- 09 Jun, 2022 17 commits
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Maxim Levitsky authored
On SVM, if preemption happens right after the call to finish_rcuwait but before call to kvm_arch_vcpu_unblocking on SVM/AVIC, it itself will re-enable AVIC, and then we will try to re-enable it again in kvm_arch_vcpu_unblocking which will lead to a warning in __avic_vcpu_load. The same problem can happen if the vCPU is preempted right after the call to kvm_arch_vcpu_blocking but before the call to prepare_to_rcuwait and in this case, we will end up with AVIC enabled during sleep - Ooops. Signed-off-by:
Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220606180829.102503-7-mlevitsk@redhat.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Maxim Levitsky authored
Currently nothing prevents preemption in kvm_vcpu_update_apicv. On SVM, If the preemption happens after we update the vcpu->arch.apicv_active, the preemption itself will 'update' the inhibition since the AVIC will be first disabled on vCPU unload and then enabled, when the current task is loaded again. Then we will try to update it again, which will lead to a warning in __avic_vcpu_load, that the AVIC is already enabled. Fix this by disabling preemption in this code. Signed-off-by:
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Maxim Levitsky authored
There are two issues in avic_kick_target_vcpus_fast 1. It is legal to issue an IPI request with APIC_DEST_NOSHORT and a physical destination of 0xFF (or 0xFFFFFFFF in case of x2apic), which must be treated as a broadcast destination. Fix this by explicitly checking for it. Also donâ€
™ t use ‘index’ in this case as it gives no new information. 2. It is legal to issue a logical IPI request to more than one target. Index field only provides index in physical id table of first such target and therefore can't be used before we are sure that only a single target was addressed. Instead, parse the ICRL/ICRH, double check that a unicast interrupt was requested, and use that info to figure out the physical id of the target vCPU. At that point there is no need to use the index field as well. In addition to fixing the above issues, also skip the call to kvm_apic_match_dest. It is possible to do this now, because now as long as AVIC is not inhibited, it is guaranteed that none of the vCPUs changed their apic id from its default value. This fixes boot of windows guest with AVIC enabled because it uses IPI with 0xFF destination and no destination shorthand. Fixes: 7223fd2d ("KVM: SVM: Use target APIC ID to complete AVIC IRQs when possible") Cc: stable@vger.kernel.org Signed-off-by: -
Maxim Levitsky authored
AVIC is now inhibited if the guest changes the apic id, and therefore this code is no longer needed. There are several ways this code was broken, including: 1. a vCPU was only allowed to change its apic id to an apic id of an existing vCPU. 2. After such change, the vCPU whose apic id entry was overwritten, could not correctly change its own apic id, because its own entry is already overwritten. Signed-off-by:
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Maxim Levitsky authored
Neither of these settings should be changed by the guest and it is a burden to support it in the acceleration code, so just inhibit this code instead. Signed-off-by:
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Maxim Levitsky authored
These days there are too many AVIC/APICv inhibit reasons, and it doesn't hurt to have some documentation for them. Signed-off-by:
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Yuan Yao authored
Assign shadow_me_value, not shadow_me_mask, to PAE root entries, a.k.a. shadow PDPTRs, when host memory encryption is supported. The "mask" is the set of all possible memory encryption bits, e.g. MKTME KeyIDs, whereas "value" holds the actual value that needs to be stuffed into host page tables. Using shadow_me_mask results in a failed VM-Entry due to setting reserved PA bits in the PDPTRs, and ultimately causes an OOPS due to physical addresses with non-zero MKTME bits sending to_shadow_page() into the weeds: set kvm_intel.dump_invalid_vmcs=1 to dump internal KVM state. BUG: unable to handle page fault for address: ffd43f00063049e8 PGD 86dfd8067 P4D 0 Oops: 0000 [#1] PREEMPT SMP RIP: 0010:mmu_free_root_page+0x3c/0x90 [kvm] kvm_mmu_free_roots+0xd1/0x200 [kvm] __kvm_mmu_unload+0x29/0x70 [kvm] kvm_mmu_unload+0x13/0x20 [kvm] kvm_arch_destroy_vm+0x8a/0x190 [kvm] kvm_put_kvm+0x197/0x2d0 [kvm] kvm_vm_release+0x21/0x30 [kvm] __fput+0x8e/0x260 ____fput+0xe/0x10 task_work_run+0x6f/0xb0 do_exit+0x327/0xa90 do_group_exit+0x35/0xa0 get_signal+0x911/0x930 arch_do_signal_or_restart+0x37/0x720 exit_to_user_mode_prepare+0xb2/0x140 syscall_exit_to_user_mode+0x16/0x30 do_syscall_64+0x4e/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: e54f1ff2 ("KVM: x86/mmu: Add shadow_me_value and repurpose shadow_me_mask") Signed-off-by:
Yuan Yao <yuan.yao@intel.com> Reviewed-by:
Kai Huang <kai.huang@intel.com> Message-Id: <20220608012015.19566-1-yuan.yao@intel.com> Signed-off-by:
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Paolo Bonzini authored
Merge tag 'kvmarm-fixes-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.19, take #1 - Properly reset the SVE/SME flags on vcpu load - Fix a vgic-v2 regression regarding accessing the pending state of a HW interrupt from userspace (and make the code common with vgic-v3) - Fix access to the idreg range for protected guests - Ignore 'kvm-arm.mode=protected' when using VHE - Return an error from kvm_arch_init_vm() on allocation failure - A bunch of small cleanups (comments, annotations, indentation)
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https://github.com/kvm-riscv/linuxPaolo Bonzini authored
KVM/riscv fixes for 5.19, take #1 - Typo fix in arch/riscv/kvm/vmid.c - Remove broken reference pattern from MAINTAINERS entry
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Marc Zyngier authored
The layout of 'struct kvm_vcpu_arch' has evolved significantly since the initial port of KVM/arm64, so remove the stale comment suggesting that a prefix of the structure is used exclusively from assembly code. Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220609121223.2551-7-will@kernel.org
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Will Deacon authored
host_stage2_try() asserts that the KVM host lock is held, so there's no need to duplicate the assertion in its wrappers. Signed-off-by:
Will Deacon <will@kernel.org> Signed-off-by:
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Will Deacon authored
has_vhe() expands to a compile-time constant when evaluated from the VHE or nVHE code, alternatively checking a static key when called from elsewhere in the kernel. On face value, this looks like a case of premature optimization, but in fact this allows symbol references on VHE-specific code paths to be dropped from the nVHE object. Expand the comment in has_vhe() to make this clearer, hopefully discouraging anybody from simplifying the code. Cc: David Brazdil <dbrazdil@google.com> Acked-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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Will Deacon authored
Ignore 'kvm-arm.mode=protected' when using VHE so that kvm_get_mode() only returns KVM_MODE_PROTECTED on systems where the feature is available. Cc: David Brazdil <dbrazdil@google.com> Acked-by:
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Marc Zyngier authored
A protected VM accessing ID_AA64ISAR2_EL1 gets punished with an UNDEF, while it really should only get a zero back if the register is not handled by the hypervisor emulation (as mandated by the architecture). Introduce all the missing ID registers (including the unallocated ones), and have them to return 0. Reported-by:
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Will Deacon authored
If we fail to allocate the 'supported_cpus' cpumask in kvm_arch_init_vm() then be sure to return -ENOMEM instead of success (0) on the failure path. Reviewed-by:
Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by:
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Lukas Bulwahn authored
Commit fed9b26b ("MAINTAINERS: Update KVM RISC-V entry to cover selftests support") optimistically adds a file entry for tools/testing/selftests/kvm/riscv/, but this directory does not exist. Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about a broken reference. The script is very useful to keep MAINTAINERS up to date and MAINTAINERS can be kept in a state where the script emits no warning. So, just drop the non-matching file entry rather than starting to collect exceptions of entries that may match in some close or distant future. Fixes: fed9b26b ("MAINTAINERS: Update KVM RISC-V entry to cover selftests support") Signed-off-by:
Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by:
Anup Patel <anup@brainfault.org>
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Julia Lawall authored
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by:
Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by:
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- 08 Jun, 2022 4 commits
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Marc Zyngier authored
A recurrent bug in the KVM/arm64 code base consists in trying to access the timer pending state outside of the vcpu context, which makes zero sense (the pending state only exists when the vcpu is loaded). In order to avoid more embarassing crashes and catch the offenders red-handed, add a warning to kvm_arch_timer_get_input_level() and return the state as non-pending. This avoids taking the system down, and still helps tracking down silly bugs. Reviewed-by:
Eric Auger <eric.auger@redhat.com> Signed-off-by:
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Marc Zyngier authored
Now that GICv2 has a proper userspace accessor for the pending state, switch GICv3 over to it, dropping the local version, moving over the specific behaviours that CGIv3 requires (such as the distinction between pending latch and line level which were never enforced with GICv2). We also gain extra locking that isn't really necessary for userspace, but that's a small price to pay for getting rid of superfluous code. Signed-off-by:
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Paolo Bonzini authored
If a vCPU is outside guest mode and is scheduled out, it might be in the process of making a memory access. A problem occurs if another vCPU uses the PV TLB flush feature during the period when the vCPU is scheduled out, and a virtual address has already been translated but has not yet been accessed, because this is equivalent to using a stale TLB entry. To avoid this, only report a vCPU as preempted if sure that the guest is at an instruction boundary. A rescheduling request will be delivered to the host physical CPU as an external interrupt, so for simplicity consider any vmexit *not* instruction boundary except for external interrupts. It would in principle be okay to report the vCPU as preempted also if it is sleeping in kvm_vcpu_block(): a TLB flush IPI will incur the vmentry/vmexit overhead unnecessarily, and optimistic spinning is also unlikely to succeed. However, leave it for later because right now kvm_vcpu_check_block() is doing memory accesses. Even though the TLB flush issue only applies to virtual memory address, it's very much preferrable to be conservative. Reported-by:
Jann Horn <jannh@google.com> Signed-off-by:
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Paolo Bonzini authored
Similar to the Xen path, only change the vCPU's reported state if the vCPU was actually preempted. The reason for KVM's behavior is that for example optimistic spinning might not be a good idea if the guest is doing repeated exits to userspace; however, it is confusing and unlikely to make a difference, because well-tuned guests will hardly ever exit KVM_RUN in the first place. Suggested-by:
Sean Christopherson <seanjc@google.com> Signed-off-by:
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- 07 Jun, 2022 11 commits
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Maxim Levitsky authored
SVM uses a per-cpu variable to cache the current value of the tsc scaling multiplier msr on each cpu. Commit 1ab9287a ("KVM: X86: Add vendor callbacks for writing the TSC multiplier") broke this caching logic. Refactor the code so that all TSC scaling multiplier writes go through a single function which checks and updates the cache. This fixes the following scenario: 1. A CPU runs a guest with some tsc scaling ratio. 2. New guest with different tsc scaling ratio starts on this CPU and terminates almost immediately. This ensures that the short running guest had set the tsc scaling ratio just once when it was set via KVM_SET_TSC_KHZ. Due to the bug, the per-cpu cache is not updated. 3. The original guest continues to run, it doesn't restore the msr value back to its own value, because the cache matches, and thus continues to run with a wrong tsc scaling ratio. Fixes: 1ab9287a ("KVM: X86: Add vendor callbacks for writing the TSC multiplier") Signed-off-by:
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Vitaly Kuznetsov authored
hyperv_clock doesn't always give a stable test result, especially with AMD CPUs. The test compares Hyper-V MSR clocksource (acquired either with rdmsr() from within the guest or KVM_GET_MSRS from the host) against rdtsc(). To increase the accuracy, increase the measured delay (done with nop loop) by two orders of magnitude and take the mean rdtsc() value before and after rdmsr()/KVM_GET_MSRS. Reported-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by:
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Ben Gardon authored
Currently disabling dirty logging with the TDP MMU is extremely slow. On a 96 vCPU / 96G VM backed with gigabyte pages, it takes ~200 seconds to disable dirty logging with the TDP MMU, as opposed to ~4 seconds with the shadow MMU. When disabling dirty logging, zap non-leaf parent entries to allow replacement with huge pages instead of recursing and zapping all of the child, leaf entries. This reduces the number of TLB flushes required. and reduces the disable dirty log time with the TDP MMU to ~3 seconds. Opportunistically add a WARN() to catch GFNs that are mapped at a higher level than their max level. Signed-off-by:
Ben Gardon <bgardon@google.com> Message-Id: <20220525230904.1584480-1-bgardon@google.com> Signed-off-by:
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Jan Beulich authored
As noted (and fixed) a couple of times in the past, "=@cc<cond>" outputs and clobbering of "cc" don't work well together. The compiler appears to mean to reject such, but doesn't - in its upstream form - quite manage to yet for "cc". Furthermore two similar macros don't clobber "cc", and clobbering "cc" is pointless in asm()-s for x86 anyway - the compiler always assumes status flags to be clobbered there. Fixes: 989b5db2 ("x86/uaccess: Implement macros for CMPXCHG on user addresses") Signed-off-by:
Jan Beulich <jbeulich@suse.com> Message-Id: <485c0c0b-a3a7-0b7c-5264-7d00c01de032@suse.com> Signed-off-by:
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Shaoqin Huang authored
When freeing obsolete previous roots, check prev_roots as intended, not the current root. Signed-off-by:
Shaoqin Huang <shaoqin.huang@intel.com> Fixes: 527d5cd7 ("KVM: x86/mmu: Zap only obsolete roots if a root shadow page is zapped") Message-Id: <20220607005905.2933378-1-shaoqin.huang@intel.com> Cc: stable@vger.kernel.org Reviewed-by:
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Marc Zyngier authored
Since 5bfa685e ("KVM: arm64: vgic: Read HW interrupt pending state from the HW"), we're able to source the pending bit for an interrupt that is stored either on the physical distributor or on a device. However, this state is only available when the vcpu is loaded, and is not intended to be accessed from userspace. Unfortunately, the GICv2 emulation doesn't provide specific userspace accessors, and we fallback with the ones that are intended for the guest, with fatal consequences. Add a new vgic_uaccess_read_pending() accessor for userspace to use, build on top of the existing vgic_mmio_read_pending(). Reported-by:
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Seth Forshee authored
A livepatch transition may stall indefinitely when a kvm vCPU is heavily loaded. To the host, the vCPU task is a user thread which is spending a very long time in the ioctl(KVM_RUN) syscall. During livepatch transition, set_notify_signal() will be called on such tasks to interrupt the syscall so that the task can be transitioned. This interrupts guest execution, but when xfer_to_guest_mode_work() sees that TIF_NOTIFY_SIGNAL is set but not TIF_SIGPENDING it concludes that an exit to user mode is unnecessary, and guest execution is resumed without transitioning the task for the livepatch. This handling of TIF_NOTIFY_SIGNAL is incorrect, as set_notify_signal() is expected to break tasks out of interruptible kernel loops and cause them to return to userspace. Change xfer_to_guest_mode_work() to handle TIF_NOTIFY_SIGNAL the same as TIF_SIGPENDING, signaling to the vCPU run loop that an exit to userpsace is needed. Any pending task_work will be run when get_signal() is called from exit_to_user_mode_loop(), so there is no longer any need to run task work from xfer_to_guest_mode_work(). Suggested-by:
"Eric W. Biederman" <ebiederm@xmission.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by:
Seth Forshee <sforshee@digitalocean.com> Message-Id: <20220504180840.2907296-1-sforshee@digitalocean.com> Signed-off-by:
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Alexey Kardashevskiy authored
A KVM device cleanup happens in either of two callbacks: 1) destroy() which is called when the VM is being destroyed; 2) release() which is called when a device fd is closed. Most KVM devices use 1) but Book3s's interrupt controller KVM devices (XICS, XIVE, XIVE-native) use 2) as they need to close and reopen during the machine execution. The error handling in kvm_ioctl_create_device() assumes destroy() is always defined which leads to NULL dereference as discovered by Syzkaller. This adds a checks for destroy!=NULL and adds a missing release(). This is not changing kvm_destroy_devices() as devices with defined release() should have been removed from the KVM devices list by then. Suggested-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
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sunliming authored
Fix the following smatch warnings: arch/arm64/kvm/vmid.c:62 flush_context() warn: inconsistent indenting Reported-by:
kernel test robot <lkp@intel.com> Signed-off-by:
sunliming <sunliming@kylinos.cn> Signed-off-by:
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Marc Zyngier authored
On each vcpu load, we set the KVM_ARM64_HOST_SME_ENABLED flag if SME is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SME for userspace. As it turns out, this is due to the SME code being more or less copied from SVE, and inheriting the same shortcomings. We never saw the issue because nothing uses SME, and the amount of testing is probably still pretty low. Fixes: 861262ab ("KVM: arm64: Handle SME host state when running guests") Signed-off-by:
Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220528113829.1043361-3-maz@kernel.org
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Marc Zyngier authored
On each vcpu load, we set the KVM_ARM64_HOST_SVE_ENABLED flag if SVE is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SVE for userspace. We probably never saw the issue because no VMM uses SVE, but that's still pretty bad. Unconditionally clearing the flag on vcpu load addresses the issue. Fixes: 8383741a ("KVM: arm64: Get rid of host SVE tracking/saving") Signed-off-by:
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- 06 Jun, 2022 3 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull file descriptor fix from Al Viro: "Fix for breakage in #work.fd this window" * tag 'pull-work.fd-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix the breakage in close_fd_get_file() calling conventions change
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds authored
Pull mm hotfixes from Andrew Morton: "Fixups for various recently-added and longer-term issues and a few minor tweaks: - fixes for material merged during this merge window - cc:stable fixes for more longstanding issues - minor mailmap and MAINTAINERS updates" * tag 'mm-hotfixes-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/oom_kill.c: fix vm_oom_kill_table[] ifdeffery x86/kexec: fix memory leak of elf header buffer mm/memremap: fix missing call to untrack_pfn() in pagemap_range() mm: page_isolation: use compound_nr() correctly in isolate_single_pageblock() mm: hugetlb_vmemmap: fix CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON MAINTAINERS: add maintainer information for z3fold mailmap: update Josh Poimboeuf's email
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- 05 Jun, 2022 5 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds authored
Pull delay-accounting update from Andrew Morton: "A single featurette for delay accounting. Delayed a bit because, unusually, it had dependencies on both the mm-stable and mm-nonmm-stable queues" * tag 'mm-nonmm-stable-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: delayacct: track delays from write-protect copy
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Linus Torvalds authored
The bluetooth code uses our bitmap infrastructure for the two bits (!) of connection setup flags, and in the process causes odd problems when it converts between a bitmap and just the regular values of said bits. It's completely pointless to do things like bitmap_to_arr32() to convert a bitmap into a u32. It shoudln't have been a bitmap in the first place. The reason to use bitmaps is if you have arbitrary number of bits you want to manage (not two!), or if you rely on the atomicity guarantees of the bitmap setting and clearing. The code could use an "atomic_t" and use "atomic_or/andnot()" to set and clear the bit values, but considering that it then copies the bitmaps around with "bitmap_to_arr32()" and friends, there clearly cannot be a lot of atomicity requirements. So just use a regular integer. In the process, this avoids the warnings about erroneous use of bitmap_from_u64() which were triggered on 32-bit architectures when conversion from a u64 would access two words (and, surprise, surprise, only one word is needed - and indeed overkill - for a 2-bit bitmap). That was always problematic, but the compiler seems to notice it and warn about the invalid pattern only after commit 0a97953f ("lib: add bitmap_{from,to}_arr64") changed the exact implementation details of 'bitmap_from_u64()', as reported by Sudip Mukherjee and Stephen Rothwell. Fixes: fe92ee64 ("Bluetooth: hci_core: Rework hci_conn_params flags") Link: https://lore.kernel.org/all/YpyJ9qTNHJzz0FHY@debian/ Link: https://lore.kernel.org/all/20220606080631.0c3014f2@canb.auug.org.au/ Link: https://lore.kernel.org/all/20220605162537.1604762-1-yury.norov@gmail.com/Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Reported-by:
Sudip Mukherjee <sudipm.mukherjee@gmail.com> Reviewed-by:
Yury Norov <yury.norov@gmail.com> Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Al Viro authored
It used to grab an extra reference to struct file rather than just transferring to caller the one it had removed from descriptor table. New variant doesn't, and callers need to be adjusted. Reported-and-tested-by: syzbot+47dd250f527cb7bebf24@syzkaller.appspotmail.com Fixes: 6319194e ("Unify the primitives for file descriptor closing") Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 SGX fix from Thomas Gleixner: "A single fix for x86/SGX to prevent that memory which is allocated for an SGX enclave is accounted to the wrong memory control group" * tag 'x86-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Set active memcg prior to shmem allocation
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 mm cleanup from Thomas Gleixner: "Use PAGE_ALIGNED() instead of open coding it in the x86/mm code" * tag 'x86-mm-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Use PAGE_ALIGNED(x) instead of IS_ALIGNED(x, PAGE_SIZE)
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