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* KVM: x86: Manually calculate reserved bits when loading PDPTRSSean Christopherson2019-10-051-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 16cfacc8085782dab8e365979356ce1ca87fd6cc upstream. Manually generate the PDPTR reserved bit mask when explicitly loading PDPTRs. The reserved bits that are being tracked by the MMU reflect the current paging mode, which is unlikely to be PAE paging in the vast majority of flows that use load_pdptrs(), e.g. CR0 and CR4 emulation, __set_sregs(), etc... This can cause KVM to incorrectly signal a bad PDPTR, or more likely, miss a reserved bit check and subsequently fail a VM-Enter due to a bad VMCS.GUEST_PDPTR. Add a one off helper to generate the reserved bits instead of sharing code across the MMU's calculations and the PDPTR emulation. The PDPTR reserved bits are basically set in stone, and pushing a helper into the MMU's calculation adds unnecessary complexity without improving readability. Oppurtunistically fix/update the comment for load_pdptrs(). Note, the buggy commit also introduced a deliberate functional change, "Also remove bit 5-6 from rsvd_bits_mask per latest SDM.", which was effectively (and correctly) reverted by commit cd9ae5fe47df ("KVM: x86: Fix page-tables reserved bits"). A bit of SDM archaeology shows that the SDM from late 2008 had a bug (likely a copy+paste error) where it listed bits 6:5 as AVL and A for PDPTEs used for 4k entries but reserved for 2mb entries. I.e. the SDM contradicted itself, and bits 6:5 are and always have been reserved. Fixes: 20c466b56168d ("KVM: Use rsvd_bits_mask in load_pdptrs()") Cc: stable@vger.kernel.org Cc: Nadav Amit <nadav.amit@gmail.com> Reported-by: Doug Reiland <doug.reiland@intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: set ctxt->have_exception in x86_decode_insn()Jan Dakinevich2019-10-052-0/+8
| | | | | | | | | | | | | | | | | | commit c8848cee74ff05638e913582a476bde879c968ad upstream. x86_emulate_instruction() takes into account ctxt->have_exception flag during instruction decoding, but in practice this flag is never set in x86_decode_insn(). Fixes: 6ea6e84309ca ("KVM: x86: inject exceptions produced by x86_decode_insn") Cc: stable@vger.kernel.org Cc: Denis Lunev <den@virtuozzo.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Denis Plotnikov <dplotnikov@virtuozzo.com> Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: always stop emulation on page faultJan Dakinevich2019-10-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8530a79c5a9f4e29e6ffb35ec1a79d81f4968ec8 upstream. inject_emulated_exception() returns true if and only if nested page fault happens. However, page fault can come from guest page tables walk, either nested or not nested. In both cases we should stop an attempt to read under RIP and give guest to step over its own page fault handler. This is also visible when an emulated instruction causes a #GP fault and the VMware backdoor is enabled. To handle the VMware backdoor, KVM intercepts #GP faults; with only the next patch applied, x86_emulate_instruction() injects a #GP but returns EMULATE_FAIL instead of EMULATE_DONE. EMULATE_FAIL causes handle_exception_nmi() (or gp_interception() for SVM) to re-inject the original #GP because it thinks emulation failed due to a non-VMware opcode. This patch prevents the issue as x86_emulate_instruction() will return EMULATE_DONE after injecting the #GP. Fixes: 6ea6e84309ca ("KVM: x86: inject exceptions produced by x86_decode_insn") Cc: stable@vger.kernel.org Cc: Denis Lunev <den@virtuozzo.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Denis Plotnikov <dplotnikov@virtuozzo.com> Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/cpu: Add Tiger Lake to Intel familyGayatri Kammela2019-10-051-0/+3
| | | | | | | | | | | | | | | | | | | [ Upstream commit 6e1c32c5dbb4b90eea8f964c2869d0bde050dbe0 ] Add the model numbers/CPUIDs of Tiger Lake mobile and desktop to the Intel family. Suggested-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rahul Tanwar <rahul.tanwar@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190905193020.14707-2-tony.luck@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/mm/pti: Handle unaligned address gracefully in pti_clone_pagetable()Song Liu2019-10-051-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 825d0b73cd7526b0bb186798583fae810091cbac ] pti_clone_pmds() assumes that the supplied address is either: - properly PUD/PMD aligned or - the address is actually mapped which means that independently of the mapping level (PUD/PMD/PTE) the next higher mapping exists. If that's not the case the unaligned address can be incremented by PUD or PMD size incorrectly. All callers supply mapped and/or aligned addresses, but for the sake of robustness it's better to handle that case properly and to emit a warning. [ tglx: Rewrote changelog and added WARN_ON_ONCE() ] Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282352470.1938@nanos.tec.linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/mm/pti: Do not invoke PTI functions when PTI is disabledThomas Gleixner2019-10-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 990784b57731192b7d90c8d4049e6318d81e887d ] When PTI is disabled at boot time either because the CPU is not affected or PTI has been disabled on the command line, the boot code still calls into pti_finalize() which then unconditionally invokes: pti_clone_entry_text() pti_clone_kernel_text() pti_clone_kernel_text() was called unconditionally before the 32bit support was added and 32bit added the call to pti_clone_entry_text(). The call has no side effects as cloning the page tables into the available second one, which was allocated for PTI does not create damage. But it does not make sense either and in case that this functionality would be extended later this might actually lead to hard to diagnose issues. Neither function should be called when PTI is runtime disabled. Make the invocation conditional. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190828143124.063353972@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/apic/vector: Warn when vector space exhaustion breaks affinityNeil Horman2019-10-051-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 743dac494d61d991967ebcfab92e4f80dc7583b3 ] On x86, CPUs are limited in the number of interrupts they can have affined to them as they only support 256 interrupt vectors per CPU. 32 vectors are reserved for the CPU and the kernel reserves another 22 for internal purposes. That leaves 202 vectors for assignement to devices. When an interrupt is set up or the affinity is changed by the kernel or the administrator, the vector assignment code attempts to honor the requested affinity mask. If the vector space on the CPUs in that affinity mask is exhausted the code falls back to a wider set of CPUs and assigns a vector on a CPU outside of the requested affinity mask silently. While the effective affinity is reflected in the corresponding /proc/irq/$N/effective_affinity* files the silent breakage of the requested affinity can lead to unexpected behaviour for administrators. Add a pr_warn() when this happens so that adminstrators get at least informed about it in the syslog. [ tglx: Massaged changelog and made the pr_warn() more informative ] Reported-by: djuran@redhat.com Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: djuran@redhat.com Link: https://lkml.kernel.org/r/20190822143421.9535-1-nhorman@tuxdriver.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/apic: Soft disable APIC before initializing itThomas Gleixner2019-10-051-0/+8
| | | | | | | | | | | | | | | | | [ Upstream commit 2640da4cccf5cc613bf26f0998b9e340f4b5f69c ] If the APIC was already enabled on entry of setup_local_APIC() then disabling it soft via the SPIV register makes a lot of sense. That masks all LVT entries and brings it into a well defined state. Otherwise previously enabled LVTs which are not touched in the setup function stay unmasked and might surprise the just booting kernel. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.068290579@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/reboot: Always use NMI fallback when shutdown via reboot vector IPI failsGrzegorz Halat2019-10-051-19/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 747d5a1bf293dcb33af755a6d285d41b8c1ea010 ] A reboot request sends an IPI via the reboot vector and waits for all other CPUs to stop. If one or more CPUs are in critical regions with interrupts disabled then the IPI is not handled on those CPUs and the shutdown hangs if native_stop_other_cpus() is called with the wait argument set. Such a situation can happen when one CPU was stopped within a lock held section and another CPU is trying to acquire that lock with interrupts disabled. There are other scenarios which can cause such a lockup as well. In theory the shutdown should be attempted by an NMI IPI after the timeout period elapsed. Though the wait loop after sending the reboot vector IPI prevents this. It checks the wait request argument and the timeout. If wait is set, which is true for sys_reboot() then it won't fall through to the NMI shutdown method after the timeout period has finished. This was an oversight when the NMI shutdown mechanism was added to handle the 'reboot IPI is not working' situation. The mechanism was added to deal with stuck panic shutdowns, which do not have the wait request set, so the 'wait request' case was probably not considered. Remove the wait check from the post reboot vector IPI wait loop and enforce that the wait loop in the NMI fallback path is invoked even if NMI IPIs are disabled or the registration of the NMI handler fails. That second wait loop will then hang if not all CPUs shutdown and the wait argument is set. [ tglx: Avoid the hard to parse line break in the NMI fallback path, add comments and massage the changelog ] Fixes: 7d007d21e539 ("x86/reboot: Use NMI to assist in shutting down if IRQ fails") Signed-off-by: Grzegorz Halat <ghalat@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Don Zickus <dzickus@redhat.com> Link: https://lkml.kernel.org/r/20190628122813.15500-1-ghalat@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/apic: Make apic_pending_intr_clear() more robustThomas Gleixner2019-10-051-44/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit cc8bf191378c1da8ad2b99cf470ee70193ace84e ] In course of developing shorthand based IPI support issues with the function which tries to clear eventually pending ISR bits in the local APIC were observed. 1) O-day testing triggered the WARN_ON() in apic_pending_intr_clear(). This warning is emitted when the function fails to clear pending ISR bits or observes pending IRR bits which are not delivered to the CPU after the stale ISR bit(s) are ACK'ed. Unfortunately the function only emits a WARN_ON() and fails to dump the IRR/ISR content. That's useless for debugging. Feng added spot on debug printk's which revealed that the stale IRR bit belonged to the APIC timer interrupt vector, but adding ad hoc debug code does not help with sporadic failures in the field. Rework the loop so the full IRR/ISR contents are saved and on failure dumped. 2) The loop termination logic is interesting at best. If the machine has no TSC or cpu_khz is not known yet it tries 1 million times to ack stale IRR/ISR bits. What? With TSC it uses the TSC to calculate the loop termination. It takes a timestamp at entry and terminates the loop when: (rdtsc() - start_timestamp) >= (cpu_hkz << 10) That's roughly one second. Both methods are problematic. The APIC has 256 vectors, which means that in theory max. 256 IRR/ISR bits can be set. In practice this is impossible and the chance that more than a few bits are set is close to zero. With the pure loop based approach the 1 million retries are complete overkill. With TSC this can terminate too early in a guest which is running on a heavily loaded host even with only a couple of IRR/ISR bits set. The reason is that after acknowledging the highest priority ISR bit, pending IRRs must get serviced first before the next round of acknowledge can take place as the APIC (real and virtualized) does not honour EOI without a preceeding interrupt on the CPU. And every APIC read/write takes a VMEXIT if the APIC is virtualized. While trying to reproduce the issue 0-day reported it was observed that the guest was scheduled out long enough under heavy load that it terminated after 8 iterations. Make the loop terminate after 512 iterations. That's plenty enough in any case and does not take endless time to complete. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.158847694@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/hyper-v: Fix overflow bug in fill_gva_list()Tianyu Lan2019-09-211-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 4030b4c585c41eeefec7bd20ce3d0e100a0f2e4d ] When the 'start' parameter is >= 0xFF000000 on 32-bit systems, or >= 0xFFFFFFFF'FF000000 on 64-bit systems, fill_gva_list() gets into an infinite loop. With such inputs, 'cur' overflows after adding HV_TLB_FLUSH_UNIT and always compares as less than end. Memory is filled with guest virtual addresses until the system crashes. Fix this by never incrementing 'cur' to be larger than 'end'. Reported-by: Jong Hyun Park <park.jonghyun@yonsei.ac.kr> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 2ffd9e33ce4a ("x86/hyper-v: Use hypercall for remote TLB flush") Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/uaccess: Don't leak the AC flags into __get_user() argument evaluationPeter Zijlstra2019-09-211-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9b8bd476e78e89c9ea26c3b435ad0201c3d7dbf5 ] Identical to __put_user(); the __get_user() argument evalution will too leak UBSAN crud into the __uaccess_begin() / __uaccess_end() region. While uncommon this was observed to happen for: drivers/xen/gntdev.c: if (__get_user(old_status, batch->status[i])) where UBSAN added array bound checking. This complements commit: 6ae865615fc4 ("x86/uaccess: Dont leak the AC flag into __put_user() argument evaluation") Tested-by Sedat Dilek <sedat.dilek@gmail.com> Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: broonie@kernel.org Cc: sfr@canb.auug.org.au Cc: akpm@linux-foundation.org Cc: Randy Dunlap <rdunlap@infradead.org> Cc: mhocko@suse.cz Cc: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20190829082445.GM2369@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org>
* perf/x86/amd/ibs: Fix sample bias for dispatched micro-opsKim Phillips2019-09-212-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0f4cd769c410e2285a4e9873a684d90423f03090 ] When counting dispatched micro-ops with cnt_ctl=1, in order to prevent sample bias, IBS hardware preloads the least significant 7 bits of current count (IbsOpCurCnt) with random values, such that, after the interrupt is handled and counting resumes, the next sample taken will be slightly perturbed. The current count bitfield is in the IBS execution control h/w register, alongside the maximum count field. Currently, the IBS driver writes that register with the maximum count, leaving zeroes to fill the current count field, thereby overwriting the random bits the hardware preloaded for itself. Fix the driver to actually retain and carry those random bits from the read of the IBS control register, through to its write, instead of overwriting the lower current count bits with zeroes. Tested with: perf record -c 100001 -e ibs_op/cnt_ctl=1/pp -a -C 0 taskset -c 0 <workload> 'perf annotate' output before: 15.70 65: addsd %xmm0,%xmm1 17.30 add $0x1,%rax 15.88 cmp %rdx,%rax je 82 17.32 72: test $0x1,%al jne 7c 7.52 movapd %xmm1,%xmm0 5.90 jmp 65 8.23 7c: sqrtsd %xmm1,%xmm0 12.15 jmp 65 'perf annotate' output after: 16.63 65: addsd %xmm0,%xmm1 16.82 add $0x1,%rax 16.81 cmp %rdx,%rax je 82 16.69 72: test $0x1,%al jne 7c 8.30 movapd %xmm1,%xmm0 8.13 jmp 65 8.24 7c: sqrtsd %xmm1,%xmm0 8.39 jmp 65 Tested on Family 15h and 17h machines. Machines prior to family 10h Rev. C don't have the RDWROPCNT capability, and have the IbsOpCurCnt bitfield reserved, so this patch shouldn't affect their operation. It is unknown why commit db98c5faf8cb ("perf/x86: Implement 64-bit counter support for IBS") ignored the lower 4 bits of the IbsOpCurCnt field; the number of preloaded random bits has always been 7, AFAICT. Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Arnaldo Carvalho de Melo" <acme@kernel.org> Cc: <x86@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Borislav Petkov" <bp@alien8.de> Cc: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: "Namhyung Kim" <namhyung@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20190826195730.30614-1-kim.phillips@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* perf/x86/intel: Restrict period on NehalemJosh Hunt2019-09-211-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 44d3bbb6f5e501b873218142fe08cdf62a4ac1f3 ] We see our Nehalem machines reporting 'perfevents: irq loop stuck!' in some cases when using perf: perfevents: irq loop stuck! WARNING: CPU: 0 PID: 3485 at arch/x86/events/intel/core.c:2282 intel_pmu_handle_irq+0x37b/0x530 ... RIP: 0010:intel_pmu_handle_irq+0x37b/0x530 ... Call Trace: <NMI> ? perf_event_nmi_handler+0x2e/0x50 ? intel_pmu_save_and_restart+0x50/0x50 perf_event_nmi_handler+0x2e/0x50 nmi_handle+0x6e/0x120 default_do_nmi+0x3e/0x100 do_nmi+0x102/0x160 end_repeat_nmi+0x16/0x50 ... ? native_write_msr+0x6/0x20 ? native_write_msr+0x6/0x20 </NMI> intel_pmu_enable_event+0x1ce/0x1f0 x86_pmu_start+0x78/0xa0 x86_pmu_enable+0x252/0x310 __perf_event_task_sched_in+0x181/0x190 ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x35/0x70 ? __switch_to_asm+0x41/0x70 ? __switch_to_asm+0x35/0x70 finish_task_switch+0x158/0x260 __schedule+0x2f6/0x840 ? hrtimer_start_range_ns+0x153/0x210 schedule+0x32/0x80 schedule_hrtimeout_range_clock+0x8a/0x100 ? hrtimer_init+0x120/0x120 ep_poll+0x2f7/0x3a0 ? wake_up_q+0x60/0x60 do_epoll_wait+0xa9/0xc0 __x64_sys_epoll_wait+0x1a/0x20 do_syscall_64+0x4e/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fdeb1e96c03 ... Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: acme@kernel.org Cc: Josh Hunt <johunt@akamai.com> Cc: bpuranda@akamai.com Cc: mingo@redhat.com Cc: jolsa@redhat.com Cc: tglx@linutronix.de Cc: namhyung@kernel.org Cc: alexander.shishkin@linux.intel.com Link: https://lkml.kernel.org/r/1566256411-18820-1-git-send-email-johunt@akamai.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machinesThomas Gleixner2019-09-211-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 3e5bedc2c258341702ddffbd7688c5e6eb01eafa ] Rahul Tanwar reported the following bug on DT systems: > 'ioapic_dynirq_base' contains the virtual IRQ base number. Presently, it is > updated to the end of hardware IRQ numbers but this is done only when IOAPIC > configuration type is IOAPIC_DOMAIN_LEGACY or IOAPIC_DOMAIN_STRICT. There is > a third type IOAPIC_DOMAIN_DYNAMIC which applies when IOAPIC configuration > comes from devicetree. > > See dtb_add_ioapic() in arch/x86/kernel/devicetree.c > > In case of IOAPIC_DOMAIN_DYNAMIC (DT/OF based system), 'ioapic_dynirq_base' > remains to zero initialized value. This means that for OF based systems, > virtual IRQ base will get set to zero. Such systems will very likely not even boot. For DT enabled machines ioapic_dynirq_base is irrelevant and not updated, so simply map the IRQ base 1:1 instead. Reported-by: Rahul Tanwar <rahul.tanwar@linux.intel.com> Tested-by: Rahul Tanwar <rahul.tanwar@linux.intel.com> Tested-by: Andy Shevchenko <andriy.shevchenko@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: alan@linux.intel.com Cc: bp@alien8.de Cc: cheol.yong.kim@intel.com Cc: qi-ming.wu@intel.com Cc: rahul.tanwar@intel.com Cc: rppt@linux.ibm.com Cc: tony.luck@intel.com Link: http://lkml.kernel.org/r/20190821081330.1187-1-rahul.tanwar@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence ↵Linus Torvalds2019-09-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC9 build warning commit 42e0e95474fc6076b5cd68cab8fa0340a1797a72 upstream. One of the very few warnings I have in the current build comes from arch/x86/boot/edd.c, where I get the following with a gcc9 build: arch/x86/boot/edd.c: In function ‘query_edd’: arch/x86/boot/edd.c:148:11: warning: taking address of packed member of ‘struct boot_params’ may result in an unaligned pointer value [-Waddress-of-packed-member] 148 | mbrptr = boot_params.edd_mbr_sig_buffer; | ^~~~~~~~~~~ This warning triggers because we throw away all the CFLAGS and then make a new set for REALMODE_CFLAGS, so the -Wno-address-of-packed-member we added in the following commit is not present: 6f303d60534c ("gcc-9: silence 'address-of-packed-member' warning") The simplest solution for now is to adjust the warning for this version of CFLAGS as well, but it would definitely make sense to examine whether REALMODE_CFLAGS could be derived from CFLAGS, so that it picks up changes in the compiler flags environment automatically. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/purgatory: Change compiler flags from -mcmodel=kernel to -mcmodel=large ↵Steve Wahl2019-09-191-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | to fix kexec relocation errors commit e16c2983fba0fa6763e43ad10916be35e3d8dc05 upstream. The last change to this Makefile caused relocation errors when loading a kdump kernel. Restore -mcmodel=large (not -mcmodel=kernel), -ffreestanding, and -fno-zero-initialized-bsss, without reverting to the former practice of resetting KBUILD_CFLAGS. Purgatory.ro is a standalone binary that is not linked against the rest of the kernel. Its image is copied into an array that is linked to the kernel, and from there kexec relocates it wherever it desires. With the previous change to compiler flags, the error "kexec: Overflow in relocation type 11 value 0x11fffd000" was encountered when trying to load the crash kernel. This is from kexec code trying to relocate the purgatory.ro object. From the error message, relocation type 11 is R_X86_64_32S. The x86_64 ABI says: "The R_X86_64_32 and R_X86_64_32S relocations truncate the computed value to 32-bits. The linker must verify that the generated value for the R_X86_64_32 (R_X86_64_32S) relocation zero-extends (sign-extends) to the original 64-bit value." This type of relocation doesn't work when kexec chooses to place the purgatory binary in memory that is not reachable with 32 bit addresses. The compiler flag -mcmodel=kernel allows those type of relocations to be emitted, so revert to using -mcmodel=large as was done before. Also restore the -ffreestanding and -fno-zero-initialized-bss flags because they are appropriate for a stand alone piece of object code which doesn't explicitly zero the bss, and one other report has said undefined symbols are encountered without -ffreestanding. These identical compiler flag changes need to happen for every object that becomes part of the purgatory.ro object, so gather them together first into PURGATORY_CFLAGS_REMOVE and PURGATORY_CFLAGS, and then apply them to each of the objects that have C source. Do not apply any of these flags to kexec-purgatory.o, which is not part of the standalone object but part of the kernel proper. Tested-by: Vaibhav Rustagi <vaibhavrustagi@google.com> Tested-by: Andreas Smas <andreas@lonelycoder.com> Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: None Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: clang-built-linux@googlegroups.com Cc: dimitri.sivanich@hpe.com Cc: mike.travis@hpe.com Cc: russ.anderson@hpe.com Fixes: b059f801a937 ("x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS") Link: https://lkml.kernel.org/r/20190905202346.GA26595@swahl-linux Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andreas Smas <andreas@lonelycoder.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: handle page fault in vmreadPaolo Bonzini2019-09-191-2/+5
| | | | | | | | | | | | commit f7eea636c3d505fe6f1d1066234f1aaf7171b681 upstream. The implementation of vmread to memory is still incomplete, as it lacks the ability to do vmread to I/O memory just like vmptrst. Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: work around leak of uninitialized stack contentsFuqian Huang2019-09-191-0/+7
| | | | | | | | | | | | | | | | | | | | commit 541ab2aeb28251bf7135c7961f3a6080eebcc705 upstream. Emulation of VMPTRST can incorrectly inject a page fault when passed an operand that points to an MMIO address. The page fault will use uninitialized kernel stack memory as the CR2 and error code. The right behavior would be to abort the VM with a KVM_EXIT_INTERNAL_ERROR exit to userspace; however, it is not an easy fix, so for now just ensure that the error code and CR2 are zero. Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com> Cc: stable@vger.kernel.org [add comment] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: VMX: check CPUID before allowing read/write of IA32_XSSWanpeng Li2019-09-161-2/+8
| | | | | | | | | | | | | | | | | [ Upstream commit 4d763b168e9c5c366b05812c7bba7662e5ea3669 ] Raise #GP when guest read/write IA32_XSS, but the CPUID bits say that it shouldn't exist. Fixes: 203000993de5 (kvm: vmx: add MSR logic for XSAVES) Reported-by: Xiaoyao Li <xiaoyao.li@linux.intel.com> Reported-by: Tao Xu <tao3.xu@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: VMX: Fix handling of #MC that occurs during VM-EntrySean Christopherson2019-09-161-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit beb8d93b3e423043e079ef3dda19dad7b28467a8 ] A previous fix to prevent KVM from consuming stale VMCS state after a failed VM-Entry inadvertantly blocked KVM's handling of machine checks that occur during VM-Entry. Per Intel's SDM, a #MC during VM-Entry is handled in one of three ways, depending on when the #MC is recognoized. As it pertains to this bug fix, the third case explicitly states EXIT_REASON_MCE_DURING_VMENTRY is handled like any other VM-Exit during VM-Entry, i.e. sets bit 31 to indicate the VM-Entry failed. If a machine-check event occurs during a VM entry, one of the following occurs: - The machine-check event is handled as if it occurred before the VM entry: ... - The machine-check event is handled after VM entry completes: ... - A VM-entry failure occurs as described in Section 26.7. The basic exit reason is 41, for "VM-entry failure due to machine-check event". Explicitly handle EXIT_REASON_MCE_DURING_VMENTRY as a one-off case in vmx_vcpu_run() instead of binning it into vmx_complete_atomic_exit(). Doing so allows vmx_vcpu_run() to handle VMX_EXIT_REASONS_FAILED_VMENTRY in a sane fashion and also simplifies vmx_complete_atomic_exit() since VMCS.VM_EXIT_INTR_INFO is guaranteed to be fresh. Fixes: b060ca3b2e9e7 ("kvm: vmx: Handle VMLAUNCH/VMRESUME failure properly") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad valueSean Christopherson2019-09-161-2/+3
| | | | | | | | | | | | | | [ Upstream commit d28f4290b53a157191ed9991ad05dffe9e8c0c89 ] The behavior of WRMSR is in no way dependent on whether or not KVM consumes the value. Fixes: 4566654bb9be9 ("KVM: vmx: Inject #GP on invalid PAT CR") Cc: stable@vger.kernel.org Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: x86: optimize check for valid PAT valuePaolo Bonzini2019-09-163-10/+12
| | | | | | | | | | | [ Upstream commit 674ea351cdeb01d2740edce31db7f2d79ce6095d ] This check will soon be done on every nested vmentry and vmexit, "parallelize" it using bitwise operations. Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* kvm: Check irqchip mode before assign irqfdPeter Xu2019-09-162-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 654f1f13ea56b92bacade8ce2725aea0457f91c0 ] When assigning kvm irqfd we didn't check the irqchip mode but we allow KVM_IRQFD to succeed with all the irqchip modes. However it does not make much sense to create irqfd even without the kernel chips. Let's provide a arch-dependent helper to check whether a specific irqfd is allowed by the arch. At least for x86, it should make sense to check: - when irqchip mode is NONE, all irqfds should be disallowed, and, - when irqchip mode is SPLIT, irqfds that are with resamplefd should be disallowed. For either of the case, previously we'll silently ignore the irq or the irq ack event if the irqchip mode is incorrect. However that can cause misterious guest behaviors and it can be hard to triage. Let's fail KVM_IRQFD even earlier to detect these incorrect configurations. CC: Paolo Bonzini <pbonzini@redhat.com> CC: Radim Krčmář <rkrcmar@redhat.com> CC: Alex Williamson <alex.williamson@redhat.com> CC: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: x86: Always use 32-bit SMRAM save state for 32-bit kernelsSean Christopherson2019-09-162-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b68f3cc7d978943fcf85148165b00594c38db776 ] Invoking the 64-bit variation on a 32-bit kenrel will crash the guest, trigger a WARN, and/or lead to a buffer overrun in the host, e.g. rsm_load_state_64() writes r8-r15 unconditionally, but enum kvm_reg and thus x86_emulate_ctxt._regs only define r8-r15 for CONFIG_X86_64. KVM allows userspace to report long mode support via CPUID, even though the guest is all but guaranteed to crash if it actually tries to enable long mode. But, a pure 32-bit guest that is ignorant of long mode will happily plod along. SMM complicates things as 64-bit CPUs use a different SMRAM save state area. KVM handles this correctly for 64-bit kernels, e.g. uses the legacy save state map if userspace has hid long mode from the guest, but doesn't fare well when userspace reports long mode support on a 32-bit host kernel (32-bit KVM doesn't support 64-bit guests). Since the alternative is to crash the guest, e.g. by not loading state or explicitly requesting shutdown, unconditionally use the legacy SMRAM save state map for 32-bit KVM. If a guest has managed to get far enough to handle SMIs when running under a weird/buggy userspace hypervisor, then don't deliberately crash the guest since there are no downsides (from KVM's perspective) to allow it to continue running. Fixes: 660a5d517aaab ("KVM: x86: save/load state on SMM switch") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/kvm: move kvm_load/put_guest_xcr0 into atomic contextWANG Chao2019-09-164-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1811d979c71621aafc7b879477202d286f7e863b ] guest xcr0 could leak into host when MCE happens in guest mode. Because do_machine_check() could schedule out at a few places. For example: kvm_load_guest_xcr0 ... kvm_x86_ops->run(vcpu) { vmx_vcpu_run vmx_complete_atomic_exit kvm_machine_check do_machine_check do_memory_failure memory_failure lock_page In this case, host_xcr0 is 0x2ff, guest vcpu xcr0 is 0xff. After schedule out, host cpu has guest xcr0 loaded (0xff). In __switch_to { switch_fpu_finish copy_kernel_to_fpregs XRSTORS If any bit i in XSTATE_BV[i] == 1 and xcr0[i] == 0, XRSTORS will generate #GP (In this case, bit 9). Then ex_handler_fprestore kicks in and tries to reinitialize fpu by restoring init fpu state. Same story as last #GP, except we get DOUBLE FAULT this time. Cc: stable@vger.kernel.org Signed-off-by: WANG Chao <chao.wang@ucloud.cn> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* kvm: mmu: Fix overflow on kvm mmu page limit calculationBen Gardon2019-09-164-16/+15
| | | | | | | | | | | | | | | | | | | | [ Upstream commit bc8a3d8925a8fa09fa550e0da115d95851ce33c6 ] KVM bases its memory usage limits on the total number of guest pages across all memslots. However, those limits, and the calculations to produce them, use 32 bit unsigned integers. This can result in overflow if a VM has more guest pages that can be represented by a u32. As a result of this overflow, KVM can use a low limit on the number of MMU pages it will allocate. This makes KVM unable to map all of guest memory at once, prompting spurious faults. Tested: Ran all kvm-unit-tests on an Intel Haswell machine. This patch introduced no new failures. Signed-off-by: Ben Gardon <bgardon@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/kvmclock: set offset for kvm unstable clockPavel Tatashin2019-09-161-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b5179ec4187251a751832193693d6e474d3445ac ] VMs may show incorrect uptime and dmesg printk offsets on hypervisors with unstable clock. The problem is produced when VM is rebooted without exiting from qemu. The fix is to calculate clock offset not only for stable clock but for unstable clock as well, and use kvm_sched_clock_read() which substracts the offset for both clocks. This is safe, because pvclock_clocksource_read() does the right thing and makes sure that clock always goes forward, so once offset is calculated with unstable clock, we won't get new reads that are smaller than offset, and thus won't get negative results. Thank you Jon DeVree for helping to reproduce this issue. Fixes: 857baa87b642 ("sched/clock: Enable sched clock early") Cc: stable@vger.kernel.org Reported-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: VMX: Compare only a single byte for VMCS' "launched" in vCPU-runSean Christopherson2019-09-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 61c08aa9606d4e48a8a50639c956448a720174c3 ] The vCPU-run asm blob does a manual comparison of a VMCS' launched status to execute the correct VM-Enter instruction, i.e. VMLAUNCH vs. VMRESUME. The launched flag is a bool, which is a typedef of _Bool. C99 does not define an exact size for _Bool, stating only that is must be large enough to hold '0' and '1'. Most, if not all, compilers use a single byte for _Bool, including gcc[1]. Originally, 'launched' was of type 'int' and so the asm blob used 'cmpl' to check the launch status. When 'launched' was moved to be stored on a per-VMCS basis, struct vcpu_vmx's "temporary" __launched flag was added in order to avoid having to pass the current VMCS into the asm blob. The new '__launched' was defined as a 'bool' and not an 'int', but the 'cmp' instruction was not updated. This has not caused any known problems, likely due to compilers aligning variables to 4-byte or 8-byte boundaries and KVM zeroing out struct vcpu_vmx during allocation. I.e. vCPU-run accesses "junk" data, it just happens to always be zero and so doesn't affect the result. [1] https://gcc.gnu.org/ml/gcc-patches/2000-10/msg01127.html Fixes: d462b8192368 ("KVM: VMX: Keep list of loaded VMCSs, instead of vcpus") Cc: <stable@vger.kernel.org> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/kvm/lapic: preserve gfn_to_hva_cache len on cache reinitVitaly Kuznetsov2019-09-161-2/+10
| | | | | | | | | | | | | | | | | | | | [ Upstream commit a7c42bb6da6b1b54b2e7bd567636d72d87b10a79 ] vcpu->arch.pv_eoi is accessible through both HV_X64_MSR_VP_ASSIST_PAGE and MSR_KVM_PV_EOI_EN so on migration userspace may try to restore them in any order. Values match, however, kvm_lapic_enable_pv_eoi() uses different length: for Hyper-V case it's the whole struct hv_vp_assist_page, for KVM native case it is 8. In case we restore KVM-native MSR last cache will be reinitialized with len=8 so trying to access VP assist page beyond 8 bytes with kvm_read_guest_cached() will fail. Check if we re-initializing cache for the same address and preserve length in case it was greater. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: hyperv: define VP assist page helpersLadi Prosek2019-09-165-6/+29
| | | | | | | | | | | | | [ Upstream commit 72bbf9358c3676bd89dc4bd8fb0b1f2a11c288fc ] The state related to the VP assist page is still managed by the LAPIC code in the pv_eoi field. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: x86: hyperv: keep track of mismatched VP indexesVitaly Kuznetsov2019-09-162-3/+26
| | | | | | | | | | | | | | | | [ Upstream commit 87ee613d076351950b74383215437f841ebbeb75 ] In most common cases VP index of a vcpu matches its vcpu index. Userspace is, however, free to set any mapping it wishes and we need to account for that when we need to find a vCPU with a particular VP index. To keep search algorithms optimal in both cases introduce 'num_mismatched_vp_indexes' counter showing how many vCPUs with mismatching VP index we have. In case the counter is zero we can assume vp_index == vcpu_idx. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: x86: hyperv: consistently use 'hv_vcpu' for 'struct kvm_vcpu_hv' variablesVitaly Kuznetsov2019-09-161-9/+9
| | | | | | | | | | | | [ Upstream commit 1779a39f786397760ae7a7cc03cf37697d8ae58d ] Rename 'hv' to 'hv_vcpu' in kvm_hv_set_msr/kvm_hv_get_msr(); 'hv' is 'reserved' for 'struct kvm_hv' variables across the file. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: x86: hyperv: enforce vp_index < KVM_MAX_VCPUSVitaly Kuznetsov2019-09-161-3/+5
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 9170200ec0ebad70e5b9902bc93e2b1b11456a3b ] Hyper-V TLFS (5.0b) states: > Virtual processors are identified by using an index (VP index). The > maximum number of virtual processors per partition supported by the > current implementation of the hypervisor can be obtained through CPUID > leaf 0x40000005. A virtual processor index must be less than the > maximum number of virtual processors per partition. Forbid userspace to set VP_INDEX above KVM_MAX_VCPUS. get_vcpu_by_vpidx() can now be optimized to bail early when supplied vpidx is >= KVM_MAX_VCPUS. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86, hibernate: Fix nosave_regions setup for hibernationZhimin Gu2019-09-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit cc55f7537db6af371e9c1c6a71161ee40f918824 ] On 32bit systems, nosave_regions(non RAM areas) located between max_low_pfn and max_pfn are not excluded from hibernation snapshot currently, which may result in a machine check exception when trying to access these unsafe regions during hibernation: [ 612.800453] Disabling lock debugging due to kernel taint [ 612.805786] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: fe00000000801136 [ 612.814344] mce: [Hardware Error]: RIP !INEXACT! 60:<00000000d90be566> {swsusp_save+0x436/0x560} [ 612.823167] mce: [Hardware Error]: TSC 1f5939fe276 ADDR dd000000 MISC 30e0000086 [ 612.830677] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1529487426 SOCKET 0 APIC 0 microcode 24 [ 612.839581] mce: [Hardware Error]: Run the above through 'mcelog --ascii' [ 612.846394] mce: [Hardware Error]: Machine check: Processor context corrupt [ 612.853380] Kernel panic - not syncing: Fatal machine check [ 612.858978] Kernel Offset: 0x18000000 from 0xc1000000 (relocation range: 0xc0000000-0xf7ffdfff) This is because on 32bit systems, pages above max_low_pfn are regarded as high memeory, and accessing unsafe pages might cause expected MCE. On the problematic 32bit system, there are reserved memory above low memory, which triggered the MCE: e820 memory mapping: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable [ 0.000000] BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000d160cfff] usable [ 0.000000] BIOS-e820: [mem 0x00000000d160d000-0x00000000d1613fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000d1614000-0x00000000d1a44fff] usable [ 0.000000] BIOS-e820: [mem 0x00000000d1a45000-0x00000000d1ecffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000d1ed0000-0x00000000d7eeafff] usable [ 0.000000] BIOS-e820: [mem 0x00000000d7eeb000-0x00000000d7ffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000d8000000-0x00000000d875ffff] usable [ 0.000000] BIOS-e820: [mem 0x00000000d8760000-0x00000000d87fffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000d8800000-0x00000000d8fadfff] usable [ 0.000000] BIOS-e820: [mem 0x00000000d8fae000-0x00000000d8ffffff] ACPI data [ 0.000000] BIOS-e820: [mem 0x00000000d9000000-0x00000000da71bfff] usable [ 0.000000] BIOS-e820: [mem 0x00000000da71c000-0x00000000da7fffff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000da800000-0x00000000dbb8bfff] usable [ 0.000000] BIOS-e820: [mem 0x00000000dbb8c000-0x00000000dbffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000dd000000-0x00000000df1fffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed03fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000041edfffff] usable Fix this problem by changing pfn limit from max_low_pfn to max_pfn. This fix does not impact 64bit system because on 64bit max_low_pfn is the same as max_pfn. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/ftrace: Fix warning and considate ftrace_jmp_replace() and ↵Steven Rostedt (VMware)2019-09-161-25/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ftrace_call_replace() [ Upstream commit 745cfeaac09ce359130a5451d90cb0bd4094c290 ] Arnd reported the following compiler warning: arch/x86/kernel/ftrace.c:669:23: error: 'ftrace_jmp_replace' defined but not used [-Werror=unused-function] The ftrace_jmp_replace() function now only has a single user and should be simply moved by that user. But looking at the code, it shows that ftrace_jmp_replace() is similar to ftrace_call_replace() except that instead of using the opcode of 0xe8 it uses 0xe9. It makes more sense to consolidate that function into one implementation that both ftrace_jmp_replace() and ftrace_call_replace() use by passing in the op code separate. The structure in ftrace_code_union is also modified to replace the "e8" field with the more appropriate name "op". Cc: stable@vger.kernel.org Reported-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/20190304200748.1418790-1-arnd@arndb.de Fixes: d2a68c4effd8 ("x86/ftrace: Do not call function graph from dynamic trampolines") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Revert "x86/apic: Include the LDR when clearing out APIC registers"Linus Torvalds2019-09-101-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 950b07c14e8c59444e2359f15fd70ed5112e11a0 ] This reverts commit 558682b5291937a70748d36fd9ba757fb25b99ae. Chris Wilson reports that it breaks his CPU hotplug test scripts. In particular, it breaks offlining and then re-onlining the boot CPU, which we treat specially (and the BIOS does too). The symptoms are that we can offline the CPU, but it then does not come back online again: smpboot: CPU 0 is now offline smpboot: Booting Node 0 Processor 0 APIC 0x0 smpboot: do_boot_cpu failed(-1) to wakeup CPU#0 Thomas says he knows why it's broken (my personal suspicion: our magic handling of the "cpu0_logical_apicid" thing), but for 5.3 the right fix is to just revert it, since we've never touched the LDR bits before, and it's not worth the risk to do anything else at this stage. [ Hotpluging of the boot CPU is special anyway, and should be off by default. See the "BOOTPARAM_HOTPLUG_CPU0" config option and the cpu0_hotplug kernel parameter. In general you should not do it, and it has various known limitations (hibernate and suspend require the boot CPU, for example). But it should work, even if the boot CPU is special and needs careful treatment - Linus ] Link: https://lore.kernel.org/lkml/156785100521.13300.14461504732265570003@skylake-alporthouse-com/ Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Bandan Das <bsd@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/boot/compressed/64: Fix missing initialization in ↵Kirill A. Shutemov2019-09-101-1/+1
| | | | | | | | | | | | | | | | | | | find_trampoline_placement() [ Upstream commit c96e8483cb2da6695c8b8d0896fe7ae272a07b54 ] Gustavo noticed that 'new' can be left uninitialized if 'bios_start' happens to be less or equal to 'entry->addr + entry->size'. Initialize the variable at the begin of the iteration to the current value of 'bios_start'. Fixes: 0a46fff2f910 ("x86/boot/compressed/64: Fix boot on machines with broken E820 table") Reported-by: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190826133326.7cxb4vbmiawffv2r@box Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/boot/compressed/64: Fix boot on machines with broken E820 tableKirill A. Shutemov2019-09-101-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0a46fff2f9108c2c44218380a43a736cf4612541 ] BIOS on Samsung 500C Chromebook reports very rudimentary E820 table that consists of 2 entries: BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] usable BIOS-e820: [mem 0x00000000fffff000-0x00000000ffffffff] reserved It breaks logic in find_trampoline_placement(): bios_start lands on the end of the first 4k page and trampoline start gets placed below 0. Detect underflow and don't touch bios_start for such cases. It makes kernel ignore E820 table on machines that doesn't have two usable pages below BIOS_START_MAX. Fixes: 1b3a62643660 ("x86/boot/compressed/64: Validate trampoline placement against E820") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203463 Link: https://lkml.kernel.org/r/20190813131654.24378-1-kirill.shutemov@linux.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/boot: Preserve boot_params.secure_boot from sanitizingJohn S. Gruber2019-09-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 29d9a0b50736768f042752070e5cdf4e4d4c00df upstream. Commit a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else") now zeroes the secure boot setting information (enabled/disabled/...) passed by the boot loader or by the kernel's EFI handover mechanism. The problem manifests itself with signed kernels using the EFI handoff protocol with grub and the kernel loses the information whether secure boot is enabled in the firmware, i.e., the log message "Secure boot enabled" becomes "Secure boot could not be determined". efi_main() arch/x86/boot/compressed/eboot.c sets this field early but it is subsequently zeroed by the above referenced commit. Include boot_params.secure_boot in the preserve field list. [ bp: restructure commit message and massage. ] Fixes: a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else") Signed-off-by: John S. Gruber <JohnSGruber@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Mark Brown <broonie@kernel.org> Cc: stable <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/CAPotdmSPExAuQcy9iAHqX3js_fc4mMLQOTr5RBGvizyCOPcTQQ@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/ptrace: fix up botched merge of spectrev1 fixGreg Kroah-Hartman2019-09-061-2/+1
| | | | | | | | | | | | | | | | | I incorrectly merged commit 31a2fbb390fe ("x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg()") when backporting it, as was graciously pointed out at https://grsecurity.net/teardown_of_a_failed_linux_lts_spectre_fix.php Resolve the upstream difference with the stable kernel merge to properly protect things. Reported-by: Brad Spengler <spender@grsecurity.net> Cc: Dianzhang Chen <dianzhangchen0@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <bp@alien8.de> Cc: <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/apic: Include the LDR when clearing out APIC registersBandan Das2019-09-061-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 558682b5291937a70748d36fd9ba757fb25b99ae upstream. Although APIC initialization will typically clear out the LDR before setting it, the APIC cleanup code should reset the LDR. This was discovered with a 32-bit KVM guest jumping into a kdump kernel. The stale bits in the LDR triggered a bug in the KVM APIC implementation which caused the destination mapping for VCPUs to be corrupted. Note that this isn't intended to paper over the KVM APIC bug. The kernel has to clear the LDR when resetting the APIC registers except when X2APIC is enabled. This lacks a Fixes tag because missing to clear LDR goes way back into pre git history. [ tglx: Made x2apic_enabled a function call as required ] Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190826101513.5080-3-bsd@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/apic: Do not initialize LDR and DFR for bigsmpBandan Das2019-09-061-22/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit bae3a8d3308ee69a7dbdf145911b18dfda8ade0d upstream. Legacy apic init uses bigsmp for smp systems with 8 and more CPUs. The bigsmp APIC implementation uses physical destination mode, but it nevertheless initializes LDR and DFR. The LDR even ends up incorrectly with multiple bit being set. This does not cause a functional problem because LDR and DFR are ignored when physical destination mode is active, but it triggered a problem on a 32-bit KVM guest which jumps into a kdump kernel. The multiple bits set unearthed a bug in the KVM APIC implementation. The code which creates the logical destination map for VCPUs ignores the disabled state of the APIC and ends up overwriting an existing valid entry and as a result, APIC calibration hangs in the guest during kdump initialization. Remove the bogus LDR/DFR initialization. This is not intended to work around the KVM APIC bug. The LDR/DFR ininitalization is wrong on its own. The issue goes back into the pre git history. The fixes tag is the commit in the bitkeeper import which introduced bigsmp support in 2003. git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Fixes: db7b9e9f26b8 ("[PATCH] Clustered APIC setup for >8 CPU systems") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190826101513.5080-2-bsd@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* uprobes/x86: Fix detection of 32-bit user modeSebastian Mayr2019-09-061-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9212ec7d8357ea630031e89d0d399c761421c83b upstream. 32-bit processes running on a 64-bit kernel are not always detected correctly, causing the process to crash when uretprobes are installed. The reason for the crash is that in_ia32_syscall() is used to determine the process's mode, which only works correctly when called from a syscall. In the case of uretprobes, however, the function is called from a exception and always returns 'false' on a 64-bit kernel. In consequence this leads to corruption of the process's return address. Fix this by using user_64bit_mode() instead of in_ia32_syscall(), which is correct in any situation. [ tglx: Add a comment and the following historical info ] This should have been detected by the rename which happened in commit abfb9498ee13 ("x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()") which states in the changelog: The is_ia32_task()/is_x32_task() function names are a big misnomer: they suggests that the compat-ness of a system call is a task property, which is not true, the compatness of a system call purely depends on how it was invoked through the system call layer. ..... and then it went and blindly renamed every call site. Sadly enough this was already mentioned here: 8faaed1b9f50 ("uprobes/x86: Introduce sizeof_long(), cleanup adjust_ret_addr() and arch_uretprobe_hijack_return_addr()") where the changelog says: TODO: is_ia32_task() is not what we actually want, TS_COMPAT does not necessarily mean 32bit. Fortunately syscall-like insns can't be probed so it actually works, but it would be better to rename and use is_ia32_frame(). and goes all the way back to: 0326f5a94dde ("uprobes/core: Handle breakpoint and singlestep exceptions") Oh well. 7+ years until someone actually tried a uretprobe on a 32bit process on a 64bit kernel.... Fixes: 0326f5a94dde ("uprobes/core: Handle breakpoint and singlestep exceptions") Signed-off-by: Sebastian Mayr <me@sam.st> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190728152617.7308-1-me@sam.st Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: Don't update RIP or do single-step on faulting emulationSean Christopherson2019-09-061-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 75ee23b30dc712d80d2421a9a547e7ab6e379b44 upstream. Don't advance RIP or inject a single-step #DB if emulation signals a fault. This logic applies to all state updates that are conditional on clean retirement of the emulation instruction, e.g. updating RFLAGS was previously handled by commit 38827dbd3fb85 ("KVM: x86: Do not update EFLAGS on faulting emulation"). Not advancing RIP is likely a nop, i.e. ctxt->eip isn't updated with ctxt->_eip until emulation "retires" anyways. Skipping #DB injection fixes a bug reported by Andy Lutomirski where a #UD on SYSCALL due to invalid state with EFLAGS.TF=1 would loop indefinitely due to emulation overwriting the #UD with #DB and thus restarting the bad SYSCALL over and over. Cc: Nadav Amit <nadav.amit@gmail.com> Cc: stable@vger.kernel.org Reported-by: Andy Lutomirski <luto@kernel.org> Fixes: 663f4c61b803 ("KVM: x86: handle singlestep during emulation") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: x86: skip populating logical dest map if apic is not sw enabledRadim Krcmar2019-09-061-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | commit b14c876b994f208b6b95c222056e1deb0a45de0e upstream. recalculate_apic_map does not santize ldr and it's possible that multiple bits are set. In that case, a previous valid entry can potentially be overwritten by an invalid one. This condition is hit when booting a 32 bit, >8 CPU, RHEL6 guest and then triggering a crash to boot a kdump kernel. This is the sequence of events: 1. Linux boots in bigsmp mode and enables PhysFlat, however, it still writes to the LDR which probably will never be used. 2. However, when booting into kdump, the stale LDR values remain as they are not cleared by the guest and there isn't a apic reset. 3. kdump boots with 1 cpu, and uses Logical Destination Mode but the logical map has been overwritten and points to an inactive vcpu. Signed-off-by: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/boot: Fix boot regression caused by bootparam sanitizingJohn Hubbard2019-08-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | commit 7846f58fba964af7cb8cf77d4d13c33254725211 upstream. commit a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else") had two errors: * It preserved boot_params.acpi_rsdp_addr, and * It failed to preserve boot_params.hdr Therefore, zero out acpi_rsdp_addr, and preserve hdr. Fixes: a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else") Reported-by: Neil MacLeod <neil@nmacleod.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Neil MacLeod <neil@nmacleod.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190821192513.20126-1-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/boot: Save fields explicitly, zero out everything elseJohn Hubbard2019-08-291-13/+47
| | | | | | | | | | | | | | | | | | | | | | commit a90118c445cc7f07781de26a9684d4ec58bfcfd1 upstream. Recent gcc compilers (gcc 9.1) generate warnings about an out of bounds memset, if the memset goes accross several fields of a struct. This generated a couple of warnings on x86_64 builds in sanitize_boot_params(). Fix this by explicitly saving the fields in struct boot_params that are intended to be preserved, and zeroing all the rest. [ tglx: Tagged for stable as it breaks the warning free build there as well ] Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16hTom Lendacky2019-08-293-13/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c49a0a80137c7ca7d6ced4c812c9e07a949f6f24 upstream. There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/apic: Handle missing global clockevent gracefullyThomas Gleixner2019-08-291-15/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f897e60a12f0b9146357780d317879bce2a877dc upstream. Some newer machines do not advertise legacy timers. The kernel can handle that situation if the TSC and the CPU frequency are enumerated by CPUID or MSRs and the CPU supports TSC deadline timer. If the CPU does not support TSC deadline timer the local APIC timer frequency has to be known as well. Some Ryzens machines do not advertize legacy timers, but there is no reliable way to determine the bus frequency which feeds the local APIC timer when the machine allows overclocking of that frequency. As there is no legacy timer the local APIC timer calibration crashes due to a NULL pointer dereference when accessing the not installed global clock event device. Switch the calibration loop to a non interrupt based one, which polls either TSC (if frequency is known) or jiffies. The latter requires a global clockevent. As the machines which do not have a global clockevent installed have a known TSC frequency this is a non issue. For older machines where TSC frequency is not known, there is no known case where the legacy timers do not exist as that would have been reported long ago. Reported-by: Daniel Drake <drake@endlessm.com> Reported-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Daniel Drake <drake@endlessm.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908091443030.21433@nanos.tec.linutronix.de Link: http://bugzilla.opensuse.org/show_bug.cgi?id=1142926#c12 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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