- 22 Dec, 2019 1 commit
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James Hogan authored
I haven't been active for 18 months, and don't have the hardware set up to test KVM for MIPS, so mark it as orphaned and remove myself as maintainer. Hopefully somebody from MIPS can pick this up. Signed-off-by:
James Hogan <jhogan@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: kvm@vger.kernel.org Cc: linux-mips@vger.kernel.org Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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- 18 Dec, 2019 3 commits
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Paolo Bonzini authored
Merge tag 'kvmarm-fixes-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm fixes for .5.5, take #1 - Fix uninitialised sysreg accessor - Fix handling of demand-paged device mappings - Stop spamming the console on IMPDEF sysregs - Relax mappings of writable memslots - Assorted cleanups
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Jim Mattson authored
The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.80000008H:EBX.AMD_SSBD[bit 24] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 4c6903a0 ("KVM: x86: fix reporting of AMD speculation bug CPUID leaf") Signed-off-by:
Jim Mattson <jmattson@google.com> Reviewed-by:
Jacob Xu <jacobhxu@google.com> Reviewed-by:
Peter Shier <pshier@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Reported-by:
Eric Biggers <ebiggers@kernel.org> Signed-off-by:
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Jim Mattson authored
The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 0c54914d ("KVM: x86: use Intel speculation bugs and features as derived in generic x86 code") Signed-off-by:
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- 12 Dec, 2019 2 commits
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Marc Zyngier authored
A device mapping is normally always mapped at Stage-2, since there is very little gain in having it faulted in. Nonetheless, it is possible to end-up in a situation where the device mapping has been removed from Stage-2 (userspace munmaped the VFIO region, and the MMU notifier did its job), but present in a userspace mapping (userpace has mapped it back at the same address). In such a situation, the device mapping will be demand-paged as the guest performs memory accesses. This requires to be careful when dealing with mapping size, cache management, and to handle potential execution of a device mapping. Reported-by:
Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Tested-by:
James Morse <james.morse@arm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191211165651.7889-2-maz@kernel.org
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Will Deacon authored
Commit 4b927b94 ("KVM: arm/arm64: vgic: Introduce find_reg_by_id()") introduced 'find_reg_by_id()', which looks up a system register only if the 'id' index parameter identifies a valid system register. As part of the patch, existing callers of 'find_reg()' were ported over to the new interface, but this breaks 'index_to_sys_reg_desc()' in the case that the initial lookup in the vCPU target table fails because we will then call into 'find_reg()' for the system register table with an uninitialised 'param' as the key to the lookup. GCC 10 is bright enough to spot this (amongst a tonne of false positives, but hey!): | arch/arm64/kvm/sys_regs.c: In function ‘index_to_sys_reg_desc.part.0.isra’: | arch/arm64/kvm/sys_regs.c:983:33: warning: ‘params.Op2’ may be used uninitialized in this function [-Wmaybe-uninitialized] | 983 | (u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2); | [...] Revert the hunk of 4b927b94 which breaks 'index_to_sys_reg_desc()' so that the old behaviour of checking the index upfront is restored. Fixes: 4b927b94 ("KVM: arm/arm64: vgic: Introduce find_reg_by_id()") Signed-off-by:
Will Deacon <will@kernel.org> Signed-off-by:
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- 06 Dec, 2019 6 commits
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Jia He authored
In kvm_arch_prepare_memory_region, arm kvm regards the memory region as writable if the flag has no KVM_MEM_READONLY, and the vm is readonly if !VM_WRITE. But there is common usage for setting kvm memory region as follows: e.g. qemu side (see the PROT_NONE flag) 1. mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); memory_region_init_ram_ptr() 2. re mmap the above area with read/write authority. Such example is used in virtio-fs qemu codes which hasn't been upstreamed [1]. But seems we can't forbid this example. Without this patch, it will cause an EPERM during kvm_set_memory_region() and cause qemu boot crash. As told by Ard, "the underlying assumption is incorrect, i.e., that the value of vm_flags at this point in time defines how the VMA is used during its lifetime. There may be other cases where a VMA is created with VM_READ vm_flags that are changed to VM_READ|VM_WRITE later, and we are currently rejecting this use case as well." [1] https://gitlab.com/virtio-fs/qemu/blob/5a356e/hw/virtio/vhost-user-fs.c#L488Suggested-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:
Jia He <justin.he@arm.com> Signed-off-by:
Christoffer Dall <christoffer.dall@arm.com> Link: https://lore.kernel.org/r/20191206020802.196108-1-justin.he@arm.com
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Mark Rutland authored
We don't intend to support IMPLEMENATION DEFINED system registers, but have to trap them (and emulate them as UNDEFINED). These traps aren't interesting to the system administrator or to the KVM developers, so let's not bother logging when we do so. Signed-off-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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Mark Rutland authored
Currently kvm_pr_unimpl() is ratelimited, so print_sys_reg_instr() won't spam the console. However, someof its callers try to print some contextual information with kvm_err(), which is not ratelimited. This means that in some cases the context may be printed without the sysreg encoding, which isn't all that useful. Let's ensure that both are consistently printed together and ratelimited, by refactoring print_sys_reg_instr() so that some callers can provide it with an arbitrary format string. Signed-off-by:
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Miaohe Lin authored
Use wrapper function lock_all_vcpus()/unlock_all_vcpus() in kvm_vgic_create() to remove duplicated code dealing with locking and unlocking all vcpus in a vm. Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
Eric Auger <eric.auger@redhat.com> Reviewed-by:
Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/1575081918-11401-1-git-send-email-linmiaohe@huawei.com
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Miaohe Lin authored
In kvm_vgic_dist_init() called from kvm_vgic_map_resources(), if dist->vgic_model is invalid, dist->spis will be freed without set dist->spis = NULL. And in vgicv2 resources clean up path, __kvm_vgic_destroy() will be called to free allocated resources. And dist->spis will be freed again in clean up chain because we forget to set dist->spis = NULL in kvm_vgic_dist_init() failed path. So double free would happen. Signed-off-by:
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Miaohe Lin authored
As arg dummy is not really needed, there's no need to pass NULL when calling cpu_init_hyp_mode(). So clean it up. Fixes: 67f69197 ("arm64: kvm: allows kvm cpu hotplug") Reviewed-by:
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- 21 Nov, 2019 5 commits
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Paolo Bonzini authored
If X86_FEATURE_RTM is disabled, the guest should not be able to access MSR_IA32_TSX_CTRL. We can therefore use it in KVM to force all transactions from the guest to abort. Tested-by:
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Paolo Bonzini authored
The current guest mitigation of TAA is both too heavy and not really sufficient. It is too heavy because it will cause some affected CPUs (those that have MDS_NO but lack TAA_NO) to fall back to VERW and get the corresponding slowdown. It is not really sufficient because it will cause the MDS_NO bit to disappear upon microcode update, so that VMs started before the microcode update will not be runnable anymore afterwards, even with tsx=on. Instead, if tsx=on on the host, we can emulate MSR_IA32_TSX_CTRL for the guest and let it run without the VERW mitigation. Even though MSR_IA32_TSX_CTRL is quite heavyweight, and we do not want to write it on every vmentry, we can use the shared MSR functionality because the host kernel need not protect itself from TSX-based side-channels. Tested-by:
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Paolo Bonzini authored
Because KVM always emulates CPUID, the CPUID clear bit (bit 1) of MSR_IA32_TSX_CTRL must be emulated "manually" by the hypervisor when performing said emulation. Right now neither kvm-intel.ko nor kvm-amd.ko implement MSR_IA32_TSX_CTRL but this will change in the next patch. Reviewed-by:
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Paolo Bonzini authored
"Shared MSRs" are guest MSRs that are written to the host MSRs but keep their value until the next return to userspace. They support a mask, so that some bits keep the host value, but this mask is only used to skip an unnecessary MSR write and the value written to the MSR is always the guest MSR. Fix this and, while at it, do not update smsr->values[slot].curr if for whatever reason the wrmsr fails. This should only happen due to reserved bits, so the value written to smsr->values[slot].curr will not match when the user-return notifier and the host value will always be restored. However, it is untidy and in rare cases this can actually avoid spurious WRMSRs on return to userspace. Cc: stable@vger.kernel.org Reviewed-by:
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Paolo Bonzini authored
KVM does not implement MSR_IA32_TSX_CTRL, so it must not be presented to the guests. It is also confusing to have !ARCH_CAP_TSX_CTRL_MSR && !RTM && ARCH_CAP_TAA_NO: lack of MSR_IA32_TSX_CTRL suggests TSX was not hidden (it actually was), yet the value says that TSX is not vulnerable to microarchitectural data sampling. Fix both. Cc: stable@vger.kernel.org Tested-by:
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- 15 Nov, 2019 1 commit
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Marc Zyngier authored
Add a comment explaining the rational behind having both no_compat open and ioctl callbacks to fend off compat tasks. Signed-off-by:
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- 14 Nov, 2019 1 commit
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Sean Christopherson authored
Acquire the per-VM slots_lock when zapping all shadow pages as part of toggling nx_huge_pages. The fast zap algorithm relies on exclusivity (via slots_lock) to identify obsolete vs. valid shadow pages, because it uses a single bit for its generation number. Holding slots_lock also obviates the need to acquire a read lock on the VM's srcu. Failing to take slots_lock when toggling nx_huge_pages allows multiple instances of kvm_mmu_zap_all_fast() to run concurrently, as the other user, KVM_SET_USER_MEMORY_REGION, does not take the global kvm_lock. (kvm_mmu_zap_all_fast() does take kvm->mmu_lock, but it can be temporarily dropped by kvm_zap_obsolete_pages(), so it is not enough to enforce exclusivity). Concurrent fast zap instances causes obsolete shadow pages to be incorrectly identified as valid due to the single bit generation number wrapping, which results in stale shadow pages being left in KVM's MMU and leads to all sorts of undesirable behavior. The bug is easily confirmed by running with CONFIG_PROVE_LOCKING and toggling nx_huge_pages via its module param. Note, until commit 4ae5acbc4936 ("KVM: x86/mmu: Take slots_lock when using kvm_mmu_zap_all_fast()", 2019-11-13) the fast zap algorithm used an ulong-sized generation instead of relying on exclusivity for correctness, but all callers except the recently added set_nx_huge_pages() needed to hold slots_lock anyways. Therefore, this patch does not have to be backported to stable kernels. Given that toggling nx_huge_pages is by no means a fast path, force it to conform to the current approach instead of reintroducing the previous generation count. Fixes: b8e8c830 ("kvm: mmu: ITLB_MULTIHIT mitigation", but NOT FOR STABLE) Signed-off-by:Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by:
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- 13 Nov, 2019 4 commits
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Marc Zyngier authored
On a system without KVM_COMPAT, we prevent IOCTLs from being issued by a compat task. Although this prevents most silly things from happening, it can still confuse a 32bit userspace that is able to open the kvm device (the qemu test suite seems to be pretty mad with this behaviour). Take a more radical approach and return a -ENODEV to the compat task. Reported-by:
Peter Maydell <peter.maydell@linaro.org> Signed-off-by:
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Xiaoyao Li authored
When applying commit 7a5ee6ed ("KVM: X86: Fix initialization of MSR lists"), it forgot to reset the three MSR lists number varialbes to 0 while removing the useless conditionals. Fixes: 7a5ee6ed (KVM: X86: Fix initialization of MSR lists) Signed-off-by:
Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by:
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Vitaly Kuznetsov authored
Glibc-2.30 gained gettid() wrapper, selftests fail to compile: lib/assert.c:58:14: error: static declaration of ‘gettid’ follows non-static declaration 58 | static pid_t gettid(void) | ^~~~~~ In file included from /usr/include/unistd.h:1170, from include/test_util.h:18, from lib/assert.c:10: /usr/include/bits/unistd_ext.h:34:16: note: previous declaration of ‘gettid’ was here 34 | extern __pid_t gettid (void) __THROW; | ^~~~~~ Signed-off-by:Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
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Paolo Bonzini authored
If a huge page is recovered (and becomes no executable) while another thread is executing it, the resulting contention on mmu_lock can cause latency spikes. Disabling recovery for PREEMPT_RT kernels fixes this issue. Signed-off-by:
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- 12 Nov, 2019 9 commits
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull kvm fixes from Paolo Bonzini: "Fix unwinding of KVM_CREATE_VM failure, VT-d posted interrupts, DAX/ZONE_DEVICE, and module unload/reload" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved KVM: VMX: Introduce pi_is_pir_empty() helper KVM: VMX: Do not change PID.NDST when loading a blocked vCPU KVM: VMX: Consider PID.PIR to determine if vCPU has pending interrupts KVM: VMX: Fix comment to specify PID.ON instead of PIR.ON KVM: X86: Fix initialization of MSR lists KVM: fix placement of refcount initialization KVM: Fix NULL-ptr deref after kvm_create_vm fails
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 TSX Async Abort and iTLB Multihit mitigations from Thomas Gleixner: "The performance deterioration departement is not proud at all of presenting the seventh installment of speculation mitigations and hardware misfeature workarounds: 1) TSX Async Abort (TAA) - 'The Annoying Affair' TAA is a hardware vulnerability that allows unprivileged speculative access to data which is available in various CPU internal buffers by using asynchronous aborts within an Intel TSX transactional region. The mitigation depends on a microcode update providing a new MSR which allows to disable TSX in the CPU. CPUs which have no microcode update can be mitigated by disabling TSX in the BIOS if the BIOS provides a tunable. Newer CPUs will have a bit set which indicates that the CPU is not vulnerable, but the MSR to disable TSX will be available nevertheless as it is an architected MSR. That means the kernel provides the ability to disable TSX on the kernel command line, which is useful as TSX is a truly useful mechanism to accelerate side channel attacks of all sorts. 2) iITLB Multihit (NX) - 'No eXcuses' iTLB Multihit is an erratum where some Intel processors may incur a machine check error, possibly resulting in an unrecoverable CPU lockup, when an instruction fetch hits multiple entries in the instruction TLB. This can occur when the page size is changed along with either the physical address or cache type. A malicious guest running on a virtualized system can exploit this erratum to perform a denial of service attack. The workaround is that KVM marks huge pages in the extended page tables as not executable (NX). If the guest attempts to execute in such a page, the page is broken down into 4k pages which are marked executable. The workaround comes with a mechanism to recover these shattered huge pages over time. Both issues come with full documentation in the hardware vulnerabilities section of the Linux kernel user's and administrator's guide. Thanks to all patch authors and reviewers who had the extraordinary priviledge to be exposed to this nuisance. Special thanks to Borislav Petkov for polishing the final TAA patch set and to Paolo Bonzini for shepherding the KVM iTLB workarounds and providing also the backports to stable kernels for those!" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUs Documentation: Add ITLB_MULTIHIT documentation kvm: x86: mmu: Recovery of shattered NX large pages kvm: Add helper function for creating VM worker threads kvm: mmu: ITLB_MULTIHIT mitigation cpu/speculation: Uninline and export CPU mitigations helpers x86/cpu: Add Tremont to the cpu vulnerability whitelist x86/bugs: Add ITLB_MULTIHIT bug infrastructure x86/tsx: Add config options to set tsx=on|off|auto x86/speculation/taa: Add documentation for TSX Async Abort x86/tsx: Add "auto" option to the tsx= cmdline parameter kvm/x86: Export MDS_NO=0 to guests when TSX is enabled x86/speculation/taa: Add sysfs reporting for TSX Async Abort x86/speculation/taa: Add mitigation for TSX Async Abort x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default x86/cpu: Add a helper function x86_read_arch_cap_msr() x86/msr: Add the IA32_TSX_CTRL MSR -
Sean Christopherson authored
Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and instead manually handle ZONE_DEVICE on a case-by-case basis. For things like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal pages, e.g. put pages grabbed via gup(). But for flows such as setting A/D bits or shifting refcounts for transparent huge pages, KVM needs to to avoid processing ZONE_DEVICE pages as the flows in question lack the underlying machinery for proper handling of ZONE_DEVICE pages. This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup() when running a KVM guest backed with /dev/dax memory, as KVM straight up doesn't put any references to ZONE_DEVICE pages acquired by gup(). Note, Dan Williams proposed an alternative solution of doing put_page() on ZONE_DEVICE pages immediately after gup() in order to simplify the auditing needed to ensure is_zone_device_page() is called if and only if the backing device is pinned (via gup()). But that approach would break kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til unmap() when accessing guest memory, unlike KVM's secondary MMU, which coordinates with mmu_notifier invalidations to avoid creating stale page references, i.e. doesn't rely on pages being pinned. [*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.plReported-by:Adam Borowski <kilobyte@angband.pl> Analyzed-by:
David Hildenbrand <david@redhat.com> Acked-by:
Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Fixes: 3565fce3 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by:
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Joao Martins authored
Streamline the PID.PIR check and change its call sites to use the newly added helper. Suggested-by:
Liran Alon <liran.alon@oracle.com> Signed-off-by:
Joao Martins <joao.m.martins@oracle.com> Signed-off-by:
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Joao Martins authored
When vCPU enters block phase, pi_pre_block() inserts vCPU to a per pCPU linked list of all vCPUs that are blocked on this pCPU. Afterwards, it changes PID.NV to POSTED_INTR_WAKEUP_VECTOR which its handler (wakeup_handler()) is responsible to kick (unblock) any vCPU on that linked list that now has pending posted interrupts. While vCPU is blocked (in kvm_vcpu_block()), it may be preempted which will cause vmx_vcpu_pi_put() to set PID.SN. If later the vCPU will be scheduled to run on a different pCPU, vmx_vcpu_pi_load() will clear PID.SN but will also *overwrite PID.NDST to this different pCPU*. Instead of keeping it with original pCPU which vCPU had entered block phase on. This results in an issue because when a posted interrupt is delivered, as the wakeup_handler() will be executed and fail to find blocked vCPU on its per pCPU linked list of all vCPUs that are blocked on this pCPU. Which is due to the vCPU being placed on a *different* per pCPU linked list i.e. the original pCPU in which it entered block phase. The regression is introduced by commit c112b5f5 ("KVM: x86: Recompute PID.ON when clearing PID.SN"). Therefore, partially revert it and reintroduce the condition in vmx_vcpu_pi_load() responsible for avoiding changing PID.NDST when loading a blocked vCPU. Fixes: c112b5f5 ("KVM: x86: Recompute PID.ON when clearing PID.SN") Tested-by:
Nathan Ni <nathan.ni@oracle.com> Co-developed-by:
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Joao Martins authored
Commit 17e433b5 ("KVM: Fix leak vCPU's VMCS value into other pCPU") introduced vmx_dy_apicv_has_pending_interrupt() in order to determine if a vCPU have a pending posted interrupt. This routine is used by kvm_vcpu_on_spin() when searching for a a new runnable vCPU to schedule on pCPU instead of a vCPU doing busy loop. vmx_dy_apicv_has_pending_interrupt() determines if a vCPU has a pending posted interrupt solely based on PID.ON. However, when a vCPU is preempted, vmx_vcpu_pi_put() sets PID.SN which cause raised posted interrupts to only set bit in PID.PIR without setting PID.ON (and without sending notification vector), as depicted in VT-d manual section 5.2.3 "Interrupt-Posting Hardware Operation". Therefore, checking PID.ON is insufficient to determine if a vCPU has pending posted interrupts and instead we should also check if there is some bit set on PID.PIR if PID.SN=1. Fixes: 17e433b5 ("KVM: Fix leak vCPU's VMCS value into other pCPU") Reviewed-by:
Jagannathan Raman <jag.raman@oracle.com> Co-developed-by:
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Liran Alon authored
The Outstanding Notification (ON) bit is part of the Posted Interrupt Descriptor (PID) as opposed to the Posted Interrupts Register (PIR). The latter is a bitmap for pending vectors. Reviewed-by:
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Chenyi Qiang authored
The three MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[]) are global arrays of kvm.ko, which are adjusted (copy supported MSRs forward to override the unsupported MSRs) when insmod kvm-{intel,amd}.ko, but it doesn't reset these three arrays to their initial value when rmmod kvm-{intel,amd}.ko. Thus, at the next installation, kvm-{intel,amd}.ko will do operations on the modified arrays with some MSRs lost and some MSRs duplicated. So define three constant arrays to hold the initial MSR lists and initialize msrs_to_save[], emulated_msrs[] and msr_based_features[] based on the constant arrays. Cc: stable@vger.kernel.org Reviewed-by:Chenyi Qiang <chenyi.qiang@intel.com> [Remove now useless conditionals. - Paolo] Signed-off-by:
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Linus Torvalds authored
This fixes two different classes of bugs in the Intel graphics hardware: MMIO register read hang: "On Intels Gen8 and Gen9 Graphics hardware, a read of specific graphics MMIO registers when the product is in certain low power states causes a system hang. There are two potential triggers for DoS: a) H/W corruption of the RC6 save/restore vector b) Hard hang within the MIPI hardware This prevents the DoS in two areas of the hardware: 1) Detect corruption of RC6 address on exit from low-power state, and if we find it corrupted, disable RC6 and RPM 2) Permanently lower the MIPI MMIO timeout" Blitter command streamer unrestricted memory accesses: "On Intels Gen9 Graphics hardware the Blitter Command Streamer (BCS) allows writing to Memory Mapped Input Output (MMIO) that should be blocked. With modifications of page tables, this can lead to privilege escalation. This exposure is limited to the Guest Physical Address space and does not allow for access outside of the graphics virtual machine. This series establishes a software parser into the Blitter command stream to scan for, and prevent, reads or writes to MMIO's that should not be accessible to non-privileged contexts. Much of the command parser infrastructure has existed for some time, and is used on Ivybridge/Haswell/Valleyview derived products to allow the use of features normally blocked by hardware. In this legacy context, the command parser is employed to allow normally unprivileged submissions to be run with elevated privileges in order to grant access to a limited set of extra capabilities. In this mode the parser is optional; In the event that the parser finds any construct that it cannot properly validate (e.g. nested command buffers), it simply aborts the scan and submits the buffer in non-privileged mode. For Gen9 Graphics, this series makes the parser mandatory for all Blitter submissions. The incoming user buffer is first copied to a kernel owned buffer, and parsed. If all checks are successful the kernel owned buffer is mapped READ-ONLY and submitted on behalf of the user. If any checks fail, or the parser is unable to complete the scan (nested buffers), it is forcibly rejected. The successfully scanned buffer is executed with NORMAL user privileges (key difference from legacy usage). Modern usermode does not use the Blitter on later hardware, having switched over to using the 3D engine instead for performance reasons. There are however some legacy usermode apps that rely on Blitter, notably the SNA X-Server. There are no known usermode applications that require nested command buffers on the Blitter, so the forcible rejection of such buffers in this patch series is considered an acceptable limitation" * Intel graphics fixes in emailed bundle from Jon Bloomfield <jon.bloomfield@intel.com>: drm/i915/cmdparser: Fix jump whitelist clearing drm/i915/gen8+: Add RC6 CTX corruption WA drm/i915: Lower RM timeout to avoid DSI hard hangs drm/i915/cmdparser: Ignore Length operands during command matching drm/i915/cmdparser: Add support for backward jumps drm/i915/cmdparser: Use explicit goto for error paths drm/i915: Add gen9 BCS cmdparsing drm/i915: Allow parsing of unsized batches drm/i915: Support ro ppgtt mapped cmdparser shadow buffers drm/i915: Add support for mandatory cmdparsing drm/i915: Remove Master tables from cmdparser drm/i915: Disable Secure Batches for gen6+ drm/i915: Rename gen7 cmdparser tables
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- 11 Nov, 2019 6 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds authored
Pull cgroup fix from Tejun Heo: "There's an inadvertent preemption point in ptrace_stop() which was reliably triggering for a test scenario significantly slowing it down. This contains Oleg's fix to remove the unwanted preemption point" * 'for-5.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: freezer: call cgroup_enter_frozen() with preemption disabled in ptrace_stop()
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Three small changes: two in the core and one in the qla2xxx driver. The sg_tablesize fix affects a thinko in the migration to blk-mq of certain legacy drivers which could cause an oops and the sd core change should only affect zoned block devices which were wrongly suppressing error messages for reset all zones" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: core: Handle drivers which set sg_tablesize to zero scsi: qla2xxx: fix NPIV tear down process scsi: sd_zbc: Fix sd_zbc_complete()
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Ben Hutchings authored
When a jump_whitelist bitmap is reused, it needs to be cleared. Currently this is done with memset() and the size calculation assumes bitmaps are made of 32-bit words, not longs. So on 64-bit architectures, only the first half of the bitmap is cleared. If some whitelist bits are carried over between successive batches submitted on the same context, this will presumably allow embedding the rogue instructions that we're trying to reject. Use bitmap_zero() instead, which gets the calculation right. Fixes: f8c08d8f ("drm/i915/cmdparser: Add support for backward jumps") Signed-off-by:
Ben Hutchings <ben@decadent.org.uk> Signed-off-by:
Jon Bloomfield <jon.bloomfield@intel.com>
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Paolo Bonzini authored
Reported by syzkaller: ============================= WARNING: suspicious RCU usage ----------------------------- ./include/linux/kvm_host.h:536 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by repro_11/12688. stack backtrace: Call Trace: dump_stack+0x7d/0xc5 lockdep_rcu_suspicious+0x123/0x170 kvm_dev_ioctl+0x9a9/0x1260 [kvm] do_vfs_ioctl+0x1a1/0xfb0 ksys_ioctl+0x6d/0x80 __x64_sys_ioctl+0x73/0xb0 do_syscall_64+0x108/0xaa0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Commit a97b0e77 (kvm: call kvm_arch_destroy_vm if vm creation fails) sets users_count to 1 before kvm_arch_init_vm(), however, if kvm_arch_init_vm() fails, we need to decrease this count. By moving it earlier, we can push the decrease to out_err_no_arch_destroy_vm without introducing yet another error label. syzkaller source: https://syzkaller.appspot.com/x/repro.c?x=15209b84e00000 Reported-by: syzbot+75475908cd0910f141ee@syzkaller.appspotmail.com Fixes: a97b0e77 ("kvm: call kvm_arch_destroy_vm if vm creation fails") Cc: Jim Mattson <jmattson@google.com> Analyzed-by:Wanpeng Li <wanpengli@tencent.com> Signed-off-by:
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Paolo Bonzini authored
Reported by syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 14727 Comm: syz-executor.3 Not tainted 5.4.0-rc4+ #0 RIP: 0010:kvm_coalesced_mmio_init+0x5d/0x110 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:121 Call Trace: kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3446 [inline] kvm_dev_ioctl+0x781/0x1490 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3494 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x196/0x1150 fs/ioctl.c:696 ksys_ioctl+0x62/0x90 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:718 do_syscall_64+0xca/0x5d0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Commit 9121923c ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm") moves memslots and buses allocations around, however, if kvm->srcu/irq_srcu fails initialization, NULL will be returned instead of error code, NULL will not be intercepted in kvm_dev_ioctl_create_vm() and be dereferenced by kvm_coalesced_mmio_init(), this patch fixes it. Moving the initialization is required anyway to avoid an incorrect synchronize_srcu that was also reported by syzkaller: wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997 kvm_page_track_unregister_notifier+0xe7/0x130 arch/x86/kvm/page_track.c:212 kvm_mmu_uninit_vm+0x1e/0x30 arch/x86/kvm/mmu.c:5828 kvm_arch_destroy_vm+0x4a2/0x5f0 arch/x86/kvm/x86.c:9579 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:702 [inline] so do it. Reported-by: syzbot+89a8060879fa0bd2db4f@syzkaller.appspotmail.com Reported-by: syzbot+e27e7027eb2b80e44225@syzkaller.appspotmail.com Fixes: 9121923c ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm") Cc: Jim Mattson <jmattson@google.com> Cc: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: -
Linus Torvalds authored
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- 10 Nov, 2019 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds authored
Pull ARM SoC fixes from Olof Johansson: "A set of fixes that have trickled in over the last couple of weeks: - MAINTAINER update for Cavium/Marvell ThunderX2 - stm32 tweaks to pinmux for Joystick/Camera, and RAM allocation for CAN interfaces - i.MX fixes for voltage regulator GPIO mappings, fixes voltage scaling issues - More i.MX fixes for various issues on i.MX eval boards: interrupt storm due to u-boot leaving pins in new states, fixing power button config, a couple of compatible-string corrections. - Powerdown and Suspend/Resume fixes for Allwinner A83-based tablets - A few documentation tweaks and a fix of a memory leak in the reset subsystem" * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: MAINTAINERS: update Cavium ThunderX2 maintainers ARM: dts: stm32: change joystick pinctrl definition on stm32mp157c-ev1 ARM: dts: stm32: remove OV5640 pinctrl definition on stm32mp157c-ev1 ARM: dts: stm32: Fix CAN RAM mapping on stm32mp157c ARM: dts: stm32: relax qspi pins slew-rate for stm32mp157 arm64: dts: zii-ultra: fix ARM regulator GPIO handle ARM: sunxi: Fix CPU powerdown on A83T ARM: dts: sun8i-a83t-tbs-a711: Fix WiFi resume from suspend arm64: dts: imx8mn: fix compatible string for sdma arm64: dts: imx8mm: fix compatible string for sdma reset: fix reset_control_ops kerneldoc comment ARM: dts: imx6-logicpd: Re-enable SNVS power key soc: imx: gpc: fix initialiser format ARM: dts: imx6qdl-sabreauto: Fix storm of accelerometer interrupts arm64: dts: ls1028a: fix a compatible issue reset: fix reset_control_get_exclusive kerneldoc comment reset: fix reset_control_lookup kerneldoc comment reset: fix of_reset_control_get_count kerneldoc comment reset: fix of_reset_simple_xlate kerneldoc comment reset: Fix memory leak in reset_control_array_put() -
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/stagingLinus Torvalds authored
Pull IIO fixes and staging driver from Greg KH: "Here is a mix of a number of IIO driver fixes for 5.4-rc7, and a whole new staging driver. The IIO fixes resolve some reported issues, all are tiny. The staging driver addition is the vboxsf filesystem, which is the VirtualBox guest shared folder code. Hans has been trying to get filesystem reviewers to review the code for many months now, and Christoph finally said to just merge it in staging now as it is stand-alone and the filesystem people can review it easier over time that way. I know it's late for this big of an addition, but it is stand-alone. The code has been in linux-next for a while, long enough to pick up a few tiny fixes for it already so people are looking at it. All of these have been in linux-next with no reported issues" * tag 'staging-5.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: staging: Fix error return code in vboxsf_fill_super() staging: vboxsf: fix dereference of pointer dentry before it is null checked staging: vboxsf: Remove unused including <linux/version.h> staging: Add VirtualBox guest shared folder (vboxsf) support iio: adc: stm32-adc: fix stopping dma iio: imu: inv_mpu6050: fix no data on MPU6050 iio: srf04: fix wrong limitation in distance measuring iio: imu: adis16480: make sure provided frequency is positive
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