1. 27 1月, 2017 1 次提交
  2. 12 1月, 2017 2 次提交
    • W
      KVM: x86: fix NULL deref in vcpu_scan_ioapic · 546d87e5
      Wanpeng Li 提交于
      Reported by syzkaller:
      
          BUG: unable to handle kernel NULL pointer dereference at 00000000000001b0
          IP: _raw_spin_lock+0xc/0x30
          PGD 3e28eb067
          PUD 3f0ac6067
          PMD 0
          Oops: 0002 [#1] SMP
          CPU: 0 PID: 2431 Comm: test Tainted: G           OE   4.10.0-rc1+ #3
          Call Trace:
           ? kvm_ioapic_scan_entry+0x3e/0x110 [kvm]
           kvm_arch_vcpu_ioctl_run+0x10a8/0x15f0 [kvm]
           ? pick_next_task_fair+0xe1/0x4e0
           ? kvm_arch_vcpu_load+0xea/0x260 [kvm]
           kvm_vcpu_ioctl+0x33a/0x600 [kvm]
           ? hrtimer_try_to_cancel+0x29/0x130
           ? do_nanosleep+0x97/0xf0
           do_vfs_ioctl+0xa1/0x5d0
           ? __hrtimer_init+0x90/0x90
           ? do_nanosleep+0x5b/0xf0
           SyS_ioctl+0x79/0x90
           do_syscall_64+0x6e/0x180
           entry_SYSCALL64_slow_path+0x25/0x25
          RIP: _raw_spin_lock+0xc/0x30 RSP: ffffa43688973cc0
      
      The syzkaller folks reported a NULL pointer dereference due to
      ENABLE_CAP succeeding even without an irqchip.  The Hyper-V
      synthetic interrupt controller is activated, resulting in a
      wrong request to rescan the ioapic and a NULL pointer dereference.
      
          #include <sys/ioctl.h>
          #include <sys/mman.h>
          #include <sys/types.h>
          #include <linux/kvm.h>
          #include <pthread.h>
          #include <stddef.h>
          #include <stdint.h>
          #include <stdlib.h>
          #include <string.h>
          #include <unistd.h>
      
          #ifndef KVM_CAP_HYPERV_SYNIC
          #define KVM_CAP_HYPERV_SYNIC 123
          #endif
      
          void* thr(void* arg)
          {
      	struct kvm_enable_cap cap;
      	cap.flags = 0;
      	cap.cap = KVM_CAP_HYPERV_SYNIC;
      	ioctl((long)arg, KVM_ENABLE_CAP, &cap);
      	return 0;
          }
      
          int main()
          {
      	void *host_mem = mmap(0, 0x1000, PROT_READ|PROT_WRITE,
      			MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
      	int kvmfd = open("/dev/kvm", 0);
      	int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
      	struct kvm_userspace_memory_region memreg;
      	memreg.slot = 0;
      	memreg.flags = 0;
      	memreg.guest_phys_addr = 0;
      	memreg.memory_size = 0x1000;
      	memreg.userspace_addr = (unsigned long)host_mem;
      	host_mem[0] = 0xf4;
      	ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg);
      	int cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
      	struct kvm_sregs sregs;
      	ioctl(cpufd, KVM_GET_SREGS, &sregs);
      	sregs.cr0 = 0;
      	sregs.cr4 = 0;
      	sregs.efer = 0;
      	sregs.cs.selector = 0;
      	sregs.cs.base = 0;
      	ioctl(cpufd, KVM_SET_SREGS, &sregs);
      	struct kvm_regs regs = { .rflags = 2 };
      	ioctl(cpufd, KVM_SET_REGS, &regs);
      	ioctl(vmfd, KVM_CREATE_IRQCHIP, 0);
      	pthread_t th;
      	pthread_create(&th, 0, thr, (void*)(long)cpufd);
      	usleep(rand() % 10000);
      	ioctl(cpufd, KVM_RUN, 0);
      	pthread_join(th, 0);
      	return 0;
          }
      
      This patch fixes it by failing ENABLE_CAP if without an irqchip.
      Reported-by: NDmitry Vyukov <dvyukov@google.com>
      Fixes: 5c919412 (kvm/x86: Hyper-V synthetic interrupt controller)
      Cc: stable@vger.kernel.org # 4.5+
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      546d87e5
    • D
      KVM: x86: flush pending lapic jump label updates on module unload · cef84c30
      David Matlack 提交于
      KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled).
      These are implemented with delayed_work structs which can still be
      pending when the KVM module is unloaded. We've seen this cause kernel
      panics when the kvm_intel module is quickly reloaded.
      
      Use the new static_key_deferred_flush() API to flush pending updates on
      module unload.
      Signed-off-by: NDavid Matlack <dmatlack@google.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      cef84c30
  3. 09 1月, 2017 8 次提交
  4. 25 12月, 2016 2 次提交
  5. 24 12月, 2016 1 次提交
  6. 19 12月, 2016 2 次提交
  7. 17 12月, 2016 1 次提交
  8. 08 12月, 2016 3 次提交
    • L
      KVM: nVMX: introduce nested_vmx_load_cr3 and call it on vmentry · 9ed38ffa
      Ladi Prosek 提交于
      Loading CR3 as part of emulating vmentry is different from regular CR3 loads,
      as implemented in kvm_set_cr3, in several ways.
      
      * different rules are followed to check CR3 and it is desirable for the caller
      to distinguish between the possible failures
      * PDPTRs are not loaded if PAE paging and nested EPT are both enabled
      * many MMU operations are not necessary
      
      This patch introduces nested_vmx_load_cr3 suitable for CR3 loads as part of
      nested vmentry and vmexit, and makes use of it on the nested vmentry path.
      Signed-off-by: NLadi Prosek <lprosek@redhat.com>
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      9ed38ffa
    • K
      KVM: x86: Do not clear RFLAGS.TF when a singlestep trap occurs. · ea07e42d
      Kyle Huey 提交于
      The trap flag stays set until software clears it.
      Signed-off-by: NKyle Huey <khuey@kylehuey.com>
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      ea07e42d
    • K
      KVM: x86: Add kvm_skip_emulated_instruction and use it. · 6affcbed
      Kyle Huey 提交于
      kvm_skip_emulated_instruction calls both
      kvm_x86_ops->skip_emulated_instruction and kvm_vcpu_check_singlestep,
      skipping the emulated instruction and generating a trap if necessary.
      
      Replacing skip_emulated_instruction calls with
      kvm_skip_emulated_instruction is straightforward, except for:
      
      - ICEBP, which is already inside a trap, so avoid triggering another trap.
      - Instructions that can trigger exits to userspace, such as the IO insns,
        MOVs to CR8, and HALT. If kvm_skip_emulated_instruction does trigger a
        KVM_GUESTDBG_SINGLESTEP exit, and the handling code for
        IN/OUT/MOV CR8/HALT also triggers an exit to userspace, the latter will
        take precedence. The singlestep will be triggered again on the next
        instruction, which is the current behavior.
      - Task switch instructions which would require additional handling (e.g.
        the task switch bit) and are instead left alone.
      - Cases where VMLAUNCH/VMRESUME do not proceed to the next instruction,
        which do not trigger singlestep traps as mentioned previously.
      Signed-off-by: NKyle Huey <khuey@kylehuey.com>
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      6affcbed
  9. 25 11月, 2016 1 次提交
  10. 23 11月, 2016 1 次提交
  11. 22 11月, 2016 1 次提交
    • P
      x86/kvm: Support the vCPU preemption check · 0b9f6c46
      Pan Xinhui 提交于
      Support the vcpu_is_preempted() functionality under KVM. This will
      enhance lock performance on overcommitted hosts (more runnable vCPUs
      than physical CPUs in the system) as doing busy waits for preempted
      vCPUs will hurt system performance far worse than early yielding.
      
      Use struct kvm_steal_time::preempted to indicate that if a vCPU
      is running or not.
      Signed-off-by: NPan Xinhui <xinhui.pan@linux.vnet.ibm.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
      Cc: David.Laight@ACULAB.COM
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: benh@kernel.crashing.org
      Cc: boqun.feng@gmail.com
      Cc: borntraeger@de.ibm.com
      Cc: bsingharora@gmail.com
      Cc: dave@stgolabs.net
      Cc: jgross@suse.com
      Cc: kernellwp@gmail.com
      Cc: konrad.wilk@oracle.com
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: mpe@ellerman.id.au
      Cc: paulmck@linux.vnet.ibm.com
      Cc: paulus@samba.org
      Cc: rkrcmar@redhat.com
      Cc: virtualization@lists.linux-foundation.org
      Cc: will.deacon@arm.com
      Cc: xen-devel-request@lists.xenproject.org
      Cc: xen-devel@lists.xenproject.org
      Link: http://lkml.kernel.org/r/1478077718-37424-9-git-send-email-xinhui.pan@linux.vnet.ibm.com
      [ Typo fixes. ]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      0b9f6c46
  12. 20 11月, 2016 4 次提交
  13. 17 11月, 2016 2 次提交
  14. 04 11月, 2016 1 次提交
  15. 03 11月, 2016 3 次提交
  16. 01 11月, 2016 1 次提交
    • A
      x86/fpu, kvm: Remove host CR0.TS manipulation · 04ac88ab
      Andy Lutomirski 提交于
      Now that x86 always uses eager FPU switching on the host, there's no
      need for KVM to manipulate the host's CR0.TS.
      
      This should be both simpler and faster.
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: kvm list <kvm@vger.kernel.org>
      Link: http://lkml.kernel.org/r/b212064922537c05d0c81d931fc4dbe769127ce7.1477951965.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      04ac88ab
  17. 28 10月, 2016 2 次提交
  18. 20 10月, 2016 1 次提交
  19. 07 10月, 2016 2 次提交
  20. 20 9月, 2016 1 次提交