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  1. Jan 27, 2014
    • Paul Mackerras's avatar
      KVM: PPC: Book3S PR: Cope with doorbell interrupts · 40688909
      Paul Mackerras authored
      
      
      When the PR host is running on a POWER8 machine in POWER8 mode, it
      will use doorbell interrupts for IPIs.  If one of them arrives while
      we are in the guest, we pop out of the guest with trap number 0xA00,
      which isn't handled by kvmppc_handle_exit_pr, leading to the following
      BUG_ON:
      
      [  331.436215] exit_nr=0xa00 | pc=0x1d2c | msr=0x800000000000d032
      [  331.437522] ------------[ cut here ]------------
      [  331.438296] kernel BUG at arch/powerpc/kvm/book3s_pr.c:982!
      [  331.439063] Oops: Exception in kernel mode, sig: 5 [#2]
      [  331.439819] SMP NR_CPUS=1024 NUMA pSeries
      [  331.440552] Modules linked in: tun nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw virtio_net kvm binfmt_misc ibmvscsi scsi_transport_srp scsi_tgt virtio_blk
      [  331.447614] CPU: 11 PID: 1296 Comm: qemu-system-ppc Tainted: G      D      3.11.7-200.2.fc19.ppc64p7 #1
      [  331.448920] task: c0000003bdc8c000 ti: c0000003bd32c000 task.ti: c0000003bd32c000
      [  331.450088] NIP: d0000000025d6b9c LR: d0000000025d6b98 CTR: c0000000004cfdd0
      [  331.451042] REGS: c0000003bd32f420 TRAP: 0700   Tainted: G      D       (3.11.7-200.2.fc19.ppc64p7)
      [  331.452331] MSR: 800000000282b032 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI>  CR: 28004824  XER: 20000000
      [  331.454616] SOFTE: 1
      [  331.455106] CFAR: c000000000848bb8
      [  331.455726]
      GPR00: d0000000025d6b98 c0000003bd32f6a0 d0000000026017b8 0000000000000032
      GPR04: c0000000018627f8 c000000001873208 320d0a3030303030 3030303030643033
      GPR08: c000000000c490a8 0000000000000000 0000000000000000 0000000000000002
      GPR12: 0000000028004822 c00000000fdc6300 0000000000000000 00000100076ec310
      GPR16: 000000002ae343b8 00003ffffd397398 0000000000000000 0000000000000000
      GPR20: 00000100076f16f4 00000100076ebe60 0000000000000008 ffffffffffffffff
      GPR24: 0000000000000000 0000008001041e60 0000000000000000 0000008001040ce8
      GPR28: c0000003a2d80000 0000000000000a00 0000000000000001 c0000003a2681810
      [  331.466504] NIP [d0000000025d6b9c] .kvmppc_handle_exit_pr+0x75c/0xa80 [kvm]
      [  331.466999] LR [d0000000025d6b98] .kvmppc_handle_exit_pr+0x758/0xa80 [kvm]
      [  331.467517] Call Trace:
      [  331.467909] [c0000003bd32f6a0] [d0000000025d6b98] .kvmppc_handle_exit_pr+0x758/0xa80 [kvm] (unreliable)
      [  331.468553] [c0000003bd32f750] [d0000000025d98f0] kvm_start_lightweight+0xb4/0xc4 [kvm]
      [  331.469189] [c0000003bd32f920] [d0000000025d7648] .kvmppc_vcpu_run_pr+0xd8/0x270 [kvm]
      [  331.469838] [c0000003bd32f9c0] [d0000000025cf748] .kvmppc_vcpu_run+0xc8/0xf0 [kvm]
      [  331.470790] [c0000003bd32fa50] [d0000000025cc19c] .kvm_arch_vcpu_ioctl_run+0x5c/0x1b0 [kvm]
      [  331.471401] [c0000003bd32fae0] [d0000000025c4888] .kvm_vcpu_ioctl+0x478/0x730 [kvm]
      [  331.472026] [c0000003bd32fc90] [c00000000026192c] .do_vfs_ioctl+0x4dc/0x7a0
      [  331.472561] [c0000003bd32fd80] [c000000000261cc4] .SyS_ioctl+0xd4/0xf0
      [  331.473095] [c0000003bd32fe30] [c000000000009ed8] syscall_exit+0x0/0x98
      [  331.473633] Instruction dump:
      [  331.473766] 4bfff9b4 2b9d0800 419efc18 60000000 60420000 3d220000 e8bf11a0 e8df12a8
      [  331.474733] 7fa4eb78 e8698660 48015165 e8410028 <0fe00000> 813f00e4 3ba00000 39290001
      [  331.475386] ---[ end trace 49fc47d994c1f8f2 ]---
      [  331.479817]
      
      This fixes the problem by making kvmppc_handle_exit_pr() recognize the
      interrupt.  We also need to jump to the doorbell interrupt handler in
      book3s_segment.S to handle the interrupt on the way out of the guest.
      Having done that, there's nothing further to be done in
      kvmppc_handle_exit_pr().
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      40688909
    • Michael Neuling's avatar
      KVM: PPC: Book3S HV: Add software abort codes for transactional memory · b17dfec0
      Michael Neuling authored
      
      
      This adds the software abort code defines for transactional memory (TM).
      These values are from PAPR.
      
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      b17dfec0
    • Michael Neuling's avatar
      KVM: PPC: Book3S HV: Add new state for transactional memory · 7b490411
      Michael Neuling authored
      
      
      Add new state for transactional memory (TM) to kvm_vcpu_arch.  Also add
      asm-offset bits that are going to be required.
      
      This also moves the existing TFHAR, TFIAR and TEXASR SPRs into a
      CONFIG_PPC_TRANSACTIONAL_MEM section.  This requires some code changes to
      ensure we still compile with CONFIG_PPC_TRANSACTIONAL_MEM=N.  Much of the added
      the added #ifdefs are removed in a later patch when the bulk of the TM code is
      added.
      
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      [agraf: fix merge conflict]
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      7b490411
    • Michael Neuling's avatar
      powerpc/Kconfig: Make TM select VSX and VMX · 7b37a123
      Michael Neuling authored
      
      
      There are no processors in existence that have TM but no VMX or VSX.  So let's
      makes CONFIG_PPC_TRANSACTIONAL_MEM select both CONFIG_VSX and CONFIG_ALTIVEC.
      This makes the code a lot simpler by removing the need for a bunch of #ifdefs.
      
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      7b37a123
    • Anton Blanchard's avatar
      KVM: PPC: Book3S HV: Basic little-endian guest support · d682916a
      Anton Blanchard authored
      
      
      We create a guest MSR from scratch when delivering exceptions in
      a few places.  Instead of extracting LPCR[ILE] and inserting it
      into MSR_LE each time, we simply create a new variable intr_msr which
      contains the entire MSR to use.  For a little-endian guest, userspace
      needs to set the ILE (interrupt little-endian) bit in the LPCR for
      each vcpu (or at least one vcpu in each virtual core).
      
      [paulus@samba.org - removed H_SET_MODE implementation from original
      version of the patch, and made kvmppc_set_lpcr update vcpu->arch.intr_msr.]
      
      Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      d682916a
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Add support for DABRX register on POWER7 · 8563bf52
      Paul Mackerras authored
      
      
      The DABRX (DABR extension) register on POWER7 processors provides finer
      control over which accesses cause a data breakpoint interrupt.  It
      contains 3 bits which indicate whether to enable accesses in user,
      kernel and hypervisor modes respectively to cause data breakpoint
      interrupts, plus one bit that enables both real mode and virtual mode
      accesses to cause interrupts.  Currently, KVM sets DABRX to allow
      both kernel and user accesses to cause interrupts while in the guest.
      
      This adds support for the guest to specify other values for DABRX.
      PAPR defines a H_SET_XDABR hcall to allow the guest to set both DABR
      and DABRX with one call.  This adds a real-mode implementation of
      H_SET_XDABR, which shares most of its code with the existing H_SET_DABR
      implementation.  To support this, we add a per-vcpu field to store the
      DABRX value plus code to get and set it via the ONE_REG interface.
      
      For Linux guests to use this new hcall, userspace needs to add
      "hcall-xdabr" to the set of strings in the /chosen/hypertas-functions
      property in the device tree.  If userspace does this and then migrates
      the guest to a host where the kernel doesn't include this patch, then
      userspace will need to implement H_SET_XDABR by writing the specified
      DABR value to the DABR using the ONE_REG interface.  In that case, the
      old kernel will set DABRX to DABRX_USER | DABRX_KERNEL.  That should
      still work correctly, at least for Linux guests, since Linux guests
      cope with getting data breakpoint interrupts in modes that weren't
      requested by just ignoring the interrupt, and Linux guests never set
      DABRX_BTI.
      
      The other thing this does is to make H_SET_DABR and H_SET_XDABR work
      on POWER8, which has the DAWR and DAWRX instead of DABR/X.  Guests that
      know about POWER8 should use H_SET_MODE rather than H_SET_[X]DABR, but
      guests running in POWER7 compatibility mode will still use H_SET_[X]DABR.
      For them, this adds the logic to convert DABR/X values into DAWR/X values
      on POWER8.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      8563bf52
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Prepare for host using hypervisor doorbells · 5d00f66b
      Paul Mackerras authored
      
      
      POWER8 has support for hypervisor doorbell interrupts.  Though the
      kernel doesn't use them for IPIs on the powernv platform yet, it
      probably will in future, so this makes KVM cope gracefully if a
      hypervisor doorbell interrupt arrives while in a guest.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      5d00f66b
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Handle new LPCR bits on POWER8 · e0622bd9
      Paul Mackerras authored
      
      
      POWER8 has a bit in the LPCR to enable or disable the PURR and SPURR
      registers to count when in the guest.  Set this bit.
      
      POWER8 has a field in the LPCR called AIL (Alternate Interrupt Location)
      which is used to enable relocation-on interrupts.  Allow userspace to
      set this field.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      e0622bd9
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Handle guest using doorbells for IPIs · aa31e843
      Paul Mackerras authored
      
      
      * SRR1 wake reason field for system reset interrupt on wakeup from nap
        is now a 4-bit field on P8, compared to 3 bits on P7.
      
      * Set PECEDP in LPCR when napping because of H_CEDE so guest doorbells
        will wake us up.
      
      * Waking up from nap because of a guest doorbell interrupt is not a
        reason to exit the guest.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      aa31e843
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Consolidate code that checks reason for wake from nap · e3bbbbfa
      Paul Mackerras authored
      
      
      Currently in book3s_hv_rmhandlers.S we have three places where we
      have woken up from nap mode and we check the reason field in SRR1
      to see what event woke us up.  This consolidates them into a new
      function, kvmppc_check_wake_reason.  It looks at the wake reason
      field in SRR1, and if it indicates that an external interrupt caused
      the wakeup, calls kvmppc_read_intr to check what sort of interrupt
      it was.
      
      This also consolidates the two places where we synthesize an external
      interrupt (0x500 vector) for the guest.  Now, if the guest exit code
      finds that there was an external interrupt which has been handled
      (i.e. it was an IPI indicating that there is now an interrupt pending
      for the guest), it jumps to deliver_guest_interrupt, which is in the
      last part of the guest entry code, where we synthesize guest external
      and decrementer interrupts.  That code has been streamlined a little
      and now clears LPCR[MER] when appropriate as well as setting it.
      
      The extra clearing of any pending IPI on a secondary, offline CPU
      thread before going back to nap mode has been removed.  It is no longer
      necessary now that we have code to read and acknowledge IPIs in the
      guest exit path.
      
      This fixes a minor bug in the H_CEDE real-mode handling - previously,
      if we found that other threads were already exiting the guest when we
      were about to go to nap mode, we would branch to the cede wakeup path
      and end up looking in SRR1 for a wakeup reason.  Now we branch to a
      point after we have checked the wakeup reason.
      
      This also fixes a minor bug in kvmppc_read_intr - previously it could
      return 0xff rather than 1, in the case where we find that a host IPI
      is pending after we have cleared the IPI.  Now it returns 1.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      e3bbbbfa
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Implement architecture compatibility modes for POWER8 · 5557ae0e
      Paul Mackerras authored
      
      
      This allows us to select architecture 2.05 (POWER6) or 2.06 (POWER7)
      compatibility modes on a POWER8 processor.  (Note that transactional
      memory is disabled for usermode if either or both of the PCR_TM_DIS
      and PCR_ARCH_206 bits are set.)
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      5557ae0e
    • Michael Ellerman's avatar
      KVM: PPC: Book3S HV: Add handler for HV facility unavailable · bd3048b8
      Michael Ellerman authored
      
      
      At present this should never happen, since the host kernel sets
      HFSCR to allow access to all facilities.  It's better to be prepared
      to handle it cleanly if it does ever happen, though.
      
      Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      bd3048b8
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Flush the correct number of TLB sets on POWER8 · ca252055
      Paul Mackerras authored
      
      
      POWER8 has 512 sets in the TLB, compared to 128 for POWER7, so we need
      to do more tlbiel instructions when flushing the TLB on POWER8.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      ca252055
    • Michael Neuling's avatar
      KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs · b005255e
      Michael Neuling authored
      
      
      This adds fields to the struct kvm_vcpu_arch to store the new
      guest-accessible SPRs on POWER8, adds code to the get/set_one_reg
      functions to allow userspace to access this state, and adds code to
      the guest entry and exit to context-switch these SPRs between host
      and guest.
      
      Note that DPDES (Directed Privileged Doorbell Exception State) is
      shared between threads on a core; hence we store it in struct
      kvmppc_vcore and have the master thread save and restore it.
      
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      b005255e
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Align physical and virtual CPU thread numbers · e0b7ec05
      Paul Mackerras authored
      
      
      On a threaded processor such as POWER7, we group VCPUs into virtual
      cores and arrange that the VCPUs in a virtual core run on the same
      physical core.  Currently we don't enforce any correspondence between
      virtual thread numbers within a virtual core and physical thread
      numbers.  Physical threads are allocated starting at 0 on a first-come
      first-served basis to runnable virtual threads (VCPUs).
      
      POWER8 implements a new "msgsndp" instruction which guest kernels can
      use to interrupt other threads in the same core or sub-core.  Since
      the instruction takes the destination physical thread ID as a parameter,
      it becomes necessary to align the physical thread IDs with the virtual
      thread IDs, that is, to make sure virtual thread N within a virtual
      core always runs on physical thread N.
      
      This means that it's possible that thread 0, which is where we call
      __kvmppc_vcore_entry, may end up running some other vcpu than the
      one whose task called kvmppc_run_core(), or it may end up running
      no vcpu at all, if for example thread 0 of the virtual core is
      currently executing in userspace.  However, we do need thread 0
      to be responsible for switching the MMU -- a previous version of
      this patch that had other threads switching the MMU was found to
      be responsible for occasional memory corruption and machine check
      interrupts in the guest on POWER7 machines.
      
      To accommodate this, we no longer pass the vcpu pointer to
      __kvmppc_vcore_entry, but instead let the assembly code load it from
      the PACA.  Since the assembly code will need to know the kvm pointer
      and the thread ID for threads which don't have a vcpu, we move the
      thread ID into the PACA and we add a kvm pointer to the virtual core
      structure.
      
      In the case where thread 0 has no vcpu to run, it still calls into
      kvmppc_hv_entry in order to do the MMU switch, and then naps until
      either its vcpu is ready to run in the guest, or some other thread
      needs to exit the guest.  In the latter case, thread 0 jumps to the
      code that switches the MMU back to the host.  This control flow means
      that now we switch the MMU before loading any guest vcpu state.
      Similarly, on guest exit we now save all the guest vcpu state before
      switching the MMU back to the host.  This has required substantial
      code movement, making the diff rather large.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      e0b7ec05
    • Michael Neuling's avatar
      KVM: PPC: Book3S HV: Don't set DABR on POWER8 · eee7ff9d
      Michael Neuling authored
      
      
      POWER8 doesn't have the DABR and DABRX registers; instead it has
      new DAWR/DAWRX registers, which will be handled in a later patch.
      
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      eee7ff9d
    • Scott Wood's avatar
      kvm/ppc: IRQ disabling cleanup · 6c85f52b
      Scott Wood authored
      
      
      Simplify the handling of lazy EE by going directly from fully-enabled
      to hard-disabled.  This replaces the lazy_irq_pending() check
      (including its misplaced kvm_guest_exit() call).
      
      As suggested by Tiejun Chen, move the interrupt disabling into
      kvmppc_prepare_to_enter() rather than have each caller do it.  Also
      move the IRQ enabling on heavyweight exit into
      kvmppc_prepare_to_enter().
      
      Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      6c85f52b
    • Mihai Caraman's avatar
      KVM: PPC: e500: Fix bad address type in deliver_tlb_misss() · 70713fe3
      Mihai Caraman authored
      
      
      Use gva_t instead of unsigned int for eaddr in deliver_tlb_miss().
      
      Signed-off-by: default avatarMihai Caraman <mihai.caraman@freescale.com>
      CC: stable@vger.kernel.org
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      70713fe3
    • Andreas Schwab's avatar
      KVM: PPC: Book3S HV: use xics_wake_cpu only when defined · 48eaef05
      Andreas Schwab authored
      
      
      Signed-off-by: default avatarAndreas Schwab <schwab@linux-m68k.org>
      CC: stable@vger.kernel.org
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      48eaef05
    • Cédric Le Goater's avatar
      KVM: PPC: Book3S: MMIO emulation support for little endian guests · 73601775
      Cédric Le Goater authored
      
      
      MMIO emulation reads the last instruction executed by the guest
      and then emulates. If the guest is running in Little Endian order,
      or more generally in a different endian order of the host, the
      instruction needs to be byte-swapped before being emulated.
      
      This patch adds a helper routine which tests the endian order of
      the host and the guest in order to decide whether a byteswap is
      needed or not. It is then used to byteswap the last instruction
      of the guest in the endian order of the host before MMIO emulation
      is performed.
      
      Finally, kvmppc_handle_load() of kvmppc_handle_store() are modified
      to reverse the endianness of the MMIO if required.
      
      Signed-off-by: default avatarCédric Le Goater <clg@fr.ibm.com>
      [agraf: add booke handling]
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      73601775
  2. Jan 09, 2014
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  4. Nov 20, 2013
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