- 02 Apr, 2022 4 commits
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David Woodhouse authored
If the cache's user host virtual address becomes invalid, there is still a path from kvm_gfn_to_pfn_cache_refresh() where __release_gpc() could release the pfn but the gpc->pfn field has not been overwritten with an error value. If this happens, kvm_gfn_to_pfn_cache_unmap will call put_page again on the same page. Cc: stable@vger.kernel.org Fixes: 982ed0de ("KVM: Reinstate gfn_to_pfn_cache with invalidation support") Signed-off-by:
David Woodhouse <dwmw2@infradead.org> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Re-introduce zapping only leaf SPTEs in kvm_zap_gfn_range() and kvm_tdp_mmu_unmap_gfn_range(), this time without losing a pending TLB flush when processing multiple roots (including nested TDP shadow roots). Dropping the TLB flush resulted in random crashes when running Hyper-V Server 2019 in a guest with KSM enabled in the host (or any source of mmu_notifier invalidations, KSM is just the easiest to force). This effectively revert commits 873dd122 and fcb93eb6, and thus restores commit cf3e2642, plus this delta on top: bool kvm_tdp_mmu_zap_leafs(struct kvm *kvm, int as_id, gfn_t start, gfn_t end, struct kvm_mmu_page *root; for_each_tdp_mmu_root_yield_safe(kvm, root, as_id) - flush = tdp_mmu_zap_leafs(kvm, root, start, end, can_yield, false); + flush = tdp_mmu_zap_leafs(kvm, root, start, end, can_yield, flush); return flush; } Cc: Ben Gardon <bgardon@google.com> Signed-off-by:
Sean Christopherson <seanjc@google.com> Tested-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20220325230348.2587437-1-seanjc@google.com> Signed-off-by:
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Yi Wang authored
As guest_irq is coming from KVM_IRQFD API call, it may trigger crash in svm_update_pi_irte() due to out-of-bounds: crash> bt PID: 22218 TASK: ffff951a6ad74980 CPU: 73 COMMAND: "vcpu8" #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397 #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9 #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51 #6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace [exception RIP: svm_update_pi_irte+227] RIP: ffffffffc0761b53 RSP: ffffb1ba6707fd08 RFLAGS: 00010086 RAX: ffffb1ba6707fd78 RBX: ffffb1ba66d91000 RCX: 0000000000000001 RDX: 00003c803f63f1c0 RSI: 000000000000019a RDI: ffffb1ba66db2ab8 RBP: 000000000000019a R8: 0000000000000040 R9: ffff94ca41b82200 R10: ffffffffffffffcf R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffffffffffcf R15: 000000000000005f ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm] #8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm] #9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm] RIP: 00007f143c36488b RSP: 00007f143a4e04b8 RFLAGS: 00000246 RAX: ffffffffffffffda RBX: 00007f05780041d0 RCX: 00007f143c36488b RDX: 00007f05780041d0 RSI: 000000004008ae6a RDI: 0000000000000020 RBP: 00000000000004e8 R8: 0000000000000008 R9: 00007f05780041e0 R10: 00007f0578004560 R11: 0000000000000246 R12: 00000000000004e0 R13: 000000000000001a R14: 00007f1424001c60 R15: 00007f0578003bc0 ORIG_RAX: 0000000000000010 CS: 0033 SS: 002b Vmx have been fix this in commit 3a8b0677 (KVM: VMX: Do not BUG() on out-of-bounds guest IRQ), so we can just copy source from that to fix this. Co-developed-by:Yi Liu <liu.yi24@zte.com.cn> Signed-off-by:
Yi Wang <wang.yi59@zte.com.cn> Message-Id: <20220309113025.44469-1-wang.yi59@zte.com.cn> Cc: stable@vger.kernel.org Signed-off-by:
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Paolo Bonzini authored
If kvm->arch.tdp_mmu_zap_wq cannot be created, the failure has to be propagated up to kvm_mmu_init_vm and kvm_arch_init_vm. kvm_arch_init_vm also has to undo all the initialization, so group all the MMU initialization code at the beginning and handle cleaning up of kvm_page_track_init. Signed-off-by:
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- 29 Mar, 2022 11 commits
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Vitaly Kuznetsov authored
Setting non-zero values to SYNIC/STIMER MSRs activates certain features, this should not happen when KVM_CAP_HYPERV_SYNIC{,2} was not activated. Note, it would've been better to forbid writing anything to SYNIC/STIMER MSRs, including zeroes, however, at least QEMU tries clearing HV_X64_MSR_STIMER0_CONFIG without SynIC. HV_X64_MSR_EOM MSR is somewhat 'special' as writing zero there triggers an action, this also should not happen when SynIC wasn't activated. Signed-off-by: -
Vitaly Kuznetsov authored
When kvm_irq_delivery_to_apic_fast() is called with APIC_DEST_SELF shorthand, 'src' must not be NULL. Crash the VM with KVM_BUG_ON() instead of crashing the host. Signed-off-by:
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Vitaly Kuznetsov authored
When KVM_CAP_HYPERV_SYNIC{,2} is activated, KVM already checks for irqchip_in_kernel() so normally SynIC irqs should never be set. It is, however, possible for a misbehaving VMM to write to SYNIC/STIMER MSRs causing erroneous behavior. The immediate issue being fixed is that kvm_irq_delivery_to_apic() (kvm_irq_delivery_to_apic_fast()) crashes when called with 'irq.shorthand = APIC_DEST_SELF' and 'src == NULL'. Signed-off-by: -
Paolo Bonzini authored
Add a section to document all the different ways in which the KVM API sucks. I am sure there are way more, give people a place to vent so that userspace authors are aware. Signed-off-by:
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Paolo Bonzini authored
Add a file to document all the different ways in which the virtual CPU emulation is imperfect. Include an example to show how to document such errata. Signed-off-by:
Jim Mattson <jmattson@google.com> Reviewed-by:
Oliver Upton <oupton@google.com> Message-Id: <20220322110712.222449-3-pbonzini@redhat.com> Signed-off-by:
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Paolo Bonzini authored
ARM already has an arm/ subdirectory, but s390 and x86 do not even though they have a relatively large number of files specific to them. Create new directories in Documentation/virt/kvm for these two architectures as well. While at it, group the API documentation and the developer documentation in the table of contents. Signed-off-by:
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Paolo Bonzini authored
kvm->mn_invalidate_lock and kvm->slots_arch_lock were not included in the documentation, add them. Signed-off-by:
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Paolo Bonzini authored
Separate the various locks clearly, and include the new names of blocked_vcpu_on_cpu_lock and blocked_vcpu_on_cpu. Signed-off-by:
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Nathan Chancellor authored
Clang warns: arch/x86/kvm/cpuid.c:739:2: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough] default: ^ arch/x86/kvm/cpuid.c:739:2: note: insert 'break;' to avoid fall-through default: ^ break; 1 error generated. Clang is a little more pedantic than GCC, which does not warn when falling through to a case that is just break or return. Clang's version is more in line with the kernel's own stance in deprecated.rst, which states that all switch/case blocks must end in either break, fallthrough, continue, goto, or return. Add the missing break to silence the warning. Fixes: f144c49e ("KVM: x86: synthesize CPUID leaf 0x80000021h if useful") Reported-by:kernel test robot <lkp@intel.com> Signed-off-by:
Nathan Chancellor <nathan@kernel.org> Message-Id: <20220322152906.112164-1-nathan@kernel.org> Signed-off-by:
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David Matlack authored
This reverts commit 3d3aab1b. Now that the KVM module's lifetime is tied to kvm.users_count, there is no need to also tie it's lifetime to the lifetime of the VM and vCPU file descriptors. Suggested-by:
David Matlack <dmatlack@google.com> Message-Id: <20220303183328.1499189-3-dmatlack@google.com> Reviewed-by:
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David Matlack authored
Tie the lifetime the KVM module to the lifetime of each VM via kvm.users_count. This way anything that grabs a reference to the VM via kvm_get_kvm() cannot accidentally outlive the KVM module. Prior to this commit, the lifetime of the KVM module was tied to the lifetime of /dev/kvm file descriptors, VM file descriptors, and vCPU file descriptors by their respective file_operations "owner" field. This approach is insufficient because references grabbed via kvm_get_kvm() do not prevent closing any of the aforementioned file descriptors. This fixes a long standing theoretical bug in KVM that at least affects async page faults. kvm_setup_async_pf() grabs a reference via kvm_get_kvm(), and drops it in an asynchronous work callback. Nothing prevents the VM file descriptor from being closed and the KVM module from being unloaded before this callback runs. Fixes: af585b92 ("KVM: Halt vcpu if page it tries to access is swapped out") Fixes: 3d3aab1b ("KVM: set owner of cpu and vm file operations") Cc: stable@vger.kernel.org Suggested-by:
Ben Gardon <bgardon@google.com> [ Based on a patch from Ben implemented for Google's kernel. ] Signed-off-by:
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- 21 Mar, 2022 8 commits
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Paolo Bonzini authored
Instead of using array_size, use a function that takes care of the multiplication. While at it, switch to kvcalloc since this allocation should not be very large. Signed-off-by: -
Oliver Upton authored
KVM_CAP_DISABLE_QUIRKS is irrevocably broken. The capability does not advertise the set of quirks which may be disabled to userspace, so it is impossible to predict the behavior of KVM. Worse yet, KVM_CAP_DISABLE_QUIRKS will tolerate any value for cap->args[0], meaning it fails to reject attempts to set invalid quirk bits. The only valid workaround for the quirky quirks API is to add a new CAP. Actually advertise the set of quirks that can be disabled to userspace so it can predict KVM's behavior. Reject values for cap->args[0] that contain invalid bits. Finally, add documentation for the new capability and describe the existing quirks. Signed-off-by:
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Thomas Gleixner authored
Non constant TSC is a nightmare on bare metal already, but with virtualization it becomes a complete disaster because the workarounds are horrible latency wise. That's also a preliminary for running RT in a guest on top of a RT host. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Message-Id: <Yh5eJSG19S2sjZfy@linutronix.de> Signed-off-by:
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Paolo Bonzini authored
Guests X86_BUG_NULL_SEG if and only if the host has them. Use the info from static_cpu_has_bug to form the 0x80000021 CPUID leaf that was defined for Zen3. Userspace can then set the bit even on older CPUs that do not have the bug, such as Zen2. Do the same for X86_FEATURE_LFENCE_RDTSC as well, since various processors have had very different ways of detecting it and not all of them are available to userspace. Signed-off-by: -
Paolo Bonzini authored
CPUID leaf 0x80000021 defines some features (or lack of bugs) of AMD processors. Expose the ones that make sense via KVM_GET_SUPPORTED_CPUID. Signed-off-by: -
Maxim Levitsky authored
KVM_X86_OP_OPTIONAL_RET0 can only be used with 32-bit return values on 32-bit systems, because unsigned long is only 32-bits wide there and 64-bit values are returned in edx:eax. Reported-by:
Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by:
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Paolo Bonzini authored
This reverts commit cf3e2642. Multi-vCPU Hyper-V guests started crashing randomly on boot with the latest kvm/queue and the problem can be bisected the problem to this particular patch. Basically, I'm not able to boot e.g. 16-vCPU guest successfully anymore. Both Intel and AMD seem to be affected. Reverting the commit saves the day. Reported-by:
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Paolo Bonzini authored
Since "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()" is going to be reverted, it's not going to be true anymore that the zap-page flow does not free any 'struct kvm_mmu_page'. Introduce an early flush before tdp_mmu_zap_leafs() returns, to preserve bisectability. Signed-off-by:
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- 18 Mar, 2022 3 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarmPaolo Bonzini authored
KVM/arm64 updates for 5.18 - Proper emulation of the OSLock feature of the debug architecture - Scalibility improvements for the MMU lock when dirty logging is on - New VMID allocator, which will eventually help with SVA in VMs - Better support for PMUs in heterogenous systems - PSCI 1.1 support, enabling support for SYSTEM_RESET2 - Implement CONFIG_DEBUG_LIST at EL2 - Make CONFIG_ARM64_ERRATUM_2077057 default y - Reduce the overhead of VM exit when no interrupt is pending - Remove traces of 32bit ARM host support from the documentation - Updated vgic selftests - Various cleanups, doc updates and spelling fixes
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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:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220318103729.157574-24-Julia.Lawall@inria.fr
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Marc Zyngier authored
We currently deal with a set of booleans for VM features, while they could be better represented as set of flags contained in an unsigned long, similarily to what we are doing on the CPU side. Signed-off-by:
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- 15 Mar, 2022 2 commits
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https://github.com/kvm-riscv/linuxPaolo Bonzini authored
KVM/riscv changes for 5.18 - Prevent KVM_COMPAT from being selected - Refine __kvm_riscv_switch_to() implementation - RISC-V SBI v0.3 support
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Paolo Bonzini authored
Merge tag 'kvm-s390-next-5.18-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fix, test and feature for 5.18 part 2 - memop selftest - fix SCK locking - adapter interruptions virtualization for secure guests
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- 14 Mar, 2022 6 commits
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Janis Schoetterl-Glausch authored
Test that errors occur if key protection disallows access, including tests for storage and fetch protection override. Perform tests for both logical vcpu and absolute vm ioctls. Also extend the existing tests to the vm ioctl. Signed-off-by:
Janis Schoetterl-Glausch <scgl@linux.ibm.com> Link: https://lore.kernel.org/r/20220308125841.3271721-6-scgl@linux.ibm.comSigned-off-by:
Christian Borntraeger <borntraeger@linux.ibm.com>
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Janis Schoetterl-Glausch authored
Do not just test the actual copy, but also that success is indicated when using the check only flag. Add copy test with storage key checking enabled, including tests for storage and fetch protection override. These test cover both logical vcpu ioctls as well as absolute vm ioctls. Signed-off-by:
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Janis Schoetterl-Glausch authored
The stages synchronize guest and host execution. This helps the reader and constraits the execution of the test -- if the observed staging differs from the expected the test fails. Signed-off-by:
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Janis Schoetterl-Glausch authored
In order to achieve good test coverage we need to be able to invoke the MEM_OP ioctl with all possible parametrizations. However, for a given test, we want to be concise and not specify a long list of default values for parameters not relevant for the test, so the readers attention is not needlessly diverted. Add a macro that enables this and convert the existing test to use it. The macro emulates named arguments and hides some of the ioctl's redundancy, e.g. sets the key flag if an access key is specified. Signed-off-by:
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Janis Schoetterl-Glausch authored
Split success case/copy test from error test, making them independent. This means they do not share state and are easier to understand. Also, new test can be added in the same manner without affecting the old ones. In order to make that simpler, introduce functionality for the setup of commonly used variables. Signed-off-by:
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Claudio Imbrenda authored
When handling the SCK instruction, the kvm lock is taken, even though the vcpu lock is already being held. The normal locking order is kvm lock first and then vcpu lock. This is can (and in some circumstances does) lead to deadlocks. The function kvm_s390_set_tod_clock is called both by the SCK handler and by some IOCTLs to set the clock. The IOCTLs will not hold the vcpu lock, so they can safely take the kvm lock. The SCK handler holds the vcpu lock, but will also somehow need to acquire the kvm lock without relinquishing the vcpu lock. The solution is to factor out the code to set the clock, and provide two wrappers. One is called like the original function and does the locking, the other is called kvm_s390_try_set_tod_clock and uses trylock to try to acquire the kvm lock. This new wrapper is then used in the SCK handler. If locking fails, -EAGAIN is returned, which is eventually propagated to userspace, thus also freeing the vcpu lock and allowing for forward progress. This is not the most efficient or elegant way to solve this issue, but the SCK instruction is deprecated and its performance is not critical. The goal of this patch is just to provide a simple but correct way to fix the bug. Fixes: 6a3f95a6 ("KVM: s390: Intercept SCK instruction") Signed-off-by:
Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by:
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- 11 Mar, 2022 6 commits
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Anup Patel authored
The SBI v0.3 specification extends SBI HSM extension by adding SBI HSM suspend call and related HART states. This patch extends the KVM RISC-V HSM implementation to provide KVM guest a minimal SBI HSM suspend call which is equivalent to a WFI instruction. Signed-off-by:
Anup Patel <apatel@ventanamicro.com> Reviewed-by:
Atish Patra <atishp@rivosinc.com> Signed-off-by:
Anup Patel <anup@brainfault.org>
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Anup Patel authored
The wait for interrupt (WFI) instruction emulation can share the VCPU halt logic with SBI HSM suspend emulation so this patch adds a common kvm_riscv_vcpu_wfi() function for this purpose. Signed-off-by:
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Anup Patel authored
We add defines related to SBI HSM suspend call and also update HSM states naming as-per the latest SBI specification. Signed-off-by:
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Anup Patel authored
The SBI v0.3 specification defines SRST (System Reset) extension which provides a standard poweroff and reboot interface. This patch implements SRST extension for the KVM Guest. Signed-off-by:
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Anup Patel authored
We rename kvm_sbi_system_shutdown() to kvm_riscv_vcpu_sbi_system_reset() and move it to vcpu_sbi.c so that it can be shared by SBI v0.1 shutdown and SBI v0.3 SRST extension. Signed-off-by:
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Anup Patel authored
We upgrade SBI spec version implemented by KVM RISC-V to v0.3 so that Guest kernel can probe and use SBI extensions added by the SBI v0.3 specification. Signed-off-by:
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