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  1. Jul 16, 2021
  3. Jul 15, 2021
    • Vitaly Kuznetsov's avatar
      KVM: selftests: smm_test: Test SMM enter from L2 · d951b221
      Vitaly Kuznetsov authored 
      

Two additional tests are added:
- SMM triggered from L2 does not currupt L1 host state.
- Save/restore during SMM triggered from L2 does not corrupt guest/host
  state.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-7-vkuznets@redhat.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      d951b221
    • Vitaly Kuznetsov's avatar
      KVM: nSVM: Restore nested control upon leaving SMM · bb00bd9c
      Vitaly Kuznetsov authored 
      

If the VM was migrated while in SMM, no nested state was saved/restored,
and therefore svm_leave_smm has to load both save and control area
of the vmcb12. Save area is already loaded from HSAVE area,
so now load the control area as well from the vmcb12.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-6-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      bb00bd9c
    • Vitaly Kuznetsov's avatar
      KVM: nSVM: Fix L1 state corruption upon return from SMM · 37be407b
      Vitaly Kuznetsov authored 
      VMCB split commit 4995a368 ("KVM: SVM: Use a separate vmcb for the
nested L2 guest") broke return from SMM when we entered there from guest
(L2) mode. Gen2 WS2016/Hyper-V is known to do this on boot. The problem
manifests itself like this:

  kvm_exit:             reason EXIT_RSM rip 0x7ffbb280 info 0 0
  kvm_emulate_insn:     0:7ffbb280: 0f aa
  kvm_smm_transition:   vcpu 0: leaving SMM, smbase 0x7ffb3000
  kvm_nested_vmrun:     rip: 0x000000007ffbb280 vmcb: 0x0000000008224000
    nrip: 0xffffffffffbbe119 int_ctl: 0x01020000 event_inj: 0x00000000
    npt: on
  kvm_nested_intercepts: cr_read: 0000 cr_write: 0010 excp: 40060002
    intercepts: fd44bfeb 0000217f 00000000
  kvm_entry:            vcpu 0, rip 0xffffffffffbbe119
  kvm_exit:             reason EXIT_NPF rip 0xffffffffffbbe119 info
    200000006 1ab000
  kvm_nested_vmexit:    vcpu 0 reason npf rip 0xffffffffffbbe119 info1
    0x0000000200000006 info2 0x00000000001ab000 intr_info 0x00000000
    error_code 0x00000000
  kvm_page_fault:       address 1ab000 error_code 6
  kvm_nested_vmexit_inject: reason EXIT_NPF info1 200000006 info2 1ab000
    int_info 0 int_info_err 0
  kvm_entry:            vcpu 0, rip 0x7ffbb280
  kvm_exit:             reason EXIT_EXCP_GP rip 0x7ffbb280 info 0 0
  kvm_emulate_insn:     0:7ffbb280: 0f aa
  kvm_inj_exception:    #GP (0x0)

Note: return to L2 succeeded but upon first exit to L1 its RIP points to
'RSM' instruction but we're not in SMM.

The problem appears to be that VMCB01 gets irreversibly destroyed during
SMM execution. Previously, we used to have 'hsave' VMCB where regular
(pre-SMM) L1's state was saved upon nested_svm_vmexit() but now we just
switch to VMCB01 from VMCB02.

Pre-split (working) flow looked like:
- SMM is triggered during L2's execution
- L2's state is pushed to SMRAM
- nested_svm_vmexit() restores L1's state from 'hsave'
- SMM -> RSM
- enter_svm_guest_mode() switches to L2 but keeps 'hsave' intact so we have
  pre-SMM (and pre L2 VMRUN) L1's state there
- L2's state is restored from SMRAM
- upon first exit L1's state is restored from L1.

This was always broken with regards to svm_get_nested_state()/
svm_set_nested_state(): 'hsave' was never a part of what's being
save and restored so migration happening during SMM triggered from L2 would
never restore L1's state correctly.

Post-split flow (broken) looks like:
- SMM is triggered during L2's execution
- L2's state is pushed to SMRAM
- nested_svm_vmexit() switches to VMCB01 from VMCB02
- SMM -> RSM
- enter_svm_guest_mode() switches from VMCB01 to VMCB02 but pre-SMM VMCB01
  is already lost.
- L2's state is restored from SMRAM
- upon first exit L1's state is restored from VMCB01 but it is corrupted
 (reflects the state during 'RSM' execution).

VMX doesn't have this problem because unlike VMCB, VMCS keeps both guest
and host state so when we switch back to VMCS02 L1's state is intact there.

To resolve the issue we need to save L1's state somewhere. We could've
created a third VMCB for SMM but that would require us to modify saved
state format. L1's architectural HSAVE area (pointed by MSR_VM_HSAVE_PA)
seems appropriate: L0 is free to save any (or none) of L1's state there.
Currently, KVM does 'none'.

Note, for nested state migration to succeed, both source and destination
hypervisors must have the fix. We, however, don't need to create a new
flag indicating the fact that HSAVE area is now populated as migration
during SMM triggered from L2 was always broken.

Fixes: 4995a368

 ("KVM: SVM: Use a separate vmcb for the nested L2 guest")
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      37be407b
    • Vitaly Kuznetsov's avatar
      KVM: nSVM: Introduce svm_copy_vmrun_state() · 0a758290
      Vitaly Kuznetsov authored 
      

Separate the code setting non-VMLOAD-VMSAVE state from
svm_set_nested_state() into its own function. This is going to be
re-used from svm_enter_smm()/svm_leave_smm().

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-4-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      0a758290
    • Vitaly Kuznetsov's avatar
      KVM: nSVM: Check that VM_HSAVE_PA MSR was set before VMRUN · fb79f566
      Vitaly Kuznetsov authored 
      

APM states that "The address written to the VM_HSAVE_PA MSR, which holds
the address of the page used to save the host state on a VMRUN, must point
to a hypervisor-owned page. If this check fails, the WRMSR will fail with
a #GP(0) exception. Note that a value of 0 is not considered valid for the
VM_HSAVE_PA MSR and a VMRUN that is attempted while the HSAVE_PA is 0 will
fail with a #GP(0) exception."

svm_set_msr() already checks that the supplied address is valid, so only
check for '0' is missing. Add it to nested_svm_vmrun().

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-3-vkuznets@redhat.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      fb79f566
    • Vitaly Kuznetsov's avatar
      KVM: nSVM: Check the value written to MSR_VM_HSAVE_PA · fce7e152
      Vitaly Kuznetsov authored 
      

APM states that #GP is raised upon write to MSR_VM_HSAVE_PA when
the supplied address is not page-aligned or is outside of "maximum
supported physical address for this implementation".
page_address_valid() check seems suitable. Also, forcefully page-align
the address when it's written from VMM.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210628104425.391276-2-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
[Add comment about behavior for host-provided values. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      fce7e152
    • Sean Christopherson's avatar
      KVM: SVM: Fix sev_pin_memory() error checks in SEV migration utilities · c7a1b2b6
      Sean Christopherson authored 
      

Use IS_ERR() instead of checking for a NULL pointer when querying for
sev_pin_memory() failures.  sev_pin_memory() always returns an error code
cast to a pointer, or a valid pointer; it never returns NULL.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Cc: Steve Rutherford <srutherford@google.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Fixes: d3d1af85 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command")
Fixes: 15fb7de1

 ("KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command")
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210506175826.2166383-3-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      c7a1b2b6
    • Sean Christopherson's avatar
      KVM: SVM: Return -EFAULT if copy_to_user() for SEV mig packet header fails · b4a69392
      Sean Christopherson authored 
      

Return -EFAULT if copy_to_user() fails; if accessing user memory faults,
copy_to_user() returns the number of bytes remaining, not an error code.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Cc: Steve Rutherford <srutherford@google.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Fixes: d3d1af85

 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command")
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210506175826.2166383-2-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      b4a69392
    • Maxim Levitsky's avatar
      KVM: SVM: add module param to control the #SMI interception · 4b639a9f
      Maxim Levitsky authored 
      

In theory there are no side effects of not intercepting #SMI,
because then #SMI becomes transparent to the OS and the KVM.

Plus an observation on recent Zen2 CPUs reveals that these
CPUs ignore #SMI interception and never deliver #SMI VMexits.

This is also useful to test nested KVM to see that L1
handles #SMIs correctly in case when L1 doesn't intercept #SMI.

Finally the default remains the same, the SMI are intercepted
by default thus this patch doesn't have any effect unless
non default module param value is used.

Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210707125100.677203-4-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      4b639a9f
    • Maxim Levitsky's avatar
      KVM: SVM: remove INIT intercept handler · 896707c2
      Maxim Levitsky authored 
      Kernel never sends real INIT even to CPUs, other than on boot.

Thus INIT interception is an error which should be caught
by a check for an unknown VMexit reason.

On top of that, the current INIT VM exit handler skips
the current instruction which is wrong.
That was added in commit 5ff3a351 ("KVM: x86: Move trivial
instruction-based exit handlers to common code").

Fixes: 5ff3a351

 ("KVM: x86: Move trivial instruction-based exit handlers to common code")
Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210707125100.677203-3-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      896707c2
    • Maxim Levitsky's avatar
      KVM: SVM: #SMI interception must not skip the instruction · 991afbbe
      Maxim Levitsky authored 
      Commit 5ff3a351 ("KVM: x86: Move trivial instruction-based
exit handlers to common code"), unfortunately made a mistake of
treating nop_on_interception and nop_interception in the same way.

Former does truly nothing while the latter skips the instruction.

SMI VM exit handler should do nothing.
(SMI itself is handled by the host when we do STGI)

Fixes: 5ff3a351

 ("KVM: x86: Move trivial instruction-based exit handlers to common code")
Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210707125100.677203-2-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      991afbbe
    • Yu Zhang's avatar
      KVM: VMX: Remove vmx_msr_index from vmx.h · c0e1303e
      Yu Zhang authored 
      

vmx_msr_index was used to record the list of MSRs which can be lazily
restored when kvm returns to userspace. It is now reimplemented as
kvm_uret_msrs_list, a common x86 list which is only used inside x86.c.
So just remove the obsolete declaration in vmx.h.

Signed-off-by: default avatarYu Zhang <yu.c.zhang@linux.intel.com>
Message-Id: <20210707235702.31595-1-yu.c.zhang@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      c0e1303e
    • Lai Jiangshan's avatar
      KVM: X86: Disable hardware breakpoints unconditionally before kvm_x86->run() · f85d4016
      Lai Jiangshan authored 
      

When the host is using debug registers but the guest is not using them
nor is the guest in guest-debug state, the kvm code does not reset
the host debug registers before kvm_x86->run().  Rather, it relies on
the hardware vmentry instruction to automatically reset the dr7 registers
which ensures that the host breakpoints do not affect the guest.

This however violates the non-instrumentable nature around VM entry
and exit; for example, when a host breakpoint is set on vcpu->arch.cr2,

Another issue is consistency.  When the guest debug registers are active,
the host breakpoints are reset before kvm_x86->run(). But when the
guest debug registers are inactive, the host breakpoints are delayed to
be disabled.  The host tracing tools may see different results depending
on what the guest is doing.

To fix the problems, we clear %db7 unconditionally before kvm_x86->run()
if the host has set any breakpoints, no matter if the guest is using
them or not.

Signed-off-by: default avatarLai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20210628172632.81029-1-jiangshanlai@gmail.com>
Cc: stable@vger.kernel.org
[Only clear %db7 instead of reloading all debug registers. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      f85d4016
    • Ricardo Koller's avatar
      KVM: selftests: Address extra memslot parameters in vm_vaddr_alloc · 6f2f86ec
      Ricardo Koller authored 
      Commit a75a895e ("KVM: selftests: Unconditionally use memslot 0 for
vaddr allocations") removed the memslot parameters from vm_vaddr_alloc.
It addressed all callers except one under lib/aarch64/, due to a race
with commit e3db7579

 ("KVM: selftests: Add exception handling
support for aarch64")

Fix the vm_vaddr_alloc call in lib/aarch64/processor.c.

Reported-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarRicardo Koller <ricarkol@google.com>
Message-Id: <20210702201042.4036162-1-ricarkol@google.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      6f2f86ec
    • Pavel Skripkin's avatar
      kvm: debugfs: fix memory leak in kvm_create_vm_debugfs · 004d62eb
      Pavel Skripkin authored 
      In commit bc9e9e67 ("KVM: debugfs: Reuse binary stats descriptors")
loop for filling debugfs_stat_data was copy-pasted 2 times, but
in the second loop pointers are saved over pointers allocated
in the first loop.  All this causes is a memory leak, fix it.

Fixes: bc9e9e67

 ("KVM: debugfs: Reuse binary stats descriptors")
Signed-off-by: default avatarPavel Skripkin <paskripkin@gmail.com>
Reviewed-by: default avatarJing Zhang <jingzhangos@google.com>
Message-Id: <20210701195500.27097-1-paskripkin@gmail.com>
Reviewed-by: default avatarJing Zhang <jingzhangos@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      004d62eb
    • Suravee Suthikulpanit's avatar
      MAINTAINERS: Add Suravee Suthikulpanit as Reviewer for AMD IOMMU (AMD-Vi) · 4a5c155a
      Suravee Suthikulpanit authored 
      

To help review changes related to AMD IOMMU.

Signed-off-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/1626296542-30454-1-git-send-email-suravee.suthikulpanit@amd.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      4a5c155a
    • Linus Torvalds's avatar
      Merge tag 'net-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · 8096acd7
      Linus Torvalds authored 
      Pull networking fixes from Jakub Kicinski.
 "Including fixes from bpf and netfilter.

  Current release - regressions:

   - sock: fix parameter order in sock_setsockopt()

  Current release - new code bugs:

   - netfilter: nft_last:
       - fix incorrect arithmetic when restoring last used
       - honor NFTA_LAST_SET on restoration

  Previous releases - regressions:

   - udp: properly flush normal packet at GRO time

   - sfc: ensure correct number of XDP queues; don't allow enabling the
     feature if there isn't sufficient resources to Tx from any CPU

   - dsa: sja1105: fix address learning getting disabled on the CPU port

   - mptcp: addresses a rmem accounting issue that could keep packets in
     subflow receive buffers longer than necessary, delaying MPTCP-level
     ACKs

   - ip_tunnel: fix mtu calculation for ETHER tunnel devices

   - do not reuse skbs allocated from skbuff_fclone_cache in the napi
     skb cache, we'd try to return them to the wrong slab cache

   - tcp: consistently disable header prediction for mptcp

  Previous releases - always broken:

   - bpf: fix subprog poke descriptor tracking use-after-free

   - ipv6:
       - allocate enough headroom in ip6_finish_output2() in case
         iptables TEE is used
       - tcp: drop silly ICMPv6 packet too big messages to avoid
         expensive and pointless lookups (which may serve as a DDOS
         vector)
       - make sure fwmark is copied in SYNACK packets
       - fix 'disable_policy' for forwarded packets (align with IPv4)

   - netfilter: conntrack:
       - do not renew entry stuck in tcp SYN_SENT state
       - do not mark RST in the reply direction coming after SYN packet
         for an out-of-sync entry

   - mptcp: cleanly handle error conditions with MP_JOIN and syncookies

   - mptcp: fix double free when rejecting a join due to port mismatch

   - validate lwtstate->data before returning from skb_tunnel_info()

   - tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path

   - mt76: mt7921: continue to probe driver when fw already downloaded

   - bonding: fix multiple issues with offloading IPsec to (thru?) bond

   - stmmac: ptp: fix issues around Qbv support and setting time back

   - bcmgenet: always clear wake-up based on energy detection

  Misc:

   - sctp: move 198 addresses from unusable to private scope

   - ptp: support virtual clocks and timestamping

   - openvswitch: optimize operation for key comparison"

* tag 'net-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (158 commits)
  net: dsa: properly check for the bridge_leave methods in dsa_switch_bridge_leave()
  sfc: add logs explaining XDP_TX/REDIRECT is not available
  sfc: ensure correct number of XDP queues
  sfc: fix lack of XDP TX queues - error XDP TX failed (-22)
  net: fddi: fix UAF in fza_probe
  net: dsa: sja1105: fix address learning getting disabled on the CPU port
  net: ocelot: fix switchdev objects synced for wrong netdev with LAG offload
  net: Use nlmsg_unicast() instead of netlink_unicast()
  octeontx2-pf: Fix uninitialized boolean variable pps
  ipv6: allocate enough headroom in ip6_finish_output2()
  net: hdlc: rename 'mod_init' & 'mod_exit' functions to be module-specific
  net: bridge: multicast: fix MRD advertisement router port marking race
  net: bridge: multicast: fix PIM hello router port marking race
  net: phy: marvell10g: fix differentiation of 88X3310 from 88X3340
  dsa: fix for_each_child.cocci warnings
  virtio_net: check virtqueue_add_sgs() return value
  mptcp: properly account bulk freed memory
  selftests: mptcp: fix case multiple subflows limited by server
  mptcp: avoid processing packet if a subflow reset
  mptcp: fix syncookie process if mptcp can not_accept new subflow
  ...
      8096acd7
    • Christian Brauner's avatar
      fs: add vfs_parse_fs_param_source() helper · d1d488d8
      Christian Brauner authored 
      Add a simple helper that filesystems can use in their parameter parser
to parse the "source" parameter. A few places open-coded this function
and that already caused a bug in the cgroup v1 parser that we fixed.
Let's make it harder to get this wrong by introducing a helper which
performs all necessary checks.

Link: https://syzkaller.appspot.com/bug?id=6312526aba5beae046fdae8f00399f87aab48b12


Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d1d488d8