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* KVM: X86: Fix read out-of-bounds vulnerability in kvm pio emulationWanpeng Li2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit cbfc6c9184ce71b52df4b1d82af5afc81a709178 upstream. Huawei folks reported a read out-of-bounds vulnerability in kvm pio emulation. - "inb" instruction to access PIT Mod/Command register (ioport 0x43, write only, a read should be ignored) in guest can get a random number. - "rep insb" instruction to access PIT register port 0x43 can control memcpy() in emulator_pio_in_emulated() to copy max 0x400 bytes but only read 1 bytes, which will disclose the unimportant kernel memory in host but no crash. The similar test program below can reproduce the read out-of-bounds vulnerability: void hexdump(void *mem, unsigned int len) { unsigned int i, j; for(i = 0; i < len + ((len % HEXDUMP_COLS) ? (HEXDUMP_COLS - len % HEXDUMP_COLS) : 0); i++) { /* print offset */ if(i % HEXDUMP_COLS == 0) { printf("0x%06x: ", i); } /* print hex data */ if(i < len) { printf("%02x ", 0xFF & ((char*)mem)[i]); } else /* end of block, just aligning for ASCII dump */ { printf(" "); } /* print ASCII dump */ if(i % HEXDUMP_COLS == (HEXDUMP_COLS - 1)) { for(j = i - (HEXDUMP_COLS - 1); j <= i; j++) { if(j >= len) /* end of block, not really printing */ { putchar(' '); } else if(isprint(((char*)mem)[j])) /* printable char */ { putchar(0xFF & ((char*)mem)[j]); } else /* other char */ { putchar('.'); } } putchar('\n'); } } } int main(void) { int i; if (iopl(3)) { err(1, "set iopl unsuccessfully\n"); return -1; } static char buf[0x40]; /* test ioport 0x40,0x41,0x42,0x43,0x44,0x45 */ memset(buf, 0xab, sizeof(buf)); asm volatile("push %rdi;"); asm volatile("mov %0, %%rdi;"::"q"(buf)); asm volatile ("mov $0x40, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x41, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x42, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x43, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x44, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("mov $0x45, %rdx;"); asm volatile ("in %dx,%al;"); asm volatile ("stosb;"); asm volatile ("pop %rdi;"); hexdump(buf, 0x40); printf("\n"); /* ins port 0x40 */ memset(buf, 0xab, sizeof(buf)); asm volatile("push %rdi;"); asm volatile("mov %0, %%rdi;"::"q"(buf)); asm volatile ("mov $0x20, %rcx;"); asm volatile ("mov $0x40, %rdx;"); asm volatile ("rep insb;"); asm volatile ("pop %rdi;"); hexdump(buf, 0x40); printf("\n"); /* ins port 0x43 */ memset(buf, 0xab, sizeof(buf)); asm volatile("push %rdi;"); asm volatile("mov %0, %%rdi;"::"q"(buf)); asm volatile ("mov $0x20, %rcx;"); asm volatile ("mov $0x43, %rdx;"); asm volatile ("rep insb;"); asm volatile ("pop %rdi;"); hexdump(buf, 0x40); printf("\n"); return 0; } The vcpu->arch.pio_data buffer is used by both in/out instrutions emulation w/o clear after using which results in some random datas are left over in the buffer. Guest reads port 0x43 will be ignored since it is write only, however, the function kernel_pio() can't distigush this ignore from successfully reads data from device's ioport. There is no new data fill the buffer from port 0x43, however, emulator_pio_in_emulated() will copy the stale data in the buffer to the guest unconditionally. This patch fixes it by clearing the buffer before in instruction emulation to avoid to grant guest the stale data in the buffer. In addition, string I/O is not supported for in kernel device. So there is no iteration to read ioport %RCX times for string I/O. The function kernel_pio() just reads one round, and then copy the io size * %RCX to the guest unconditionally, actually it copies the one round ioport data w/ other random datas which are left over in the vcpu->arch.pio_data buffer to the guest. This patch fixes it by introducing the string I/O support for in kernel device in order to grant the right ioport datas to the guest. Before the patch: 0x000000: fe 38 93 93 ff ff ab ab .8...... 0x000008: ab ab ab ab ab ab ab ab ........ 0x000010: ab ab ab ab ab ab ab ab ........ 0x000018: ab ab ab ab ab ab ab ab ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: f6 00 00 00 00 00 00 00 ........ 0x000008: 00 00 00 00 00 00 00 00 ........ 0x000010: 00 00 00 00 4d 51 30 30 ....MQ00 0x000018: 30 30 20 33 20 20 20 20 00 3 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: f6 00 00 00 00 00 00 00 ........ 0x000008: 00 00 00 00 00 00 00 00 ........ 0x000010: 00 00 00 00 4d 51 30 30 ....MQ00 0x000018: 30 30 20 33 20 20 20 20 00 3 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ After the patch: 0x000000: 1e 02 f8 00 ff ff ab ab ........ 0x000008: ab ab ab ab ab ab ab ab ........ 0x000010: ab ab ab ab ab ab ab ab ........ 0x000018: ab ab ab ab ab ab ab ab ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: d2 e2 d2 df d2 db d2 d7 ........ 0x000008: d2 d3 d2 cf d2 cb d2 c7 ........ 0x000010: d2 c4 d2 c0 d2 bc d2 b8 ........ 0x000018: d2 b4 d2 b0 d2 ac d2 a8 ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ 0x000000: 00 00 00 00 00 00 00 00 ........ 0x000008: 00 00 00 00 00 00 00 00 ........ 0x000010: 00 00 00 00 00 00 00 00 ........ 0x000018: 00 00 00 00 00 00 00 00 ........ 0x000020: ab ab ab ab ab ab ab ab ........ 0x000028: ab ab ab ab ab ab ab ab ........ 0x000030: ab ab ab ab ab ab ab ab ........ 0x000038: ab ab ab ab ab ab ab ab ........ Reported-by: Moguofang <moguofang@huawei.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Moguofang <moguofang@huawei.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: Fix potential preemption when get the current kvmclock timestampWanpeng Li2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e2c2206a18993bc9f62393d49c7b2066c3845b25 upstream. BUG: using __this_cpu_read() in preemptible [00000000] code: qemu-system-x86/2809 caller is __this_cpu_preempt_check+0x13/0x20 CPU: 2 PID: 2809 Comm: qemu-system-x86 Not tainted 4.11.0+ #13 Call Trace: dump_stack+0x99/0xce check_preemption_disabled+0xf5/0x100 __this_cpu_preempt_check+0x13/0x20 get_kvmclock_ns+0x6f/0x110 [kvm] get_time_ref_counter+0x5d/0x80 [kvm] kvm_hv_process_stimers+0x2a1/0x8a0 [kvm] ? kvm_hv_process_stimers+0x2a1/0x8a0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xac9/0x1ce0 [kvm] kvm_arch_vcpu_ioctl_run+0x5bf/0x1ce0 [kvm] kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? __fget+0xf3/0x210 do_vfs_ioctl+0xa4/0x700 ? __fget+0x114/0x210 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 RIP: 0033:0x7f9d164ed357 ? __this_cpu_preempt_check+0x13/0x20 This can be reproduced by run kvm-unit-tests/hyperv_stimer.flat w/ CONFIG_PREEMPT and CONFIG_DEBUG_PREEMPT enabled. Safe access to per-CPU data requires a couple of constraints, though: the thread working with the data cannot be preempted and it cannot be migrated while it manipulates per-CPU variables. If the thread is preempted, the thread that replaces it could try to work with the same variables; migration to another CPU could also cause confusion. However there is no preemption disable when reads host per-CPU tsc rate to calculate the current kvmclock timestamp. This patch fixes it by utilizing get_cpu/put_cpu pair to guarantee both __this_cpu_read() and rdtsc() are not preempted. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: Fix load damaged SSEx MXCSR registerWanpeng Li2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a575813bfe4bc15aba511a5e91e61d242bff8b9d upstream. Reported by syzkaller: BUG: unable to handle kernel paging request at ffffffffc07f6a2e IP: report_bug+0x94/0x120 PGD 348e12067 P4D 348e12067 PUD 348e14067 PMD 3cbd84067 PTE 80000003f7e87161 Oops: 0003 [#1] SMP CPU: 2 PID: 7091 Comm: kvm_load_guest_ Tainted: G OE 4.11.0+ #8 task: ffff92fdfb525400 task.stack: ffffbda6c3d04000 RIP: 0010:report_bug+0x94/0x120 RSP: 0018:ffffbda6c3d07b20 EFLAGS: 00010202 do_trap+0x156/0x170 do_error_trap+0xa3/0x170 ? kvm_load_guest_fpu.part.175+0x12a/0x170 [kvm] ? mark_held_locks+0x79/0xa0 ? retint_kernel+0x10/0x10 ? trace_hardirqs_off_thunk+0x1a/0x1c do_invalid_op+0x20/0x30 invalid_op+0x1e/0x30 RIP: 0010:kvm_load_guest_fpu.part.175+0x12a/0x170 [kvm] ? kvm_load_guest_fpu.part.175+0x1c/0x170 [kvm] kvm_arch_vcpu_ioctl_run+0xed6/0x1b70 [kvm] kvm_vcpu_ioctl+0x384/0x780 [kvm] ? kvm_vcpu_ioctl+0x384/0x780 [kvm] ? sched_clock+0x13/0x20 ? __do_page_fault+0x2a0/0x550 do_vfs_ioctl+0xa4/0x700 ? up_read+0x1f/0x40 ? __do_page_fault+0x2a0/0x550 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 SDM mentioned that "The MXCSR has several reserved bits, and attempting to write a 1 to any of these bits will cause a general-protection exception(#GP) to be generated". The syzkaller forks' testcase overrides xsave area w/ random values and steps on the reserved bits of MXCSR register. The damaged MXCSR register values of guest will be restored to SSEx MXCSR register before vmentry. This patch fixes it by catching userspace override MXCSR register reserved bits w/ random values and bails out immediately. Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: fix user triggerable warning in kvm_apic_accept_events()David Hildenbrand2017-05-20
| | | | | | | | | | | | | | | | | | commit 28bf28887976d8881a3a59491896c718fade7355 upstream. If we already entered/are about to enter SMM, don't allow switching to INIT/SIPI_RECEIVED, otherwise the next call to kvm_apic_accept_events() will report a warning. Same applies if we are already in MP state INIT_RECEIVED and SMM is requested to be turned on. Refuse to set the VCPU events in this case. Fixes: cd7764fe9f73 ("KVM: x86: latch INITs while in system management mode") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: do not leak PML full vmexit to L1Ladi Prosek2017-05-14
| | | | | | | | | | | | | | | | | commit ab007cc94ff9d82f5a8db8363b3becbd946e58cf upstream. The PML feature is not exposed to guests so we should not be forwarding the vmexit either. This commit fixes BSOD 0x20001 (HYPERVISOR_ERROR) when running Hyper-V enabled Windows Server 2016 in L1 on hardware that supports PML. Fixes: 843e4330573c ("KVM: VMX: Add PML support in VMX") Signed-off-by: Ladi Prosek <lprosek@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: initialize PML fields in vmcs02Ladi Prosek2017-05-14
| | | | | | | | | | | | | | commit 1fb883bb827ee8efc1cc9ea0154f953f8a219d38 upstream. L2 was running with uninitialized PML fields which led to incomplete dirty bitmap logging. This manifested as all kinds of subtle erratic behavior of the nested guest. Fixes: 843e4330573c ("KVM: VMX: Add PML support in VMX") Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "KVM: nested VMX: disable perf cpuid reporting"Jim Mattson2017-05-14
| | | | | | | | | | | | | | | | | commit 0b4c208d443ba2af82b4c70f99ca8df31e9a0020 upstream. This reverts commit bc6134942dbbf31c25e9bd7c876be5da81c9e1ce. A CPUID instruction executed in VMX non-root mode always causes a VM-exit, regardless of the leaf being queried. Fixes: bc6134942dbb ("KVM: nested VMX: disable perf cpuid reporting") Signed-off-by: Jim Mattson <jmattson@google.com> [The issue solved by bc6134942dbb has been resolved with ff651cb613b4 ("KVM: nVMX: Add nested msr load/restore algorithm").] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: fix page struct leak in handle_vmonPaolo Bonzini2017-04-21
| | | | | | | | | | | | | | | commit 06ce521af9558814b8606c0476c54497cf83a653 upstream. handle_vmon gets a reference on VMXON region page, but does not release it. Release the reference. Found by syzkaller; based on a patch by Dmitry. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: use skip_emulated_instruction()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: cleanup the page tracking SRCU instancePaolo Bonzini2017-03-31
| | | | | | | | | | | | | | | commit 2beb6dad2e8f95d710159d5befb390e4f62ab5cf upstream. SRCU uses a delayed work item. Skip cleaning it up, and the result is use-after-free in the work item callbacks. Reported-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 0eb05bf290cfe8610d9680b49abef37febd1c38a Reviewed-by: Xiao Guangrong <xiaoguangrong.eric@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: VMX: use correct vmcs_read/write for guest segment selector/baseChao Peng2017-03-14
| | | | | | | | | | | | | | commit 96794e4ed4d758272c486e1529e431efb7045265 upstream. Guest segment selector is 16 bit field and guest segment base is natural width field. Fix two incorrect invocations accordingly. Without this patch, build fails when aggressive inlining is used with ICC. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: do not save guest-unsupported XSAVE stateRadim Krčmář2017-02-09
| | | | | | | | | | | | | | | | | | commit 00c87e9a70a17b355b81c36adedf05e84f54e10d upstream. Saving unsupported state prevents migration when the new host does not support a XSAVE feature of the original host, even if the feature is not exposed to the guest. We've masked host features with guest-visible features before, with 4344ee981e21 ("KVM: x86: only copy XSAVE state for the supported features") and dropped it when implementing XSAVES. Do it again. Fixes: df1daba7d1cb ("KVM: x86: support XSAVES usage in the host") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: Introduce segmented_write_stdSteve Rutherford2017-01-19
| | | | | | | | | | | | | | | | | | | | | | | commit 129a72a0d3c8e139a04512325384fe5ac119e74d upstream. Introduces segemented_write_std. Switches from emulated reads/writes to standard read/writes in fxsave, fxrstor, sgdt, and sidt. This fixes CVE-2017-2584, a longstanding kernel memory leak. Since commit 283c95d0e389 ("KVM: x86: emulate FXSAVE and FXRSTOR", 2016-11-09), which is luckily not yet in any final release, this would also be an exploitable kernel memory *write*! Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 96051572c819194c37a8367624b285be10297eca Fixes: 283c95d0e3891b64087706b344a4b545d04a6e62 Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: emulate FXSAVE and FXRSTORRadim Krčmář2017-01-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 283c95d0e3891b64087706b344a4b545d04a6e62 upstream. Internal errors were reported on 16 bit fxsave and fxrstor with ipxe. Old Intels don't have unrestricted_guest, so we have to emulate them. The patch takes advantage of the hardware implementation. AMD and Intel differ in saving and restoring other fields in first 32 bytes. A test wrote 0xff to the fxsave area, 0 to upper bits of MCSXR in the fxsave area, executed fxrstor, rewrote the fxsave area to 0xee, and executed fxsave: Intel (Nehalem): 7f 1f 7f 7f ff 00 ff 07 ff ff ff ff ff ff 00 00 ff ff ff ff ff ff 00 00 ff ff 00 00 ff ff 00 00 Intel (Haswell -- deprecated FPU CS and FPU DS): 7f 1f 7f 7f ff 00 ff 07 ff ff ff ff 00 00 00 00 ff ff ff ff 00 00 00 00 ff ff 00 00 ff ff 00 00 AMD (Opteron 2300-series): 7f 1f 7f 7f ff 00 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ff ff 00 00 ff ff 02 00 fxsave/fxrstor will only be emulated on early Intels, so KVM can't do much to improve the situation. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: add asm_safe wrapperRadim Krčmář2017-01-19
| | | | | | | | | | | | commit aabba3c6abd50b05b1fc2c6ec44244aa6bcda576 upstream. Move the existing exception handling for inline assembly into a macro and switch its return values to X86EMUL type. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: add Align16 instruction flagRadim Krčmář2017-01-19
| | | | | | | | | | | commit d3fe959f81024072068e9ed86b39c2acfd7462a9 upstream. Needed for FXSAVE and FXRSTOR. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: fix NULL deref in vcpu_scan_ioapicWanpeng Li2017-01-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 546d87e5c903a7f3ee7b9f998949a94729fbc65b upstream. 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: Dmitry Vyukov <dvyukov@google.com> Fixes: 5c919412fe61 (kvm/x86: Hyper-V synthetic interrupt controller) Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: flush pending lapic jump label updates on module unloadDavid Matlack2017-01-19
| | | | | | | | | | | | | | | | | commit cef84c302fe051744b983a92764d3fcca933415d upstream. 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: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: fix emulation of "MOV SS, null selector"Paolo Bonzini2017-01-19
| | | | | | | | | | | | | | | | | | | | | | | commit 33ab91103b3415e12457e3104f0e4517ce12d0f3 upstream. This is CVE-2017-2583. On Intel this causes a failed vmentry because SS's type is neither 3 nor 7 (even though the manual says this check is only done for usable SS, and the dmesg splat says that SS is unusable!). On AMD it's worse: svm.c is confused and sets CPL to 0 in the vmcb. The fix fabricates a data segment descriptor when SS is set to a null selector, so that CPL and SS.DPL are set correctly in the VMCS/vmcb. Furthermore, only allow setting SS to a NULL selector if SS.RPL < 3; this in turn ensures CPL < 3 because RPL must be equal to CPL. Thanks to Andy Lutomirski and Willy Tarreau for help in analyzing the bug and deciphering the manuals. Reported-by: Xiaohan Zhang <zhangxiaohan1@huawei.com> Fixes: 79d5b4c3cd809c770d4bf9812635647016c56011 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: reset MMU on KVM_SET_VCPU_EVENTSXiao Guangrong2017-01-12
| | | | | | | | | | | | commit 6ef4e07ecd2db21025c446327ecf34414366498b upstream. Otherwise, mismatch between the smm bit in hflags and the MMU role can cause a NULL pointer dereference. Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: nVMX: Allow L1 to intercept software exceptions (#BP and #OF)Jim Mattson2017-01-09
| | | | | | | | | | | | | | commit ef85b67385436ddc1998f45f1d6a210f935b3388 upstream. When L2 exits to L0 due to "exception or NMI", software exceptions (#BP and #OF) for which L1 has requested an intercept should be handled by L1 rather than L0. Previously, only hardware exceptions were forwarded to L1. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: check for pic and ioapic presence before useRadim Krčmář2016-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split irqchip allows pic and ioapic routes to be used without them being created, which results in NULL access. Check for NULL and avoid it. (The setup is too racy for a nicer solutions.) Found by syzkaller: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 3 PID: 11923 Comm: kworker/3:2 Not tainted 4.9.0-rc5+ #27 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: events irqfd_inject task: ffff88006a06c7c0 task.stack: ffff880068638000 RIP: 0010:[...] [...] __lock_acquire+0xb35/0x3380 kernel/locking/lockdep.c:3221 RSP: 0000:ffff88006863ea20 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000039 RSI: 0000000000000000 RDI: 1ffff1000d0c7d9e RBP: ffff88006863ef58 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000000001c8 R11: 0000000000000000 R12: ffff88006a06c7c0 R13: 0000000000000001 R14: ffffffff8baab1a0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004abdd0 CR3: 000000003e2f2000 CR4: 00000000000026e0 Stack: ffffffff894d0098 1ffff1000d0c7d56 ffff88006863ecd0 dffffc0000000000 ffff88006a06c7c0 0000000000000000 ffff88006863ecf8 0000000000000082 0000000000000000 ffffffff815dd7c1 ffffffff00000000 ffffffff00000000 Call Trace: [...] lock_acquire+0x2a2/0x790 kernel/locking/lockdep.c:3746 [...] __raw_spin_lock include/linux/spinlock_api_smp.h:144 [...] _raw_spin_lock+0x38/0x50 kernel/locking/spinlock.c:151 [...] spin_lock include/linux/spinlock.h:302 [...] kvm_ioapic_set_irq+0x4c/0x100 arch/x86/kvm/ioapic.c:379 [...] kvm_set_ioapic_irq+0x8f/0xc0 arch/x86/kvm/irq_comm.c:52 [...] kvm_set_irq+0x239/0x640 arch/x86/kvm/../../../virt/kvm/irqchip.c:101 [...] irqfd_inject+0xb4/0x150 arch/x86/kvm/../../../virt/kvm/eventfd.c:60 [...] process_one_work+0xb40/0x1ba0 kernel/workqueue.c:2096 [...] worker_thread+0x214/0x18a0 kernel/workqueue.c:2230 [...] kthread+0x328/0x3e0 kernel/kthread.c:209 [...] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Fixes: 49df6397edfc ("KVM: x86: Split the APIC from the rest of IRQCHIP.") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: fix out-of-bounds accesses of rtc_eoi mapRadim Krčmář2016-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM was using arrays of size KVM_MAX_VCPUS with vcpu_id, but ID can be bigger that the maximal number of VCPUs, resulting in out-of-bounds access. Found by syzkaller: BUG: KASAN: slab-out-of-bounds in __apic_accept_irq+0xb33/0xb50 at addr [...] Write of size 1 by task a.out/27101 CPU: 1 PID: 27101 Comm: a.out Not tainted 4.9.0-rc5+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [...] Call Trace: [...] __apic_accept_irq+0xb33/0xb50 arch/x86/kvm/lapic.c:905 [...] kvm_apic_set_irq+0x10e/0x180 arch/x86/kvm/lapic.c:495 [...] kvm_irq_delivery_to_apic+0x732/0xc10 arch/x86/kvm/irq_comm.c:86 [...] ioapic_service+0x41d/0x760 arch/x86/kvm/ioapic.c:360 [...] ioapic_set_irq+0x275/0x6c0 arch/x86/kvm/ioapic.c:222 [...] kvm_ioapic_inject_all arch/x86/kvm/ioapic.c:235 [...] kvm_set_ioapic+0x223/0x310 arch/x86/kvm/ioapic.c:670 [...] kvm_vm_ioctl_set_irqchip arch/x86/kvm/x86.c:3668 [...] kvm_arch_vm_ioctl+0x1a08/0x23c0 arch/x86/kvm/x86.c:3999 [...] kvm_vm_ioctl+0x1fa/0x1a70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3099 Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Fixes: af1bae5497b9 ("KVM: x86: bump KVM_MAX_VCPU_ID to 1023") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: drop error recovery in em_jmp_far and em_ret_farRadim Krčmář2016-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | em_jmp_far and em_ret_far assumed that setting IP can only fail in 64 bit mode, but syzkaller proved otherwise (and SDM agrees). Code segment was restored upon failure, but it was left uninitialized outside of long mode, which could lead to a leak of host kernel stack. We could have fixed that by always saving and restoring the CS, but we take a simpler approach and just break any guest that manages to fail as the error recovery is error-prone and modern CPUs don't need emulator for this. Found by syzkaller: WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480 Kernel panic - not syncing: panic_on_warn set ... CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [...] Call Trace: [...] __dump_stack lib/dump_stack.c:15 [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51 [...] panic+0x1b7/0x3a3 kernel/panic.c:179 [...] __warn+0x1c4/0x1e0 kernel/panic.c:542 [...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217 [...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227 [...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294 [...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545 [...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116 [...] complete_emulated_io arch/x86/kvm/x86.c:6870 [...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934 [...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978 [...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557 [...] vfs_ioctl fs/ioctl.c:43 [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679 [...] SYSC_ioctl fs/ioctl.c:694 [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [...] entry_SYSCALL_64_fastpath+0x1f/0xc2 Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Fixes: d1442d85cc30 ("KVM: x86: Handle errors when RIP is set during far jumps") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: fix out-of-bounds access in lapicRadim Krčmář2016-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cluster xAPIC delivery incorrectly assumed that dest_id <= 0xff. With enabled KVM_X2APIC_API_USE_32BIT_IDS in KVM_CAP_X2APIC_API, a userspace can send an interrupt with dest_id that results in out-of-bounds access. Found by syzkaller: BUG: KASAN: slab-out-of-bounds in kvm_irq_delivery_to_apic_fast+0x11fa/0x1210 at addr ffff88003d9ca750 Read of size 8 by task syz-executor/22923 CPU: 0 PID: 22923 Comm: syz-executor Not tainted 4.9.0-rc4+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [...] Call Trace: [...] __dump_stack lib/dump_stack.c:15 [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51 [...] kasan_object_err+0x1c/0x70 mm/kasan/report.c:156 [...] print_address_description mm/kasan/report.c:194 [...] kasan_report_error mm/kasan/report.c:283 [...] kasan_report+0x231/0x500 mm/kasan/report.c:303 [...] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:329 [...] kvm_irq_delivery_to_apic_fast+0x11fa/0x1210 arch/x86/kvm/lapic.c:824 [...] kvm_irq_delivery_to_apic+0x132/0x9a0 arch/x86/kvm/irq_comm.c:72 [...] kvm_set_msi+0x111/0x160 arch/x86/kvm/irq_comm.c:157 [...] kvm_send_userspace_msi+0x201/0x280 arch/x86/kvm/../../../virt/kvm/irqchip.c:74 [...] kvm_vm_ioctl+0xba5/0x1670 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3015 [...] vfs_ioctl fs/ioctl.c:43 [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679 [...] SYSC_ioctl fs/ioctl.c:694 [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [...] entry_SYSCALL_64_fastpath+0x1f/0xc2 Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Fixes: e45115b62f9a ("KVM: x86: use physical LAPIC array for logical x2APIC") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kvm: x86: merge kvm_arch_set_irq and kvm_arch_set_irq_inatomicPaolo Bonzini2016-11-19
| | | | | | | | | | kvm_arch_set_irq is unused since commit b97e6de9c96. Merge its functionality with kvm_arch_set_irq_inatomic. Reported-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: fix missed SRCU usage in kvm_lapic_set_vapic_addrPaolo Bonzini2016-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported by syzkaller: [ INFO: suspicious RCU usage. ] 4.9.0-rc4+ #47 Not tainted ------------------------------- ./include/linux/kvm_host.h:536 suspicious rcu_dereference_check() usage! stack backtrace: CPU: 1 PID: 6679 Comm: syz-executor Not tainted 4.9.0-rc4+ #47 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff880039e2f6d0 ffffffff81c2e46b ffff88003e3a5b40 0000000000000000 0000000000000001 ffffffff83215600 ffff880039e2f700 ffffffff81334ea9 ffffc9000730b000 0000000000000004 ffff88003c4f8420 ffff88003d3f8000 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff81c2e46b>] dump_stack+0xb3/0x118 lib/dump_stack.c:51 [<ffffffff81334ea9>] lockdep_rcu_suspicious+0x139/0x180 kernel/locking/lockdep.c:4445 [< inline >] __kvm_memslots include/linux/kvm_host.h:534 [< inline >] kvm_memslots include/linux/kvm_host.h:541 [<ffffffff8105d6ae>] kvm_gfn_to_hva_cache_init+0xa1e/0xce0 virt/kvm/kvm_main.c:1941 [<ffffffff8112685d>] kvm_lapic_set_vapic_addr+0xed/0x140 arch/x86/kvm/lapic.c:2217 Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: fda4e2e85589191b123d31cdc21fd33ee70f50fd Cc: Andrew Honig <ahonig@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kvm: kvmclock: let KVM_GET_CLOCK return whether the master clock is in usePaolo Bonzini2016-11-19
| | | | | | | | | | | | | | Userspace can read the exact value of kvmclock by reading the TSC and fetching the timekeeping parameters out of guest memory. This however is brittle and not necessary anymore with KVM 4.11. Provide a mechanism that lets userspace know if the new KVM_GET_CLOCK semantics are in effect, and---since we are at it---if the clock is stable across all VCPUs. Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: Disable irq while unregistering user notifierIgnacio Alvarado2016-11-19
| | | | | | | | | | | | | | | Function user_notifier_unregister should be called only once for each registered user notifier. Function kvm_arch_hardware_disable can be executed from an IPI context which could cause a race condition with a VCPU returning to user mode and attempting to unregister the notifier. Signed-off-by: Ignacio Alvarado <ikalvarado@google.com> Cc: stable@vger.kernel.org Fixes: 18863bdd60f8 ("KVM: x86 shared msr infrastructure") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: do not go through vcpu in __get_kvmclock_nsPaolo Bonzini2016-11-19
| | | | | | | | | | | | | | Going through the first VCPU is wrong if you follow a KVM_SET_CLOCK with a KVM_GET_CLOCK immediately after, without letting the VCPU run and call kvm_guest_time_update. To fix this, compute the kvmclock value ourselves, using the master clock (tsc, nsec) pair as the base and the host CPU frequency as the scale. Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kvm: x86: Check memopp before dereference (CVE-2016-8630)Owen Hofmann2016-11-02
| | | | | | | | | | | | Commit 41061cdb98 ("KVM: emulate: do not initialize memopp") removes a check for non-NULL under incorrect assumptions. An undefined instruction with a ModR/M byte with Mod=0 and R/M-5 (e.g. 0xc7 0x15) will attempt to dereference a null pointer here. Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 Message-Id: <1477592752-126650-2-git-send-email-osh@google.com> Signed-off-by: Owen Hofmann <osh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kvm: nVMX: VMCLEAR an active shadow VMCS after last useJim Mattson2016-11-02
| | | | | | | | | | | | | | | | | After a successful VM-entry with the "VMCS shadowing" VM-execution control set, the shadow VMCS referenced by the VMCS link pointer field in the current VMCS becomes active on the logical processor. A VMCS that is made active on more than one logical processor may become corrupted. Therefore, before an active VMCS can be migrated to another logical processor, the first logical processor must execute a VMCLEAR for the active VMCS. VMCLEAR both ensures that all VMCS data are written to memory and makes the VMCS inactive. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-By: David Matlack <dmatlack@google.com> Message-Id: <1477668579-22555-1-git-send-email-jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: drop TSC offsetting kvm_x86_ops to fix KVM_GET/SET_CLOCKPaolo Bonzini2016-11-02
| | | | | | | | | | | | | | | | | | | | | Since commit a545ab6a0085 ("kvm: x86: add tsc_offset field to struct kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is cached and need not be fished out of the VMCS or VMCB. This means that we can implement adjust_tsc_offset_guest and read_l1_tsc entirely in generic code. The simplification is particularly significant for VMX code, where vmx->nested.vmcs01_tsc_offset was duplicating what is now in vcpu->arch.tsc_offset. Therefore the vmcs01_tsc_offset can be dropped completely. More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK which, after commit 108b249c453d ("KVM: x86: introduce get_kvmclock_ns", 2016-09-01) called read_l1_tsc while the VMCS was not loaded. It thus returned bogus values on Intel CPUs. Fixes: 108b249c453dd7132599ab6dc7e435a7036c193f Reported-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: fix wbinvd_dirty_mask use-after-freeIdo Yariv2016-10-28
| | | | | | | | | | | | | | | | | | vcpu->arch.wbinvd_dirty_mask may still be used after freeing it, corrupting memory. For example, the following call trace may set a bit in an already freed cpu mask: kvm_arch_vcpu_load vcpu_load vmx_free_vcpu_nested vmx_free_vcpu kvm_arch_vcpu_free Fix this by deferring freeing of wbinvd_dirty_mask. Cc: stable@vger.kernel.org Signed-off-by: Ido Yariv <ido@wizery.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kvm/x86: Show WRMSR data is in hexBorislav Petkov2016-10-27
| | | | | | | | | | | Add the "0x" prefix to the error messages format to make it unambiguous about what kind of value we're talking about. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Message-Id: <20161027181445.25319-1-bp@alien8.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kvm: nVMX: Fix kernel panics induced by illegal INVEPT/INVVPID typesJim Mattson2016-10-27
| | | | | | | | | | | Bitwise shifts by amounts greater than or equal to the width of the left operand are undefined. A malicious guest can exploit this to crash a 32-bit host, due to the BUG_ON(1)'s in handle_{invept,invvpid}. Signed-off-by: Jim Mattson <jmattson@google.com> Message-Id: <1477496318-17681-1-git-send-email-jmattson@google.com> [Change 1UL to 1, to match the range check on the shift count. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kvm: x86: memset whole irq_eoiJiri Slaby2016-10-20
| | | | | | | | | | | | | | | | | | | | | | gcc 7 warns: arch/x86/kvm/ioapic.c: In function 'kvm_ioapic_reset': arch/x86/kvm/ioapic.c:597:2: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size] And it is right. Memset whole array using sizeof operator. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> [Added x86 subject tag] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kvm/x86: Fix unused variable warning in kvm_timer_init()Borislav Petkov2016-10-20
| | | | | | | | | | | | | | | | When CONFIG_CPU_FREQ is not set, int cpu is unused and gcc rightfully warns about it: arch/x86/kvm/x86.c: In function ‘kvm_timer_init’: arch/x86/kvm/x86.c:5697:6: warning: unused variable ‘cpu’ [-Wunused-variable] int cpu; ^~~ But since it is used only in the CONFIG_CPU_FREQ block, simply move it there, thus squashing the warning too. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kthread: kthread worker API cleanupPetr Mladek2016-10-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A good practice is to prefix the names of functions by the name of the subsystem. The kthread worker API is a mix of classic kthreads and workqueues. Each worker has a dedicated kthread. It runs a generic function that process queued works. It is implemented as part of the kthread subsystem. This patch renames the existing kthread worker API to use the corresponding name from the workqueues API prefixed by kthread_: __init_kthread_worker() -> __kthread_init_worker() init_kthread_worker() -> kthread_init_worker() init_kthread_work() -> kthread_init_work() insert_kthread_work() -> kthread_insert_work() queue_kthread_work() -> kthread_queue_work() flush_kthread_work() -> kthread_flush_work() flush_kthread_worker() -> kthread_flush_worker() Note that the names of DEFINE_KTHREAD_WORK*() macros stay as they are. It is common that the "DEFINE_" prefix has precedence over the subsystem names. Note that INIT() macros and init() functions use different naming scheme. There is no good solution. There are several reasons for this solution: + "init" in the function names stands for the verb "initialize" aka "initialize worker". While "INIT" in the macro names stands for the noun "INITIALIZER" aka "worker initializer". + INIT() macros are used only in DEFINE() macros + init() functions are used close to the other kthread() functions. It looks much better if all the functions use the same scheme. + There will be also kthread_destroy_worker() that will be used close to kthread_cancel_work(). It is related to the init() function. Again it looks better if all functions use the same naming scheme. + there are several precedents for such init() function names, e.g. amd_iommu_init_device(), free_area_init_node(), jump_label_init_type(), regmap_init_mmio_clk(), + It is not an argument but it was inconsistent even before. [arnd@arndb.de: fix linux-next merge conflict] Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2016-10-06
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM updates from Radim Krčmář: "All architectures: - move `make kvmconfig` stubs from x86 - use 64 bits for debugfs stats ARM: - Important fixes for not using an in-kernel irqchip - handle SError exceptions and present them to guests if appropriate - proxying of GICV access at EL2 if guest mappings are unsafe - GICv3 on AArch32 on ARMv8 - preparations for GICv3 save/restore, including ABI docs - cleanups and a bit of optimizations MIPS: - A couple of fixes in preparation for supporting MIPS EVA host kernels - MIPS SMP host & TLB invalidation fixes PPC: - Fix the bug which caused guests to falsely report lockups - other minor fixes - a small optimization s390: - Lazy enablement of runtime instrumentation - up to 255 CPUs for nested guests - rework of machine check deliver - cleanups and fixes x86: - IOMMU part of AMD's AVIC for vmexit-less interrupt delivery - Hyper-V TSC page - per-vcpu tsc_offset in debugfs - accelerated INS/OUTS in nVMX - cleanups and fixes" * tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (140 commits) KVM: MIPS: Drop dubious EntryHi optimisation KVM: MIPS: Invalidate TLB by regenerating ASIDs KVM: MIPS: Split kernel/user ASID regeneration KVM: MIPS: Drop other CPU ASIDs on guest MMU changes KVM: arm/arm64: vgic: Don't flush/sync without a working vgic KVM: arm64: Require in-kernel irqchip for PMU support KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register KVM: PPC: Book3S PR: Support 64kB page size on POWER8E and POWER8NVL KVM: PPC: Book3S: Remove duplicate setting of the B field in tlbie KVM: PPC: BookE: Fix a sanity check KVM: PPC: Book3S HV: Take out virtual core piggybacking code KVM: PPC: Book3S: Treat VTB as a per-subcore register, not per-thread ARM: gic-v3: Work around definition of gic_write_bpr1 KVM: nVMX: Fix the NMI IDT-vectoring handling KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive KVM: nVMX: Fix reload apic access page warning kvmconfig: add virtio-gpu to config fragment config: move x86 kvm_guest.config to a common location arm64: KVM: Remove duplicating init code for setting VMID ARM: KVM: Support vgic-v3 ...
| * KVM: nVMX: Fix the NMI IDT-vectoring handlingWanpeng Li2016-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Run kvm-unit-tests/eventinj.flat in L1: Sending NMI to self After NMI to self FAIL: NMI This test scenario is to test whether VMM can handle NMI IDT-vectoring info correctly. At the beginning, L2 writes LAPIC to send a self NMI, the EPT page tables on both L1 and L0 are empty so: - The L2 accesses memory can generate EPT violation which can be intercepted by L0. The EPT violation vmexit occurred during delivery of this NMI, and the NMI info is recorded in vmcs02's IDT-vectoring info. - L0 walks L1's EPT12 and L0 sees the mapping is invalid, it injects the EPT violation into L1. The vmcs02's IDT-vectoring info is reflected to vmcs12's IDT-vectoring info since it is a nested vmexit. - L1 receives the EPT violation, then fixes its EPT12. - L1 executes VMRESUME to resume L2 which generates vmexit and causes L1 exits to L0. - L0 emulates VMRESUME which is called from L1, then return to L2. L0 merges the requirement of vmcs12's IDT-vectoring info and injects it to L2 through vmcs02. - The L2 re-executes the fault instruction and cause EPT violation again. - Since the L1's EPT12 is valid, L0 can fix its EPT02 - L0 resume L2 The EPT violation vmexit occurred during delivery of this NMI again, and the NMI info is recorded in vmcs02's IDT-vectoring info. L0 should inject the NMI through vmentry event injection since it is caused by EPT02's EPT violation. However, vmx_inject_nmi() refuses to inject NMI from IDT-vectoring info if vCPU is in guest mode, this patch fix it by permitting to inject NMI from IDT-vectoring if it is the L0's responsibility to inject NMI from IDT-vectoring info to L2. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Bandan Das <bsd@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactiveWanpeng Li2016-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I observed that kvmvapic(to optimize flexpriority=N or AMD) is used to boost TPR access when testing kvm-unit-test/eventinj.flat tpr case on my haswell desktop (w/ flexpriority, w/o APICv). Commit (8d14695f9542 x86, apicv: add virtual x2apic support) disable virtual x2apic mode completely if w/o APICv, and the author also told me that windows guest can't enter into x2apic mode when he developed the APICv feature several years ago. However, it is not truth currently, Interrupt Remapping and vIOMMU is added to qemu and the developers from Intel test windows 8 can work in x2apic mode w/ Interrupt Remapping enabled recently. This patch enables TPR shadow for virtual x2apic mode to boost windows guest in x2apic mode even if w/o APICv. Can pass the kvm-unit-test. Suggested-by: Radim Krčmář <rkrcmar@redhat.com> Suggested-by: Wincy Van <fanwenyi0529@gmail.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Wincy Van <fanwenyi0529@gmail.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * KVM: nVMX: Fix reload apic access page warningWanpeng Li2016-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARNING: CPU: 1 PID: 4230 at kernel/sched/core.c:7564 __might_sleep+0x7e/0x80 do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8d0de7f9>] prepare_to_swait+0x39/0xa0 CPU: 1 PID: 4230 Comm: qemu-system-x86 Not tainted 4.8.0-rc5+ #47 Call Trace: dump_stack+0x99/0xd0 __warn+0xd1/0xf0 warn_slowpath_fmt+0x4f/0x60 ? prepare_to_swait+0x39/0xa0 ? prepare_to_swait+0x39/0xa0 __might_sleep+0x7e/0x80 __gfn_to_pfn_memslot+0x156/0x480 [kvm] gfn_to_pfn+0x2a/0x30 [kvm] gfn_to_page+0xe/0x20 [kvm] kvm_vcpu_reload_apic_access_page+0x32/0xa0 [kvm] nested_vmx_vmexit+0x765/0xca0 [kvm_intel] ? _raw_spin_unlock_irqrestore+0x36/0x80 vmx_check_nested_events+0x49/0x1f0 [kvm_intel] kvm_arch_vcpu_runnable+0x2d/0xe0 [kvm] kvm_vcpu_check_block+0x12/0x60 [kvm] kvm_vcpu_block+0x94/0x4c0 [kvm] kvm_arch_vcpu_ioctl_run+0x619/0x1aa0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xdf1/0x1aa0 [kvm] kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm] =============================== [ INFO: suspicious RCU usage. ] 4.8.0-rc5+ #47 Not tainted ------------------------------- ./include/linux/kvm_host.h:535 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by qemu-system-x86/4230: #0: (&vcpu->mutex){+.+.+.}, at: [<ffffffffc062975c>] vcpu_load+0x1c/0x60 [kvm] stack backtrace: CPU: 1 PID: 4230 Comm: qemu-system-x86 Not tainted 4.8.0-rc5+ #47 Call Trace: dump_stack+0x99/0xd0 lockdep_rcu_suspicious+0xe7/0x120 gfn_to_memslot+0x12a/0x140 [kvm] gfn_to_pfn+0x12/0x30 [kvm] gfn_to_page+0xe/0x20 [kvm] kvm_vcpu_reload_apic_access_page+0x32/0xa0 [kvm] nested_vmx_vmexit+0x765/0xca0 [kvm_intel] ? _raw_spin_unlock_irqrestore+0x36/0x80 vmx_check_nested_events+0x49/0x1f0 [kvm_intel] kvm_arch_vcpu_runnable+0x2d/0xe0 [kvm] kvm_vcpu_check_block+0x12/0x60 [kvm] kvm_vcpu_block+0x94/0x4c0 [kvm] kvm_arch_vcpu_ioctl_run+0x619/0x1aa0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xdf1/0x1aa0 [kvm] kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm] ? __fget+0xfd/0x210 ? __lock_is_held+0x54/0x70 do_vfs_ioctl+0x96/0x6a0 ? __fget+0x11c/0x210 ? __fget+0x5/0x210 SyS_ioctl+0x79/0x90 do_syscall_64+0x81/0x220 entry_SYSCALL64_slow_path+0x25/0x25 These can be triggered by running kvm-unit-test: ./x86-run x86/vmx.flat The nested preemption timer is based on hrtimer which is started on L2 entry, stopped on L2 exit and evaluated via the new check_nested_events hook. The current logic adds vCPU to a simple waitqueue (TASK_INTERRUPTIBLE) if need to yield pCPU and w/o holding srcu read lock when accesses memslots, both can be in nested preemption timer evaluation path which results in the warning above. This patch fix it by leveraging request bit to async reload APIC access page before vmentry in order to avoid to reload directly during the nested preemption timer evaluation, it is safe since the vmcs01 is loaded and current is nested vmexit. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * kvm: svm: fix unsigned compare less than zero comparisonColin Ian King2016-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | vm_data->avic_vm_id is a u32, so the check for a error return (less than zero) such as -EAGAIN from avic_get_next_vm_id currently has no effect whatsoever. Fix this by using a temporary int for the comparison and assign vm_data->avic_vm_id to this. I used an explicit u32 cast in the assignment to show why vm_data->avic_vm_id cannot be used in the assign/compare steps. Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: x86: Hyper-V tsc page setupPaolo Bonzini2016-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lately tsc page was implemented but filled with empty values. This patch setup tsc page scale and offset based on vcpu tsc, tsc_khz and HV_X64_MSR_TIME_REF_COUNT value. The valid tsc page drops HV_X64_MSR_TIME_REF_COUNT msr reads count to zero which potentially improves performance. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Peter Hornyack <peterhornyack@google.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> [Computation of TSC page parameters rewritten to use the Linux timekeeper parameters. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: x86: introduce get_kvmclock_nsPaolo Bonzini2016-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a function that reads the exact nanoseconds value that is provided to the guest in kvmclock. This crystallizes the notion of kvmclock as a thin veneer over a stable TSC, that the guest will (hopefully) convert with NTP. In other words, kvmclock is *not* a paravirtualized host-to-guest NTP. Drop the get_kernel_ns() function, that was used both to get the base value of the master clock and to get the current value of kvmclock. The former use is replaced by ktime_get_boot_ns(), the latter is the purpose of get_kernel_ns(). This also allows KVM to provide a Hyper-V time reference counter that is synchronized with the time that is computed from the TSC page. Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: x86: initialize kvmclock_offsetPaolo Bonzini2016-09-20
| | | | | | | | | | | | | | | | | | | | Make the guest's kvmclock count up from zero, not from the host boot time. The guest cannot rely on that anyway because it changes on migration, the numbers are easier on the eye and finally it matches the desired semantics of the Hyper-V time reference counter. Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * KVM: x86: always fill in vcpu->arch.hv_clockPaolo Bonzini2016-09-20
| | | | | | | | | | | | | | | | | | We will use it in the next patches for KVM_GET_CLOCK and as a basis for the contents of the Hyper-V TSC page. Get the values from the Linux timekeeper even if kvmclock is not enabled. Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * kvm: x86: export TSC information to user-spaceLuiz Capitulino2016-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit exports the following information to user-space via the newly created per-vcpu debugfs directory: - TSC offset (as a signed number) - TSC scaling ratio - TSC scaling ratio fractinal bits The original intention of this commit was to export only the TSC offset, but the TSC scaling information is exported for completeness. We need to retrieve the TSC offset from user-space in order to support the merging of host and guest traces in trace-cmd. Today, we use the kvm_write_tsc_offset tracepoint, but it has a number of problems (mainly, it requires a running VM to be rebooted, ftrace setup, and also tracepoints are not supposed to be ABIs). The merging of host and guest traces is explained in more detail in this thread: [Qemu-devel] [RFC] host and guest kernel trace merging https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg00887.html This commit creates the following files in debugfs: /sys/kernel/debug/kvm/66828-10/vcpu0/tsc-offset /sys/kernel/debug/kvm/66828-10/vcpu0/tsc-scaling-ratio /sys/kernel/debug/kvm/66828-10/vcpu0/tsc-scaling-ratio-frac-bits The last two are only created if TSC scaling is supported. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * kvm: add stubs for arch specific debugfs supportLuiz Capitulino2016-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two stubs are added: o kvm_arch_has_vcpu_debugfs(): must return true if the arch supports creating debugfs entries in the vcpu debugfs dir (which will be implemented by the next commit) o kvm_arch_create_vcpu_debugfs(): code that creates debugfs entries in the vcpu debugfs dir For x86, this commit introduces a new file to avoid growing arch/x86/kvm/x86.c even more. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * kvm: x86: drop read_tsc_offset()Luiz Capitulino2016-09-16
| | | | | | | | | | | | | | The TSC offset can now be read directly from struct kvm_arch_vcpu. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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