- 04 Sep, 2024 10 commits
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Sean Christopherson authored
Register the "disable virtualization in an emergency" callback just before KVM enables virtualization in hardware, as there is no functional need to keep the callbacks registered while KVM happens to be loaded, but is inactive, i.e. if KVM hasn't enabled virtualization. Note, unregistering the callback every time the last VM is destroyed could have measurable latency due to the synchronize_rcu() needed to ensure all references to the callback are dropped before KVM is unloaded. But the latency should be a small fraction of the total latency of disabling virtualization across all CPUs, and userspace can set enable_virt_at_load to completely eliminate the runtime overhead. Add a pointer in kvm_x86_ops to allow vendor code to provide its callback. There is no reason to force vendor code to do the registration, and either way KVM would need a new kvm_x86_ops hook. Suggested-by: Kai Huang <kai.huang@intel.com> Reviewed-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-11-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Define cpu_emergency_virt_cb even if the kernel is being built without KVM support so that KVM can reference the typedef in asm/kvm_host.h without needing yet more #ifdefs. No functional change intended. Acked-by: Kai Huang <kai.huang@intel.com> Reviewed-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Add arch hooks that are invoked when KVM enables/disable virtualization. x86 will use the hooks to register an "emergency disable" callback, which is essentially an x86-specific shutdown notifier that is used when the kernel is doing an emergency reboot/shutdown/kexec. Add comments for the declarations to help arch code understand exactly when the callbacks are invoked. Alternatively, the APIs themselves could communicate most of the same info, but kvm_arch_pre_enable_virtualization() and kvm_arch_post_disable_virtualization() are a bit cumbersome, and make it a bit less obvious that they are intended to be implemented as a pair. Reviewed-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Add an on-by-default module param, enable_virt_at_load, to let userspace force virtualization to be enabled in hardware when KVM is initialized, i.e. just before /dev/kvm is exposed to userspace. Enabling virtualization during KVM initialization allows userspace to avoid the additional latency when creating/destroying the first/last VM (or more specifically, on the 0=>1 and 1=>0 edges of creation/destruction). Now that KVM uses the cpuhp framework to do per-CPU enabling, the latency could be non-trivial as the cpuhup bringup/teardown is serialized across CPUs, e.g. the latency could be problematic for use case that need to spin up VMs quickly. Prior to commit 10474ae8 ("KVM: Activate Virtualization On Demand"), KVM _unconditionally_ enabled virtualization during load, i.e. there's no fundamental reason KVM needs to dynamically toggle virtualization. These days, the only known argument for not enabling virtualization is to allow KVM to be autoloaded without blocking other out-of-tree hypervisors, and such use cases can simply change the module param, e.g. via command line. Note, the aforementioned commit also mentioned that enabling SVM (AMD's virtualization extensions) can result in "using invalid TLB entries". It's not clear whether the changelog was referring to a KVM bug, a CPU bug, or something else entirely. Regardless, leaving virtualization off by default is not a robust "fix", as any protection provided is lost the instant userspace creates the first VM. Reviewed-by: Chao Gao <chao.gao@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Rename x86's the per-CPU vendor hooks used to enable virtualization in hardware to align with the recently renamed arch hooks. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240830043600.127750-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Rename MIPS's trampoline hooks for virtualization enabling to match the recently renamed arch hooks. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Rename the per-CPU hooks used to enable virtualization in hardware to align with the KVM-wide helpers in kvm_main.c, and to better capture that the callbacks are invoked on every online CPU. No functional change intended. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240830043600.127750-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Rename the various functions (and a variable) that enable virtualization to prepare for upcoming changes, and to clean up artifacts of KVM's previous behavior, which required manually juggling locks around kvm_usage_count. Drop the "nolock" qualifier from per-CPU functions now that there are no "nolock" implementations of the "all" variants, i.e. now that calling a non-nolock function from a nolock function isn't confusing (unlike this sentence). Drop "all" from the outer helpers as they no longer manually iterate over all CPUs, and because it might not be obvious what "all" refers to. In lieu of the above qualifiers, append "_cpu" to the end of the functions that are per-CPU helpers for the outer APIs. Opportunistically prepend "kvm" to all functions to help make it clear that they are KVM helpers, but mostly because there's no reason not to. Lastly, use "virtualization" instead of "hardware", because while the functions do enable virtualization in hardware, there are a _lot_ of things that KVM enables in hardware. Defer renaming the arch hooks to future patches, purely to reduce the amount of churn in a single commit. Reviewed-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Register KVM's cpuhp and syscore callback when enabling virtualization in hardware instead of registering the callbacks during initialization, and let the CPU up/down framework invoke the inner enable/disable functions. Registering the callbacks during initialization makes things more complex than they need to be, as KVM needs to be very careful about handling races between enabling CPUs being onlined/offlined and hardware being enabled/disabled. Intel TDX support will require KVM to enable virtualization during KVM initialization, i.e. will add another wrinkle to things, at which point sorting out the potential races with kvm_usage_count would become even more complex. Note, using the cpuhp framework has a subtle behavioral change: enabling will be done serially across all CPUs, whereas KVM currently sends an IPI to all CPUs in parallel. While serializing virtualization enabling could create undesirable latency, the issue is limited to the 0=>1 transition of VM creation. And even that can be mitigated, e.g. by letting userspace force virtualization to be enabled when KVM is initialized. Cc: Chao Gao <chao.gao@intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the fairness of r/w semaphores). CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu); Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier(): cpuhp_cpufreq_online() | -> cpufreq_online() | -> cpufreq_gov_performance_limits() | -> __cpufreq_driver_target() | -> __target_index() | -> cpufreq_freq_transition_begin() | -> cpufreq_notify_transition() | -> ... __kvmclock_cpufreq_notifier() But, actually triggering such deadlocks is beyond rare due to the combination of dependencies and timings involved. E.g. the cpufreq notifier is only used on older CPUs without a constant TSC, mucking with the NX hugepage mitigation while VMs are running is very uncommon, and doing so while also onlining/offlining a CPU (necessary to generate contention on cpu_hotplug_lock) would be even more unusual. The most robust solution to the general cpu_hotplug_lock issue is likely to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq notifier doesn't to take kvm_lock. For now, settle for fixing the most blatant deadlock, as switching to an RCU-protected list is a much more involved change, but add a comment in locking.rst to call out that care needs to be taken when walking holding kvm_lock and walking vm_list. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S O ------------------------------------------------------ tee/35048 is trying to acquire lock: ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm] but task is already holding lock: ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kvm_lock){+.+.}-{3:3}: __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 kvm_dev_ioctl+0x4fb/0xe50 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2e/0xb0 static_key_slow_inc+0x16/0x30 kvm_lapic_set_base+0x6a/0x1c0 [kvm] kvm_set_apic_base+0x8f/0xe0 [kvm] kvm_set_msr_common+0x9ae/0xf80 [kvm] vmx_set_msr+0xa54/0xbe0 [kvm_intel] __kvm_set_msr+0xb6/0x1a0 [kvm] kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm] kvm_vcpu_ioctl+0x485/0x5b0 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&kvm->srcu){.+.+}-{0:0}: __synchronize_srcu+0x44/0x1a0 synchronize_srcu_expedited+0x21/0x30 kvm_swap_active_memslots+0x110/0x1c0 [kvm] kvm_set_memslot+0x360/0x620 [kvm] __kvm_set_memory_region+0x27b/0x300 [kvm] kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm] kvm_vm_ioctl+0x295/0x650 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&kvm->slots_lock){+.+.}-{3:3}: __lock_acquire+0x15ef/0x2e30 lock_acquire+0xe0/0x260 __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 set_nx_huge_pages+0x179/0x1e0 [kvm] param_attr_store+0x93/0x100 module_attr_store+0x22/0x40 sysfs_kf_write+0x81/0xb0 kernfs_fop_write_iter+0x133/0x1d0 vfs_write+0x28d/0x380 ksys_write+0x70/0xe0 __x64_sys_write+0x1f/0x30 x64_sys_call+0x281b/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Cc: Chao Gao <chao.gao@intel.com> Fixes: 0bf50497 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock") Cc: stable@vger.kernel.org Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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- 14 Aug, 2024 5 commits
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Yan Zhao authored
Add a new user option to memslot_perf_test to allow testing memslot move with quirk KVM_X86_QUIRK_SLOT_ZAP_ALL disabled. Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Message-ID: <20240703021219.13939-1-yan.y.zhao@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Yan Zhao authored
Add a new user option to memslot_modification_stress_test to allow testing with slot zap quirk KVM_X86_QUIRK_SLOT_ZAP_ALL disabled. Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Message-ID: <20240703021206.13923-1-yan.y.zhao@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Yan Zhao authored
Update set_memory_region_test to make sure memslot move and deletion function correctly both when slot zap quirk KVM_X86_QUIRK_SLOT_ZAP_ALL is enabled and disabled. Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Message-ID: <20240703021119.13904-1-yan.y.zhao@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Yan Zhao authored
Introduce the quirk KVM_X86_QUIRK_SLOT_ZAP_ALL to allow users to select KVM's behavior when a memslot is moved or deleted for KVM_X86_DEFAULT_VM VMs. Make sure KVM behave as if the quirk is always disabled for non-KVM_X86_DEFAULT_VM VMs. The KVM_X86_QUIRK_SLOT_ZAP_ALL quirk offers two behavior options: - when enabled: Invalidate/zap all SPTEs ("zap-all"), - when disabled: Precisely zap only the leaf SPTEs within the range of the moving/deleting memory slot ("zap-slot-leafs-only"). "zap-all" is today's KVM behavior to work around a bug [1] where the changing the zapping behavior of memslot move/deletion would cause VM instability for VMs with an Nvidia GPU assigned; while "zap-slot-leafs-only" allows for more precise zapping of SPTEs within the memory slot range, improving performance in certain scenarios [2], and meeting the functional requirements for TDX. Previous attempts to select "zap-slot-leafs-only" include a per-VM capability approach [3] (which was not preferred because the root cause of the bug remained unidentified) and a per-memslot flag approach [4]. Sean and Paolo finally recommended the implementation of this quirk and explained that it's the least bad option [5]. By default, the quirk is enabled on KVM_X86_DEFAULT_VM VMs to use "zap-all". Users have the option to disable the quirk to select "zap-slot-leafs-only" for specific KVM_X86_DEFAULT_VM VMs that are unaffected by this bug. For non-KVM_X86_DEFAULT_VM VMs, the "zap-slot-leafs-only" behavior is always selected without user's opt-in, regardless of if the user opts for "zap-all". This is because it is assumed until proven otherwise that non- KVM_X86_DEFAULT_VM VMs will not be exposed to the bug [1], and most importantly, it's because TDX must have "zap-slot-leafs-only" always selected. In TDX's case a memslot's GPA range can be a mixture of "private" or "shared" memory. Shared is roughly analogous to how EPT is handled for normal VMs, but private GPAs need lots of special treatment: 1) "zap-all" would require to zap private root page or non-leaf entries or at least leaf-entries beyond the deleting memslot scope. However, TDX demands that the root page of the private page table remains unchanged, with leaf entries being zapped before non-leaf entries, and any dropped private guest pages must be re-accepted by the guest. 2) if "zap-all" zaps only shared page tables, it would result in private pages still being mapped when the memslot is gone. This may affect even other processes if later the gmem fd was whole punched, causing the pages being freed on the host while still mapped in the TD, because there's no pgoff to the gfn information to zap the private page table after memslot is gone. So, simply go "zap-slot-leafs-only" as if the quirk is always disabled for non-KVM_X86_DEFAULT_VM VMs to avoid manual opt-in for every VM type [6] or complicating quirk disabling interface (current quirk disabling interface is limited, no way to query quirks, or force them to be disabled). Add a new function kvm_mmu_zap_memslot_leafs() to implement "zap-slot-leafs-only". This function does not call kvm_unmap_gfn_range(), bypassing special handling to APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, as 1) The APIC_ACCESS_PAGE_PRIVATE_MEMSLOT cannot be created by users, nor can it be moved. It is only deleted by KVM when APICv is permanently inhibited. 2) kvm_vcpu_reload_apic_access_page() effectively does nothing when APIC_ACCESS_PAGE_PRIVATE_MEMSLOT is deleted. 3) Avoid making all cpus request of KVM_REQ_APIC_PAGE_RELOAD can save on costly IPIs. Suggested-by: Kai Huang <kai.huang@intel.com> Suggested-by: Sean Christopherson <seanjc@google.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://patchwork.kernel.org/project/kvm/patch/20190205210137.1377-11-sean.j.christopherson@intel.com [1] Link: https://patchwork.kernel.org/project/kvm/patch/20190205210137.1377-11-sean.j.christopherson@intel.com/#25054908 [2] Link: https://lore.kernel.org/kvm/20200713190649.GE29725@linux.intel.com/T/#mabc0119583dacf621025e9d873c85f4fbaa66d5c [3] Link: https://lore.kernel.org/all/20240515005952.3410568-3-rick.p.edgecombe@intel.com [4] Link: https://lore.kernel.org/all/7df9032d-83e4-46a1-ab29-6c7973a2ab0b@redhat.com [5] Link: https://lore.kernel.org/all/ZnGa550k46ow2N3L@google.com [6] Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> Message-ID: <20240703021043.13881-1-yan.y.zhao@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Disallow read-only memslots for SEV-{ES,SNP} VM types, as KVM can't directly emulate instructions for ES/SNP, and instead the guest must explicitly request emulation. Unless the guest explicitly requests emulation without accessing memory, ES/SNP relies on KVM creating an MMIO SPTE, with the subsequent #NPF being reflected into the guest as a #VC. But for read-only memslots, KVM deliberately doesn't create MMIO SPTEs, because except for ES/SNP, doing so requires setting reserved bits in the SPTE, i.e. the SPTE can't be readable while also generating a #VC on writes. Because KVM never creates MMIO SPTEs and jumps directly to emulation, the guest never gets a #VC. And since KVM simply resumes the guest if ES/SNP guests trigger emulation, KVM effectively puts the vCPU into an infinite #NPF loop if the vCPU attempts to write read-only memory. Disallow read-only memory for all VMs with protected state, i.e. for upcoming TDX VMs as well as ES/SNP VMs. For TDX, it's actually possible to support read-only memory, as TDX uses EPT Violation #VE to reflect the fault into the guest, e.g. KVM could configure read-only SPTEs with RX protections and SUPPRESS_VE=0. But there is no strong use case for supporting read-only memslots on TDX, e.g. the main historical usage is to emulate option ROMs, but TDX disallows executing from shared memory. And if someone comes along with a legitimate, strong use case, the restriction can always be lifted for TDX. Don't bother trying to retroactively apply the restriction to SEV-ES VMs that are created as type KVM_X86_DEFAULT_VM. Read-only memslots can't possibly work for SEV-ES, i.e. disallowing such memslots is really just means reporting an error to userspace instead of silently hanging vCPUs. Trying to deal with the ordering between KVM_SEV_INIT and memslot creation isn't worth the marginal benefit it would provide userspace. Fixes: 26c44aa9 ("KVM: SEV: define VM types for SEV and SEV-ES") Fixes: 1dfe571c ("KVM: SEV: Add initial SEV-SNP support") Cc: Peter Gonda <pgonda@google.com> Cc: Michael Roth <michael.roth@amd.com> Cc: Vishal Annapurve <vannapurve@google.com> Cc: Ackerly Tng <ackerleytng@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240809190319.1710470-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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- 13 Aug, 2024 9 commits
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Li RongQing authored
When hot-unplug a device which has many queues, and guest CPU will has huge jitter, and unplugging is very slow. It turns out synchronize_srcu() in irqfd_shutdown() caused the guest jitter and unplugging latency, so replace synchronize_srcu() with synchronize_srcu_expedited(), to accelerate the unplugging, and reduce the guest OS jitter, this accelerates the VM reboot too. Signed-off-by: Li RongQing <lirongqing@baidu.com> Message-ID: <20240711121130.38917-1-lirongqing@baidu.com> [Call it just once in irqfd_resampler_shutdown. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Michal Luczaj authored
Add a test to verify that userspace can't change a vCPU's x2APIC ID by abusing KVM_SET_LAPIC. KVM models the x2APIC ID (and x2APIC LDR) as readonly, and silently ignores userspace attempts to change the x2APIC ID for backwards compatibility. Signed-off-by: Michal Luczaj <mhal@rbox.co> [sean: write changelog, add to existing test] Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240802202941.344889-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Ignore the userspace provided x2APIC ID when fixing up APIC state for KVM_SET_LAPIC, i.e. make the x2APIC fully readonly in KVM. Commit a92e2543 ("KVM: x86: use hardware-compatible format for APIC ID register"), which added the fixup, didn't intend to allow userspace to modify the x2APIC ID. In fact, that commit is when KVM first started treating the x2APIC ID as readonly, apparently to fix some race: static inline u32 kvm_apic_id(struct kvm_lapic *apic) { - return (kvm_lapic_get_reg(apic, APIC_ID) >> 24) & 0xff; + /* To avoid a race between apic_base and following APIC_ID update when + * switching to x2apic_mode, the x2apic mode returns initial x2apic id. + */ + if (apic_x2apic_mode(apic)) + return apic->vcpu->vcpu_id; + + return kvm_lapic_get_reg(apic, APIC_ID) >> 24; } Furthermore, KVM doesn't support delivering interrupts to vCPUs with a modified x2APIC ID, but KVM *does* return the modified value on a guest RDMSR and for KVM_GET_LAPIC. I.e. no remotely sane setup can actually work with a modified x2APIC ID. Making the x2APIC ID fully readonly fixes a WARN in KVM's optimized map calculation, which expects the LDR to align with the x2APIC ID. WARNING: CPU: 2 PID: 958 at arch/x86/kvm/lapic.c:331 kvm_recalculate_apic_map+0x609/0xa00 [kvm] CPU: 2 PID: 958 Comm: recalc_apic_map Not tainted 6.4.0-rc3-vanilla+ #35 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.2-1-1 04/01/2014 RIP: 0010:kvm_recalculate_apic_map+0x609/0xa00 [kvm] Call Trace: <TASK> kvm_apic_set_state+0x1cf/0x5b0 [kvm] kvm_arch_vcpu_ioctl+0x1806/0x2100 [kvm] kvm_vcpu_ioctl+0x663/0x8a0 [kvm] __x64_sys_ioctl+0xb8/0xf0 do_syscall_64+0x56/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fade8b9dd6f Unfortunately, the WARN can still trigger for other CPUs than the current one by racing against KVM_SET_LAPIC, so remove it completely. Reported-by: Michal Luczaj <mhal@rbox.co> Closes: https://lore.kernel.org/all/814baa0c-1eaa-4503-129f-059917365e80@rbox.coReported-by: Haoyu Wu <haoyuwu254@gmail.com> Closes: https://lore.kernel.org/all/20240126161633.62529-1-haoyuwu254@gmail.com Reported-by: syzbot+545f1326f405db4e1c3e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000c2a6b9061cbca3c3@google.comSigned-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240802202941.344889-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Isaku Yamahata authored
Use this_cpu_ptr() instead of open coding the equivalent in various user return MSR helpers. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Reviewed-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Yuan Yao <yuan.yao@intel.com> [sean: massage changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Message-ID: <20240802201630.339306-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Yue Haibing authored
There is no caller in tree since introduction in commit b4f69df0 ("KVM: x86: Make Hyper-V emulation optional") Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Message-ID: <20240803113233.128185-1-yuehaibing@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Dan Carpenter authored
The copy_from_user() function returns the number of bytes which it was not able to copy. Return -EFAULT instead. Fixes: dee5a47c ("KVM: SEV: Add KVM_SEV_SNP_LAUNCH_UPDATE command") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Message-ID: <20240612115040.2423290-4-dan.carpenter@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Paolo Bonzini authored
Merge tag 'kvm-s390-master-6.11-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD Fix invalid gisa designation value when gisa is not in use. Panic if (un)share fails to maintain security.
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Paolo Bonzini authored
Merge tag 'kvmarm-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.11, round #1 - Use kvfree() for the kvmalloc'd nested MMUs array - Set of fixes to address warnings in W=1 builds - Make KVM depend on assembler support for ARMv8.4 - Fix for vgic-debug interface for VMs without LPIs - Actually check ID_AA64MMFR3_EL1.S1PIE in get-reg-list selftest - Minor code / comment cleanups for configuring PAuth traps - Take kvm->arch.config_lock to prevent destruction / initialization race for a vCPU's CPUIF which may lead to a UAF
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Dan Carpenter authored
If snp_lookup_rmpentry() fails then "assigned" is printed in the error message but it was never initialized. Initialize it to false. Fixes: dee5a47c ("KVM: SEV: Add KVM_SEV_SNP_LAUNCH_UPDATE command") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Message-ID: <20240612115040.2423290-3-dan.carpenter@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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- 11 Aug, 2024 9 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: - Fix 32-bit PTI for real. pti_clone_entry_text() is called twice, once before initcalls so that initcalls can use the user-mode helper and then again after text is set read only. Setting read only on 32-bit might break up the PMD mapping, which makes the second invocation of pti_clone_entry_text() find the mappings out of sync and failing. Allow the second call to split the existing PMDs in the user mapping and synchronize with the kernel mapping. - Don't make acpi_mp_wake_mailbox read-only after init as the mail box must be writable in the case that CPU hotplug operations happen after boot. Otherwise the attempt to start a CPU crashes with a write to read only memory. - Add a missing sanity check in mtrr_save_state() to ensure that the fixed MTRR MSRs are supported. Otherwise mtrr_save_state() ends up in a #GP, which is fixed up, but the WARN_ON() can bring systems down when panic on warn is set. * tag 'x86-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mtrr: Check if fixed MTRRs exist before saving them x86/paravirt: Fix incorrect virt spinlock setting on bare metal x86/acpi: Remove __ro_after_init from acpi_mp_wake_mailbox x86/mm: Fix PTI for i386 some more
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull time keeping fixes from Thomas Gleixner: - Fix a couple of issues in the NTP code where user supplied values are neither sanity checked nor clamped to the operating range. This results in integer overflows and eventualy NTP getting out of sync. According to the history the sanity checks had been removed in favor of clamping the values, but the clamping never worked correctly under all circumstances. The NTP people asked to not bring the sanity checks back as it might break existing applications. Make the clamping work correctly and add it where it's missing - If adjtimex() sets the clock it has to trigger the hrtimer subsystem so it can adjust and if the clock was set into the future expire timers if needed. The caller should provide a bitmask to tell hrtimers which clocks have been adjusted. adjtimex() uses not the proper constant and uses CLOCK_REALTIME instead, which is 0. So hrtimers adjusts only the clocks, but does not check for expired timers, which might make them expire really late. Use the proper bitmask constant instead. * tag 'timers-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Fix bogus clock_was_set() invocation in do_adjtimex() ntp: Safeguard against time_constant overflow ntp: Clamp maxerror and esterror to operating range
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull irq fixes from Thomas Gleixner: "Three small fixes for interrupt core and drivers: - The interrupt core fails to honor caller supplied affinity hints for non-managed interrupts and uses the system default affinity on startup instead. Set the missing flag in the descriptor to tell the core to use the provided affinity. - Fix a shift out of bounds error in the Xilinx driver - Handle switching to level trigger correctly in the RISCV APLIC driver. It failed to retrigger the interrupt which causes it to become stale" * tag 'irq-urgent-2024-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/riscv-aplic: Retrigger MSI interrupt on source configuration irqchip/xilinx: Fix shift out of bounds genirq/irqdesc: Honor caller provided affinity in alloc_desc()
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usbLinus Torvalds authored
Pull USB fixes from Greg KH: "Here are a number of small USB driver fixes for reported issues for 6.11-rc3. Included in here are: - usb serial driver MODULE_DESCRIPTION() updates - usb serial driver fixes - typec driver fixes - usb-ip driver fix - gadget driver fixes - dt binding update All of these have been in linux-next with no reported issues" * tag 'usb-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: usb: typec: ucsi: Fix a deadlock in ucsi_send_command_common() usb: typec: tcpm: avoid sink goto SNK_UNATTACHED state if not received source capability message usb: gadget: f_fs: pull out f->disable() from ffs_func_set_alt() usb: gadget: f_fs: restore ffs_func_disable() functionality USB: serial: debug: do not echo input by default usb: typec: tipd: Delete extra semi-colon usb: typec: tipd: Fix dereferencing freeing memory in tps6598x_apply_patch() usb: gadget: u_serial: Set start_delayed during suspend usb: typec: tcpci: Fix error code in tcpci_check_std_output_cap() usb: typec: fsa4480: Check if the chip is really there usb: gadget: core: Check for unset descriptor usb: vhci-hcd: Do not drop references before new references are gained usb: gadget: u_audio: Check return codes from usb_ep_enable and config_ep_by_speed. usb: gadget: midi2: Fix the response for FB info with block 0xff dt-bindings: usb: microchip,usb2514: Add USB2517 compatible USB: serial: garmin_gps: use struct_size() to allocate pkt USB: serial: garmin_gps: annotate struct garmin_packet with __counted_by USB: serial: add missing MODULE_DESCRIPTION() macros USB: serial: spcp8x5: remove unused struct 'spcp8x5_usb_ctrl_arg'
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/ttyLinus Torvalds authored
Pull tty / serial driver fixes from Greg KH: "Here are some small tty and serial driver fixes for reported problems for 6.11-rc3. Included in here are: - sc16is7xx serial driver fixes - uartclk bugfix for a divide by zero issue - conmakehash userspace build issue fix All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: vt: conmakehash: cope with abs_srctree no longer in env serial: sc16is7xx: fix invalid FIFO access with special register set serial: sc16is7xx: fix TX fifo corruption serial: core: check uartclk for zero to avoid divide by zero
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Linus Torvalds authored
Merge tag 'driver-core-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core / documentation fixes from Greg KH: "Here are some small fixes, and some documentation updates for 6.11-rc3. Included in here are: - embargoed hardware documenation updates based on a lot of review by legal-types in lots of companies to try to make the process a _bit_ easier for us to manage over time. - rust firmware documentation fix - driver detach race fix for the fix that went into 6.11-rc1 All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: driver core: Fix uevent_show() vs driver detach race Documentation: embargoed-hardware-issues.rst: add a section documenting the "early access" process Documentation: embargoed-hardware-issues.rst: minor cleanups and fixes rust: firmware: fix invalid rustdoc link
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscLinus Torvalds authored
Pull char/misc fixes from Greg KH: "Here are some small char/misc/other driver fixes for 6.11-rc3 for reported issues. Included in here are: - binder driver fixes - fsi MODULE_DESCRIPTION() additions (people seem to love them...) - eeprom driver fix - Kconfig dependency fix to resolve build issues - spmi driver fixes All of these have been in linux-next for a while with no reported problems" * tag 'char-misc-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: spmi: pmic-arb: add missing newline in dev_err format strings spmi: pmic-arb: Pass the correct of_node to irq_domain_add_tree binder_alloc: Fix sleeping function called from invalid context binder: fix descriptor lookup for context manager char: add missing NetWinder MODULE_DESCRIPTION() macros misc: mrvl-cn10k-dpi: add PCI_IOV dependency eeprom: ee1004: Fix locking issues in ee1004_probe() fsi: add missing MODULE_DESCRIPTION() macros
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Two core fixes: one to prevent discard type changes (seen on iSCSI) during intermittent errors and the other is fixing a lockdep problem caused by the queue limits change. And one driver fix in ufs" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: sd: Keep the discard mode stable scsi: sd: Move sd_read_cpr() out of the q->limits_lock region scsi: ufs: core: Fix hba->last_dme_cmd_tstamp timestamp updating logic
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- 10 Aug, 2024 7 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds authored
Pull nfsd fixes from Chuck Lever: - Two minor fixes for recent changes * tag 'nfsd-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: don't set SVC_SOCK_ANONYMOUS when creating nfsd sockets sunrpc: avoid -Wformat-security warning
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fixes from Wolfram Sang: - Two fixes for SMBusAlert handling in the I2C core: one to avoid an endless loop when scanning for handlers and one to make sure handlers are always called even if HW has broken behaviour - I2C header build fix for when ACPI is enabled but I2C isn't - The testunit gets a rename in the code to match the documentation - Two fixes for the Qualcomm GENI I2C controller are cleaning up the error exit patch in the runtime_resume() function. The first is disabling the clock, the second disables the icc on the way out * tag 'i2c-for-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: testunit: match HostNotify test name with docs i2c: qcom-geni: Add missing geni_icc_disable in geni_i2c_runtime_resume i2c: qcom-geni: Add missing clk_disable_unprepare in geni_i2c_runtime_resume i2c: Fix conditional for substituting empty ACPI functions i2c: smbus: Send alert notifications to all devices if source not found i2c: smbus: Improve handling of stuck alerts
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git://git.infradead.org/users/hch/dma-mappingLinus Torvalds authored
Pull dma-mapping fix from Christoph Hellwig: - avoid a deadlock with dma-debug and netconsole (Rik van Riel) * tag 'dma-mapping-6.11-2024-08-10' of git://git.infradead.org/users/hch/dma-mapping: dma-debug: avoid deadlock between dma debug vs printk and netconsole
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git://evilpiepirate.org/bcachefsLinus Torvalds authored
Pull more bcachefs fixes from Kent Overstreet: "A couple last minute fixes for the new disk accounting - fix a bug that was causing ACLs to seemingly "disappear" - new on disk format version, bcachefs_metadata_version_disk_accounting_v3 bcachefs_metadata_version_disk_accounting_v2 accidentally included padding in disk_accounting_key; fortunately, 6.11 isn't out yet so we can fix this with another version bump" * tag 'bcachefs-2024-08-10' of git://evilpiepirate.org/bcachefs: bcachefs: bcachefs_metadata_version_disk_accounting_v3 bcachefs: improve bch2_dev_usage_to_text() bcachefs: bch2_accounting_invalid() bcachefs: Switch to .get_inode_acl()
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Yong-Xuan Wang authored
The section 4.5.2 of the RISC-V AIA specification says that "any write to a sourcecfg register of an APLIC might (or might not) cause the corresponding interrupt-pending bit to be set to one if the rectified input value is high (= 1) under the new source mode." When the interrupt type is changed in the sourcecfg register, the APLIC device might not set the corresponding pending bit, so the interrupt might never become pending. To handle sourcecfg register changes for level-triggered interrupts in MSI mode, manually set the pending bit for retriggering interrupt so it gets retriggered if it was already asserted. Fixes: ca8df97f ("irqchip/riscv-aplic: Add support for MSI-mode") Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240809071049.2454-1-yongxuan.wang@sifive.com
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Radhey Shyam Pandey authored
The device tree property 'xlnx,kind-of-intr' is sanity checked that the bitmask contains only set bits which are in the range of the number of interrupts supported by the controller. The check is done by shifting the mask right by the number of supported interrupts and checking the result for zero. The data type of the mask is u32 and the number of supported interrupts is up to 32. In case of 32 interrupts the shift is out of bounds, resulting in a mismatch warning. The out of bounds condition is also reported by UBSAN: UBSAN: shift-out-of-bounds in irq-xilinx-intc.c:332:22 shift exponent 32 is too large for 32-bit type 'unsigned int' Fix it by promoting the mask to u64 for the test. Fixes: d50466c9 ("microblaze: intc: Refactor DT sanity check") Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/1723186944-3571957-1-git-send-email-radhey.shyam.pandey@amd.com
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull smb client fixes from Steve French: - DFS fix - fix for security flags for requiring encryption - minor cleanup * tag '6.11-rc2-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: cifs_inval_name_dfs_link_error: correct the check for fullpath Fix spelling errors in Server Message Block smb3: fix setting SecurityFlags when encryption is required
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