Commit Graph

38438 Commits

Author SHA1 Message Date
Linus Torvalds 224478289c ARM fixes:
* Another state update on exit to userspace fix
 
 * Prevent the creation of mixed 32/64 VMs
 
 * Fix regression with irqbypass not restarting the guest on failed connect
 
 * Fix regression with debug register decoding resulting in overlapping access
 
 * Commit exception state on exit to usrspace
 
 * Fix the MMU notifier return values
 
 * Add missing 'static' qualifiers in the new host stage-2 code
 
 x86 fixes:
 * fix guest missed wakeup with assigned devices
 
 * fix WARN reported by syzkaller
 
 * do not use BIT() in UAPI headers
 
 * make the kvm_amd.avic parameter bool
 
 PPC fixes:
 * make halt polling heuristics consistent with other architectures
 
 selftests:
 * various fixes
 
 * new performance selftest memslot_perf_test
 
 * test UFFD minor faults in demand_paging_test
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "ARM fixes:

   - Another state update on exit to userspace fix

   - Prevent the creation of mixed 32/64 VMs

   - Fix regression with irqbypass not restarting the guest on failed
     connect

   - Fix regression with debug register decoding resulting in
     overlapping access

   - Commit exception state on exit to usrspace

   - Fix the MMU notifier return values

   - Add missing 'static' qualifiers in the new host stage-2 code

  x86 fixes:

   - fix guest missed wakeup with assigned devices

   - fix WARN reported by syzkaller

   - do not use BIT() in UAPI headers

   - make the kvm_amd.avic parameter bool

  PPC fixes:

   - make halt polling heuristics consistent with other architectures

  selftests:

   - various fixes

   - new performance selftest memslot_perf_test

   - test UFFD minor faults in demand_paging_test"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (44 commits)
  selftests: kvm: fix overlapping addresses in memslot_perf_test
  KVM: X86: Kill off ctxt->ud
  KVM: X86: Fix warning caused by stale emulation context
  KVM: X86: Use kvm_get_linear_rip() in single-step and #DB/#BP interception
  KVM: x86/mmu: Fix comment mentioning skip_4k
  KVM: VMX: update vcpu posted-interrupt descriptor when assigning device
  KVM: rename KVM_REQ_PENDING_TIMER to KVM_REQ_UNBLOCK
  KVM: x86: add start_assignment hook to kvm_x86_ops
  KVM: LAPIC: Narrow the timer latency between wait_lapic_expire and world switch
  selftests: kvm: do only 1 memslot_perf_test run by default
  KVM: X86: Use _BITUL() macro in UAPI headers
  KVM: selftests: add shared hugetlbfs backing source type
  KVM: selftests: allow using UFFD minor faults for demand paging
  KVM: selftests: create alias mappings when using shared memory
  KVM: selftests: add shmem backing source type
  KVM: selftests: refactor vm_mem_backing_src_type flags
  KVM: selftests: allow different backing source types
  KVM: selftests: compute correct demand paging size
  KVM: selftests: simplify setup_demand_paging error handling
  KVM: selftests: Print a message if /dev/kvm is missing
  ...
2021-05-29 06:02:25 -10:00
Wanpeng Li b35491e66c KVM: X86: Kill off ctxt->ud
ctxt->ud is consumed only by x86_decode_insn(), we can kill it off by
passing emulation_type to x86_decode_insn() and dropping ctxt->ud
altogether. Tracking that info in ctxt for literally one call is silly.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <1622160097-37633-2-git-send-email-wanpengli@tencent.com>
2021-05-28 12:59:10 -04:00
Wanpeng Li da6393cdd8 KVM: X86: Fix warning caused by stale emulation context
Reported by syzkaller:

  WARNING: CPU: 7 PID: 10526 at linux/arch/x86/kvm//x86.c:7621 x86_emulate_instruction+0x41b/0x510 [kvm]
  RIP: 0010:x86_emulate_instruction+0x41b/0x510 [kvm]
  Call Trace:
   kvm_mmu_page_fault+0x126/0x8f0 [kvm]
   vmx_handle_exit+0x11e/0x680 [kvm_intel]
   vcpu_enter_guest+0xd95/0x1b40 [kvm]
   kvm_arch_vcpu_ioctl_run+0x377/0x6a0 [kvm]
   kvm_vcpu_ioctl+0x389/0x630 [kvm]
   __x64_sys_ioctl+0x8e/0xd0
   do_syscall_64+0x3c/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Commit 4a1e10d5b5 ("KVM: x86: handle hardware breakpoints during emulation())
adds hardware breakpoints check before emulation the instruction and parts of
emulation context initialization, actually we don't have the EMULTYPE_NO_DECODE flag
here and the emulation context will not be reused. Commit c8848cee74 ("KVM: x86:
set ctxt->have_exception in x86_decode_insn()) triggers the warning because it
catches the stale emulation context has #UD, however, it is not during instruction
decoding which should result in EMULATION_FAILED. This patch fixes it by moving
the second part emulation context initialization into init_emulate_ctxt() and
before hardware breakpoints check. The ctxt->ud will be dropped by a follow-up
patch.

syzkaller source: https://syzkaller.appspot.com/x/repro.c?x=134683fdd00000

Reported-by: syzbot+71271244f206d17f6441@syzkaller.appspotmail.com
Fixes: 4a1e10d5b5 (KVM: x86: handle hardware breakpoints during emulation)
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <1622160097-37633-1-git-send-email-wanpengli@tencent.com>
2021-05-28 12:59:09 -04:00
Yuan Yao e87e46d5f3 KVM: X86: Use kvm_get_linear_rip() in single-step and #DB/#BP interception
The kvm_get_linear_rip() handles x86/long mode cases well and has
better readability, __kvm_set_rflags() also use the paired
function kvm_is_linear_rip() to check the vcpu->arch.singlestep_rip
set in kvm_arch_vcpu_ioctl_set_guest_debug(), so change the
"CS.BASE + RIP" code in kvm_arch_vcpu_ioctl_set_guest_debug() and
handle_exception_nmi() to this one.

Signed-off-by: Yuan Yao <yuan.yao@intel.com>
Message-Id: <20210526063828.1173-1-yuan.yao@linux.intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-28 12:57:53 -04:00
David Matlack bedd9195df KVM: x86/mmu: Fix comment mentioning skip_4k
This comment was left over from a previous version of the patch that
introduced wrprot_gfn_range, when skip_4k was passed in instead of
min_level.

Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20210526163227.3113557-1-dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 08:51:25 -04:00
Marcelo Tosatti a2486020a8 KVM: VMX: update vcpu posted-interrupt descriptor when assigning device
For VMX, when a vcpu enters HLT emulation, pi_post_block will:

1) Add vcpu to per-cpu list of blocked vcpus.

2) Program the posted-interrupt descriptor "notification vector"
to POSTED_INTR_WAKEUP_VECTOR

With interrupt remapping, an interrupt will set the PIR bit for the
vector programmed for the device on the CPU, test-and-set the
ON bit on the posted interrupt descriptor, and if the ON bit is clear
generate an interrupt for the notification vector.

This way, the target CPU wakes upon a device interrupt and wakes up
the target vcpu.

Problem is that pi_post_block only programs the notification vector
if kvm_arch_has_assigned_device() is true. Its possible for the
following to happen:

1) vcpu V HLTs on pcpu P, kvm_arch_has_assigned_device is false,
notification vector is not programmed
2) device is assigned to VM
3) device interrupts vcpu V, sets ON bit
(notification vector not programmed, so pcpu P remains in idle)
4) vcpu 0 IPIs vcpu V (in guest), but since pi descriptor ON bit is set,
kvm_vcpu_kick is skipped
5) vcpu 0 busy spins on vcpu V's response for several seconds, until
RCU watchdog NMIs all vCPUs.

To fix this, use the start_assignment kvm_x86_ops callback to kick
vcpus out of the halt loop, so the notification vector is
properly reprogrammed to the wakeup vector.

Reported-by: Pei Zhang <pezhang@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Message-Id: <20210526172014.GA29007@fuller.cnet>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:58:23 -04:00
Marcelo Tosatti 084071d5e9 KVM: rename KVM_REQ_PENDING_TIMER to KVM_REQ_UNBLOCK
KVM_REQ_UNBLOCK will be used to exit a vcpu from
its inner vcpu halt emulation loop.

Rename KVM_REQ_PENDING_TIMER to KVM_REQ_UNBLOCK, switch
PowerPC to arch specific request bit.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Message-Id: <20210525134321.303768132@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:57:38 -04:00
Marcelo Tosatti 57ab87947a KVM: x86: add start_assignment hook to kvm_x86_ops
Add a start_assignment hook to kvm_x86_ops, which is called when
kvm_arch_start_assignment is done.

The hook is required to update the wakeup vector of a sleeping vCPU
when a device is assigned to the guest.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Message-Id: <20210525134321.254128742@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:50:13 -04:00
Wanpeng Li 9805cf03fd KVM: LAPIC: Narrow the timer latency between wait_lapic_expire and world switch
Let's treat lapic_timer_advance_ns automatic tuning logic as hypervisor
overhead, move it before wait_lapic_expire instead of between wait_lapic_expire
and the world switch, the wait duration should be calculated by the
up-to-date guest_tsc after the overhead of automatic tuning logic. This
patch reduces ~30+ cycles for kvm-unit-tests/tscdeadline-latency when testing
busy waits.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1621339235-11131-5-git-send-email-wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:45:58 -04:00
Wanpeng Li da6d63a006 KVM: X86: hyper-v: Task srcu lock when accessing kvm_memslots()
WARNING: suspicious RCU usage
   5.13.0-rc1 #4 Not tainted
   -----------------------------
   ./include/linux/kvm_host.h:710 suspicious rcu_dereference_check() usage!

  other info that might help us debug this:

  rcu_scheduler_active = 2, debug_locks = 1
   1 lock held by hyperv_clock/8318:
    #0: ffffb6b8cb05a7d8 (&hv->hv_lock){+.+.}-{3:3}, at: kvm_hv_invalidate_tsc_page+0x3e/0xa0 [kvm]

  stack backtrace:
  CPU: 3 PID: 8318 Comm: hyperv_clock Not tainted 5.13.0-rc1 #4
  Call Trace:
   dump_stack+0x87/0xb7
   lockdep_rcu_suspicious+0xce/0xf0
   kvm_write_guest_page+0x1c1/0x1d0 [kvm]
   kvm_write_guest+0x50/0x90 [kvm]
   kvm_hv_invalidate_tsc_page+0x79/0xa0 [kvm]
   kvm_gen_update_masterclock+0x1d/0x110 [kvm]
   kvm_arch_vm_ioctl+0x2a7/0xc50 [kvm]
   kvm_vm_ioctl+0x123/0x11d0 [kvm]
   __x64_sys_ioctl+0x3ed/0x9d0
   do_syscall_64+0x3d/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

kvm_memslots() will be called by kvm_write_guest(), so we should take the srcu lock.

Fixes: e880c6ea5 (KVM: x86: hyper-v: Prevent using not-yet-updated TSC page by secondary CPUs)
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1621339235-11131-4-git-send-email-wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:45:53 -04:00
Wanpeng Li 1eff0ada88 KVM: X86: Fix vCPU preempted state from guest's point of view
Commit 66570e966d (kvm: x86: only provide PV features if enabled in guest's
CPUID) avoids to access pv tlb shootdown host side logic when this pv feature
is not exposed to guest, however, kvm_steal_time.preempted not only leveraged
by pv tlb shootdown logic but also mitigate the lock holder preemption issue.
From guest's point of view, vCPU is always preempted since we lose the reset
of kvm_steal_time.preempted before vmentry if pv tlb shootdown feature is not
exposed. This patch fixes it by clearing kvm_steal_time.preempted before
vmentry.

Fixes: 66570e966d (kvm: x86: only provide PV features if enabled in guest's CPUID)
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1621339235-11131-3-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:45:53 -04:00
Wanpeng Li 72b268a8e9 KVM: X86: Bail out of direct yield in case of under-committed scenarios
In case of under-committed scenarios, vCPUs can be scheduled easily;
kvm_vcpu_yield_to adds extra overhead, and it is also common to see
when vcpu->ready is true but yield later failing due to p->state is
TASK_RUNNING.

Let's bail out in such scenarios by checking the length of current cpu
runqueue, which can be treated as a hint of under-committed instead of
guarantee of accuracy. 30%+ of directed-yield attempts can now avoid
the expensive lookups in kvm_sched_yield() in an under-committed scenario.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1621339235-11131-2-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 07:45:52 -04:00
Paolo Bonzini 28a4aa1160 KVM: SVM: make the avic parameter a bool
Make it consistent with kvm_intel.enable_apicv.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-24 13:10:27 -04:00
Vitaly Kuznetsov 377872b335 KVM: VMX: Drop unneeded CONFIG_X86_LOCAL_APIC check
CONFIG_X86_LOCAL_APIC is always on when CONFIG_KVM (on x86) since
commit e42eef4ba3 ("KVM: add X86_LOCAL_APIC dependency").

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210518144339.1987982-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
2021-05-24 18:47:39 +02:00
Vitaly Kuznetsov 778a136e48 KVM: SVM: Drop unneeded CONFIG_X86_LOCAL_APIC check
AVIC dependency on CONFIG_X86_LOCAL_APIC is dead code since
commit e42eef4ba3 ("KVM: add X86_LOCAL_APIC dependency").

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210518144339.1987982-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
2021-05-24 18:47:39 +02:00
Linus Torvalds 6ebb6814a1 Two perf fixes:
- Do not check the LBR_TOS MSR when setting up unrelated LBR MSRs as this
    can cause malfunction when TOS is not supported.
 
  - Allocate the LBR XSAVE buffers along with the DS buffers upfront because
    allocating them when adding an event can deadlock.
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Merge tag 'perf-urgent-2021-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "Two perf fixes:

   - Do not check the LBR_TOS MSR when setting up unrelated LBR MSRs as
     this can cause malfunction when TOS is not supported

   - Allocate the LBR XSAVE buffers along with the DS buffers upfront
     because allocating them when adding an event can deadlock"

* tag 'perf-urgent-2021-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/lbr: Remove cpuc->lbr_xsave allocation from atomic context
  perf/x86: Avoid touching LBR_TOS MSR for Arch LBR
2021-05-23 06:32:40 -10:00
Linus Torvalds 7de7ac8d60 - Fix how SEV handles MMIO accesses by forwarding potential page faults instead
of killing the machine and by using the accessors with the exact functionality
 needed when accessing memory.
 
 - Fix a confusion with Clang LTO compiler switches passed to the it
 
 - Handle the case gracefully when VMGEXIT has been executed in userspace
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Merge tag 'x86_urgent_for_v5.13_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Fix how SEV handles MMIO accesses by forwarding potential page faults
   instead of killing the machine and by using the accessors with the
   exact functionality needed when accessing memory.

 - Fix a confusion with Clang LTO compiler switches passed to the it

 - Handle the case gracefully when VMGEXIT has been executed in
   userspace

* tag 'x86_urgent_for_v5.13_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev-es: Use __put_user()/__get_user() for data accesses
  x86/sev-es: Forward page-faults which happen during emulation
  x86/sev-es: Don't return NULL from sev_es_get_ghcb()
  x86/build: Fix location of '-plugin-opt=' flags
  x86/sev-es: Invalidate the GHCB after completing VMGEXIT
  x86/sev-es: Move sev_es_put_ghcb() in prep for follow on patch
2021-05-23 06:12:25 -10:00
Linus Torvalds 23d7292630 xen: branch for v5.13-rc3
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Merge tag 'for-linus-5.13b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a fix for a boot regression when running as PV guest on hardware
   without NX support

 - a small series fixing a bug in the Xen pciback driver when
   configuring a PCI card with multiple virtual functions

* tag 'for-linus-5.13b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-pciback: reconfigure also from backend watch handler
  xen-pciback: redo VF placement in the virtual topology
  x86/Xen: swap NX determination and GDT setup on BSP
2021-05-22 07:33:09 -10:00
Linus Torvalds a0e31f3a38 Merge branch 'for-v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo fix from Eric Biederman:
 "During the merge window an issue with si_perf and the siginfo ABI came
  up. The alpha and sparc siginfo structure layout had changed with the
  addition of SIGTRAP TRAP_PERF and the new field si_perf.

  The reason only alpha and sparc were affected is that they are the
  only architectures that use si_trapno.

  Looking deeper it was discovered that si_trapno is used for only a few
  select signals on alpha and sparc, and that none of the other
  _sigfault fields past si_addr are used at all. Which means technically
  no regression on alpha and sparc.

  While the alignment concerns might be dismissed the abuse of si_errno
  by SIGTRAP TRAP_PERF does have the potential to cause regressions in
  existing userspace.

  While we still have time before userspace starts using and depending
  on the new definition siginfo for SIGTRAP TRAP_PERF this set of
  changes cleans up siginfo_t.

   - The si_trapno field is demoted from magic alpha and sparc status
     and made an ordinary union member of the _sigfault member of
     siginfo_t. Without moving it of course.

   - si_perf is replaced with si_perf_data and si_perf_type ending the
     abuse of si_errno.

   - Unnecessary additions to signalfd_siginfo are removed"

* 'for-v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signalfd: Remove SIL_PERF_EVENT fields from signalfd_siginfo
  signal: Deliver all of the siginfo perf data in _perf
  signal: Factor force_sig_perf out of perf_sigtrap
  signal: Implement SIL_FAULT_TRAPNO
  siginfo: Move si_trapno inside the union inside _si_fault
2021-05-21 06:12:52 -10:00
Jan Beulich ae897fda4f x86/Xen: swap NX determination and GDT setup on BSP
xen_setup_gdt(), via xen_load_gdt_boot(), wants to adjust page tables.
For this to work when NX is not available, x86_configure_nx() needs to
be called first.

[jgross] Note that this is a revert of 36104cb901 ("x86/xen:
Delay get_cpu_cap until stack canary is established"), which is possible
now that we no longer support running as PV guest in 32-bit mode.

Cc: <stable.vger.kernel.org> # 5.9
Fixes: 36104cb901 ("x86/xen: Delay get_cpu_cap until stack canary is established")
Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

Link: https://lore.kernel.org/r/12a866b0-9e89-59f7-ebeb-a2a6cec0987a@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2021-05-21 09:53:52 +02:00
Linus Torvalds 7ac177143c \n
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Merge tag 'quota_for_v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull quota fixes from Jan Kara:
 "The most important part in the pull is disablement of the new syscall
  quotactl_path() which was added in rc1.

  The reason is some people at LWN discussion pointed out dirfd would be
  useful for this path based syscall and Christian Brauner agreed.

  Without dirfd it may be indeed problematic for containers. So let's
  just disable the syscall for now when it doesn't have users yet so
  that we have more time to mull over how to best specify the filesystem
  we want to work on"

* tag 'quota_for_v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: Disable quotactl_path syscall
  quota: Use 'hlist_for_each_entry' to simplify code
2021-05-20 06:20:15 -10:00
Joerg Roedel 4954f5b8ef x86/sev-es: Use __put_user()/__get_user() for data accesses
The put_user() and get_user() functions do checks on the address which is
passed to them. They check whether the address is actually a user-space
address and whether its fine to access it. They also call might_fault()
to indicate that they could fault and possibly sleep.

All of these checks are neither wanted nor needed in the #VC exception
handler, which can be invoked from almost any context and also for MMIO
instructions from kernel space on kernel memory. All the #VC handler
wants to know is whether a fault happened when the access was tried.

This is provided by __put_user()/__get_user(), which just do the access
no matter what. Also add comments explaining why __get_user() and
__put_user() are the best choice here and why it is safe to use them
in this context. Also explain why copy_to/from_user can't be used.

In addition, also revert commit

  7024f60d65 ("x86/sev-es: Handle string port IO to kernel memory properly")

because using __get_user()/__put_user() fixes the same problem while
the above commit introduced several problems:

  1) It uses access_ok() which is only allowed in task context.

  2) It uses memcpy() which has no fault handling at all and is
     thus unsafe to use here.

  [ bp: Fix up commit ID of the reverted commit above. ]

Fixes: f980f9c31a ("x86/sev-es: Compile early handler code into kernel image")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org # v5.10+
Link: https://lkml.kernel.org/r/20210519135251.30093-4-joro@8bytes.org
2021-05-19 18:45:37 +02:00
Joerg Roedel c25bbdb564 x86/sev-es: Forward page-faults which happen during emulation
When emulating guest instructions for MMIO or IOIO accesses, the #VC
handler might get a page-fault and will not be able to complete. Forward
the page-fault in this case to the correct handler instead of killing
the machine.

Fixes: 0786138c78 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org # v5.10+
Link: https://lkml.kernel.org/r/20210519135251.30093-3-joro@8bytes.org
2021-05-19 17:13:04 +02:00
Joerg Roedel b250f2f779 x86/sev-es: Don't return NULL from sev_es_get_ghcb()
sev_es_get_ghcb() is called from several places but only one of them
checks the return value. The reaction to returning NULL is always the
same: calling panic() and kill the machine.

Instead of adding checks to all call sites, move the panic() into the
function itself so that it will no longer return NULL.

Fixes: 0786138c78 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org # v5.10+
Link: https://lkml.kernel.org/r/20210519135251.30093-2-joro@8bytes.org
2021-05-19 17:05:13 +02:00
Nathan Chancellor 0024430e92 x86/build: Fix location of '-plugin-opt=' flags
Commit b33fff07e3 ("x86, build: allow LTO to be selected") added a
couple of '-plugin-opt=' flags to KBUILD_LDFLAGS because the code model
and stack alignment are not stored in LLVM bitcode.

However, these flags were added to KBUILD_LDFLAGS prior to the
emulation flag assignment, which uses ':=', so they were overwritten
and never added to $(LD) invocations.

The absence of these flags caused misalignment issues in the
AMDGPU driver when compiling with CONFIG_LTO_CLANG, resulting in
general protection faults.

Shuffle the assignment below the initial one so that the flags are
properly passed along and all of the linker flags stay together.

At the same time, avoid any future issues with clobbering flags by
changing the emulation flag assignment to '+=' since KBUILD_LDFLAGS is
already defined with ':=' in the main Makefile before being exported for
modification here as a result of commit:

  ce99d0bf31 ("kbuild: clear LDFLAGS in the top Makefile")

Fixes: b33fff07e3 ("x86, build: allow LTO to be selected")
Reported-by: Anthony Ruhier <aruhier@mailbox.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Anthony Ruhier <aruhier@mailbox.org>
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1374
Link: https://lore.kernel.org/r/20210518190106.60935-1-nathan@kernel.org
2021-05-19 13:05:53 +02:00
Eric W. Biederman 0683b53197 signal: Deliver all of the siginfo perf data in _perf
Don't abuse si_errno and deliver all of the perf data in _perf member
of siginfo_t.

Note: The data field in the perf data structures in a u64 to allow a
pointer to be encoded without needed to implement a 32bit and 64bit
version of the same structure.  There already exists a 32bit and 64bit
versions siginfo_t, and the 32bit version can not include a 64bit
member as it only has 32bit alignment.  So unsigned long is used in
siginfo_t instead of a u64 as unsigned long can encode a pointer on
all architectures linux supports.

v1: https://lkml.kernel.org/r/m11rarqqx2.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210503203814.25487-10-ebiederm@xmission.com
v3: https://lkml.kernel.org/r/20210505141101.11519-11-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20210517195748.8880-4-ebiederm@xmission.com
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-05-18 16:20:54 -05:00
Eric W. Biederman add0b32ef9 siginfo: Move si_trapno inside the union inside _si_fault
It turns out that linux uses si_trapno very sparingly, and as such it
can be considered extra information for a very narrow selection of
signals, rather than information that is present with every fault
reported in siginfo.

As such move si_trapno inside the union inside of _si_fault.  This
results in no change in placement, and makes it eaiser
to extend _si_fault in the future as this reduces the number of
special cases.  In particular with si_trapno included in the union it
is no longer a concern that the union must be pointer aligned on most
architectures because the union follows immediately after si_addr
which is a pointer.

This change results in a difference in siginfo field placement on
sparc and alpha for the fields si_addr_lsb, si_lower, si_upper,
si_pkey, and si_perf.  These architectures do not implement the
signals that would use si_addr_lsb, si_lower, si_upper, si_pkey, and
si_perf.  Further these architecture have not yet implemented the
userspace that would use si_perf.

The point of this change is in fact to correct these placement issues
before sparc or alpha grow userspace that cares.  This change was
discussed[1] and the agreement is that this change is currently safe.

[1]: https://lkml.kernel.org/r/CAK8P3a0+uKYwL1NhY6Hvtieghba2hKYGD6hcKx5n8=4Gtt+pHA@mail.gmail.com
Acked-by: Marco Elver <elver@google.com>
v1: https://lkml.kernel.org/r/m1tunns7yf.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210505141101.11519-5-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20210517195748.8880-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-05-18 16:17:03 -05:00
Like Xu 488e13a489 perf/x86/lbr: Remove cpuc->lbr_xsave allocation from atomic context
If the kernel is compiled with the CONFIG_LOCKDEP option, the conditional
might_sleep_if() deep in kmem_cache_alloc() will generate the following
trace, and potentially cause a deadlock when another LBR event is added:

  [] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:196
  [] Call Trace:
  []  kmem_cache_alloc+0x36/0x250
  []  intel_pmu_lbr_add+0x152/0x170
  []  x86_pmu_add+0x83/0xd0

Make it symmetric with the release_lbr_buffers() call and mirror the
existing DS buffers.

Fixes: c085fb8774 ("perf/x86/intel/lbr: Support XSAVES for arch LBR read")
Signed-off-by: Like Xu <like.xu@linux.intel.com>
[peterz: simplified]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lkml.kernel.org/r/20210430052247.3079672-2-like.xu@linux.intel.com
2021-05-18 12:53:47 +02:00
Like Xu 3317c26a4b perf/x86: Avoid touching LBR_TOS MSR for Arch LBR
The Architecture LBR does not have MSR_LBR_TOS (0x000001c9).
In a guest that should support Architecture LBR, check_msr()
will be a non-related check for the architecture MSR 0x0
(IA32_P5_MC_ADDR) that is also not supported by KVM.

The failure will cause x86_pmu.lbr_nr = 0, thereby preventing
the initialization of the guest Arch LBR. Fix it by avoiding
this extraneous check in intel_pmu_init() for Arch LBR.

Fixes: 47125db27e ("perf/x86/intel/lbr: Support Architectural LBR")
Signed-off-by: Like Xu <like.xu@linux.intel.com>
[peterz: simpler still]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210430052247.3079672-1-like.xu@linux.intel.com
2021-05-18 12:53:47 +02:00
Tom Lendacky a50c5bebc9 x86/sev-es: Invalidate the GHCB after completing VMGEXIT
Since the VMGEXIT instruction can be issued from userspace, invalidate
the GHCB after performing VMGEXIT processing in the kernel.

Invalidation is only required after userspace is available, so call
vc_ghcb_invalidate() from sev_es_put_ghcb(). Update vc_ghcb_invalidate()
to additionally clear the GHCB exit code so that it is always presented
as 0 when VMGEXIT has been issued by anything else besides the kernel.

Fixes: 0786138c78 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/5a8130462e4f0057ee1184509cd056eedd78742b.1621273353.git.thomas.lendacky@amd.com
2021-05-18 07:06:29 +02:00
Tom Lendacky fea63d54f7 x86/sev-es: Move sev_es_put_ghcb() in prep for follow on patch
Move the location of sev_es_put_ghcb() in preparation for an update to it
in a follow-on patch. This will better highlight the changes being made
to the function.

No functional change.

Fixes: 0786138c78 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/8c07662ec17d3d82e5c53841a1d9e766d3bdbab6.1621273353.git.thomas.lendacky@amd.com
2021-05-18 06:49:37 +02:00
Jan Kara 5b9fedb31e quota: Disable quotactl_path syscall
In commit fa8b90070a ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the path based syscall is missing dirfd and flags argument
which is mostly standard for contemporary path based syscalls. Indeed
they have a point and after a discussion with Christian Brauner and
Sascha Hauer I've decided to disable the syscall for now and update its
API. Since there is no userspace currently using that syscall and it
hasn't been released in any major release, we should be fine.

CC: Christian Brauner <christian.brauner@ubuntu.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara <jack@suse.cz>
2021-05-17 14:39:56 +02:00
Paolo Bonzini a4345a7cec KVM/arm64 fixes for 5.13, take #1
- Fix regression with irqbypass not restarting the guest on failed connect
 - Fix regression with debug register decoding resulting in overlapping access
 - Commit exception state on exit to usrspace
 - Fix the MMU notifier return values
 - Add missing 'static' qualifiers in the new host stage-2 code
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Merge tag 'kvmarm-fixes-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.13, take #1

- Fix regression with irqbypass not restarting the guest on failed connect
- Fix regression with debug register decoding resulting in overlapping access
- Commit exception state on exit to usrspace
- Fix the MMU notifier return values
- Add missing 'static' qualifiers in the new host stage-2 code
2021-05-17 09:55:12 +02:00
Linus Torvalds 8ce3648158 Two fixes for timers:
- Use the ALARM feature check in the alarmtimer core code insted of
     the old method of checking for the set_alarm() callback. Drivers
     can have that callback set but the feature bit cleared. If such
     a RTC device is selected then alarms wont work.
 
   - Use a proper define to let the preprocessor check whether Hyper-V VDSO
     clocksource should be active. The code used a constant in an enum with
     #ifdef, which evaluates to always false and disabled the clocksource
     for VDSO.
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Merge tag 'timers-urgent-2021-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "Two fixes for timers:

   - Use the ALARM feature check in the alarmtimer core code insted of
     the old method of checking for the set_alarm() callback.

     Drivers can have that callback set but the feature bit cleared. If
     such a RTC device is selected then alarms wont work.

   - Use a proper define to let the preprocessor check whether Hyper-V
     VDSO clocksource should be active.

     The code used a constant in an enum with #ifdef, which evaluates to
     always false and disabled the clocksource for VDSO"

* tag 'timers-urgent-2021-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/hyper-v: Re-enable VDSO_CLOCKMODE_HVCLOCK on X86
  alarmtimer: Check RTC features instead of ops
2021-05-16 09:42:13 -07:00
Linus Torvalds ccb013c29d - Enable -Wundef for the compressed kernel build stage
- Reorganize SEV code to streamline and simplify future development
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Merge tag 'x86_urgent_for_v5.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "The three SEV commits are not really urgent material. But we figured
  since getting them in now will avoid a huge amount of conflicts
  between future SEV changes touching tip, the kvm and probably other
  trees, sending them to you now would be best.

  The idea is that the tip, kvm etc branches for 5.14 will all base
  ontop of -rc2 and thus everything will be peachy. What is more, those
  changes are purely mechanical and defines movement so they should be
  fine to go now (famous last words).

  Summary:

   - Enable -Wundef for the compressed kernel build stage

   - Reorganize SEV code to streamline and simplify future development"

* tag 'x86_urgent_for_v5.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/compressed: Enable -Wundef
  x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG
  x86/sev: Move GHCB MSR protocol and NAE definitions in a common header
  x86/sev-es: Rename sev-es.{ch} to sev.{ch}
2021-05-16 09:31:06 -07:00
Vitaly Kuznetsov 3486d2c9be clocksource/drivers/hyper-v: Re-enable VDSO_CLOCKMODE_HVCLOCK on X86
Mohammed reports (https://bugzilla.kernel.org/show_bug.cgi?id=213029)
the commit e4ab4658f1 ("clocksource/drivers/hyper-v: Handle vDSO
differences inline") broke vDSO on x86. The problem appears to be that
VDSO_CLOCKMODE_HVCLOCK is an enum value in 'enum vdso_clock_mode' and
'#ifdef VDSO_CLOCKMODE_HVCLOCK' branch evaluates to false (it is not
a define).

Use a dedicated HAVE_VDSO_CLOCKMODE_HVCLOCK define instead.

Fixes: e4ab4658f1 ("clocksource/drivers/hyper-v: Handle vDSO differences inline")
Reported-by: Mohammed Gamal <mgamal@redhat.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210513073246.1715070-1-vkuznets@redhat.com
2021-05-14 14:55:13 +02:00
Huang Rui 3743d55b28 x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations
Some AMD Ryzen generations has different calculation method on maximum
performance. 255 is not for all ASICs, some specific generations should use 166
as the maximum performance. Otherwise, it will report incorrect frequency value
like below:

  ~ → lscpu | grep MHz
  CPU MHz:                         3400.000
  CPU max MHz:                     7228.3198
  CPU min MHz:                     2200.0000

[ mingo: Tidied up whitespace use. ]
[ Alexander Monakov <amonakov@ispras.ru>: fix 225 -> 255 typo. ]

Fixes: 41ea667227 ("x86, sched: Calculate frequency invariance for AMD systems")
Fixes: 3c55e94c0a ("cpufreq: ACPI: Extend frequency tables to cover boost frequencies")
Reported-by: Jason Bagavatsingham <jason.bagavatsingham@gmail.com>
Fixed-by: Alexander Monakov <amonakov@ispras.ru>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jason Bagavatsingham <jason.bagavatsingham@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210425073451.2557394-1-ray.huang@amd.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211791
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-05-13 12:10:24 +02:00
Nick Desaulniers a554e740b6 x86/boot/compressed: Enable -Wundef
A discussion around -Wundef showed that there were still a few boolean
Kconfigs where #if was used rather than #ifdef to guard different code.
Kconfig doesn't define boolean configs, which can result in -Wundef
warnings.

arch/x86/boot/compressed/Makefile resets the CFLAGS used for this
directory, and doesn't re-enable -Wundef as the top level Makefile does.
If re-added, with RANDOMIZE_BASE and X86_NEED_RELOCS disabled, the
following warnings are visible.

  arch/x86/boot/compressed/misc.h:82:5: warning: 'CONFIG_RANDOMIZE_BASE'
  is not defined, evaluates to 0 [-Wundef]
      ^
  arch/x86/boot/compressed/misc.c:175:5: warning: 'CONFIG_X86_NEED_RELOCS'
  is not defined, evaluates to 0 [-Wundef]
      ^

Simply fix these and re-enable this warning for this directory.

Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20210422190450.3903999-1-ndesaulniers@google.com
2021-05-12 21:39:56 +02:00
Linus Torvalds 0aa099a312 * Lots of bug fixes.
* Fix virtualization of RDPID
 
 * Virtualization of DR6_BUS_LOCK, which on bare metal is new in
   the 5.13 merge window
 
 * More nested virtualization migration fixes (nSVM and eVMCS)
 
 * Fix for KVM guest hibernation
 
 * Fix for warning in SEV-ES SRCU usage
 
 * Block KVM from loading on AMD machines with 5-level page tables,
   due to the APM not mentioning how host CR4.LA57 exactly impacts
   the guest.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:

 - Lots of bug fixes.

 - Fix virtualization of RDPID

 - Virtualization of DR6_BUS_LOCK, which on bare metal is new to this
   release

 - More nested virtualization migration fixes (nSVM and eVMCS)

 - Fix for KVM guest hibernation

 - Fix for warning in SEV-ES SRCU usage

 - Block KVM from loading on AMD machines with 5-level page tables, due
   to the APM not mentioning how host CR4.LA57 exactly impacts the
   guest.

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (48 commits)
  KVM: SVM: Move GHCB unmapping to fix RCU warning
  KVM: SVM: Invert user pointer casting in SEV {en,de}crypt helpers
  kvm: Cap halt polling at kvm->max_halt_poll_ns
  tools/kvm_stat: Fix documentation typo
  KVM: x86: Prevent deadlock against tk_core.seq
  KVM: x86: Cancel pvclock_gtod_work on module removal
  KVM: x86: Prevent KVM SVM from loading on kernels with 5-level paging
  KVM: X86: Expose bus lock debug exception to guest
  KVM: X86: Add support for the emulation of DR6_BUS_LOCK bit
  KVM: PPC: Book3S HV: Fix conversion to gfn-based MMU notifier callbacks
  KVM: x86: Hide RDTSCP and RDPID if MSR_TSC_AUX probing failed
  KVM: x86: Tie Intel and AMD behavior for MSR_TSC_AUX to guest CPU model
  KVM: x86: Move uret MSR slot management to common x86
  KVM: x86: Export the number of uret MSRs to vendor modules
  KVM: VMX: Disable loading of TSX_CTRL MSR the more conventional way
  KVM: VMX: Use common x86's uret MSR list as the one true list
  KVM: VMX: Use flag to indicate "active" uret MSRs instead of sorting list
  KVM: VMX: Configure list of user return MSRs at module init
  KVM: x86: Add support for RDPID without RDTSCP
  KVM: SVM: Probe and load MSR_TSC_AUX regardless of RDTSCP support in host
  ...
2021-05-10 12:30:45 -07:00
Brijesh Singh 059e5c321a x86/msr: Rename MSR_K8_SYSCFG to MSR_AMD64_SYSCFG
The SYSCFG MSR continued being updated beyond the K8 family; drop the K8
name from it.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-4-brijesh.singh@amd.com
2021-05-10 07:51:38 +02:00
Brijesh Singh b81fc74d53 x86/sev: Move GHCB MSR protocol and NAE definitions in a common header
The guest and the hypervisor contain separate macros to get and set
the GHCB MSR protocol and NAE event fields. Consolidate the GHCB
protocol definitions and helper macros in one place.

Leave the supported protocol version define in separate files to keep
the guest and hypervisor flexibility to support different GHCB version
in the same release.

There is no functional change intended.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-3-brijesh.singh@amd.com
2021-05-10 07:46:39 +02:00
Brijesh Singh e759959fe3 x86/sev-es: Rename sev-es.{ch} to sev.{ch}
SEV-SNP builds upon the SEV-ES functionality while adding new hardware
protection. Version 2 of the GHCB specification adds new NAE events that
are SEV-SNP specific. Rename the sev-es.{ch} to sev.{ch} so that all
SEV* functionality can be consolidated in one place.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-2-brijesh.singh@amd.com
2021-05-10 07:40:27 +02:00
Linus Torvalds 85bbba1c07 Handle power-gating of AMD IOMMU perf counters properly when they are used.
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Merge tag 'perf_urgent_for_v5.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf fix from Borislav Petkov:
 "Handle power-gating of AMD IOMMU perf counters properly when they are
  used"

* tag 'perf_urgent_for_v5.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/events/amd/iommu: Fix invalid Perf result due to IOMMU PMC power-gating
2021-05-09 13:00:26 -07:00
Linus Torvalds dd3e4012dd - Fix guest vtime accounting so that ticks happening while the guest is running
can also be accounted to it. Along with a consolidation to the guest-specific context
 tracking helpers.
 
 - Provide for the host NMI handler running after a VMX VMEXIT to be able to run
 on the kernel stack correctly.
 
 - Initialize MSR_TSC_AUX when RDPID is supported and not RDTSCP (virt relevant -
   real hw supports both)
 
 - A code generation improvement to TASK_SIZE_MAX through the use of alternatives
 
 - The usual misc. and related cleanups and improvements
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Merge tag 'x86_urgent_for_v5.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "A bunch of things accumulated for x86 in the last two weeks:

   - Fix guest vtime accounting so that ticks happening while the guest
     is running can also be accounted to it. Along with a consolidation
     to the guest-specific context tracking helpers.

   - Provide for the host NMI handler running after a VMX VMEXIT to be
     able to run on the kernel stack correctly.

   - Initialize MSR_TSC_AUX when RDPID is supported and not RDTSCP (virt
     relevant - real hw supports both)

   - A code generation improvement to TASK_SIZE_MAX through the use of
     alternatives

   - The usual misc and related cleanups and improvements"

* tag 'x86_urgent_for_v5.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: x86: Consolidate guest enter/exit logic to common helpers
  context_tracking: KVM: Move guest enter/exit wrappers to KVM's domain
  context_tracking: Consolidate guest enter/exit wrappers
  sched/vtime: Move guest enter/exit vtime accounting to vtime.h
  sched/vtime: Move vtime accounting external declarations above inlines
  KVM: x86: Defer vtime accounting 'til after IRQ handling
  context_tracking: Move guest exit vtime accounting to separate helpers
  context_tracking: Move guest exit context tracking to separate helpers
  KVM/VMX: Invoke NMI non-IST entry instead of IST entry
  x86/cpu: Remove write_tsc() and write_rdtscp_aux() wrappers
  x86/cpu: Initialize MSR_TSC_AUX if RDTSCP *or* RDPID is supported
  x86/resctrl: Fix init const confusion
  x86: Delete UD0, UD1 traces
  x86/smpboot: Remove duplicate includes
  x86/cpu: Use alternative to generate the TASK_SIZE_MAX constant
2021-05-09 12:52:25 -07:00
Linus Torvalds 28b4afeb59 io_uring-5.13-2021-05-07
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Merge tag 'io_uring-5.13-2021-05-07' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "Mostly fixes for merge window merged code. In detail:

   - Error case memory leak fixes (Colin, Zqiang)

   - Add the tools/io_uring/ to the list of maintained files (Lukas)

   - Set of fixes for the modified buffer registration API (Pavel)

   - Sanitize io thread setup on x86 (Stefan)

   - Ensure we truncate transfer count for registered buffers (Thadeu)"

* tag 'io_uring-5.13-2021-05-07' of git://git.kernel.dk/linux-block:
  x86/process: setup io_threads more like normal user space threads
  MAINTAINERS: add io_uring tool to IO_URING
  io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers
  io_uring: Fix memory leak in io_sqe_buffers_register()
  io_uring: Fix premature return from loop and memory leak
  io_uring: fix unchecked error in switch_start()
  io_uring: allow empty slots for reg buffers
  io_uring: add more build check for uapi
  io_uring: dont overlap internal and user req flags
  io_uring: fix drain with rsrc CQEs
2021-05-07 11:29:23 -07:00
Tom Lendacky ce7ea0cfdc KVM: SVM: Move GHCB unmapping to fix RCU warning
When an SEV-ES guest is running, the GHCB is unmapped as part of the
vCPU run support. However, kvm_vcpu_unmap() triggers an RCU dereference
warning with CONFIG_PROVE_LOCKING=y because the SRCU lock is released
before invoking the vCPU run support.

Move the GHCB unmapping into the prepare_guest_switch callback, which is
invoked while still holding the SRCU lock, eliminating the RCU dereference
warning.

Fixes: 291bd20d5d ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <b2f9b79d15166f2c3e4375c0d9bc3268b7696455.1620332081.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:23 -04:00
Sean Christopherson 368340a3c7 KVM: SVM: Invert user pointer casting in SEV {en,de}crypt helpers
Invert the user pointer params for SEV's helpers for encrypting and
decrypting guest memory so that they take a pointer and cast to an
unsigned long as necessary, as opposed to doing the opposite.  Tagging a
non-pointer as __user is confusing and weird since a cast of some form
needs to occur to actually access the user data.  This also fixes Sparse
warnings triggered by directly consuming the unsigned longs, which are
"noderef" due to the __user tag.

Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210506231542.2331138-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:22 -04:00
Thomas Gleixner 3f804f6d20 KVM: x86: Prevent deadlock against tk_core.seq
syzbot reported a possible deadlock in pvclock_gtod_notify():

CPU 0  		  	   	    	    CPU 1
write_seqcount_begin(&tk_core.seq);
  pvclock_gtod_notify()			    spin_lock(&pool->lock);
    queue_work(..., &pvclock_gtod_work)	    ktime_get()
     spin_lock(&pool->lock);		      do {
     						seq = read_seqcount_begin(tk_core.seq)
						...
				              } while (read_seqcount_retry(&tk_core.seq, seq);

While this is unlikely to happen, it's possible.

Delegate queue_work() to irq_work() which postpones it until the
tk_core.seq write held region is left and interrupts are reenabled.

Fixes: 16e8d74d2d ("KVM: x86: notifier for clocksource changes")
Reported-by: syzbot+6beae4000559d41d80f8@syzkaller.appspotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Message-Id: <87h7jgm1zy.ffs@nanos.tec.linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:21 -04:00
Thomas Gleixner 594b27e677 KVM: x86: Cancel pvclock_gtod_work on module removal
Nothing prevents the following:

  pvclock_gtod_notify()
    queue_work(system_long_wq, &pvclock_gtod_work);
  ...
  remove_module(kvm);
  ...
  work_queue_run()
    pvclock_gtod_work()	<- UAF

Ditto for any other operation on that workqueue list head which touches
pvclock_gtod_work after module removal.

Cancel the work in kvm_arch_exit() to prevent that.

Fixes: 16e8d74d2d ("KVM: x86: notifier for clocksource changes")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Message-Id: <87czu4onry.ffs@nanos.tec.linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:21 -04:00
Sean Christopherson 03ca4589fa KVM: x86: Prevent KVM SVM from loading on kernels with 5-level paging
Disallow loading KVM SVM if 5-level paging is supported.  In theory, NPT
for L1 should simply work, but there unknowns with respect to how the
guest's MAXPHYADDR will be handled by hardware.

Nested NPT is more problematic, as running an L1 VMM that is using
2-level page tables requires stacking single-entry PDP and PML4 tables in
KVM's NPT for L2, as there are no equivalent entries in L1's NPT to
shadow.  Barring hardware magic, for 5-level paging, KVM would need stack
another layer to handle PML5.

Opportunistically rename the lm_root pointer, which is used for the
aforementioned stacking when shadowing 2-level L1 NPT, to pml4_root to
call out that it's specifically for PML4.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210505204221.1934471-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:21 -04:00