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2014-11-03KVM: x86: detect SPIV changes under APICvRadim Krčmář
APIC-write VM exits are "trap-like": they save CS:RIP values for the instruction after the write, and more importantly, the handler will already see the new value in the virtual-APIC page. This caused a bug if you used KVM_SET_IRQCHIP to set the SW-enabled bit in the SPIV register. The chain of events is as follows: * When the irqchip is added to the destination VM, the apic_sw_disabled static key is incremented (1) * When the KVM_SET_IRQCHIP ioctl is invoked, it is decremented (0) * When the guest disables the bit in the SPIV register, e.g. as part of shutdown, apic_set_spiv does not notice the change and the static key is _not_ incremented. * When the guest is destroyed, the static key is decremented (-1), resulting in this trace: WARNING: at kernel/jump_label.c:81 __static_key_slow_dec+0xa6/0xb0() jump label: negative count! [<ffffffff816bf898>] dump_stack+0x19/0x1b [<ffffffff8107c6f1>] warn_slowpath_common+0x61/0x80 [<ffffffff8107c76c>] warn_slowpath_fmt+0x5c/0x80 [<ffffffff811931e6>] __static_key_slow_dec+0xa6/0xb0 [<ffffffff81193226>] static_key_slow_dec_deferred+0x16/0x20 [<ffffffffa0637698>] kvm_free_lapic+0x88/0xa0 [kvm] [<ffffffffa061c63e>] kvm_arch_vcpu_uninit+0x2e/0xe0 [kvm] [<ffffffffa05ff301>] kvm_vcpu_uninit+0x21/0x40 [kvm] [<ffffffffa067cec7>] vmx_free_vcpu+0x47/0x70 [kvm_intel] [<ffffffffa061bc50>] kvm_arch_vcpu_free+0x50/0x60 [kvm] [<ffffffffa061ca22>] kvm_arch_destroy_vm+0x102/0x260 [kvm] [<ffffffff810b68fd>] ? synchronize_srcu+0x1d/0x20 [<ffffffffa06030d1>] kvm_put_kvm+0xe1/0x1c0 [kvm] [<ffffffffa06036f8>] kvm_vcpu_release+0x18/0x20 [kvm] [<ffffffff81215c62>] __fput+0x102/0x310 [<ffffffff81215f4e>] ____fput+0xe/0x10 [<ffffffff810ab664>] task_work_run+0xb4/0xe0 [<ffffffff81083944>] do_exit+0x304/0xc60 [<ffffffff816c8dfc>] ? _raw_spin_unlock_irq+0x2c/0x50 [<ffffffff810fd22d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff8108432c>] do_group_exit+0x4c/0xc0 [<ffffffff810843b4>] SyS_exit_group+0x14/0x20 [<ffffffff816d33a9>] system_call_fastpath+0x16/0x1b Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Enable Intel AVX-512 for guestChao Peng
Expose Intel AVX-512 feature bits to guest. Also add checks for xcr0 AVX512 related bits according to spec: http://download-software.intel.com/sites/default/files/managed/71/2e/319433-017.pdf Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: fix deadline tsc interrupt injectionRadim Krčmář
The check in kvm_set_lapic_tscdeadline_msr() was trying to prevent a situation where we lose a pending deadline timer in a MSR write. Losing it is fine, because it effectively occurs before the timer fired, so we should be able to cancel or postpone it. Another problem comes from interaction with QEMU, or other userspace that can set deadline MSR without a good reason, when timer is already pending: one guest's deadline request results in more than one interrupt because one is injected immediately on MSR write from userspace and one through hrtimer later. The solution is to remove the injection when replacing a pending timer and to improve the usual QEMU path, we inject without a hrtimer when the deadline has already passed. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reported-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: add apic_timer_expired()Radim Krčmář
Make the code reusable. If the timer was already pending, we shouldn't be waiting in a queue, so wake_up can be skipped, simplifying the path. There is no 'reinject' case => the comment is removed. Current race behaves correctly. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: vmx: Unavailable DR4/5 is checked before CPLNadav Amit
If DR4/5 is accessed when it is unavailable (since CR4.DE is set), then #UD should be generated even if CPL>0. This is according to Intel SDM Table 6-2: "Priority Among Simultaneous Exceptions and Interrupts". Note, that this may happen on the first DR access, even if the host does not sets debug breakpoints. Obviously, it occurs when the host debugs the guest. This patch moves the DR4/5 checks from __kvm_set_dr/_kvm_get_dr to handle_dr. The emulator already checks DR4/5 availability in check_dr_read. Nested virutalization related calls to kvm_set_dr/kvm_get_dr would not like to inject exceptions to the guest. As for SVM, the patch follows the previous logic as much as possible. Anyhow, it appears the DR interception code might be buggy - even if the DR access may cause an exception, the instruction is skipped. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Emulator performs code segment checks on read accessNadav Amit
When read access is performed using a readable code segment, the "conforming" and "non-conforming" checks should not be done. As a result, read using non-conforming readable code segment fails. This is according to Intel SDM 5.6.1 ("Accessing Data in Code Segments"). The fix is not to perform the "non-conforming" checks if the access is not a fetch; the relevant checks are already done when loading the segment. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Clear DR7.LE during task-switchNadav Amit
DR7.LE should be cleared during task-switch. This feature is poorly documented. For reference, see: http://pdos.csail.mit.edu/6.828/2005/readings/i386/s12_02.htm SDM [17.2.4]: This feature is not supported in the P6 family processors, later IA-32 processors, and Intel 64 processors. AMD [2:13.1.1.4]: This bit is ignored by implementations of the AMD64 architecture. Intel's formulation could mean that it isn't even zeroed, but current hardware indeed does not behave like that. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Emulator does not calculate address correctlyNadav Amit
In long-mode, when the address size is 4 bytes, the linear address is not truncated as the emulator mistakenly does. Instead, the offset within the segment (the ea field) should be truncated according to the address size. As Intel SDM says: "In 64-bit mode, the effective address components are added and the effective address is truncated ... before adding the full 64-bit segment base." Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: DR7.GD should be cleared upon any #DB exceptionNadav Amit
Intel SDM 17.2.4 (Debug Control Register (DR7)) says: "The processor clears the GD flag upon entering to the debug exception handler." This sentence may be misunderstood as if it happens only on #DB due to debug-register protection, but it happens regardless to the cause of the #DB. Fix the behavior to match both real hardware and Bochs. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: some apic broadcast modes does not workNadav Amit
KVM does not deliver x2APIC broadcast messages with physical mode. Intel SDM (10.12.9 ICR Operation in x2APIC Mode) states: "A destination ID value of FFFF_FFFFH is used for broadcast of interrupts in both logical destination and physical destination modes." In addition, the local-apic enables cluster mode broadcast. As Intel SDM 10.6.2.2 says: "Broadcast to all local APICs is achieved by setting all destination bits to one." This patch enables cluster mode broadcast. The fix tries to combine broadcast in different modes through a unified code. One rare case occurs when the source of IPI has its APIC disabled. In such case, the source can still issue IPIs, but since the source is not obliged to have the same LAPIC mode as the enabled ones, we cannot rely on it. Since it is a rare case, it is unoptimized and done on the slow-path. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Wanpeng Li <wanpeng.li@linux.intel.com> [As per Radim's review, use unsigned int for X2APIC_BROADCAST, return bool from kvm_apic_broadcast. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03x86,kvm,vmx: Don't trap writes to CR4.TSDAndy Lutomirski
CR4.TSD is guest-owned; don't trap writes to it in VMX guests. This avoids a VM exit on context switches into or out of a PR_TSC_SIGSEGV task. I think that this fixes an unintentional side-effect of: 4c38609ac569 KVM: VMX: Make guest cr4 mask more conservative Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Sysexit emulation does not mask RIP/RSPNadav Amit
If the operand size is not 64-bit, then the sysexit instruction should assign ECX to RSP and EDX to RIP. The current code assigns the full 64-bits. Fix it by masking. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Distinguish between stack operation and near branchesNadav Amit
In 64-bit, stack operations default to 64-bits, but can be overriden (to 16-bit) using opsize override prefix. In contrast, near-branches are always 64-bit. This patch distinguish between the different behaviors. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Getting rid of grp45 in emulatorNadav Amit
Breaking grp45 to the relevant functions to speed up the emulation and simplify the code. In addition, it is necassary the next patch will distinguish between far and near branches according to the flags. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: x86: Use new is_noncanonical_address in _linearizeNadav Amit
Replace the current canonical address check with the new function which is identical. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03KVM: emulator: always inline __linearizePaolo Bonzini
The two callers have a lot of constant arguments that can be optimized out. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "A small set of x86 fixes. The most serious is an SRCU lockdep fix. A bit late - needed some time to test the SRCU fix, which only came in on Friday" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: vmx: defer load of APIC access page address during reset KVM: nVMX: Disable preemption while reading from shadow VMCS KVM: x86: Fix far-jump to non-canonical check KVM: emulator: fix execution close to the segment limit KVM: emulator: fix error code for __linearize
2014-11-02KVM: vmx: defer load of APIC access page address during resetPaolo Bonzini
Most call paths to vmx_vcpu_reset do not hold the SRCU lock. Defer loading the APIC access page to the next vmentry. This avoids the following lockdep splat: [ INFO: suspicious RCU usage. ] 3.18.0-rc2-test2+ #70 Not tainted ------------------------------- include/linux/kvm_host.h:474 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-x86/2371: #0: (&vcpu->mutex){+.+...}, at: [<ffffffffa037d800>] vcpu_load+0x20/0xd0 [kvm] stack backtrace: CPU: 4 PID: 2371 Comm: qemu-system-x86 Not tainted 3.18.0-rc2-test2+ #70 Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A12 01/10/2013 0000000000000001 ffff880209983ca8 ffffffff816f514f 0000000000000000 ffff8802099b8990 ffff880209983cd8 ffffffff810bd687 00000000000fee00 ffff880208a2c000 ffff880208a10000 ffff88020ef50040 ffff880209983d08 Call Trace: [<ffffffff816f514f>] dump_stack+0x4e/0x71 [<ffffffff810bd687>] lockdep_rcu_suspicious+0xe7/0x120 [<ffffffffa037d055>] gfn_to_memslot+0xd5/0xe0 [kvm] [<ffffffffa03807d3>] __gfn_to_pfn+0x33/0x60 [kvm] [<ffffffffa0380885>] gfn_to_page+0x25/0x90 [kvm] [<ffffffffa038aeec>] kvm_vcpu_reload_apic_access_page+0x3c/0x80 [kvm] [<ffffffffa08f0a9c>] vmx_vcpu_reset+0x20c/0x460 [kvm_intel] [<ffffffffa039ab8e>] kvm_vcpu_reset+0x15e/0x1b0 [kvm] [<ffffffffa039ac0c>] kvm_arch_vcpu_setup+0x2c/0x50 [kvm] [<ffffffffa037f7e0>] kvm_vm_ioctl+0x1d0/0x780 [kvm] [<ffffffff810bc664>] ? __lock_is_held+0x54/0x80 [<ffffffff812231f0>] do_vfs_ioctl+0x300/0x520 [<ffffffff8122ee45>] ? __fget+0x5/0x250 [<ffffffff8122f0fa>] ? __fget_light+0x2a/0xe0 [<ffffffff81223491>] SyS_ioctl+0x81/0xa0 [<ffffffff816fed6d>] system_call_fastpath+0x16/0x1b Reported-by: Takashi Iwai <tiwai@suse.de> Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Reviewed-by: Wanpeng Li <wanpeng.li@linux.intel.com> Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com> Fixes: 38b9917350cb2946e368ba684cfc33d1672f104e Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-02KVM: nVMX: Disable preemption while reading from shadow VMCSJan Kiszka
In order to access the shadow VMCS, we need to load it. At this point, vmx->loaded_vmcs->vmcs and the actually loaded one start to differ. If we now get preempted by Linux, vmx_vcpu_put and, on return, the vmx_vcpu_load will work against the wrong vmcs. That can cause copy_shadow_to_vmcs12 to corrupt the vmcs12 state. Fix the issue by disabling preemption during the copy operation. copy_vmcs12_to_shadow is safe from this issue as it is executed by vmx_vcpu_run when preemption is already disabled before vmentry. This bug is exposed by running Jailhouse within KVM on CPUs with shadow VMCS support. Jailhouse never expects an interrupt pending vmexit, but the bug can cause it if, after copy_shadow_to_vmcs12 is preempted, the active VMCS happens to have the virtual interrupt pending flag set in the CPU-based execution controls. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-02KVM: x86: Fix far-jump to non-canonical checkNadav Amit
Commit d1442d85cc30 ("KVM: x86: Handle errors when RIP is set during far jumps") introduced a bug that caused the fix to be incomplete. Due to incorrect evaluation, far jump to segment with L bit cleared (i.e., 32-bit segment) and RIP with any of the high bits set (i.e, RIP[63:32] != 0) set may not trigger #GP. As we know, this imposes a security problem. In addition, the condition for two warnings was incorrect. Fixes: d1442d85cc30ea75f7d399474ca738e0bc96f715 Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> [Add #ifdef CONFIG_X86_64 to avoid complaints of undefined behavior. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-31x86_64, entry: Fix out of bounds read on sysenterAndy Lutomirski
Rusty noticed a Really Bad Bug (tm) in my NT fix. The entry code reads out of bounds, causing the NT fix to be unreliable. But, and this is much, much worse, if your stack is somehow just below the top of the direct map (or a hole), you read out of bounds and crash. Excerpt from the crash: [ 1.129513] RSP: 0018:ffff88001da4bf88 EFLAGS: 00010296 2b:* f7 84 24 90 00 00 00 testl $0x4000,0x90(%rsp) That read is deterministically above the top of the stack. I thought I even single-stepped through this code when I wrote it to check the offset, but I clearly screwed it up. Fixes: 8c7aa698baca ("x86_64, entry: Filter RFLAGS.NT on entry from userspace") Reported-by: Rusty Russell <rusty@ozlabs.org> Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-31Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Fixes from all around the place: - hyper-V 32-bit PAE guest kernel fix - two IRQ allocation fixes on certain x86 boards - intel-mid boot crash fix - intel-quark quirk - /proc/interrupts duplicate irq chip name fix - cma boot crash fix - syscall audit fix - boot crash fix with certain TSC configurations (seen on Qemu) - smpboot.c build warning fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE ACPI, irq, x86: Return IRQ instead of GSI in mp_register_gsi() x86, intel-mid: Create IRQs for APB timers and RTC timers x86: Don't enable F00F workaround on Intel Quark processors x86/irq: Fix XT-PIC-XT-PIC in /proc/interrupts x86, cma: Reserve DMA contiguous area after initmem_init() i386/audit: stop scribbling on the stack frame x86, apic: Handle a bad TSC more gracefully x86: ACPI: Do not translate GSI number if IOAPIC is disabled x86/smpboot: Move data structure to its primary usage scope
2014-10-31Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Various scheduler fixes all over the place: three SCHED_DL fixes, three sched/numa fixes, two generic race fixes and a comment fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/dl: Fix preemption checks sched: Update comments for CLONE_NEWNS sched: stop the unbound recursion in preempt_schedule_context() sched/fair: Fix division by zero sysctl_numa_balancing_scan_size sched/fair: Care divide error in update_task_scan_period() sched/numa: Fix unsafe get_task_struct() in task_numa_assign() sched/deadline: Fix races between rt_mutex_setprio() and dl_task_timer() sched/deadline: Don't replenish from a !SCHED_DEADLINE entity sched: Fix race between task_group and sched_task_group
2014-10-31Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Mostly tooling fixes, plus on the kernel side: - a revert for a newly introduced PMU driver which isn't complete yet and where we ran out of time with fixes (to be tried again in v3.19) - this makes up for a large chunk of the diffstat. - compilation warning fixes - a printk message fix - event_idx usage fixes/cleanups" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf probe: Trivial typo fix for --demangle perf tools: Fix report -F dso_from for data without branch info perf tools: Fix report -F dso_to for data without branch info perf tools: Fix report -F symbol_from for data without branch info perf tools: Fix report -F symbol_to for data without branch info perf tools: Fix report -F mispredict for data without branch info perf tools: Fix report -F in_tx for data without branch info perf tools: Fix report -F abort for data without branch info perf tools: Make CPUINFO_PROC an array to support different kernel versions perf callchain: Use global caching provided by libunwind perf/x86/intel: Revert incomplete and undocumented Broadwell client support perf/x86: Fix compile warnings for intel_uncore perf: Fix typos in sample code in the perf_event.h header perf: Fix and clean up initialization of pmu::event_idx perf: Fix bogus kernel printk perf diff: Add missing hists__init() call at tool start
2014-10-29KVM: emulator: fix execution close to the segment limitPaolo Bonzini
Emulation of code that is 14 bytes to the segment limit or closer (e.g. RIP = 0xFFFFFFF2 after reset) is broken because we try to read as many as 15 bytes from the beginning of the instruction, and __linearize fails when the passed (address, size) pair reaches out of the segment. To fix this, let __linearize return the maximum accessible size (clamped to 2^32-1) for usage in __do_insn_fetch_bytes, and avoid the limit check by passing zero for the desired size. For expand-down segments, __linearize is performing a redundant check. (u32)(addr.ea + size - 1) <= lim can only happen if addr.ea is close to 4GB; in this case, addr.ea + size - 1 will also fail the check against the upper bound of the segment (which is provided by the D/B bit). After eliminating the redundant check, it is simple to compute the *max_size for expand-down segments too. Now that the limit check is done in __do_insn_fetch_bytes, we want to inject a general protection fault there if size < op_size (like __linearize would have done), instead of just aborting. This fixes booting Tiano Core from emulated flash with EPT disabled. Cc: stable@vger.kernel.org Fixes: 719d5a9b2487e0562f178f61e323c3dc18a8b200 Reported-by: Borislav Petkov <bp@suse.de> Tested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-29KVM: emulator: fix error code for __linearizePaolo Bonzini
The error code for #GP and #SS is zero when the segment is used to access an operand or an instruction. It is only non-zero when a segment register is being loaded; for limit checks this means cases such as: * for #GP, when RIP is beyond the limit on a far call (before the first instruction is executed). We do not implement this check, but it would be in em_jmp_far/em_call_far. * for #SS, if the new stack overflows during an inter-privilege-level call to a non-conforming code segment. We do not implement stack switching at all. So use an error code of zero. Reviewed-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-29perf/x86/intel: Revert incomplete and undocumented Broadwell client supportIngo Molnar
These patches: 86a349a28b24 ("perf/x86/intel: Add Broadwell core support") c46e665f0377 ("perf/x86: Add INST_RETIRED.ALL workarounds") fdda3c4aacec ("perf/x86/intel: Use Broadwell cache event list for Haswell") introduced magic constants and unexplained changes: https://lkml.org/lkml/2014/10/28/1128 https://lkml.org/lkml/2014/10/27/325 https://lkml.org/lkml/2014/8/27/546 https://lkml.org/lkml/2014/10/28/546 Peter Zijlstra has attempted to help out, to clean up the mess: https://lkml.org/lkml/2014/10/28/543 But has not received helpful and constructive replies which makes me doubt wether it can all be finished in time until v3.18 is released. Despite various review feedback the author (Andi Kleen) has answered only few of the review questions and has generally been uncooperative, only giving replies when prompted repeatedly, and only giving minimal answers instead of constructively explaining and helping along the effort. That kind of behavior is not acceptable. There's also a boot crash on Intel E5-1630 v3 CPUs reported for another commit from Andi Kleen: e735b9db12d7 ("perf/x86/intel/uncore: Add Haswell-EP uncore support") https://lkml.org/lkml/2014/10/22/730 Which is not yet resolved. The uncore driver is independent in theory, but the crash makes me worry about how well all these patches were tested and makes me uneasy about the level of interminging that the Broadwell and Haswell code has received by the commits above. As a first step to resolve the mess revert the Broadwell client commits back to the v3.17 version, before we run out of time and problematic code hits a stable upstream kernel. ( If the Haswell-EP crash is not resolved via a simple fix then we'll have to revert the Haswell-EP uncore driver as well. ) The Broadwell client series has to be submitted in a clean fashion, with single, well documented changes per patch. If they are submitted in time and are accepted during review then they can possibly go into v3.19 but will need additional scrutiny due to the rocky history of this patch set. Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: eranian@google.com Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1409683455-29168-3-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-29x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAEDexuan Cui
pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "long << PAGE_SHIFT" will overflow for PFNs above 4GB. Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V, with 5GB memory assigned, can't load the netvsc driver successfully and hence the synthetic network device can't work (we can use the kernel parameter mem=3000M to work around the issue). Cast pte_pfn() to phys_addr_t before shifting. Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()" Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: gregkh@linuxfoundation.org Cc: linux-mm@kvack.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: dave.hansen@intel.com Cc: riel@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-10-29ACPI, irq, x86: Return IRQ instead of GSI in mp_register_gsi()Jiang Liu
Function mp_register_gsi() returns blindly the GSI number for the ACPI SCI interrupt. That causes a regression when the GSI for ACPI SCI is shared with other devices. The regression was caused by commit 84245af7297ced9e8fe "x86, irq, ACPI: Change __acpi_register_gsi to return IRQ number instead of GSI" and exposed on a SuperMicro system, which shares one GSI between ACPI SCI and PCI device, with following failure: http://sourceforge.net/p/linux1394/mailman/linux1394-user/?viewmonth=201410 [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level) [ 2.699224] firewire_ohci 0000:06:00.0: failed to allocate interrupt 20 Return mp_map_gsi_to_irq(gsi, 0) instead of the GSI number. Reported-and-Tested-by: Daniel Robbins <drobbins@funtoo.org> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: <stable@vger.kernel.org> # 3.17 Link: http://lkml.kernel.org/r/1414387308-27148-4-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-29x86, intel-mid: Create IRQs for APB timers and RTC timersJiang Liu
Intel MID platforms has no legacy interrupts, so no IRQ descriptors preallocated. We need to call mp_map_gsi_to_irq() to create IRQ descriptors for APB timers and RTC timers, otherwise it may cause invalid memory access as: [ 0.116839] BUG: unable to handle kernel NULL pointer dereference at 0000003a [ 0.123803] IP: [<c1071c0e>] setup_irq+0xf/0x4d Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: David Cohen <david.a.cohen@linux.intel.com> Cc: <stable@vger.kernel.org> # 3.17 Link: http://lkml.kernel.org/r/1414387308-27148-3-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-29x86: Don't enable F00F workaround on Intel Quark processorsDave Jones
The Intel Quark processor is a part of family 5, but does not have the F00F bug present in Pentiums of the same family. Pentiums were models 0 through 8, Quark is model 9. Signed-off-by: Dave Jones <davej@redhat.com> Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie> Link: http://lkml.kernel.org/r/20141028175753.GA12743@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-28x86/irq: Fix XT-PIC-XT-PIC in /proc/interruptsMaciej W. Rozycki
Fix duplicate XT-PIC seen in /proc/interrupts on x86 systems that make use of 8259A Programmable Interrupt Controllers. Specifically convert output like this: CPU0 0: 76573 XT-PIC-XT-PIC timer 1: 11 XT-PIC-XT-PIC i8042 2: 0 XT-PIC-XT-PIC cascade 4: 8 XT-PIC-XT-PIC serial 6: 3 XT-PIC-XT-PIC floppy 7: 0 XT-PIC-XT-PIC parport0 8: 1 XT-PIC-XT-PIC rtc0 10: 448 XT-PIC-XT-PIC fddi0 12: 23 XT-PIC-XT-PIC eth0 14: 2464 XT-PIC-XT-PIC ide0 NMI: 0 Non-maskable interrupts ERR: 0 to one like this: CPU0 0: 122033 XT-PIC timer 1: 11 XT-PIC i8042 2: 0 XT-PIC cascade 4: 8 XT-PIC serial 6: 3 XT-PIC floppy 7: 0 XT-PIC parport0 8: 1 XT-PIC rtc0 10: 145 XT-PIC fddi0 12: 31 XT-PIC eth0 14: 2245 XT-PIC ide0 NMI: 0 Non-maskable interrupts ERR: 0 that is one like we used to have from ~2.2 till it was changed sometime. The rationale is there is no value in this duplicate information, it merely clutters output and looks ugly. We only have one handler for 8259A interrupts so there is no need to give it a name separate from the name already given to irq_chip. We could define meaningful names for handlers based on bits in the ELCR register on systems that have it or the value of the LTIM bit we use in ICW1 otherwise (hardcoded to 0 though with MCA support gone), to tell edge-triggered and level-triggered inputs apart. While that information does not affect 8259A interrupt handlers it could help people determine which lines are shareable and which are not. That is material for a separate change though. Any tools that parse /proc/interrupts are supposed not to be affected since it was many years we used the format this change converts back to. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.11.1410260147190.21390@eddie.linux-mips.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-28perf/x86: Fix compile warnings for intel_uncorePeter Zijlstra
The uncore drivers require PCI and generate compile time warnings when !CONFIG_PCI. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Stephane Eranian <eranian@google.com> Cc: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-28perf: Fix bogus kernel printkPeter Zijlstra (Intel)
Andy spotted the fail in what was intended as a conditional printk level. Reported-by: Andy Lutomirski <luto@amacapital.net> Fixes: cc6cd47e7395 ("perf/x86: Tone down kernel messages when the PMU check fails in a virtual environment") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141007124757.GH19379@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-28sched: stop the unbound recursion in preempt_schedule_context()Oleg Nesterov
preempt_schedule_context() does preempt_enable_notrace() at the end and this can call the same function again; exception_exit() is heavy and it is quite possible that need-resched is true again. 1. Change this code to dec preempt_count() and check need_resched() by hand. 2. As Linus suggested, we can use the PREEMPT_ACTIVE bit and avoid the enable/disable dance around __schedule(). But in this case we need to move into sched/core.c. 3. Cosmetic, but x86 forgets to declare this function. This doesn't really matter because it is only called by asm helpers, still it make sense to add the declaration into asm/preempt.h to match preempt_schedule(). Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Graf <agraf@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20141005202322.GB27962@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-28x86, cma: Reserve DMA contiguous area after initmem_init()Weijie Yang
Fengguang Wu reported a boot crash on the x86 platform via the 0-day Linux Kernel Performance Test: cma: dma_contiguous_reserve: reserving 31 MiB for global area BUG: Int 6: CR2 (null) [<41850786>] dump_stack+0x16/0x18 [<41d2b1db>] early_idt_handler+0x6b/0x6b [<41072227>] ? __phys_addr+0x2e/0xca [<41d4ee4d>] cma_declare_contiguous+0x3c/0x2d7 [<41d6d359>] dma_contiguous_reserve_area+0x27/0x47 [<41d6d4d1>] dma_contiguous_reserve+0x158/0x163 [<41d33e0f>] setup_arch+0x79b/0xc68 [<41d2b7cf>] start_kernel+0x9c/0x456 [<41d2b2ca>] i386_start_kernel+0x79/0x7d (See details at: https://lkml.org/lkml/2014/10/8/708) It is because dma_contiguous_reserve() is called before initmem_init() in x86, the variable high_memory is not initialized but accessed by __pa(high_memory) in dma_contiguous_reserve(). This patch moves dma_contiguous_reserve() after initmem_init() so that high_memory is initialized before accessed. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Weijie Yang <weijie.yang@samsung.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: iamjoonsoo.kim@lge.com Cc: 'Linux-MM' <linux-mm@kvack.org> Cc: 'Weijie Yang' <weijie.yang.kh@gmail.com> Link: http://lkml.kernel.org/r/000101cfef69%2431e528a0%2495af79e0%24%25yang@samsung.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-24i386/audit: stop scribbling on the stack frameEric Paris
git commit b4f0d3755c5e9cc86292d5fd78261903b4f23d4a was very very dumb. It was writing over %esp/pt_regs semi-randomly on i686 with the expected "system can't boot" results. As noted in: https://bugs.freedesktop.org/show_bug.cgi?id=85277 This patch stops fscking with pt_regs. Instead it sets up the registers for the call to __audit_syscall_entry in the most obvious conceivable way. It then does just a tiny tiny touch of magic. We need to get what started in PT_EDX into 0(%esp) and PT_ESI into 4(%esp). This is as easy as a pair of pushes. After the call to __audit_syscall_entry all we need to do is get that now useless junk off the stack (pair of pops) and reload %eax with the original syscall so other stuff can keep going about it's business. Reported-by: Paulo Zanoni <przanoni@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com> Link: http://lkml.kernel.org/r/1414037043-30647-1-git-send-email-eparis@redhat.com Cc: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-10-24Merge tag 'v3.18-rc1' into x86/urgentH. Peter Anvin
Reason: Need to apply audit patch on top of v3.18-rc1. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-10-24Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "This is a pretty large update. I think it is roughly as big as what I usually had for the _whole_ rc period. There are a few bad bugs where the guest can OOPS or crash the host. We have also started looking at attack models for nested virtualization; bugs that usually result in the guest ring 0 crashing itself become more worrisome if you have nested virtualization, because the nested guest might bring down the non-nested guest as well. For current uses of nested virtualization these do not really have a security impact, but you never know and bugs are bugs nevertheless. A lot of these bugs are in 3.17 too, resulting in a large number of stable@ Ccs. I checked that all the patches apply there with no conflicts" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: vfio: fix unregister kvm_device_ops of vfio KVM: x86: Wrong assertion on paging_tmpl.h kvm: fix excessive pages un-pinning in kvm_iommu_map error path. KVM: x86: PREFETCH and HINT_NOP should have SrcMem flag KVM: x86: Emulator does not decode clflush well KVM: emulate: avoid accessing NULL ctxt->memopp KVM: x86: Decoding guest instructions which cross page boundary may fail kvm: x86: don't kill guest on unknown exit reason kvm: vmx: handle invvpid vm exit gracefully KVM: x86: Handle errors when RIP is set during far jumps KVM: x86: Emulator fixes for eip canonical checks on near branches KVM: x86: Fix wrong masking on relative jump/call KVM: x86: Improve thread safety in pit KVM: x86: Prevent host from panicking on shared MSR writes. KVM: x86: Check non-canonical addresses upon WRMSR
2014-10-24Merge tag 'stable/for-linus-3.18-b-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen bug fixes from David Vrabel: - Fix regression in xen_clocksource_read() which caused all Xen guests to crash early in boot. - Several fixes for super rare race conditions in the p2m. - Assorted other minor fixes. * tag 'stable/for-linus-3.18-b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/pci: Allocate memory for physdev_pci_device_add's optarr x86/xen: panic on bad Xen-provided memory map x86/xen: Fix incorrect per_cpu accessor in xen_clocksource_read() x86/xen: avoid race in p2m handling x86/xen: delay construction of mfn_list_list x86/xen: avoid writing to freed memory after race in p2m handling xen/balloon: Don't continue ballooning when BP_ECANCELED is encountered
2014-10-24KVM: x86: Wrong assertion on paging_tmpl.hNadav Amit
Even after the recent fix, the assertion on paging_tmpl.h is triggered. Apparently, the assertion wants to check that the PAE is always set on long-mode, but does it in incorrect way. Note that the assertion is not enabled unless the code is debugged by defining MMU_DEBUG. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: x86: PREFETCH and HINT_NOP should have SrcMem flagNadav Amit
The decode phase of the x86 emulator assumes that every instruction with the ModRM flag, and which can be used with RIP-relative addressing, has either SrcMem or DstMem. This is not the case for several instructions - prefetch, hint-nop and clflush. Adding SrcMem|NoAccess for prefetch and hint-nop and SrcMem for clflush. This fixes CVE-2014-8480. Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: x86: Emulator does not decode clflush wellNadav Amit
Currently, all group15 instructions are decoded as clflush (e.g., mfence, xsave). In addition, the clflush instruction requires no prefix (66/f2/f3) would exist. If prefix exists it may encode a different instruction (e.g., clflushopt). Creating a group for clflush, and different group for each prefix. This has been the case forever, but the next patch needs the cflush group in order to fix a bug introduced in 3.17. Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: emulate: avoid accessing NULL ctxt->memoppPaolo Bonzini
A failure to decode the instruction can cause a NULL pointer access. This is fixed simply by moving the "done" label as close as possible to the return. This fixes CVE-2014-8481. Reported-by: Andy Lutomirski <luto@amacapital.net> Cc: stable@vger.kernel.org Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: x86: Decoding guest instructions which cross page boundary may failNadav Amit
Once an instruction crosses a page boundary, the size read from the second page disregards the common case that part of the operand resides on the first page. As a result, fetch of long insturctions may fail, and thereby cause the decoding to fail as well. Cc: stable@vger.kernel.org Fixes: 5cfc7e0f5e5e1adf998df94f8e36edaf5d30d38e Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24kvm: x86: don't kill guest on unknown exit reasonMichael S. Tsirkin
KVM_EXIT_UNKNOWN is a kvm bug, we don't really know whether it was triggered by a priveledged application. Let's not kill the guest: WARN and inject #UD instead. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24kvm: vmx: handle invvpid vm exit gracefullyPetr Matousek
On systems with invvpid instruction support (corresponding bit in IA32_VMX_EPT_VPID_CAP MSR is set) guest invocation of invvpid causes vm exit, which is currently not handled and results in propagation of unknown exit to userspace. Fix this by installing an invvpid vm exit handler. This is CVE-2014-3646. Cc: stable@vger.kernel.org Signed-off-by: Petr Matousek <pmatouse@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: x86: Handle errors when RIP is set during far jumpsNadav Amit
Far jmp/call/ret may fault while loading a new RIP. Currently KVM does not handle this case, and may result in failed vm-entry once the assignment is done. The tricky part of doing so is that loading the new CS affects the VMCS/VMCB state, so if we fail during loading the new RIP, we are left in unconsistent state. Therefore, this patch saves on 64-bit the old CS descriptor and restores it if loading RIP failed. This fixes CVE-2014-3647. Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: x86: Emulator fixes for eip canonical checks on near branchesNadav Amit
Before changing rip (during jmp, call, ret, etc.) the target should be asserted to be canonical one, as real CPUs do. During sysret, both target rsp and rip should be canonical. If any of these values is noncanonical, a #GP exception should occur. The exception to this rule are syscall and sysenter instructions in which the assigned rip is checked during the assignment to the relevant MSRs. This patch fixes the emulator to behave as real CPUs do for near branches. Far branches are handled by the next patch. This fixes CVE-2014-3647. Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24KVM: x86: Fix wrong masking on relative jump/callNadav Amit
Relative jumps and calls do the masking according to the operand size, and not according to the address size as the KVM emulator does today. This patch fixes KVM behavior. Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>