uses a bit in our record of the guest view of the HPTE to record
      when the HPTE gets modified.  We use a reserved bit for this, and ensure
      that this bit is always cleared in HPTE values returned to the guest.
      
      The recording of modified HPTEs is only done if other code indicates
      its interest by setting kvm->arch.hpte_mod_interest to a non-zero value.
      The reason for this is that when later commits add facilities for
      userspace to read the HPT, the first pass of reading the HPT will be
      quicker if there are no (or very few) HPTEs marked as modified,
      rather than having most HPTEs marked as modified.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      44e5f6be
  15. 30 10月, 2012 1 次提交
  16. 30 5月, 2012 1 次提交
    • P
      KVM: PPC: Book3S HV: Make the guest hash table size configurable · 32fad281
      Paul Mackerras 提交于
      This adds a new ioctl to enable userspace to control the size of the guest
      hashed page table (HPT) and to clear it out when resetting the guest.
      The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter
      a pointer to a u32 containing the desired order of the HPT (log base 2
      of the size in bytes), which is updated on successful return to the
      actual order of the HPT which was allocated.
      
      There must be no vcpus running at the time of this ioctl.  To enforce
      this, we now keep a count of the number of vcpus running in
      kvm->arch.vcpus_running.
      
      If the ioctl is called when a HPT has already been allocated, we don't
      reallocate the HPT but just clear it out.  We first clear the
      kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold
      the kvm->lock mutex, it will prevent any vcpus from starting to run until
      we're done, and (b) it means that the first vcpu to run after we're done
      will re-establish the VRMA if necessary.
      
      If userspace doesn't call this ioctl before running the first vcpu, the
      kernel will allocate a default-sized HPT at that point.  We do it then
      rather than when creating the VM, as the code did previously, so that
      userspace has a chance to do the ioctl if it wants.
      
      When allocating the HPT, we can allocate either from the kernel page
      allocator, or from the preallocated pool.  If userspace is asking for
      a different size from the preallocated HPTs, we first try to allocate
      using the kernel page allocator.  Then we try to allocate from the
      preallocated pool, and then if that fails, we try allocating decreasing
      sizes from the kernel page allocator, down to the minimum size allowed
      (256kB).  Note that the kernel page allocator limits allocations to
      1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to
      16MB (on 64-bit powerpc, at least).
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      [agraf: fix module compilation]
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      32fad281
  17. 05 3月, 2012 10 次提交
    • P
      KVM: PPC: Allow for read-only pages backing a Book3S HV guest · 4cf302bc
      Paul Mackerras 提交于
      With this, if a guest does an H_ENTER with a read/write HPTE on a page
      which is currently read-only, we make the actual HPTE inserted be a
      read-only version of the HPTE.  We now intercept protection faults as
      well as HPTE not found faults, and for a protection fault we work out
      whether it should be reflected to the guest (e.g. because the guest HPTE
      didn't allow write access to usermode) or handled by switching to
      kernel context and calling kvmppc_book3s_hv_page_fault, which will then
      request write access to the page and update the actual HPTE.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      4cf302bc
    • P
      KVM: PPC: Implement MMU notifiers for Book3S HV guests · 342d3db7
      Paul Mackerras 提交于
      This adds the infrastructure to enable us to page out pages underneath
      a Book3S HV guest, on processors that support virtualized partition
      memory, that is, POWER7.  Instead of pinning all the guest's pages,
      we now look in the host userspace Linux page tables to find the
      mapping for a given guest page.  Then, if the userspace Linux PTE
      gets invalidated, kvm_unmap_hva() gets called for that address, and
      we replace all the guest HPTEs that refer to that page with absent
      HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit
      set, which will cause an HDSI when the guest tries to access them.
      Finally, the page fault handler is extended to reinstantiate the
      guest HPTE when the guest tries to access a page which has been paged
      out.
      
      Since we can't intercept the guest DSI and ISI interrupts on PPC970,
      we still have to pin all the guest pages on PPC970.  We have a new flag,
      kvm->arch.using_mmu_notifiers, that indicates whether we can page
      guest pages out.  If it is not set, the MMU notifier callbacks do
      nothing and everything operates as before.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      342d3db7
    • P
      KVM: PPC: Implement MMIO emulation support for Book3S HV guests · 697d3899
      Paul Mackerras 提交于
      This provides the low-level support for MMIO emulation in Book3S HV
      guests.  When the guest tries to map a page which is not covered by
      any memslot, that page is taken to be an MMIO emulation page.  Instead
      of inserting a valid HPTE, we insert an HPTE that has the valid bit
      clear but another hypervisor software-use bit set, which we call
      HPTE_V_ABSENT, to indicate that this is an absent page.  An
      absent page is treated much like a valid page as far as guest hcalls
      (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that
      an absent HPTE doesn't need to be invalidated with tlbie since it
      was never valid as far as the hardware is concerned.
      
      When the guest accesses a page for which there is an absent HPTE, it
      will take a hypervisor data storage interrupt (HDSI) since we now set
      the VPM1 bit in the LPCR.  Our HDSI handler for HPTE-not-present faults
      looks up the hash table and if it finds an absent HPTE mapping the
      requested virtual address, will switch to kernel mode and handle the
      fault in kvmppc_book3s_hv_page_fault(), which at present just calls
      kvmppc_hv_emulate_mmio() to set up the MMIO emulation.
      
      This is based on an earlier patch by Benjamin Herrenschmidt, but since
      heavily reworked.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      697d3899
    • P
      KVM: PPC: Maintain a doubly-linked list of guest HPTEs for each gfn · 06ce2c63
      Paul Mackerras 提交于
      This expands the reverse mapping array to contain two links for each
      HPTE which are used to link together HPTEs that correspond to the
      same guest logical page.  Each circular list of HPTEs is pointed to
      by the rmap array entry for the guest logical page, pointed to by
      the relevant memslot.  Links are 32-bit HPT entry indexes rather than
      full 64-bit pointers, to save space.  We use 3 of the remaining 32
      bits in the rmap array entries as a lock bit, a referenced bit and
      a present bit (the present bit is needed since HPTE index 0 is valid).
      The bit lock for the rmap chain nests inside the HPTE lock bit.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      06ce2c63
    • P
      KVM: PPC: Allow I/O mappings in memory slots · 9d0ef5ea
      Paul Mackerras 提交于
      This provides for the case where userspace maps an I/O device into the
      address range of a memory slot using a VM_PFNMAP mapping.  In that
      case, we work out the pfn from vma->vm_pgoff, and record the cache
      enable bits from vma->vm_page_prot in two low-order bits in the
      slot_phys array entries.  Then, in kvmppc_h_enter() we check that the
      cache bits in the HPTE that the guest wants to insert match the cache
      bits in the slot_phys array entry.  However, we do allow the guest to
      create what it thinks is a non-cacheable or write-through mapping to
      memory that is actually cacheable, so that we can use normal system
      memory as part of an emulated device later on.  In that case the actual
      HPTE we insert is a cacheable HPTE.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      9d0ef5ea
    • P
      KVM: PPC: Allow use of small pages to back Book3S HV guests · da9d1d7f
      Paul Mackerras 提交于
      This relaxes the requirement that the guest memory be provided as
      16MB huge pages, allowing it to be provided as normal memory, i.e.
      in pages of PAGE_SIZE bytes (4k or 64k).  To allow this, we index
      the kvm->arch.slot_phys[] arrays with a small page index, even if
      huge pages are being used, and use the low-order 5 bits of each
      entry to store the order of the enclosing page with respect to
      normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE).
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      da9d1d7f
    • P
      KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() · c77162de
      Paul Mackerras 提交于
      This removes the code from kvmppc_core_prepare_memory_region() that
      looked up the VMA for the region being added and called hva_to_page
      to get the pfns for the memory.  We have no guarantee that there will
      be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION
      ioctl call; userspace can do that ioctl and then map memory into the
      region later.
      
      Instead we defer looking up the pfn for each memory page until it is
      needed, which generally means when the guest does an H_ENTER hcall on
      the page.  Since we can't call get_user_pages in real mode, if we don't
      already have the pfn for the page, kvmppc_h_enter() will return
      H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back
      to kernel context.  That calls kvmppc_get_guest_page() to get the pfn
      for the page, and then calls back to kvmppc_h_enter() to redo the HPTE
      insertion.
      
      When the first vcpu starts executing, we need to have the RMO or VRMA
      region mapped so that the guest's real mode accesses will work.  Thus
      we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set
      up and if not, call kvmppc_hv_setup_rma().  It checks if the memslot
      starting at guest physical 0 now has RMO memory mapped there; if so it
      sets it up for the guest, otherwise on POWER7 it sets up the VRMA.
      The function that does that, kvmppc_map_vrma, is now a bit simpler,
      as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself.
      
      Since we are now potentially updating entries in the slot_phys[]
      arrays from multiple vcpu threads, we now have a spinlock protecting
      those updates to ensure that we don't lose track of any references
      to pages.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      c77162de
    • P
      KVM: PPC: Make the H_ENTER hcall more reliable · 075295dd
      Paul Mackerras 提交于
      At present, our implementation of H_ENTER only makes one try at locking
      each slot that it looks at, and doesn't even retry the ldarx/stdcx.
      atomic update sequence that it uses to attempt to lock the slot.  Thus
      it can return the H_PTEG_FULL error unnecessarily, particularly when
      the H_EXACT flag is set, meaning that the caller wants a specific PTEG
      slot.
      
      This improves the situation by making a second pass when no free HPTE
      slot is found, where we spin until we succeed in locking each slot in
      turn and then check whether it is full while we hold the lock.  If the
      second pass fails, then we return H_PTEG_FULL.
      
      This also moves lock_hpte to a header file (since later commits in this
      series will need to use it from other source files) and renames it to
      try_lock_hpte, which is a somewhat less misleading name.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      075295dd
    • P
      KVM: PPC: Keep a record of HV guest view of hashed page table entries · 8936dda4
      Paul Mackerras 提交于
      This adds an array that parallels the guest hashed page table (HPT),
      that is, it has one entry per HPTE, used to store the guest's view
      of the second doubleword of the corresponding HPTE.  The first
      doubleword in the HPTE is the same as the guest's idea of it, so we
      don't need to store a copy, but the second doubleword in the HPTE has
      the real page number rather than the guest's logical page number.
      This allows us to remove the back_translate() and reverse_xlate()
      functions.
      
      This "reverse mapping" array is vmalloc'd, meaning that to access it
      in real mode we have to walk the kernel's page tables explicitly.
      That is done by the new real_vmalloc_addr() function.  (In fact this
      returns an address in the linear mapping, so the result is usable
      both in real mode and in virtual mode.)
      
      There are also some minor cleanups here: moving the definitions of
      HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      8936dda4
    • A
      KVM: PPC: Use get/set for to_svcpu to help preemption · 468a12c2
      Alexander Graf 提交于
      When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were
      doing a few things wrong, most notably access to PACA fields without making
      sure that the pointers stay stable accross the access (preempt_disable()).
      
      This patch moves to_svcpu towards a get/put model which allows us to disable
      preemption while accessing the shadow vcpu fields in the PACA. That way we
      can run preemptible and everyone's happy!
      Reported-by: NJörg Sommer <joerg@alea.gnuu.de>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      468a12c2
  18. 26 12月, 2011 1 次提交
  19. 12 7月, 2011 2 次提交
    • D
      KVM: PPC: Accelerate H_PUT_TCE by implementing it in real mode · 54738c09
      David Gibson 提交于
      This improves I/O performance for guests using the PAPR
      paravirtualization interface by making the H_PUT_TCE hcall faster, by
      implementing it in real mode.  H_PUT_TCE is used for updating virtual
      IOMMU tables, and is used both for virtual I/O and for real I/O in the
      PAPR interface.
      
      Since this moves the IOMMU tables into the kernel, we define a new
      KVM_CREATE_SPAPR_TCE ioctl to allow qemu to create the tables.  The
      ioctl returns a file descriptor which can be used to mmap the newly
      created table.  The qemu driver models use them in the same way as
      userspace managed tables, but they can be updated directly by the
      guest with a real-mode H_PUT_TCE implementation, reducing the number
      of host/guest context switches during guest IO.
      
      There are certain circumstances where it is useful for userland qemu
      to write to the TCE table even if the kernel H_PUT_TCE path is used
      most of the time.  Specifically, allowing this will avoid awkwardness
      when we need to reset the table.  More importantly, we will in the
      future need to write the table in order to restore its state after a
      checkpoint resume or migration.
      Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      54738c09
    • P
      KVM: PPC: Add support for Book3S processors in hypervisor mode · de56a948
      Paul Mackerras 提交于
      This adds support for KVM running on 64-bit Book 3S processors,
      specifically POWER7, in hypervisor mode.  Using hypervisor mode means
      that the guest can use the processor's supervisor mode.  That means
      that the guest can execute privileged instructions and access privileged
      registers itself without trapping to the host.  This gives excellent
      performance, but does mean that KVM cannot emulate a processor
      architecture other than the one that the hardware implements.
      
      This code assumes that the guest is running paravirtualized using the
      PAPR (Power Architecture Platform Requirements) interface, which is the
      interface that IBM's PowerVM hypervisor uses.  That means that existing
      Linux distributions that run on IBM pSeries machines will also run
      under KVM without modification.  In order to communicate the PAPR
      hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code
      to include/linux/kvm.h.
      
      Currently the choice between book3s_hv support and book3s_pr support
      (i.e. the existing code, which runs the guest in user mode) has to be
      made at kernel configuration time, so a given kernel binary can only
      do one or the other.
      
      This new book3s_hv code doesn't support MMIO emulation at present.
      Since we are running paravirtualized guests, this isn't a serious
      restriction.
      
      With the guest running in supervisor mode, most exceptions go straight
      to the guest.  We will never get data or instruction storage or segment
      interrupts, alignment interrupts, decrementer interrupts, program
      interrupts, single-step interrupts, etc., coming to the hypervisor from
      the guest.  Therefore this introduces a new KVMTEST_NONHV macro for the
      exception entry path so that we don't have to do the KVM test on entry
      to those exception handlers.
      
      We do however get hypervisor decrementer, hypervisor data storage,
      hypervisor instruction storage, and hypervisor emulation assist
      interrupts, so we have to handle those.
      
      In hypervisor mode, real-mode accesses can access all of RAM, not just
      a limited amount.  Therefore we put all the guest state in the vcpu.arch
      and use the shadow_vcpu in the PACA only for temporary scratch space.
      We allocate the vcpu with kzalloc rather than vzalloc, and we don't use
      anything in the kvmppc_vcpu_book3s struct, so we don't allocate it.
      We don't have a shared page with the guest, but we still need a
      kvm_vcpu_arch_shared struct to store the values of various registers,
      so we include one in the vcpu_arch struct.
      
      The POWER7 processor has a restriction that all threads in a core have
      to be in the same partition.  MMU-on kernel code counts as a partition
      (partition 0), so we have to do a partition switch on every entry to and
      exit from the guest.  At present we require the host and guest to run
      in single-thread mode because of this hardware restriction.
      
      This code allocates a hashed page table for the guest and initializes
      it with HPTEs for the guest's Virtual Real Memory Area (VRMA).  We
      require that the guest memory is allocated using 16MB huge pages, in
      order to simplify the low-level memory management.  This also means that
      we can get away without tracking paging activity in the host for now,
      since huge pages can't be paged or swapped.
      
      This also adds a few new exports needed by the book3s_hv code.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      de56a948
  20. 17 5月, 2010 1 次提交
    • A
      KVM: PPC: Add kvm_book3s_64.h · 3ae07890
      Alexander Graf 提交于
      In the process of generalizing as much code as possible, I also moved
      the shadow vcpu code together to a generic book3s file. Unfortunately
      the location of the shadow vcpu is different on 32 and 64 bit, so we
      need a wrapper function to tell us where it is.
      
      That sounded like a perfect fit for a subarch specific header file.
      Here we can put anything that needs to be different between those two.
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      3ae07890
  21. 04 8月, 2008 1 次提交
  22. 27 4月, 2008 1 次提交
  23. 04 10月, 2006 1 次提交
  24. 13 9月, 2006 1 次提交
  25. 23 6月, 2006 1 次提交