1. 05 12月, 2012 2 次提交
  2. 01 12月, 2012 2 次提交
    • W
      KVM: x86: Emulate IA32_TSC_ADJUST MSR · ba904635
      Will Auld 提交于
      CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported
      
      Basic design is to emulate the MSR by allowing reads and writes to a guest
      vcpu specific location to store the value of the emulated MSR while adding
      the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will
      be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This
      is of course as long as the "use TSC counter offsetting" VM-execution control
      is enabled as well as the IA32_TSC_ADJUST control.
      
      However, because hardware will only return the TSC + IA32_TSC_ADJUST +
      vmsc tsc_offset for a guest process when it does and rdtsc (with the correct
      settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one
      of these three locations. The argument against storing it in the actual MSR
      is performance. This is likely to be seldom used while the save/restore is
      required on every transition. IA32_TSC_ADJUST was created as a way to solve
      some issues with writing TSC itself so that is not an option either.
      
      The remaining option, defined above as our solution has the problem of
      returning incorrect vmcs tsc_offset values (unless we intercept and fix, not
      done here) as mentioned above. However, more problematic is that storing the
      data in vmcs tsc_offset will have a different semantic effect on the system
      than does using the actual MSR. This is illustrated in the following example:
      
      The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest
      process performs a rdtsc. In this case the guest process will get
      TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including
      IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics
      as seen by the guest do not and hence this will not cause a problem.
      Signed-off-by: NWill Auld <will.auld@intel.com>
      Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      ba904635
    • W
      KVM: x86: Add code to track call origin for msr assignment · 8fe8ab46
      Will Auld 提交于
      In order to track who initiated the call (host or guest) to modify an msr
      value I have changed function call parameters along the call path. The
      specific change is to add a struct pointer parameter that points to (index,
      data, caller) information rather than having this information passed as
      individual parameters.
      
      The initial use for this capability is for updating the IA32_TSC_ADJUST msr
      while setting the tsc value. It is anticipated that this capability is
      useful for other tasks.
      Signed-off-by: NWill Auld <will.auld@intel.com>
      Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      8fe8ab46
  3. 30 11月, 2012 1 次提交
  4. 29 11月, 2012 1 次提交
  5. 28 11月, 2012 2 次提交
  6. 18 10月, 2012 2 次提交
  7. 23 9月, 2012 1 次提交
    • J
      KVM: x86: Fix guest debug across vcpu INIT reset · c8639010
      Jan Kiszka 提交于
      If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
      KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.
      
      Fix this by saving the dr7 used for guest debugging and calculating the
      effective register value as well as switch_db_regs on any potential
      change. This will change to focus of the set_guest_debug vendor op to
      update_dp_bp_intercept.
      
      Found while trying to stop on start_secondary.
      Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      c8639010
  8. 22 9月, 2012 1 次提交
    • S
      x86, kvm: fix kvm's usage of kernel_fpu_begin/end() · b1a74bf8
      Suresh Siddha 提交于
      Preemption is disabled between kernel_fpu_begin/end() and as such
      it is not a good idea to use these routines in kvm_load/put_guest_fpu()
      which can be very far apart.
      
      kvm_load/put_guest_fpu() routines are already called with
      preemption disabled and KVM already uses the preempt notifier to save
      the guest fpu state using kvm_put_guest_fpu().
      
      So introduce __kernel_fpu_begin/end() routines which don't touch
      preemption and use them instead of kernel_fpu_begin/end()
      for KVM's use model of saving/restoring guest FPU state.
      
      Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit
      state in the case of VMX. For eagerFPU case, host cr0.TS is always clear.
      So no need to worry about it. For the traditional lazyFPU restore case,
      change the cr0.TS bit for the host state during vm-exit to be always clear
      and cr0.TS bit is set in the __vmx_load_host_state() when the FPU
      (guest FPU or the host task's FPU) state is not active. This ensures
      that the host/guest FPU state is properly saved, restored
      during context-switch and with interrupts (using irq_fpu_usable()) not
      stomping on the active FPU state.
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
      Cc: Avi Kivity <avi@redhat.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      b1a74bf8
  9. 19 9月, 2012 1 次提交
  10. 17 9月, 2012 2 次提交
  11. 10 9月, 2012 1 次提交
    • X
      KVM: fix error paths for failed gfn_to_page() calls · 4484141a
      Xiao Guangrong 提交于
      This bug was triggered:
      [ 4220.198458] BUG: unable to handle kernel paging request at fffffffffffffffe
      [ 4220.203907] IP: [<ffffffff81104d85>] put_page+0xf/0x34
      ......
      [ 4220.237326] Call Trace:
      [ 4220.237361]  [<ffffffffa03830d0>] kvm_arch_destroy_vm+0xf9/0x101 [kvm]
      [ 4220.237382]  [<ffffffffa036fe53>] kvm_put_kvm+0xcc/0x127 [kvm]
      [ 4220.237401]  [<ffffffffa03702bc>] kvm_vcpu_release+0x18/0x1c [kvm]
      [ 4220.237407]  [<ffffffff81145425>] __fput+0x111/0x1ed
      [ 4220.237411]  [<ffffffff8114550f>] ____fput+0xe/0x10
      [ 4220.237418]  [<ffffffff81063511>] task_work_run+0x5d/0x88
      [ 4220.237424]  [<ffffffff8104c3f7>] do_exit+0x2bf/0x7ca
      
      The test case:
      
      	printf(fmt, ##args);		\
      	exit(-1);} while (0)
      
      static int create_vm(void)
      {
      	int sys_fd, vm_fd;
      
      	sys_fd = open("/dev/kvm", O_RDWR);
      	if (sys_fd < 0)
      		die("open /dev/kvm fail.\n");
      
      	vm_fd = ioctl(sys_fd, KVM_CREATE_VM, 0);
      	if (vm_fd < 0)
      		die("KVM_CREATE_VM fail.\n");
      
      	return vm_fd;
      }
      
      static int create_vcpu(int vm_fd)
      {
      	int vcpu_fd;
      
      	vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);
      	if (vcpu_fd < 0)
      		die("KVM_CREATE_VCPU ioctl.\n");
      	printf("Create vcpu.\n");
      	return vcpu_fd;
      }
      
      static void *vcpu_thread(void *arg)
      {
      	int vm_fd = (int)(long)arg;
      
      	create_vcpu(vm_fd);
      	return NULL;
      }
      
      int main(int argc, char *argv[])
      {
      	pthread_t thread;
      	int vm_fd;
      
      	(void)argc;
      	(void)argv;
      
      	vm_fd = create_vm();
      	pthread_create(&thread, NULL, vcpu_thread, (void *)(long)vm_fd);
      	printf("Exit.\n");
      	return 0;
      }
      
      It caused by release kvm->arch.ept_identity_map_addr which is the
      error page.
      
      The parent thread can send KILL signal to the vcpu thread when it was
      exiting which stops faulting pages and potentially allocating memory.
      So gfn_to_pfn/gfn_to_page may fail at this time
      
      Fixed by checking the page before it is used
      Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      4484141a
  12. 09 9月, 2012 1 次提交
  13. 05 9月, 2012 1 次提交
  14. 28 8月, 2012 10 次提交
  15. 14 8月, 2012 2 次提交
  16. 06 8月, 2012 1 次提交
  17. 02 8月, 2012 1 次提交
    • A
      KVM: VMX: Fix ds/es corruption on i386 with preemption · aa67f609
      Avi Kivity 提交于
      Commit b2da15ac ("KVM: VMX: Optimize %ds, %es reload") broke i386
      in the following scenario:
      
        vcpu_load
        ...
        vmx_save_host_state
        vmx_vcpu_run
        (ds.rpl, es.rpl cleared by hardware)
      
        interrupt
          push ds, es  # pushes bad ds, es
          schedule
            vmx_vcpu_put
              vmx_load_host_state
                reload ds, es (with __USER_DS)
          pop ds, es  # of other thread's stack
          iret
        # other thread runs
        interrupt
          push ds, es
          schedule  # back in vcpu thread
          pop ds, es  # now with rpl=0
          iret
        ...
        vcpu_put
        resume_userspace
        iret  # clears ds, es due to mismatched rpl
      
      (instead of resume_userspace, we might return with SYSEXIT and then
      take an exception; when the exception IRETs we end up with cleared
      ds, es)
      
      Fix by avoiding the optimization on i386 and reloading ds, es on the
      lightweight exit path.
      Reported-by: NChris Clayron <chris2553@googlemail.com>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      aa67f609
  18. 21 7月, 2012 1 次提交
  19. 12 7月, 2012 1 次提交
    • M
      KVM: VMX: Implement PCID/INVPCID for guests with EPT · ad756a16
      Mao, Junjie 提交于
      This patch handles PCID/INVPCID for guests.
      
      Process-context identifiers (PCIDs) are a facility by which a logical processor
      may cache information for multiple linear-address spaces so that the processor
      may retain cached information when software switches to a different linear
      address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual
      Volume 3A for details.
      
      For guests with EPT, the PCID feature is enabled and INVPCID behaves as running
      natively.
      For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD.
      Signed-off-by: NJunjie Mao <junjie.mao@intel.com>
      Signed-off-by: NAvi Kivity <avi@redhat.com>
      ad756a16
  20. 11 7月, 2012 1 次提交
  21. 09 7月, 2012 5 次提交